SpringMVC教程2[处理响应请求]

时间 2019-12-05

标签 springmvc 教程处理响应请求栏目 Spring 繁體版

原文原文链接

一,基本操做

1.响应请求的方式

不响应 | void+@ResponseBody注解 |html

ModelAndView | 经过setViewName方法 | 直接指定响应页面 | 返回值为String类型，返回结果指定跳转地址 |java

重定向 | 跳转地址前加redirect:前缀便可 |web

HttpServletRequest和HttpServletResponse | 形参中声明这两个变量。而后经过相关api跳转|spring

上一篇看过ModelAndView的响应方式这里就从void开始

1.返回void

返回值为void时,方法中能够不用作任何返回,在浏览器中,springmvc会默认去查找和方法同名的页面做为方法的视图返回。若是确实不须要该方法返回页面，可使用@ResponseBody注解，表示一个请求到此为止。api

@RequestMapping("/test1")
@ResponseBody
public void test1() {    
   System.out.println("test1");
}

下面讲述各类请求的方式与实现代码,结果就不一一演示了

配置web.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>SpringMVC-01-hello</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
	<servlet>
		<servlet-name>springmvc</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<init-param>
			<param-name>contextConfigLocation</param-name>
			<param-value>classpath:Spring-MVC.xml</param-value>
		</init-param>
		<load-on-startup>1</load-on-startup>
	</servlet>

	<!-- Map all requests to the DispatcherServlet for handling -->
	<servlet-mapping>
		<servlet-name>springmvc</servlet-name>
		<url-pattern>/</url-pattern>
	</servlet-mapping>
</web-app>

配置spring-mvc的配置文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd">
	<!-- 开启扫描 -->
	<context:component-scan base-package="com.sxt"/>
	
	<!-- 开启SpringMVC注解的方式 -->
	<mvc:annotation-driven></mvc:annotation-driven>
	
	<!-- 配置视图解析器 和Controller的一个方法一块儿使用后面有标记-->
	<!--  <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
			<property name="prefix" value="/"/>
			<property name="suffix" value=".jsp"/>
	</bean>  -->
</beans>

自定义的Controller,index的jsp页面内容自定义

package com.sxt;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;

@Controller
@RequestMapping("/hello")
public class HelloController {

	//ModelAndView,响应方式
	@RequestMapping("/hello1")
	public ModelAndView hello1(){
		System.out.println("-----hello1---");
		ModelAndView m = new ModelAndView();
		m.setViewName("/index.jsp");
		return m;
	}
	//返回一个字符串
	@RequestMapping("/hello2")
	@ResponseBody//该注解表示一个请求到此结束
	public void  hello2(){
		
		System.out.println("aaaa");
	}
	/*
	 * 此方法须要在spring-mvc的配置文件配置视图解析器，自动添加index的前缀后缀,开启后可用这个方法
	@RequestMapping("/h1")
	public String hello3(){
		System.out.println("111");
		return "index";
	}*/
	//重定向跳转 ：返回路径注意: 返回的字符带"/“表示从根目录下开始找，不带”/"从当前目录下查找
	@RequestMapping("/h2")
	public String hello4(){
		System.out.println("111");
		return "redirect:/index.jsp";
	}
	//经过request和response
	@RequestMapping("/h5")
	public void hello5(HttpServletRequest request,HttpServletResponse response) throws IOException, Exception{
		System.out.println("333");
		request.getRequestDispatcher("/index.jsp").forward(request, response);
	}

}

上面方法除了视图解析器须要在配置文件配置,其他的都同样数组

@RequertMapping的说明

1.映射路径 @RequestMapping最基本的功能，用法:浏览器

@RequestMapping("/delete")
 public String delete(){
 	System.out.println("波波烤鸭：删除数据操做....");
 	return "/hello";
 }

窄化请求窄化请求用来限定请求路径，即将@RequestMapping放在类上，这样，方法的请求路径是类上的@ReqmestMapping+方法上的@RequestMapping 请求方法限定 spring-mvc

基本数据类型

java基本数据类型+string 使用基本数据类型时,参数名称和浏览器传来的参数的key一致,这样才能实现自动映射session

/**
 * 接收参数
 *    基本数据类型
 * @param id
 * @param name
 * @return
 */ @RequestMapping("add") public String add(int id,String name){ System.out.println(id+"---"+name); return "/hello"; }

若是参数名和浏览器传来的key不一致，能够经过@RequestParam来解决。以下mvc

/**
 * 接收参数
 *    基本数据类型
 *    请求参数若是和形参名称不一致能够经过@RequestParam类指定
 * @param id
 * @param name
 * @return
 */ @RequestMapping("add") 
 public String add(int id,@RequestParam("username")String name){
  			System.out.println(id+"---"+name); 
 			 return "/hello";
   }

加@ReuestParam,若是为从新指定参数名,则默认的参数名依然是本来的参数名,同时也要注意,添加了这个注解后,对应的参数将成为必填参数.若是没有传递相关的参数,则会抛异常但若是不想传参数,也有两种方式解决

1.经过required属性指定该参数不是必填的

/**
 * 接收参数
 *    基本数据类型
 *    请求参数若是和形参名称不一致能够经过@RequestParam类指定
 * @param id
 * @param name
 * @return
 */ @RequestMapping("add")
  public String add(int id ,@RequestParam(value="username",required=false)String name){ 
 				 System.out.println(id+"---"+name); 
 				 return "/hello";
   }

2.经过defaultValue属性给指定参数一个默认值

/**
 * 接收参数
 *    基本数据类型
 *    请求参数若是和形参名称不一致能够经过@RequestParam类指定
 * @param id
 * @param name
 * @return
 */ @RequestMapping("add")
  public String add(int id ,@RequestParam(value="username",defaultValue="kaoya")String name){
   					System.out.println(id+"---"+name);
   						 return "/hello";
     }

对象

建立一个book对象和user对象

package com.sxt.bean;

public class Book {
	private Integer id;
	
	private String name;

	@Override
	public String toString() {
		return "Book [id=" + id + ", name=" + name + "]";
	}

	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}
}

package com.sxt.bean;

import java.util.Arrays;
import java.util.Date;
import java.util.List;

public class User {
	private Integer id;

	private Integer age;

	private String unama;
	private String[] favorites;

	private List<String> list;

	private Date birth;

	private Book book;

	@Override
	public String toString() {
		return "User [id=" + id + ", age=" + age + ", unama=" + unama + ", favorites=" + Arrays.toString(favorites)
				+ ", list=" + list + ", birth=" + birth + ", book=" + book + "]";
	}

	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public Integer getAge() {
		return age;
	}

	public void setAge(Integer age) {
		this.age = age;
	}

	public String getUnama() {
		return unama;
	}

	public void setUnama(String unama) {
		this.unama = unama;
	}

	public String[] getFavorites() {
		return favorites;
	}

	public void setFavorites(String[] favorites) {
		this.favorites = favorites;
	}

	public List<String> getList() {
		return list;
	}

	public void setList(List<String> list) {
		this.list = list;
	}

	public Date getBirth() {
		return birth;
	}

	public void setBirth(Date birth) {
		this.birth = birth;
	}

	public Book getBook() {
		return book;
	}

	public void setBook(Book book) {
		this.book = book;
	}

	
}

建立配置文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd">
	<!-- 开启扫描 -->
	<context:component-scan base-package="com.sxt"/>
	
	<!-- 开启SpringMVC注解的方式 -->
	<mvc:annotation-driven></mvc:annotation-driven>
</beans>

创建user.jsp页面

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="add" method="post">
	<table>
		<tr>
			<td>编号</td>
			<td><input type="text" name="id"></td>
		</tr>
		<tr>
			<td>名字</td>
			<td><input type="text" name="unama"></td>
		</tr>
		<tr>
			<td>年龄</td>
			<td><input type="text" name="age"></td>
		</tr>
		<tr>
			<td>id</td>
			<td><input type="text" name="book.id"></td>
		</tr>
		<tr>
			<td>做者</td>
			<td><input type="text" name="book.name"></td>
		</tr>
		<tr>
			<td><input type="submit" value="添加"></td>
		</tr>
	</table>
</form>

</body>
</html>

建立自定义的Controller

package com.sxt;

import java.util.Date;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import com.sxt.bean.User;

@Controller
public class UserController {

	@RequestMapping("/add")//对象接受数据方法
	@ResponseBody
	public void add(User user) {
		System.out.println(user);
	}

}

测试

由于测试的对象因此其余都没给值

数组与集合的数据接受

bean层和配置文件,web.xml文件都同样

package com.sxt;

import java.util.Date;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import com.sxt.bean.User;

@Controller
public class UserController {
	//数组数据获取
	@RequestMapping("/add2")
	@ResponseBody
	public void add3(User user) {
		System.out.println(user);
		String[] favorites = user.getFavorites();
		for (String f : favorites) {
			System.out.println(f);
		}

	}
	//集合数据获取
	@RequestMapping("/add3")
	@ResponseBody
	public void add4(User user) {
		System.out.println(user);
		System.out.println(user.getList());

	}

}

建立对应的jsp页面

获取数组类的jsp页面获取集合类的jsp页面

测试访问路径

数组的输出结果

集合输出结果

总结： 1.数组（不管是基本数据类型仍是对象数组）均可以直接写在接口参数中。 2.集合（不管是基本数据类型仍是对象）都须要一个包装类将其包装起来，不能直接写在接口参数中。 3.对于基本数据类型，数组和集合在表单中的写法是同样的 4.对于对象数据类型，数组和集合在表单中的写法是同样的

Data类型接受

接受数据类型是Data类型的须要经过转换器进行接受

自定义Controller

建立自定义的转换器

package com.sxt;

import java.util.Date;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import com.sxt.bean.User;

@Controller
public class UserController {
	@RequestMapping("/add4")
	@ResponseBody
	public void add4(Date d) {
		System.out.println(d);

	}

}

package com.sxt;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.springframework.core.convert.converter.Converter;
/**
 * Data类型转换器
 * @author Administrator
 *
 */
public class Convert implements Converter<String, Date>{

	@Override
	public Date convert(String arg0) {
		SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
		try {
			return format.parse(arg0);
		} catch (ParseException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return null;
	}

}

在spring-mvc.xml配置文件配置

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd">
		<!-- 开启扫描 -->
	<context:component-scan base-package="com.sxt"/>
	
	<!-- 开启SpringMVC注解的方式 -->
	<mvc:annotation-driven conversion-service="formattingConversionServiceFactoryBean"></mvc:annotation-driven>
	<bean class="org.springframework.format.support.FormattingConversionServiceFactoryBean" id="formattingConversionServiceFactoryBean">
		<property name="converters">
			<set>
				<bean class="com.sxt.Convert"/>
			</set>
		</property>
	</bean>
	
</beans>

测试

响应数据

3.1ModelAndView 3.2HttpServletRequest 3.3HttpSession 3.4Map

建立自定义controller

package com.sxt;

import java.util.Map;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.SessionAttributes;
import org.springframework.web.servlet.ModelAndView;

@Controller
public class HelloController {
	@RequestMapping("query1")
	public String add(Map<String, Object> map){
		map.put("msg", "aaaa");
		return "/index.jsp";
	}
	
	@RequestMapping("query2")
	public String add1(Model m){
		m.addAttribute("msg", "bbb");
		return "/index.jsp";
	}
	
	@RequestMapping("query3")
	public String add2(ModelMap mm){
		mm.addAttribute("msg", "ccc");
		return "/index.jsp";
	}
	
	@RequestMapping("query4")
	public ModelAndView add3(){
			ModelAndView view = new ModelAndView();
			view.addObject("msg", "ddd");
			view.setViewName("index.jsp");
			return view;
	}
}

建立springmvc配置文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd">
		<!-- 开启扫描 -->
	<context:component-scan base-package="com.sxt"/>
	
	<!-- 开启SpringMVC注解的方式 -->
	<mvc:annotation-driven ></mvc:annotation-driven>
	
</beans>

建立index.jsp页面

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
${msg}

<h3>request:${requestScope.msg }</h3>
	<h3>session:${sessionScope.msg }</h3>
	<h3>application:${applicationScope.msg }</h3>
</body>
</html>

request:${requestScope.msg }
session:${sessionScope.msg }
application:${applicationScope.msg }
检查msg是保存在哪个做用域的,结果证实都是保存在request做用域的

注意：加上@SessionAttributes这个注解是将数据保存在session做用域中的.

post方式提交中文乱码问题

在web.xml文件添加以下代码

<!-- spring框架提供的字符集过滤器 -->
 <!-- spring Web MVC框架提供了org.springframework.web.filter.CharacterEncodingFilter用于解决POST方式形成的中文乱码问题  --> 
 <filter>
 	 <filter-name>encodingFilter</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>encodingFilter</filter-name>
 	  	  	  <url-pattern>/*</url-pattern> 
 </filter-mapping>