服务器和客户端json数据传输

例如客户端通过ajax发送json请求数据

$.ajax({
		type:"get",
		url:"${ctxPath}/login",
		contentType:"application/json,charset=UTF-8",
		data:{
			"handle":"login",
			"name":"张三"
		},
		dataType:'json',
		success: function(data){			
			console.log(data);
			
		},
		error: function(){
			console.log("请求数据失败");
		}
		

服务器端取查询数据库做出响应

req.setCharacterEncoding("utf-8");
resp.setContentType("text/html");
resp.setCharacterEncoding("utf-8");
PrintWriter writer=resp.getWriter();

String handle=req.getParameter("handle");
String account=req.getParameter("name");
System.out.println("handle="+handle+",account="+account);
Connection conn=null;
try {
	conn=DBUtil.getConnection();
	String sql="select * from person";
	PreparedStatement psmt=conn.prepareStatement(sql);
	ResultSet rs=psmt.executeQuery();
	ResultSetMetaData rsm=rs.getMetaData();
	int num=rsm.getColumnCount();
	JSONObject json=new JSONObject();
	JSONObject user=new JSONObject();
	while(rs.next()) {
		String name=rs.getString("name");
		json.put("code", "0");
		json.put("message", "success");
		if(account.equals(name)) {
			for(int i=1;i<=num;i++){
				user.put(rsm.getColumnName(i), rs.getObject(i));
			}
			json.put("data", user);
			System.out.println(json.toString());
			
			writer.write(json.toString());
			writer.flush();
			writer.close();
		}
		
	}
	
} catch (Exception e) {
	e.printStackTrace();
}finally {
	DBUtil.closeConnection(conn);
}

关于json数据和实体类的转化

Person person=(Person) JSONObject.toBean(user,Person.class);//json转person实体类
System.out.println(person.getName());
System.out.println(person);
JSONObject data=JSONObject.fromObject(person);//person实体类转json
System.out.println(data.get("name"));
System.out.println(data.toString());