spring mvc返回json字符串的方式
方案一：使用@ResponseBody 注解返回響應體 直接將返回值序列化json
優點：不需要自己再處理
步驟一：在spring-servlet.xml文件中配置如下代碼
<?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 -->
<!--讓spring掃描包下所有的類，讓標注spring注解的類生效 -->
<context:component-scan base-package="cn.hmy.controller"/>
<mvc:annotation-driven/>
<!--視圖解析器 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
</beans>
步驟二：在處理器方法中打上@ResponseBody 標簽
@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;
}
步驟三：使用ajax進行獲取數據
<%@ 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){
//解析對象
//alert(data.uname+"\n"+data.age);
//解析map
//alert(data.info.age+"\n"+data.info.uname);
//解析list
$.each(data,function(i,dom){
alert(dom.uname+"\n"+dom.age);
});
}
});
});
});
</script>
</head>
<body>
<input type="button" value="ajax" id="btn"/>
</body>
</html>
方案二：處理器方法的返回值---Object
由於返回Object數據，一般都是將數據轉化為JSON對象后傳遞給瀏覽器頁面的，而這個由Object轉換為Json，是由Jackson工具完成的，所以要導入jar包，將Object數據轉化為json數據，需要Http消息轉換器 HttpMessageConverter完成。而轉換器的開啟，需要由<mvc:annotation-driven/> 來完成，當spring容器進行初始化過程中，在<mvc:annotation-driven/> 處創建注解驅動時，默認創建了七個HttpMessageConverter對象，也就是說，我們注冊<mvc:annotation-driven/>，就是為了讓容器幫我們創建HttpMessageConverter對象
詳細代碼看
方案二、使用返回字符串的處理器方法，去掉@ResponseBody注解
步驟一、同上
步驟二
@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;
}
步驟三、在前台取值的時候需要我么做一遍處理
<%@ 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指的是從server打印到瀏覽器的數據
//jsonString jsonObject
//{"001":{"age":122,"name":"順利就業"}}
var result= eval("("+data+")");
$.each(result,function(i,dom){
alert(dom.age+"\n"+dom.uname);
});
// alert(result["001"]["age"]);
}
});
});
});
</script>
</head>
<body>
<input type="button" value="ajax" id="btn"/>
</body>
</html>
方案三：使用無返回值的處理器方法
步驟一：同上
步驟二：使用響應流回送數據
@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();
}
步驟三：在前台取值也需要做處理
<%@ 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指的是從server打印到瀏覽器的數據
//jsonString jsonObject
//{"001":{"age":122,"name":"順利就業"}}
var result= eval("("+data+")");
$.each(result,function(i,dom){
alert(dom.age+"\n"+dom.uname);
});
// alert(result["001"]["age"]);
}
});
});
});
</script>
</head>
<body>
<input type="button" value="ajax" id="btn"/>
</body>
</html>