接收json并反序列化为spring mvc控制器上的对象列表

Question

我的代码如下:

调节器

@RequestMapping(value="/setTest", method=RequestMethod.POST, consumes="application/json")
public @ResponseBody ModelMap setTest(@RequestBody List<TestS> refunds, ModelMap map) {
    for(TestS r : refunds) {
        System.out.println(r.getName());
    }
    // other codes
}

TestS pojo

public class TestS implements Serializable {
    private String name;
    private String age;
    //getter setter
}

Json请求

var z = '[{"name":"1","age":"2"},{"name":"1","age":"3"}]';
$.ajax({
    url: "/setTest",
    data: z,
    type: "POST",
    dataType:"json",
    contentType:'application/json'               
});

它给出了这个错误

java.lang.ClassCastException:java.util.LinkedHashMap无法强制转换为com.gogoair.cidb.entities.TestS

我使用的是Spring 3.1.2和jackson 2.0.4

编辑:我想在我的控制器方法中接收TestS对象列表,并处理它们.我无法找到我发送错误的json或我的方法签名是错误的.

Answer 1

这是适合我的代码.关键是你需要一个包装类.

public class Person {

    private String name;
    private Integer age;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Person [name=" + name + ", age=" + age + "]";
    }

一个PersonWrapper类

public class PersonWrapper {

    private List<Person> persons;

    /**
     * @return the persons
     */
    public List<Person> getPersons() {
        return persons;
    }

    /**
     * @param persons the persons to set
     */
    public void setPersons(List<Person> persons) {
        this.persons = persons;
    }
}

我的控制器方法

@RequestMapping(value="person", method=RequestMethod.POST,consumes="application/json",produces="application/json")
    @ResponseBody
    public List<String> savePerson(@RequestBody PersonWrapper wrapper) {
        List<String> response = new ArrayList<String>();
        for (Person person: wrapper.getPersons()){
        personService.save(person);
         response.add("Saved person: " + person.toString());
    }
        return response;
    }

发送的请求是POST中的json

{"persons":[{"name":"shail1","age":"2"},{"name":"shail2","age":"3"}]}

而且回应是

["Saved person: Person [name=shail1, age=2]","Saved person: Person [name=shail2, age=3]"]

Answer 2

这是你尝试它的方式所不可能的.杰克逊解组在类型擦除后对编译的java代码起作用.所以你的

public @ResponseBody ModelMap setTest(@RequestBody List<TestS> refunds, ModelMap map) 

真的只是

public @ResponseBody ModelMap setTest(@RequestBody List refunds, ModelMap map) 

(列表中没有泛型arg).

当解组a List是a 时,Jackson创建的默认类型LinkedHashMap.

正如@Saint所提到的,您可以通过为列表创建自己的类型来避免这种情况:

class TestSList extends ArrayList<TestS> { }

然后将控制器签名修改为

public @ResponseBody ModelMap setTest(@RequestBody TestSList refunds, ModelMap map) {

Answer 3

@RequestMapping(
         value="person", 
         method=RequestMethod.POST,
         consumes="application/json",
         produces="application/json")
@ResponseBody
public List<String> savePerson(@RequestBody Person[] personArray) {
    List<String> response = new ArrayList<String>();
    for (Person person: personArray) {
        personService.save(person);
        response.add("Saved person: " + person.toString());
    }
    return response;
}

我们可以使用如上所示的Array.