spring mvc返回json字符串的方式
方案一：使用@ResponseBody 注解返回响应体 直接将返回值序列化json
优点：不需要自己再处理
步骤一：在spring-servlet.xml文件中配置如下代码
<?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:p="http://www.springframework.org/schema/p" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation=" 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.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd "> <!--使用Annotation方式 完成映射 --> <!--让spring扫描包下所有的类，让标注spring注解的类生效 --> <context:component-scan base-package="cn.yxj.controller"/> <mvc:annotation-driven/> <!--视图解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/jsp/"></property> <property name="suffix" value=".jsp"></property> </bean> </beans>
步骤二：在处理器方法中打上@ResponseBody 标签
@RequestMapping(value="/hello5.do") @ResponseBody public String hello(HttpServletResponse response) throws IOException{ UserInfo u1=new UserInfo(); u1.setAge(15); u1.setUname("你好"); UserInfo u2=new UserInfo(); u2.setAge(152); u2.setUname("你好2"); Map<String,UserInfo> map=new HashMap<String, UserInfo>(); map.put("001", u1); map.put("002", u2); String jsonString = JSON.toJSONString(map); return jsonString; }
步骤三：使用ajax进行获取数据
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title> <script type="text/javascript" src="js/jquery-1.8.3.js"></script> <script type="text/javascript"> $(function(){ $("#btn").click(function(){ $.ajax({ url:"<%=path%>/Five.do", success:function(data){ //解析对象 //alert(data.uname+" "+data.age); //解析map //alert(data.info.age+" "+data.info.uname); //解析list $.each(data,function(i,dom){ alert(dom.uname+" "+dom.age); }); } }); }); }); </script> </head> <body> <input type="button" value="ajax" id="btn"/> </body> </html>
方案二：处理器方法的返回值---Object
由于返回Object数据，一般都是将数据转化为JSON对象后传递给浏览器页面的，而这个由Object转换为Json，是由Jackson工具完成的，所以要导入jar包，将Object数据转化为json数据，需要Http消息
转换器 HttpMessageConverter完成。而转换器的开启，需要由<mvc:annotation-driven/> 来完成，当spring容器进行初始化过程中，在<mvc:annotation-driven/> 处创建注解驱动时，默认创
建了七个HttpMessageConverter对象，也就是说，我们注册<mvc:annotation-driven/>，就是为了让容器帮我们创建HttpMessageConverter对象
详细代码看
方案二、使用返回字符串的处理器方法，去掉@ResponseBody注解
步骤一、同上
步骤二
@RequestMapping(value="/hello5.do") public String hello(HttpServletResponse response) throws IOException{ UserInfo u1=new UserInfo(); u1.setAge(15); u1.setUname("你好"); UserInfo u2=new UserInfo(); u2.setAge(152); u2.setUname("你好2"); Map<String,UserInfo> map=new HashMap<String, UserInfo>(); map.put("001", u1); map.put("002", u2); String jsonString = JSON.toJSONString(map); return jsonString; }
步骤三、在前台取值的时候需要我么做一遍处理
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title> <script type="text/javascript" src="js/jquery-1.8.3.js"></script> <script type="text/javascript"> $(function(){ $("#btn").click(function(){ $.ajax({ url:"<%=path%>/hello5.do", success:function(data){ //data指的是从server打印到浏览器的数据 //jsonString jsonObject //{"001":{"age":122,"name":"顺利就业"}} var result= eval("("+data+")"); $.each(result,function(i,dom){ alert(dom.age+" "+dom.uname); }); // alert(result["001"]["age"]); } }); }); }); </script> </head> <body> <input type="button" value="ajax" id="btn"/> </body> </html>
方案三：使用无返回值的处理器方法
步骤一：同上
步骤二：使用响应流回送数据
@RequestMapping(value="/hello5.do") public void hello(HttpServletResponse response) throws IOException{ UserInfo u1=new UserInfo(); u1.setAge(15); u1.setUname("你好"); UserInfo u2=new UserInfo(); u2.setAge(152); u2.setUname("你好2"); Map<String,UserInfo> map=new HashMap<String, UserInfo>(); map.put("001", u1); map.put("002", u2); String jsonString = JSON.toJSONString(map); response.setCharacterEncoding("utf-8"); response.getWriter().write(jsonString); response.getWriter().close(); }
步骤三：在前台取值也需要做处理
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title> <script type="text/javascript" src="js/jquery-1.8.3.js"></script> <script type="text/javascript"> $(function(){ $("#btn").click(function(){ $.ajax({ url:"<%=path%>/hello5.do", success:function(data){ //data指的是从server打印到浏览器的数据 //jsonString jsonObject //{"001":{"age":122,"name":"顺利就业"}} var result= eval("("+data+")"); $.each(result,function(i,dom){ alert(dom.age+" "+dom.uname); }); // alert(result["001"]["age"]); } }); }); }); </script> </head> <body> <input type="button" value="ajax" id="btn"/> </body> </html>