前言：
现时各位老铁们对“java的demo”可能比较关切，兄弟们都想要知道一些“java的demo”的相关知识。那么小编在网摘上搜集了一些关于“java的demo””的相关内容，希望小伙伴们能喜欢，兄弟们一起来了解一下吧！1、springmvc的原理：利用servlet请求与注解机制实现页面不同的业务处理，它与struts2的主要区别是：struts2是类处理级别，每个业务请求需要特定类的execute()方法进行处理，而springmvc是方法级处理，每个业务请求可以通过同一个类的方法的@RequestMapping注解进行区分处理。
2、依赖的jar包：
3、工程结构：
4、User/Product两个实体类（因篇幅简化）：
public class User {
private int userid;
private String username;
private String password;
set和get方法，以及构造方法
}
public class Product {
private int prdid;
private String prdname;
private String prdtype;
private String prdprice;
set和get方法，以及构造方法
｝
5、UserController.java控制器：实现页面不同的业务请求处理：
package com.springmvcDemo.controller;
import java.util.ArrayList;
import java.util.List;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.servlet.ModelAndView;
import com.springmvcDemo.domain.Product;
import com.springmvcDemo.domain.User;
@Controller
@RequestMapping(value = "/user")
public class UserController {
ModelAndView modelAndView = new ModelAndView();
@RequestMapping(value = "/register", method = RequestMethod.POST)
public String register(@RequestParam("password") String password,
@RequestParam("username") String username) {
User user = new User(username, password);
System.out.println(user);
return "register";
}
@RequestMapping(value = "/login")
public ModelAndView login(@RequestParam("username") String username, @RequestParam("password") String password,
Model model) {
User user = new User(username, password);
model.addAttribute("username", user.getUsername());
Product product1 = new Product(1,"商品1", "衣服", "100");
Product product2 = new Product(2,"商品2", "电器", "200");
List<Product> prdlist = new ArrayList<Product>();
prdlist.add(product1);
prdlist.add(product2);
modelAndView.addObject("prdlist", prdlist);
modelAndView.setViewName("welcome");
return modelAndView;
}
}
6、springmvc.xml：springmvc控制器配置，主要是实现类的注册与页面路径的配置：
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns=";
xmlns:xsi="; xmlns:mvc=";
xmlns:context=";
xsi:schemaLocation="
;>
<!-- 使用基于注解的控制器，spring会自动扫描base-package下的子包和类，如果扫描到会把这些类注册为bean -->
<context:component-scan base-package="com.springmvcDemo.*" />
<!-- 配置处理映射器和处理器适配器 在Spring4.0后，不配置，会默认加载 -->
<!-- <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping"/> -->
<!-- <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"/> -->
<!-- 配置视图解析器，经过视图解析器后，视图的的完成路径为[prefix]+返回的视图字符串+[suffix] -->
<bean id="viewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix">
<value>/WEB-INF/view/</value>
</property>
<property name="suffix">
<value>.jsp</value>
</property>
</bean>
</beans>
7、web.xml:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi=";
xmlns=";
xsi:schemaLocation=" ;
id="WebApp_ID" version="3.0">
<filter>
<filter-name>characterEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<init-param>
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>characterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<servlet>
<servlet-name>SpringMVC</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!-- 配置SpringMVC下的配置文件位置及名称 -->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>SpringMVC</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
8、index.jsp ：
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<html>
<head>
<meta http-equiv="content-type" content="text/html;charset=utf-8">
<%@ taglib prefix="c" uri=";%>
<title>My JSP 'index.jsp' starting page</title>
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<form name="login_form" action="user" method="post">
<table>
<tr>
<td>用户名：</td>
<td><input name="userid" type="text" /></td>
</tr>
<tr>
<td>姓 名 ：</td>
<td><input name="username" type="text" /></td>
</tr>
<tr>
<td>密 码 ：</td>
<td><input name="password" type="text" /></td>
</tr>
<tr>
<td align="right"><input type="submit" value="登陆" onclick="logup()" /></td>
<td align="center"><input type="submit" value="注册" onclick="register()" /></td>
</tr>
</table>
</form>
<script type="text/javascript">
function logup() {
document.login_form.action = "user/login";
element.submit();
}
function register() {
document.login_form.action = "user/register";
element.submit();
}
</script>
</body>
</html>
9、welcome.jsp登陆成功的页面：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" ";>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<%@ taglib prefix="c" uri=";%>
<title>欢迎页面</title>
</head>
<body>
欢迎${requestScope.username}用户登陆成功
<table border="1" cellspacing="0" cellpadding="0">
<tr align="center">
<td>商品编号</td>
<td>商品名称</td>
<td>商品类型</td>
<td>商品价格</td>
</tr>
<c:forEach items="${prdlist}" var="product">
<tr>
<td>${product.prdid}</td>
<td>${product.prdname}</td>
<td>${product.prdtype}</td>
<td>${product.prdprice}</td>
<td><a
href="${pageContext.request.contextPath}/product/queryproduct?id=${product.prdid}">查询</a></td>
</tr>
</c:forEach>
</table>
</body>
</html>
标签： #java的demo
