jackson-databind在SpringMVC使用

其中重要的一个功能是可以将JSON格式的数据转化为类对象。比如下面这个例子：

首先要引入一个jar包，如果是MAVEN项目，直接在pom.xml中导入就可以了

<!-- json解析 -->

<dependency>

    <groupId>com.fasterxml.jackson.core</groupId>

    <artifactId>jackson-databind</artifactId>

    <version>2.8.7</version>

 </dependency>

 我们如果要创建一个People类，其类的结构是：

public class People {

     String name;

     int age;  

     public String getName() {

          return name;

     }

     public void setName(String name) {

          this.name = name;

     }

     public int getAge() {

          return age;

     }

     public void setAge(int age) {

          this.age = age;

     }

}​

前端页面是

   <button id="submit">创建对象</button>

     <script src="jq.js"></script>

     <script>

          $(function() {

              var url = "/springmvc/hello.do";

              $("#submit").click(function() {

                   var name = "jack";

                   var age = 18;

                   var people = {};

                   people.name = name;

                   people.age = age;

                   var formData = new FormData();

                   formData.append("people", JSON.stringify(people));     //将其转化为JSON格式并插入fromdata中

                   console.log(JSON.stringify(people));     //{"name":"jack","age":18}

                   $.ajax({

                        url : url,

                        type : "post",

                        data : formData,

                        contentType : false,

                        processData : false, // 是否将参数序列化，如{ width:1680, height:1050}

                        // 参数对象序列化为width=1680&height=1050这样的字符串

                        success : function(data) {

                        }

                   })

              })

          })

     </script>

后端接受页面:

    @RequestMapping(value = "/hello.do")

     public void say(HttpServletRequest request) {

          ObjectMapper mapper=new ObjectMapper();

          People people=new People();

          String msg=request.getParameter("people");    //从前端接收JSON数据

          try {

              people=mapper.readValue(msg, People.class);    //将JSON数据转为类对象

          } catch (JsonParseException e) {

              e.printStackTrace();

          } catch (JsonMappingException e) {

              e.printStackTrace();

          } catch (IOException e) {

              e.printStackTrace();

          }

          System.out.println(people.getName());    //打印的结果为jack

     }

注意：若标红的声明processData : false没有写，jq将报错，无法将数据传送到后台。 contentType : false没写，后台将会报错。

由于本人水平有限，不知道什么原因。知道的同学可以在评论区回复我，谢谢~~