3个用例说明 ajax请求+springmvc 的主要的2种 contentType （除开multipart/form-data ）

springmvc 后端接收ajax请求, 常见的有3种contentType 类型, 这里主要讲两种contentType 请求类型
1：contentType = “application/json;charset=UTF-8”
2：contentType = “application/x-www-form-urlencoded;charset=UTF-8” （默认）

另外还可通过 dataType 约定了服务器数据访问类型
dataType 默认= “json” 可写可不写 .

用例1

• 前端

function search1() {
        var carid = $("input[name='carid']").val();        
        var data1 = {
            "pageindex" : "1",
            "pagesize" : "10",
            "carid" : carid
        };
        $.ajax({
            type : "POST",
            url : "list1.do",
            contentType : "application/json;charset=UTF-8",
            data : JSON.stringify(data1),
            success : function(data) {
                console.log(data);
            }
        });
    }

注意：此时

contentType = “application/json;charset=UTF-8”
data =JSON.stringify(data1)

• 后端

@RequestMapping("/list1.do")
@ResponseBody
public List<Map<String, Object>> flist1 ( @RequestBody Map mp) {  
    System.out.println(mp.get("pageindex")+",");
    System.out.println(mp.get("pagesize")+",");
    System.out.println(mp.get("carid")+",");
    //List<Map<String, Object>> list=   dao_charge.selectcharge(gets);
    List<Map<String, Object>> list=new ArrayList();
    return list;
}

用例2

• 前端

function search2() {
    var carid = $("input[name='carid']").val();
    var data1 = {
        "pageindex" : "1",
        "pagesize" : "10",
        "carid" : carid
    };
    $.post("list2.do", data1).success(function(result) {
    });
}

注意：此时

contentType =application/x-www-form-urlencoded;charset=UTF-8
data=data1

• 后端

@RequestMapping("/list2.do")
@ResponseBody
public List<Map<String, Object>> flist2 (HttpServletRequest req,
    String pageindex ,String pagesize,String carid  ) {      
    System.out.println(req.getParameter("pageindex")+",");
    System.out.println(req.getParameter("pagesize")+",");
    System.out.println(req.getParameter("carid")+",");
    System.out.println(",,,,,,,");
    System.out.println(pageindex+",");
    System.out.println(pagesize+",");
    System.out.println(carid+",");  
    List<Map<String, Object>> list=new ArrayList();
    return list;
}

用例3

• 前端

function search3() {
    var carid = $("input[name='carid']").val();    
    var data1 = {
        "pageindex" : "1",
        "carid" : carid
    };  
    $.ajax({
    type : "POST",
    url : "list2.do",
    contentType : "application/x-www-form-urlencoded;charset=UTF-8",
    data : data1,
    success : function(data) {
        console.log(data);
    }
    });
}

注意： 此时

contentType =application/x-www-form-urlencoded;charset=UTF-8
data=data1
如果省略 contentType 会自动识别为application/x-www-form-urlencoded

• 后端
  同用例2的后端写法

附3篇扩展

这三篇博文在其他方面 讲明了ajax 与springmvc 的关系，

1. springMVC返回数据的四种方式
2. SpringMVC的REST风格的四种请求方式
3. SSpringMVC前台利用ajax和FormData上传文件