spring_mvc用法.java

@Controller  //让该类成为控制器
     public class HelloController {
        
	@RequestMapping(value={"/","/hello"})
	public String hello(int id,Map<String,Object> map) {  //使用Map传值
		System.out.println(id);
		System.out.println("hello");
		map.put("hello", "world");
		return "hello";
	}
	
	@RequestMapping(value="/say")
	public String say(@RequestParam int id,Model model) {  //建议使用model传值
		System.out.println("say");
		model.addAttribute("hello", "value");
		//使用Object的类型作为key,String-->string
		model.addAttribute("ok");
		return "hello";
	}
	//访问servlet api
	@RequestMapping("/req")
	public String req(HttpServletRequest req) {
		System.out.println(req.getParameter("username"));
		return "hello";
	}

decorators.xml

<?xml version="1.0" encoding="utf-8"?>  

<decorators defaultdir="/decorators">  

    <!-- 此处用来定义不需要过滤的页面 -->  

    <excludes>  

    </excludes>  

 <!-- 用来定义装饰器要过滤的页面 -->  

    <decorator name="main" page="main.jsp">  

        <pattern>/*</pattern>  

    </decorator>  

</decorators>  

spring mvc环境搭建.md

####1.web.xml####

   <servlet>
	<servlet-name>hello</servlet-name>
	<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
            //启动时默认运行
	<load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
	<servlet-name>hello</servlet-name>
            //spring支持RESTful风格，故为斜杠
	<url-pattern>/</url-pattern>
</servlet-mapping>

####2.xxx-servlet.xml

<mvc:annotation-driven/>
<context:component-scan base-package="com.wjch.controller"></context:component-scan>


<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
	<property name="prefix" value="/WEB-INF/jsp/"></property>
	<property name="suffix" value=".jsp"></property>
</bean>

####3.controller####

 @Controller  //让该类成为控制器
 public class HelloController {
    
@RequestMapping(value={"/","/hello"})    
public String hello(int id,Map<String,Object> map) {
	System.out.println(id);
	System.out.println("hello");
	map.put("hello", "world");
	return "hello";
}

   //url为：/say?id=10
@RequestMapping(value="/say")  
public String say(@RequestParam int id,Model model) {
	System.out.println("say");
	model.addAttribute("hello", "value");
	//使用Object的类型作为key,String-->string
	model.addAttribute("ok");
	return "hello";
}

   //利用HttpServletRequest传值，url为:req?username=10
@RequestMapping("/req")
public String req(HttpServletRequest req) {
	System.out.println(req.getParameter("username"));
	return "hello";
}

####4.siteMesh标签####

   <%@ taglib uri="http://www.opensymphony.com/sitemesh/decorator" prefix="decorator" %>

和 <decorator:body />

####5.关系####

spring_mvc字符编码.xml

<!-- utf8编码配置  -->  
 <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>
  </filter>
  <filter-mapping>
    <filter-name>CharacterEncodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
  
<!--启用siteMesh来装饰页面-->
  <filter>
    <filter-name>sitemesh</filter-name>
    <filter-class>com.opensymphony.sitemesh.webapp.SiteMeshFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>sitemesh</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

  <!--对应相应的user_servlet.xml文件-->
  <servlet>
  	<servlet-name>user</servlet-name>
  	<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  </servlet>
  
  <servlet-mapping>
  	<servlet-name>user</servlet-name>
  	<url-pattern>/</url-pattern>
  </servlet-mapping>

UserController.java

package cn.edu.zttc.controller;

import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.validation.Valid;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.SessionAttributes;
import org.springframework.web.servlet.mvc.support.RedirectAttributes;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

import cn.edu.zttc.vo.User;
import cn.edu.zttc.vo.UserException;


@Controller
@RequestMapping("/user")
@SessionAttributes("loginUser")
public class UserController {
	
	private final static Map<String,User> users = new HashMap<String,User>();
	
	public UserController() {
		users.put("ldh",new User("ldh","刘德华","123","123123"));
		users.put("zxy",new User("zxy","张学友","123","123123"));
		users.put("gfc",new User("gfc","郭富城","123","123123"));
		users.put("lm",new User("lm","黎明","123","123123"));
	}
	
	@RequestMapping({"/users","/"})
	public String list(Model model) {
		model.addAttribute("users",users);//map
		return "user/list";
	}
	
	@RequestMapping(value="/add",method=RequestMethod.GET)
	public String add(Model model) {
		model.addAttribute(new User());//User-->user
		return "user/add";
	}
	
	@RequestMapping(value="/add",method=RequestMethod.POST)
	public String add(@Valid User user,BindingResult binding) {
		if(binding.hasErrors()) {
			return "user/add";
		}
		users.put(user.getUsername(), user);
		return InternalResourceViewResolver.REDIRECT_URL_PREFIX+"/user/users";
	}
	
	@RequestMapping(value="/{username}",method=RequestMethod.GET)
	public String show(@PathVariable String username,Model model) {
		model.addAttribute(users.get(username));
		return "user/show";
	}
	
	@RequestMapping(value="/{username}/update",method=RequestMethod.GET)
	public String update(@PathVariable String username,Model model) {
		model.addAttribute(users.get(username));
		return "user/update";
	}
	
	@RequestMapping(value="/{username}/update",method=RequestMethod.POST)
	public String update(@PathVariable String username,@Valid User user,BindingResult br,Model model) {
		if(br.hasErrors()) {
			return "user/update";
		}
		users.put(username, user);
		return "redirect:/user/users";
	}
	
	@RequestMapping(value="/{username}/delete",method=RequestMethod.GET)
	public String delete(@PathVariable String username) {
		users.remove(username);
		return "redirect:/user/users";
	}
	
        //使用响应体来传递json对象
	@ResponseBody
	@RequestMapping(value="/{username}",params="json")
	public User showJson(@PathVariable String username,Model model) {
		System.out.println(username);
		return users.get(username);
	}
	
        //使用GET方法传值
	@RequestMapping(value="/login",method=RequestMethod.GET)
	public String login() {
		return "user/login";
	}
	
        //使用POST方法传值
	@RequestMapping(value="/login",method=RequestMethod.POST)
	public String login(String username,String password,Model model) {
		if(!users.containsKey(username)) {
			throw new UserException("用户名不存在");
		}
		if(!password.equals(users.get(username).getPassword())) {
			throw new UserException("用户密码不正确");
		}
		model.addAttribute("loginUser", users.get(username));
		return "redirect:/user/users";
	}
	
	@ExceptionHandler(value={UserException.class})
	public String handlerException(Exception ex,HttpServletRequest req) {
		req.setAttribute("ex",ex);
		return "error";
	}
	
       //使用RedirectAttribute来进行flash attribute的传值。
	@RequestMapping("/redir")
	public String redir(Model model,RedirectAttributes ra) {、
                //默认可以使用model.addAttribute("tttt", "吞吞吐吐");但是跳转时务必使用RedirectAttributes
		ra.addFlashAttribute("tttt", "吞吞吐吐");
		return "redirect:/user/users";
	}
	
}