【SpringMVC學習筆記】JSON數據交互

額外添加依賴

<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.9.8</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core -->
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-core</artifactId>
      <version>2.9.8</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-annotations -->
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-annotations</artifactId>
      <version>2.9.8</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/net.sf.json-lib/json-lib -->
    <dependency>
      <groupId>net.sf.json-lib</groupId>
      <artifactId>json-lib</artifactId>
      <version>2.4</version>
    </dependency>

<!--    添加處理json爲javaBean-->
    <!-- https://mvnrepository.com/artifact/org.codehaus.jackson/jackson-core-asl -->
    <dependency>
      <groupId>org.codehaus.jackson</groupId>
      <artifactId>jackson-core-asl</artifactId>
      <version>1.9.13</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.codehaus.jackson/jackson-mapper-asl -->
    <dependency>
      <groupId>org.codehaus.jackson</groupId>
      <artifactId>jackson-mapper-asl</artifactId>
      <version>1.9.13</version>
    </dependency>

JSON數據返回前臺以及如何解析

JSON後臺解析

1.返回POJO

@RequestMapping("/m1")
    @ResponseBody   //這個註解將知道現在返回的不是視圖，它會將這個數據轉換爲JSON格式
    public User m1(){
        User user = new User();
        user.setName("cyk");
        user.setPwd("123");
        return user;
    }

2.返回Map

@RequestMapping("/m2")
    @ResponseBody
    public Map<String,Object> m2(){
        Map<String, Object> map = new HashMap<>();
        map.put("name","cyk");
        map.put("age",12);
        return map;
    }

3.返回數組

@RequestMapping("/m3")
    @ResponseBody
    public User[] m3(){
        User user = new User();
        user.setName("cyk");
        user.setPwd("123");
        User user2 = new User();
        user2.setName("cyk2");
        user2.setPwd("1234");
        return new User[]{user,user2};
    }

4.返回List

@RequestMapping("/m4")
    @ResponseBody
    public List<User> m4(){
        List<User> l = new ArrayList<>();
        User user = new User();
        user.setName("王菲");
        user.setPwd("123");
        User user2 = new User();
        user2.setName("程蕭");
        user2.setPwd("1234");
        l.add(user);
        l.add(user2);
        return l;
    }

JSON前臺解析

1.解析返回的POJO

<script>
    $(function () {
        $('#b1').click(function () {
            $.ajax({
                url:'${path}/json/m1',
                type:'post',
                success:function (data) {
                    alert(data.name);
                    alert(data.pwd);
                }
            })
        })
    })
</script>

2.解析返回的Map

$('#b2').click(function () {
            $.ajax({
                url:'${path}/json/m2',
                type:'post',
                success:function (data) {
                    alert(data.name);
                    alert(data.age);
                }
            })
        })

3.解析返回的數組

$('#b3').click(function () {
            $.ajax({
                url:'${path}/json/m3',
                type:'post',
                success:function (data) {
                    for(var i = 0; i < data.length; i++){
                        alert(data[i].name);
                        alert(data[i].pwd);
                    }
                }
            })
        })

4.解析返回的List

$('#b4').click(function () {
            $.ajax({
                url:'${path}/json/m4',
                type:'post',
                success:function (data) {
                    for(var i = 0; i < data.length; i++){
                        alert(data[i].name);
                        alert(data[i].pwd);
                    }
                }
            })
        })

 5.解析返回的List<Map<String,User>>

$('#b5').click(function () {
            $.ajax({
                url:'${path}/json/m5',
                type:'post',
                success:function (data) {
                    for(var i = 0; i < data.length; i++){
                        alert(data[i].u1.name);
                        alert(data[i].u1.pwd);
                        alert(data[i].u2.name);
                        alert(data[i].u2.pwd);
                    }
                }
            })
        })

 

JSON數據如何使用Ajax提交到後臺，後臺如何解析

contentType:"application/json;charset=utf-8"

 

1.發送一個POJO到後臺

前臺

$('#b1').click(function () {
            var obj = {
                'name':'葉問',
                'pwd':'哈哈哈'
            }

            $.ajax({
                url:'${path}/json2/add',
                type:'post',
                contentType:'application/json',
                data:JSON.stringify(obj),
                success:function (data) {

                }
            })
            
        })

後臺

//前臺如何提交一個User對象
    @RequestMapping("/add")
    //User user入參只能提供表單數據
    public String add(@RequestBody User user){
        System.out.println(user.getName()+user.getPwd());
        return "msg";
    }

記得一定要添加@RequestBody，否則無法解析

 

2.發送一組POJO到後臺

前臺

$('#b2').click(function () {
            var obj = {
                'name':'葉問',
                'pwd':'哈哈哈'
            };

            var obj2 = {
                'name':'小葉問',
                'pwd':'哈哈哈hhhh'
            };

            var arr = new Array();
            arr.push(obj);
            arr.push(obj2);

            $.ajax({
                url:'${path}/json2/addList',
                type:'post',
                contentType:'application/json',
                data:JSON.stringify(arr),
                success:function (data) {
                    if(data.code === 2000)
                        alert("ok");
                }
            })

        })

後臺

@RequestMapping("/addList")
    @ResponseBody
    public Map<String,Integer> addList(@RequestBody List<User> list){
        Map<String,Integer> map = new HashMap<>();
        System.out.println(list);
        map.put("code",2000);
        return map;
    }

 

關於Form提交數據與Ajax自定義JSON數據提交的區別

1.form提交方式請求截圖

 2.通過ajax組裝的json數據發送分析

二者發送組裝數據的區域不同，所以處理方式也不同

對於form表單提交數據它的contentType是屬於Content-Type:application/x-www-form-urlencoded

對於ajax發送json則是 Content-Type:application/json

 

XML數據交互

對於很多第三方開發，還是有很多會採用XML作爲數據交互，比如微信

1.添加額外依賴

<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.dataformat/jackson-dataformat-xml -->
<dependency>
    <groupId>com.fasterxml.jackson.dataformat</groupId>
    <artifactId>jackson-dataformat-xml</artifactId>
    <version>2.9.8</version>
</dependency>

2.方法返回數據類型定義

@Controller
@RequestMapping("/xml")
public class XMLController {

    @RequestMapping(value = "/m1", produces = {MediaType.APPLICATION_XML_VALUE})
    @ResponseBody
    public User m1(){
        //將數據轉換爲xml形式user
        User u = new User();
        u.setName("小明");
        u.setPwd("哈哈哈");
        return u;
    }
}

 3.結果