一个简单的代码生成器

风后奇门柳坤生 07-24 607

前言：

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　　前言

　　逆向工程从数据库表直接生成代码，是日常开发中常用的敏捷开发手段，常见的例如：mybatis-plus的代码生成器等

　　为什么要自己写代码生成器呢？MP的生成器不香吗？香！

　　但是自己写的工具用起来最顺手，可以随意扩展，想怎么玩就怎么玩，只要自己有想法，玩出花来都没问题，当然了，能力有限，现在还只能实现简单版本，更多骚操作自己发挥！

　　思路：

　　1、建立jdbc连接，执行查询sql，获取表结构信息。

　　2、在指定的路径上创建文件。

　　3、按照我们的布局排版要求，根据表结构信息拼接文件的内容。

　　4、将字符输出到文件中。

　　以上即可完成一个文件的自动生成

　　编码　　通用部分

　　几个内部工具类

　　file工具类：创建、读取文件

　　字符串工具类：驼峰标识、下划线互转，首字母大写，数据库字段类型转java类型等

　　jdbc连接：连接数据库

　　表注释、表结构信息实体类、执行sql获取表结构信息的方法

　　表结构信息

private String columnName;//字段名private String dataType;//字段类型private String columnComment;//字段注释private String columnKey;//主键private String extra;//主键类型

　　mysql查询表注释、表字段信息使用的是

　　表字段信息

SELECT    column_name,    data_type,    column_comment,    column_key,    extra FROM    information_schema.COLUMNS WHERE    table_schema = (    SELECT DATABASE    ())     AND table_name =?

　　表注释

SELECT    table_comment FROM    information_schema.TABLES WHERE    table_schema = (    SELECT DATABASE    ())     AND table_name =?

　　需要支持其他数据库类型的，自己调整就好了，例如oracle获取表注释、表结构sql如下：

-- 表、表注释SELECT    t.table_name,    t1.comments FROM    user_tables t    JOIN user_tab_comments t1 ON t.table_name = t1.table_name;-- 表字段、字段注释SELECT    t.table_name,    c.column_name,    c.data_type,    cc.comments FROM    USER_TAB_COLUMNS c    JOIN user_tables t ON c.table_name = t.table_name    JOIN user_col_comments cc ON cc.table_name = t.table_name WHERE    cc.column_name = c.column_name;

　　另外，数据连接、基础路径的配置也是一样

/** * 数据连接相关，需要手动设置 */private static final String URL = "jdbc:mysql://localhost:3306/test?serverTimezone=GMT%2B8&characterEncoding=utf-8";private static final String USERNAME = "root";private static final String PASSWORD = "123456";private static final String DRIVER_CLASSNAME = "com.mysql.cj.jdbc.Driver";

/** * 基础路径，需要手动设置 */private String basePackage = "cn\\huanzi\\qch\\baseadmin\\";//根包位置private String filePackage = basePackage + "sys\\";//文件所在包位置

　　2.0版本多一个模板文件路径

private String tlfPath = System.getProperty("user.dir") + "\\src\\main\\resources\\tlf\\";//模板文件位置

　　main函数也一样，调用构造参数，传入表名，调用入口函数

public static void main(String[] args) {//        String[] tables = {"sys_user","sys_menu","sys_authority","sys_user_menu","sys_user_authority","sys_shortcut_menu","sys_setting"};    String[] tables = {"tb_user"};    for (String table : tables) {        String msg = new AutoGenerator(table).create();        System.out.println(msg);    }}

　　V1.0版本

　　AutoGenerator，1.0版本采用原始的在代码拼接字符串，然后创建文件将字符串输出的方法，比较原始但个人觉得可玩性较高

　　几个创建方法，就拿实体类来举例

/** * 创建pojo实体类 */private void createPojo(List<TableInfo> tableInfos) {    //创建文件    File file = FileUtil.createFile(filePath + "pojo\\" + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + ".java");        //拼接文件内容    StringBuffer stringBuffer = new StringBuffer();    stringBuffer.append(            "package " + filePackage.replaceAll("\\\\", ".") + "pojo;\n" +                    "\n" +                    "import lombok.Data;\n" +                    "import javax.persistence.*;\n" +                    "import java.io.Serializable;\n" +                    "import java.util.Date;\n" +                    "\n" +                    "@Entity\n" +                    "@Table(name = \"" + tableName + "\")\n" +                    "@Data\n" +                    "public class " + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + " implements Serializable {\n"    );    //遍历设置属性    for (TableInfo tableInfo : tableInfos) {        //主键        if ("PRI".equals(tableInfo.getColumnKey())) {            stringBuffer.append("    @Id\n");        }        //自增        if ("auto_increment".equals(tableInfo.getExtra())) {            stringBuffer.append("    @GeneratedValue(strategy= GenerationType.IDENTITY)\n");        }        stringBuffer.append("    private ").append(StringUtil.typeMapping(tableInfo.getDataType())).append(" ").append(StringUtil.camelCaseName(tableInfo.getColumnName())).append(";//").append(tableInfo.getColumnComment()).append("\n\n");    }    stringBuffer.append("}");        //写入文件内容    FileUtil.fileWriter(file, stringBuffer);}

　　其他的也一样，无非就：创建文件、拼接文件内容、输出文件内容

　　入口函数，供main函数直接调用

/** * 快速创建，供外部调用，调用之前先设置一下项目的基础路径 */private String create() {    System.out.println("生成路径位置：" + filePath);    //获取表信息    List<TableInfo> tableInfo = getTableInfo();    //开始生成代码    createPojo(tableInfo);    createVo(tableInfo);    createRepository(tableInfo);    createService(tableInfo);    createController(tableInfo);    return tableName + " 后台代码生成完毕！";}

　　V2.0版本

　　AutoGeneratorPlus，2.0版本升级了，设置了模板文件、文件内容的字符串从模板读取，再根据关键字替换参数，最后再输出到创建的文件中，这个版本就比较好理解，大部分的代码生成器也都这样干

　　需要先定义模板文件（文件名后缀无所谓，自己随便定义），拿entity来举例

package cn.huanzi.qch.baseadmin.sys.${entityToLowerCase}.pojo;import lombok.Data;import javax.persistence.*;import java.io.Serializable;import java.util.Date;/** * ${tableComment} 实体类 * * ${author} * ${date} */@Entity@Table(name = "${tableName}")@Datapublic class ${entity} implements Serializable {  #for    #ifPri    #ifAutoIncrement    private ${tableInfo.dataType} ${tableInfo.columnName};//${tableInfo.columnComment}  #end}

　　${}，用于取参数，替换成我们的值

　　#for、#if，循环遍历表字段以及判断是否为主键、是否主键自增

　　各种关键字随便定义，我们在读取模板文件处理时能对上就行

　　文件内容处理

/** * 读取模板，设置内容，生成文件 * @param templatePath 模板文件路径 * @param outputFile 文件生成路径 * @param tableInfos 表字段信息 * @param customParameter 自定义参数 */private void writer(String templatePath, String outputFile,List<TableInfo> tableInfos,Map<String,String> customParameter){    //主键    TableInfo prikey = new TableInfo();    //for循环标识    boolean forFlag = false;    StringBuilder forContent = new StringBuilder();    //驼峰标识映射后的表名    String replacement = StringUtil.captureName(StringUtil.camelCaseName(tableName));    //遍历属性    for (TableInfo tableInfo : tableInfos) {        //主键        if ("PRI".equals(tableInfo.getColumnKey())) {            prikey = tableInfo;            break;        }    }    try(FileReader fileReader = new FileReader(templatePath);        BufferedReader reader = new BufferedReader(fileReader)) {        //生成文件        File file = FileUtil.createFile(outputFile);        StringBuffer stringBuffer = new StringBuffer();        //读取模板文件，拼接文件内容        Object[] lines = reader.lines().toArray();        for (Object o : lines) {            String line = String.valueOf(o);            /* 设置值 */            //${tableName} 表名称，例如：tb_user            if(line.contains("${tableName}")){                line = line.replaceAll("\\$\\{tableName}", tableName);            }            //${tableComment} 表注释，例如：tb_user            if(line.contains("${tableComment}")){                line = line.replaceAll("\\$\\{tableComment}", tableComment);            }            //${entity} 实体类名称，例如：TbUser            if(line.contains("${entity}")){                line = line.replaceAll("\\$\\{entity}", replacement);            }            //${entityFirstToLowerCase} 实体类名称首字母小写，例如：tbUser            if(line.contains("${entityFirstToLowerCase}")){                line = line.replaceAll("\\$\\{entityFirstToLowerCase}", StringUtil.camelCaseName(tableName));            }            //${entityToLowerCase} 实体类名称全小写，例如：tbuser            if(line.contains("${entityToLowerCase}")){                line = line.replaceAll("\\$\\{entityToLowerCase}", replacement.toLowerCase());            }            //${priDataType} 实体类主键类型，例如：String            if(line.contains("${priDataType}")){                line = line.replaceAll("\\$\\{priDataType}", StringUtil.typeMapping(prikey.getDataType()));            }            //处理自定义参数            line = customParameter(line,customParameter);            //先取得循环体的内容            if(forFlag){                forContent.append(line).append("\n");            }            //是否为for循环遍历表字段            if(line.contains("#for")){                forFlag = true;            }            if(line.contains("#end")){                forFlag = false;                line = line.replaceAll("#end", "");            }            //遍历循环体的内容，并设置值            if(!forFlag && forContent.length() > 0){                //遍历表字段                for (TableInfo tableInfo : tableInfos) {                    String tableColumns = forContent.toString()                            //表字段信息：类型、名称、注释                            .replaceAll("\\$\\{tableInfo.dataType}", StringUtil.typeMapping(tableInfo.getDataType()))                            .replaceAll("\\$\\{tableInfo.columnName}", StringUtil.camelCaseName(tableInfo.getColumnName()))                            .replaceAll("\\$\\{tableInfo.columnComment}", tableInfo.getColumnComment());                    //清除多余#end，以及换行符                    tableColumns = tableColumns.replaceAll("#end", "").replaceAll("\n", "");                    //设置是否主键、是否自增                    String pri = "",autoIncrement="";                    //主键                    if ("PRI".equals(tableInfo.getColumnKey())) {                        pri = " @Id\n";                        //自增id                        if ("auto_increment".equals(tableInfo.getExtra())){                            autoIncrement = "@GeneratedValue(strategy= GenerationType.IDENTITY)\n";                        }                    }                    tableColumns = tableColumns                            .replaceAll("#ifPri", pri)                            .replaceAll("#ifAutoIncrement", autoIncrement);                    //处理自定义参数                    tableColumns = customParameter(tableColumns,customParameter);                    //前补tab，后补换行符                    stringBuffer.append("    ").append(tableColumns.trim()).append("\n\n");                }                //置空                forContent.setLength(0);            }            if(!forFlag){                stringBuffer.append(line).append("\n");            }        }        //写入数据到到文件中        FileUtil.fileWriter(file, stringBuffer);    }catch (Exception e){        e.printStackTrace();    }}

　　内置了几个重要参数

${tableName} 表名称，例如：tb_user${tableComment} 表注释，例如：tb_user${entity} 实体类名称，例如：TbUser${entityFirstToLowerCase} 实体类名称首字母小写，例如：tbUser${entityToLowerCase} 实体类名称全小写，例如：tbuser${priDataType} 实体类主键类型，例如：String还有三个表字段信息：类型、名称、注释${tableInfo.dataType}${tableInfo.columnName}${tableInfo.columnComment}

　　支持自定义参数Map<String,String> customParameter，例如模板文件中的注释：

/** * ${author} * ${date} */

　　入口函数

/** * 快速创建，供外部调用，调用之前先设置一下项目的基础路径 */private String create() {    System.out.println("生成路径位置：" + filePath);    //获取表信息    List<TableInfo> tableInfo = getTableInfo();    //驼峰标识映射后的表名    String captureName = StringUtil.captureName(StringUtil.camelCaseName(tableName));    //自定义参数    HashMap<String, String> customParameter = new HashMap<>();    customParameter.put("author","作者：Auto Generator By 'huanzi-qch'");    customParameter.put("date","生成日期："+new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()));    //读取模板、生成代码    writer(tlfPath+"controller.tlf",            filePath + "controller\\" + captureName + "Controller.java",            tableInfo,customParameter);    writer(tlfPath+"entity.tlf",            filePath + "pojo\\" + captureName + ".java",            tableInfo,customParameter);    writer(tlfPath+"entityvo.tlf",            filePath + "vo\\" + captureName + "Vo.java",            tableInfo,customParameter);    writer(tlfPath+"repository.tlf",            filePath + "repository\\" + captureName + "Repository.java",            tableInfo,customParameter);    writer(tlfPath+"service.tlf",            filePath + "service\\" + captureName + "Service.java",            tableInfo,customParameter);    writer(tlfPath+"serviceimpl.tlf",            filePath + "service\\" + captureName + "ServiceImpl.java",            tableInfo,customParameter);    return tableName + " 后台代码生成完毕！";}

　　比较复杂的就是#for、#if的处理，我这里只是简单实现，不过也完全够我们用了

　　效果　　V1.0版本

　　V2.0版本　　后记

　　大部分项目的代码都是可以复用的，特别是像我们这种封装了一套通用代码，单表直接继承实现CRUD、分页等功能，每个模块高度相似的代码，代码生成器就成了敏捷开发中重要的一步，直接根据数据库表生成我们想要的代码，省去了一步步创建文件、复制粘贴文件内容的繁琐步骤，实现快速开发！

　　自己写的代码生成器，扩展性更强，满足每个业务模块的代码要求不成问题

　　开源

　　在这里贴出完整代码，全都在一个类里面，并且没有其他依赖包，很纯！

　　v1.0 AutoGenerator

package cn.huanzi.qch.baseadmin.autogenerator;import java.io.File;import java.io.FileWriter;import java.io.PrintWriter;import java.sql.*;import java.util.ArrayList;import java.util.List;/** * 代码生成工具 V1.0 */public class AutoGenerator {    /**     * 程序自动设置     */    private String tableName;//表名    private String tableComment;//表注释    private String filePath;//最终文件生成位置    /**     * 数据连接相关，需要手动设置     */    private static final String URL = "jdbc:mysql://localhost:3306/test?serverTimezone=GMT%2B8&characterEncoding=utf-8";    private static final String USERNAME = "root";    private static final String PASSWORD = "123456";    private static final String DRIVER_CLASSNAME = "com.mysql.cj.jdbc.Driver";    /**     * 基础路径，需要手动设置     */    private String basePackage = "cn\\huanzi\\qch\\baseadmin\\";//根包位置    private String filePackage = basePackage + "sys\\";//文件所在包位置    /**     * 构造参数，设置表名     */    private AutoGenerator(String tableName) {        //设置表名        this.tableName = tableName;        //文件所在包位置        filePackage = filePackage + StringUtil.camelCaseName(tableName).toLowerCase() + "\\";        //拼接完整最终位置 System.getProperty("user.dir") 获取的是项目所在路径，如果我们是子项目，则需要添加一层路径        filePath = System.getProperty("user.dir") + "\\src\\main\\java\\" + filePackage;    }    /**     * 创建pojo实体类     */    private void createPojo(List<TableInfo> tableInfos) {        //创建文件        File file = FileUtil.createFile(filePath + "pojo\\" + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + ".java");        //拼接文件内容        StringBuffer stringBuffer = new StringBuffer();        stringBuffer.append(                "package " + filePackage.replaceAll("\\\\", ".") + "pojo;\n" +                        "\n" +                        "import lombok.Data;\n" +                        "import javax.persistence.*;\n" +                        "import java.io.Serializable;\n" +                        "import java.util.Date;\n" +                        "\n" +                        "@Entity\n" +                        "@Table(name = \"" + tableName + "\")\n" +                        "@Data\n" +                        "public class " + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + " implements Serializable {\n"        );        //遍历设置属性        for (TableInfo tableInfo : tableInfos) {            //主键            if ("PRI".equals(tableInfo.getColumnKey())) {                stringBuffer.append("    @Id\n");            }            //自增            if ("auto_increment".equals(tableInfo.getExtra())) {                stringBuffer.append("    @GeneratedValue(strategy= GenerationType.IDENTITY)\n");            }            stringBuffer.append("    private ").append(StringUtil.typeMapping(tableInfo.getDataType())).append(" ").append(StringUtil.camelCaseName(tableInfo.getColumnName())).append(";//").append(tableInfo.getColumnComment()).append("\n\n");        }        stringBuffer.append("}");        //写入文件内容        FileUtil.fileWriter(file, stringBuffer);    }    /**     * 创建vo类     */    private void createVo(List<TableInfo> tableInfos) {        File file = FileUtil.createFile(filePath + "vo\\" + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Vo.java");        StringBuffer stringBuffer = new StringBuffer();        stringBuffer.append(                "package " + filePackage.replaceAll("\\\\", ".") + "vo;\n" +                        "\n" +                        "import "+ basePackage.replaceAll("\\\\", ".") +" common.pojo.PageCondition;"+                        "import lombok.Data;\n" +                        "import java.io.Serializable;\n" +                        "import java.util.Date;\n" +                        "\n" +                        "@Data\n" +                        "public class " + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Vo extends PageCondition implements Serializable {\n"        );        //遍历设置属性        for (TableInfo tableInfo : tableInfos) {            stringBuffer.append("    private ").append(StringUtil.typeMapping(tableInfo.getDataType())).append(" ").append(StringUtil.camelCaseName(tableInfo.getColumnName())).append(";//").append(tableInfo.getColumnComment()).append("\n\n");        }        stringBuffer.append("}");        FileUtil.fileWriter(file, stringBuffer);    }    /**     * 创建repository类     */    private void createRepository(List<TableInfo> tableInfos) {        File file = FileUtil.createFile(filePath + "repository\\" + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Repository.java");        StringBuffer stringBuffer = new StringBuffer();        String t = "String";        //遍历属性        for (TableInfo tableInfo : tableInfos) {            //主键            if ("PRI".equals(tableInfo.getColumnKey())) {                t = StringUtil.typeMapping(tableInfo.getDataType());            }        }        stringBuffer.append(                "package " + filePackage.replaceAll("\\\\", ".") + "repository;\n" +                        "\n" +                        "import " + basePackage.replaceAll("\\\\", ".") + "common.repository.*;\n" +                        "import " + filePackage.replaceAll("\\\\", ".") + "pojo." + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + ";\n" +                        "import org.springframework.stereotype.Repository;\n" +                        "\n" +                        "@Repository\n" +                        "public interface " + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Repository extends CommonRepository<" + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + ", " + t + "> {"        );        stringBuffer.append("\n");        stringBuffer.append("}");        FileUtil.fileWriter(file, stringBuffer);    }    /**     * 创建service类     */    private void createService(List<TableInfo> tableInfos) {        File file = FileUtil.createFile(filePath + "service\\" + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Service.java");        StringBuffer stringBuffer = new StringBuffer();        String t = "String";        //遍历属性        for (TableInfo tableInfo : tableInfos) {            //主键            if ("PRI".equals(tableInfo.getColumnKey())) {                t = StringUtil.typeMapping(tableInfo.getDataType());            }        }        stringBuffer.append(                "package " + filePackage.replaceAll("\\\\", ".") + "service;\n" +                        "\n" +                        "import " + basePackage.replaceAll("\\\\", ".") + "common.service.*;\n" +                        "import " + filePackage.replaceAll("\\\\", ".") + "pojo." + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + ";\n" +                        "import " + filePackage.replaceAll("\\\\", ".") + "vo." + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Vo;\n" +                        "\n" +                        "public interface " + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Service extends CommonService<" + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Vo, " + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + ", " + t + "> {"        );        stringBuffer.append("\n");        stringBuffer.append("}");        FileUtil.fileWriter(file, stringBuffer);        //Impl        File file1 = FileUtil.createFile(filePath + "service\\" + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "ServiceImpl.java");        StringBuffer stringBuffer1 = new StringBuffer();        stringBuffer1.append(                "package " + filePackage.replaceAll("\\\\", ".") + "service;\n" +                        "\n" +                        "import " + basePackage.replaceAll("\\\\", ".") + "common.service.*;\n" +                        "import " + filePackage.replaceAll("\\\\", ".") + "pojo." + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + ";\n" +                        "import " + filePackage.replaceAll("\\\\", ".") + "vo." + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Vo;\n" +                        "import " + filePackage.replaceAll("\\\\", ".") + "repository." + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Repository;\n" +                        "import org.springframework.beans.factory.annotation.Autowired;\n" +                        "import org.springframework.stereotype.Service;\n" +                        "import org.springframework.transaction.annotation.Transactional;\n" +                        "import javax.persistence.EntityManager;\n" +                        "import javax.persistence.PersistenceContext;\n" +                        "\n" +                        "@Service\n" +                        "@Transactional\n" +                        "public class " + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "ServiceImpl extends CommonServiceImpl<" + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Vo, " + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + ", " + t + "> implements " + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Service{"        );        stringBuffer1.append("\n\n");        stringBuffer1.append(                "    @PersistenceContext\n" +                        "    private EntityManager em;\n");        stringBuffer1.append("" +                "    @Autowired\n" +                "    private " + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Repository " + StringUtil.camelCaseName(tableName) + "Repository;\n");        stringBuffer1.append("}");        FileUtil.fileWriter(file1, stringBuffer1);    }    /**     * 创建controller类     */    private void createController(List<TableInfo> tableInfos) {        File file = FileUtil.createFile(filePath + "controller\\" + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Controller.java");        StringBuffer stringBuffer = new StringBuffer();        String t = "String";        //遍历属性        for (TableInfo tableInfo : tableInfos) {            //主键            if ("PRI".equals(tableInfo.getColumnKey())) {                t = StringUtil.typeMapping(tableInfo.getDataType());            }        }        stringBuffer.append(                "package " + filePackage.replaceAll("\\\\", ".") + "controller;\n" +                        "\n" +                        "import " + basePackage.replaceAll("\\\\", ".") + "common.controller.*;\n" +                        "import " + filePackage.replaceAll("\\\\", ".") + "pojo." + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + ";\n" +                        "import " + filePackage.replaceAll("\\\\", ".") + "vo." + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Vo;\n" +                        "import " + filePackage.replaceAll("\\\\", ".") + "service." + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Service;\n" +                        "import org.springframework.beans.factory.annotation.Autowired;\n" +                        "import org.springframework.web.bind.annotation.*;\n" +                        "\n" +                        "@RestController\n" +                        "@RequestMapping(\"/sys/" + StringUtil.camelCaseName(tableName) + "/\")\n" +                        "public class " + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Controller extends CommonController<" + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Vo, " + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + ", " + t + "> {"        );        stringBuffer.append("\n");        stringBuffer.append("" +                "    @Autowired\n" +                "    private " + StringUtil.captureName(StringUtil.camelCaseName(tableName)) + "Service " + StringUtil.camelCaseName(tableName) + "Service;\n");        stringBuffer.append("}");        FileUtil.fileWriter(file, stringBuffer);    }    /**     * file工具类     */    private static class FileUtil {        /**         * 创建文件         *         * @param pathNameAndFileName 路径跟文件名         * @return File对象         */        private static File createFile(String pathNameAndFileName) {            File file = new File(pathNameAndFileName);            try {                //获取父目录                File fileParent = file.getParentFile();                if (!fileParent.exists()) {                    fileParent.mkdirs();                }                //创建文件                if (!file.exists()) {                    file.createNewFile();                }            } catch (Exception e) {                file = null;                System.err.println("新建文件操作出错");                e.printStackTrace();            }            return file;        }        /**         * 字符流写入文件         *         * @param file         file对象         * @param stringBuffer 要写入的数据         */        private static void fileWriter(File file, StringBuffer stringBuffer) {            //字符流            try {                FileWriter resultFile = new FileWriter(file, false);//true,则追加写入 false,则覆盖写入                PrintWriter myFile = new PrintWriter(resultFile);                //写入                myFile.println(stringBuffer.toString());                myFile.close();                resultFile.close();            } catch (Exception e) {                System.err.println("写入操作出错");                e.printStackTrace();            }        }    }    /**     * 字符串处理工具类     */    private static class StringUtil {        /**         * 数据库类型->JAVA类型         *         * @param dbType 数据库类型         * @return JAVA类型         */        private static String typeMapping(String dbType) {            String javaType;            if ("int|integer".contains(dbType)) {                javaType = "Integer";            } else if ("float|double|decimal|real".contains(dbType)) {                javaType = "Double";            } else if ("date|time|datetime|timestamp".contains(dbType)) {                javaType = "Date";            } else {                javaType = "String";            }            return javaType;        }        /**         * 驼峰转换为下划线         */        private static String underscoreName(String camelCaseName) {            StringBuilder result = new StringBuilder();            if (camelCaseName != null && camelCaseName.length() > 0) {                result.append(camelCaseName.substring(0, 1).toLowerCase());                for (int i = 1; i < camelCaseName.length(); i++) {                    char ch = camelCaseName.charAt(i);                    if (Character.isUpperCase(ch)) {                        result.append("_");                        result.append(Character.toLowerCase(ch));                    } else {                        result.append(ch);                    }                }            }            return result.toString();        }        /**         * 首字母大写         */        private static String captureName(String name) {            char[] cs = name.toCharArray();            cs[0] -= 32;            return String.valueOf(cs);        }        /**         * 下划线转换为驼峰         */        private static String camelCaseName(String underscoreName) {            StringBuilder result = new StringBuilder();            if (underscoreName != null && underscoreName.length() > 0) {                boolean flag = false;                for (int i = 0; i < underscoreName.length(); i++) {                    char ch = underscoreName.charAt(i);                    if ("_".charAt(0) == ch) {                        flag = true;                    } else {                        if (flag) {                            result.append(Character.toUpperCase(ch));                            flag = false;                        } else {                            result.append(ch);                        }                    }                }            }            return result.toString();        }    }    /**     * JDBC连接数据库工具类     */    private static class DBConnectionUtil {        static {            // 1、加载驱动            try {                Class.forName(DRIVER_CLASSNAME);            } catch (ClassNotFoundException e) {                                e.printStackTrace();            }        }        /**         * 返回一个Connection连接         */        static Connection getConnection() {            Connection conn = null;            // 2、连接数据库            try {                conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);            } catch (SQLException e) {                                e.printStackTrace();            }            return conn;        }        /**         * 关闭Connection，Statement连接         */        public static void close(Connection conn, Statement stmt) {            try {                conn.close();                stmt.close();            } catch (SQLException e) {                e.printStackTrace();            }        }        /**         * 关闭Connection，Statement，ResultSet连接         */        public static void close(Connection conn, Statement stmt, ResultSet rs) {            try {                close(conn, stmt);                rs.close();            } catch (SQLException e) {                e.printStackTrace();            }        }    }    /**     * 表结构信息实体类     */    private class TableInfo {        private String columnName;//字段名        private String dataType;//字段类型        private String columnComment;//字段注释        private String columnKey;//主键        private String extra;//主键类型        public String getColumnName() {            return columnName;        }        public void setColumnName(String columnName) {            this.columnName = columnName;        }        public String getDataType() {            return dataType;        }        public void setDataType(String dataType) {            this.dataType = dataType;        }        public String getColumnComment() {            return columnComment;        }        public void setColumnComment(String columnComment) {            this.columnComment = columnComment;        }        public String getColumnKey() {            return columnKey;        }        public void setColumnKey(String columnKey) {            this.columnKey = columnKey;        }        public String getExtra() {            return extra;        }        public void setExtra(String extra) {            this.extra = extra;        }    }    /**     * 获取表结构信息     * 目前仅支持mysql     */    private List<TableInfo> getTableInfo() {        Connection conn = null;        PreparedStatement ps = null;        ResultSet rs = null;        ArrayList<TableInfo> list = new ArrayList<>();        try {            conn = DBConnectionUtil.getConnection();            //表字段信息            String sql = "select column_name,data_type,column_comment,column_key,extra from information_schema.columns where table_schema = (select database()) and table_name=?";            ps = conn.prepareStatement(sql);            ps.setString(1, tableName);            rs = ps.executeQuery();            while (rs.next()) {                TableInfo tableInfo = new TableInfo();                //列名，全部转为小写                tableInfo.setColumnName(rs.getString("column_name").toLowerCase());                //列类型                tableInfo.setDataType(rs.getString("data_type"));                //列注释                tableInfo.setColumnComment(rs.getString("column_comment"));                //主键                tableInfo.setColumnKey(rs.getString("column_key"));                //主键类型                tableInfo.setExtra(rs.getString("extra"));                list.add(tableInfo);            }            //表注释            sql = "select table_comment from information_schema.tables where table_schema = (select database()) and table_name=?";            ps = conn.prepareStatement(sql);            ps.setString(1, tableName);            rs = ps.executeQuery();            while (rs.next()) {                //表注释                tableComment = rs.getString("table_comment");            }        } catch (SQLException e) {            e.printStackTrace();        } finally {            if(rs != null){                DBConnectionUtil.close(conn, ps, rs);            }        }        return list;    }    /**     * 快速创建，供外部调用，调用之前先设置一下项目的基础路径     */    private String create() {        System.out.println("生成路径位置：" + filePath);        //获取表信息        List<TableInfo> tableInfo = getTableInfo();        //开始生成代码        createPojo(tableInfo);        createVo(tableInfo);        createRepository(tableInfo);        createService(tableInfo);        createController(tableInfo);        return tableName + " 后台代码生成完毕！";    }    public static void main(String[] args) {//        String[] tables = {"sys_user","sys_menu","sys_authority","sys_user_menu","sys_user_authority","sys_shortcut_menu","sys_setting"};        String[] tables = {"tb_user"};        for (String table : tables) {            String msg = new AutoGenerator(table).create();            System.out.println(msg);        }    }}

　　v2.0 AutoGeneratorPlus

package cn.huanzi.qch.baseadmin.autogenerator;import java.io.*;import java.sql.*;import java.text.SimpleDateFormat;import java.util.ArrayList;import java.util.Date;import java.util.HashMap;import java.util.List;import java.util.Map;/** * 代码生成工具 V2.0 */public class AutoGeneratorPlus {    /**     * 程序自动设置     */    private String tableName;//表名    private String tableComment;//表注释    private String filePath;//最终文件生成位置    /**     * 数据连接相关，需要手动设置     */    private static final String URL = "jdbc:mysql://localhost:3306/test?serverTimezone=GMT%2B8&characterEncoding=utf-8";    private static final String USERNAME = "root";    private static final String PASSWORD = "123456";    private static final String DRIVER_CLASSNAME = "com.mysql.cj.jdbc.Driver";    /**     * 基础路径，需要手动设置     */    private String tlfPath = System.getProperty("user.dir") + "\\src\\main\\resources\\tlf\\";//模板文件位置    private String basePackage = "cn\\huanzi\\qch\\baseadmin\\";//根包位置    private String filePackage = basePackage + "sys\\";//文件所在包位置    /**     * 构造参数，设置表名     */    private AutoGeneratorPlus(String tableName) {        //设置表名        this.tableName = tableName;        //文件所在包位置        filePackage = filePackage + StringUtil.camelCaseName(tableName).toLowerCase() + "\\";        //拼接完整最终位置 System.getProperty("user.dir") 获取的是项目所在路径，如果我们是子项目，则需要添加一层路径        filePath = System.getProperty("user.dir") + "\\src\\main\\java\\" + filePackage;    }    /**     * 读取模板，设置内容，生成文件     * @param templatePath 模板文件路径     * @param outputFile 文件生成路径     * @param tableInfos 表字段信息     * @param customParameter 自定义参数     */    private void writer(String templatePath, String outputFile,List<TableInfo> tableInfos,Map<String,String> customParameter){        //主键        TableInfo prikey = new TableInfo();        //for循环标识        boolean forFlag = false;        StringBuilder forContent = new StringBuilder();        //驼峰标识映射后的表名        String replacement = StringUtil.captureName(StringUtil.camelCaseName(tableName));        //遍历属性        for (TableInfo tableInfo : tableInfos) {            //主键            if ("PRI".equals(tableInfo.getColumnKey())) {                prikey = tableInfo;                break;            }        }        try(FileReader fileReader = new FileReader(templatePath);            BufferedReader reader = new BufferedReader(fileReader)) {            //生成文件            File file = FileUtil.createFile(outputFile);            StringBuffer stringBuffer = new StringBuffer();            //读取模板文件，拼接文件内容            Object[] lines = reader.lines().toArray();            for (Object o : lines) {                String line = String.valueOf(o);                /* 设置值 */                //${tableName} 表名称，例如：tb_user                if(line.contains("${tableName}")){                    line = line.replaceAll("\\$\\{tableName}", tableName);                }                //${tableComment} 表注释，例如：tb_user                if(line.contains("${tableComment}")){                    line = line.replaceAll("\\$\\{tableComment}", tableComment);                }                //${entity} 实体类名称，例如：TbUser                if(line.contains("${entity}")){                    line = line.replaceAll("\\$\\{entity}", replacement);                }                //${entityFirstToLowerCase} 实体类名称首字母小写，例如：tbUser                if(line.contains("${entityFirstToLowerCase}")){                    line = line.replaceAll("\\$\\{entityFirstToLowerCase}", StringUtil.camelCaseName(tableName));                }                //${entityToLowerCase} 实体类名称全小写，例如：tbuser                if(line.contains("${entityToLowerCase}")){                    line = line.replaceAll("\\$\\{entityToLowerCase}", replacement.toLowerCase());                }                //${priDataType} 实体类主键类型，例如：String                if(line.contains("${priDataType}")){                    line = line.replaceAll("\\$\\{priDataType}", StringUtil.typeMapping(prikey.getDataType()));                }                //处理自定义参数                line = customParameter(line,customParameter);                //先取得循环体的内容                if(forFlag){                    forContent.append(line).append("\n");                }                //是否为for循环遍历表字段                if(line.contains("#for")){                    forFlag = true;                }                if(line.contains("#end")){                    forFlag = false;                    line = line.replaceAll("#end", "");                }                //遍历循环体的内容，并设置值                if(!forFlag && forContent.length() > 0){                    //遍历表字段                    for (TableInfo tableInfo : tableInfos) {                        String tableColumns = forContent.toString()                                //表字段信息：类型、名称、注释                                .replaceAll("\\$\\{tableInfo.dataType}", StringUtil.typeMapping(tableInfo.getDataType()))                                .replaceAll("\\$\\{tableInfo.columnName}", StringUtil.camelCaseName(tableInfo.getColumnName()))                                .replaceAll("\\$\\{tableInfo.columnComment}", tableInfo.getColumnComment());                        //清除多余#end，以及换行符                        tableColumns = tableColumns.replaceAll("#end", "").replaceAll("\n", "");                        //设置是否主键、是否自增                        String pri = "",autoIncrement="";                        //主键                        if ("PRI".equals(tableInfo.getColumnKey())) {                            pri = " @Id\n";                            //自增id                            if ("auto_increment".equals(tableInfo.getExtra())){                                autoIncrement = "@GeneratedValue(strategy= GenerationType.IDENTITY)\n";                            }                        }                        tableColumns = tableColumns                                .replaceAll("#ifPri", pri)                                .replaceAll("#ifAutoIncrement", autoIncrement);                        //处理自定义参数                        tableColumns = customParameter(tableColumns,customParameter);                        //前补tab，后补换行符                        stringBuffer.append("    ").append(tableColumns.trim()).append("\n\n");                    }                    //置空                    forContent.setLength(0);                }                if(!forFlag){                    stringBuffer.append(line).append("\n");                }            }            //写入数据到到文件中            FileUtil.fileWriter(file, stringBuffer);        }catch (Exception e){            e.printStackTrace();        }    }    private void writer(String templatePath, String outputFile,List<TableInfo> tableInfos){        writer(templatePath,outputFile,tableInfos,new HashMap<>());    }    /**     * 处理自定义参数     */    private String customParameter(String str,Map<String,String> customParameter){        for (String key : customParameter.keySet()) {            str = str.replaceAll("\\$\\{"+key+"}",customParameter.get(key));        }        return str;    }    /**     * file工具类     */    private static class FileUtil {        /**         * 创建文件         *         * @param pathNameAndFileName 路径跟文件名         * @return File对象         */        private static File createFile(String pathNameAndFileName) {            File file = new File(pathNameAndFileName);            try {                //获取父目录                File fileParent = file.getParentFile();                if (!fileParent.exists()) {                    fileParent.mkdirs();                }                //创建文件                if (!file.exists()) {                    file.createNewFile();                }            } catch (Exception e) {                file = null;                System.err.println("新建文件操作出错");                e.printStackTrace();            }            return file;        }        /**         * 字符流写入文件         *         * @param file         file对象         * @param stringBuffer 要写入的数据         */        private static void fileWriter(File file, StringBuffer stringBuffer) {            //字符流            try {                FileWriter resultFile = new FileWriter(file, false);//true,则追加写入 false,则覆盖写入                PrintWriter myFile = new PrintWriter(resultFile);                //写入                myFile.println(stringBuffer.toString());                myFile.close();                resultFile.close();            } catch (Exception e) {                System.err.println("写入操作出错");                e.printStackTrace();            }        }    }    /**     * 字符串处理工具类     */    private static class StringUtil {        /**         * 数据库类型->JAVA类型         *         * @param dbType 数据库类型         * @return JAVA类型         */        private static String typeMapping(String dbType) {            String javaType;            if ("int|integer".contains(dbType)) {                javaType = "Integer";            } else if ("float|double|decimal|real".contains(dbType)) {                javaType = "Double";            } else if ("date|time|datetime|timestamp".contains(dbType)) {                javaType = "Date";            } else {                javaType = "String";            }            return javaType;        }        /**         * 驼峰转换为下划线         */        private static String underscoreName(String camelCaseName) {            StringBuilder result = new StringBuilder();            if (camelCaseName != null && camelCaseName.length() > 0) {                result.append(camelCaseName.substring(0, 1).toLowerCase());                for (int i = 1; i < camelCaseName.length(); i++) {                    char ch = camelCaseName.charAt(i);                    if (Character.isUpperCase(ch)) {                        result.append("_");                        result.append(Character.toLowerCase(ch));                    } else {                        result.append(ch);                    }                }            }            return result.toString();        }        /**         * 首字母大写         */        private static String captureName(String name) {            char[] cs = name.toCharArray();            cs[0] -= 32;            return String.valueOf(cs);        }        /**         * 下划线转换为驼峰         */        private static String camelCaseName(String underscoreName) {            StringBuilder result = new StringBuilder();            if (underscoreName != null && underscoreName.length() > 0) {                boolean flag = false;                for (int i = 0; i < underscoreName.length(); i++) {                    char ch = underscoreName.charAt(i);                    if ("_".charAt(0) == ch) {                        flag = true;                    } else {                        if (flag) {                            result.append(Character.toUpperCase(ch));                            flag = false;                        } else {                            result.append(ch);                        }                    }                }            }            return result.toString();        }    }    /**     * JDBC连接数据库工具类     */    private static class DBConnectionUtil {        static {            // 1、加载驱动            try {                Class.forName(DRIVER_CLASSNAME);            } catch (ClassNotFoundException e) {                e.printStackTrace();            }        }        /**         * 返回一个Connection连接         */        static Connection getConnection() {            Connection conn = null;            // 2、连接数据库            try {                conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);            } catch (SQLException e) {                e.printStackTrace();            }            return conn;        }        /**         * 关闭Connection，Statement连接         */        public static void close(Connection conn, Statement stmt) {            try {                conn.close();                stmt.close();            } catch (SQLException e) {                e.printStackTrace();            }        }        /**         * 关闭Connection，Statement，ResultSet连接         */        public static void close(Connection conn, Statement stmt, ResultSet rs) {            try {                close(conn, stmt);                rs.close();            } catch (SQLException e) {                e.printStackTrace();            }        }    }    /**     * 表结构信息实体类     */    private class TableInfo {        private String columnName;//字段名        private String dataType;//字段类型        private String columnComment;//字段注释        private String columnKey;//主键        private String extra;//主键类型        public String getColumnName() {            return columnName;        }        public void setColumnName(String columnName) {            this.columnName = columnName;        }        public String getDataType() {            return dataType;        }        public void setDataType(String dataType) {            this.dataType = dataType;        }        public String getColumnComment() {            return columnComment;        }        public void setColumnComment(String columnComment) {            this.columnComment = columnComment;        }        public String getColumnKey() {            return columnKey;        }        public void setColumnKey(String columnKey) {            this.columnKey = columnKey;        }        public String getExtra() {            return extra;        }        public void setExtra(String extra) {            this.extra = extra;        }    }    /**     * 获取表结构信息     * 目前仅支持mysql     */    private List<TableInfo> getTableInfo() {        Connection conn = null;        PreparedStatement ps = null;        ResultSet rs = null;        ArrayList<TableInfo> list = new ArrayList<>();        try {            conn = DBConnectionUtil.getConnection();            //表字段信息            String sql = "select column_name,data_type,column_comment,column_key,extra from information_schema.columns where table_schema = (select database()) and table_name=?";            ps = conn.prepareStatement(sql);            ps.setString(1, tableName);            rs = ps.executeQuery();            while (rs.next()) {                TableInfo tableInfo = new TableInfo();                //列名，全部转为小写                tableInfo.setColumnName(rs.getString("column_name").toLowerCase());                //列类型                tableInfo.setDataType(rs.getString("data_type"));                //列注释                tableInfo.setColumnComment(rs.getString("column_comment"));                //主键                tableInfo.setColumnKey(rs.getString("column_key"));                //主键类型                tableInfo.setExtra(rs.getString("extra"));                list.add(tableInfo);            }            //表注释            sql = "select table_comment from information_schema.tables where table_schema = (select database()) and table_name=?";            ps = conn.prepareStatement(sql);            ps.setString(1, tableName);            rs = ps.executeQuery();            while (rs.next()) {                //表注释                tableComment = rs.getString("table_comment");            }        } catch (SQLException e) {            e.printStackTrace();        } finally {            if(rs != null){                DBConnectionUtil.close(conn, ps, rs);            }        }        return list;    }    /**     * 快速创建，供外部调用，调用之前先设置一下项目的基础路径     */    private String create() {        System.out.println("生成路径位置：" + filePath);        //获取表信息        List<TableInfo> tableInfo = getTableInfo();        //驼峰标识映射后的表名        String captureName = StringUtil.captureName(StringUtil.camelCaseName(tableName));        //自定义参数        HashMap<String, String> customParameter = new HashMap<>();        customParameter.put("author","作者：Auto Generator By 'huanzi-qch'");        customParameter.put("date","生成日期："+new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()));        //读取模板、生成代码        writer(tlfPath+"controller.tlf",                filePath + "controller\\" + captureName + "Controller.java",                tableInfo,customParameter);        writer(tlfPath+"entity.tlf",                filePath + "pojo\\" + captureName + ".java",                tableInfo,customParameter);        writer(tlfPath+"entityvo.tlf",                filePath + "vo\\" + captureName + "Vo.java",                tableInfo,customParameter);        writer(tlfPath+"repository.tlf",                filePath + "repository\\" + captureName + "Repository.java",                tableInfo,customParameter);        writer(tlfPath+"service.tlf",                filePath + "service\\" + captureName + "Service.java",                tableInfo,customParameter);        writer(tlfPath+"serviceimpl.tlf",                filePath + "service\\" + captureName + "ServiceImpl.java",                tableInfo,customParameter);        return tableName + " 后台代码生成完毕！";    }    public static void main(String[] args) {//        String[] tables = {"sys_user","sys_menu","sys_authority","sys_user_menu","sys_user_authority","sys_shortcut_menu","sys_setting"};        String[] tables = {"tb_user"};        for (String table : tables) {            String msg = new AutoGeneratorPlus(table).create();            System.out.println(msg);        }    }}

　　同时，所有代码都在base admin项目里，代码已经开源、托管到我的GitHub、码云：

　　GitHub：

　　码云：

作者：huanzi-qch

出处：

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