将JSON映射传递给Spring MVC Controller

Question

我正在尝试将Map的JSON表示作为POST参数发送到我的控制器中.

@RequestMapping(value = "/search.do", method = RequestMethod.GET, consumes = { "application/json" })
public @ResponseBody Results search(@RequestParam("filters") HashMap<String,String> filters, HttpServletRequest request) {
       //do stuff
}

我发现@RequestParam只会抛出500错误,所以我尝试使用@ModelAttribute.

@RequestMapping(value = "/search.do", method = RequestMethod.GET, consumes = { "application/json" })
public @ResponseBody Results search(@ModelAttribute("filters") HashMap<String,String> filters, HttpServletRequest request) {
       //do stuff
}

这将正确响应请求,但我意识到地图是空的.随后的实验,我发现任何对象(不仅仅是HashMap)都会被实例化,但是不会填充任何字段.我的类路径上有Jackson,而我的控制器将使用JSON进行响应.但是,我的当前配置似乎不允许Spring通过GET/POST参数读取JSON.

如何将客户端AJAX请求中的对象的JSON表示作为请求参数传递给Spring控制器并获取Java对象？

编辑添加我的相关Spring配置

  <bean class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">
    <property name="mediaTypes">
      <map>
        <entry key="html" value="text/html" />
        <entry key="json" value="application/json" />
      </map>
    </property>
    <property name="viewResolvers">
      <list>
        <bean class="org.springframework.web.servlet.view.UrlBasedViewResolver">
          <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" />
          <property name="prefix" value="/WEB-INF/jsp/" />
          <property name="suffix" value=".jsp" />
        </bean>
      </list>
    </property>
    <property name="defaultViews">
      <list>
        <bean class="org.springframework.web.servlet.view.json.MappingJacksonJsonView">
          <property name="prefixJson" value="true" />
        </bean>
      </list>
    </property>
  </bean>
  <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
    <property name="messageConverters">
      <list>
        <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"/>
      </list>
    </property>
  </bean>

根据评论者的建议,我尝试了@RequestBody.这将起作用,只要JSON字符串引用双引号即可.

@RequestMapping(value = "/search.do", method = RequestMethod.POST, consumes = { "application/json" })
public @ResponseBody Results<T> search(@RequestBody HashMap<String,String> filters, HttpServletRequest request) {
      //do stuff
}

这确实解决了我的直接问题,但我仍然对如何通过AJAX调用传递多个JSON对象感到好奇.

Answer 1

这确实解决了我眼前的问题，但我仍然对ou如何通过AJAX调用传递多个JSON对象感到好奇。

最好的方法是使包装对象包含要传递的两个（或多个）对象。然后，您将JSON对象构造为两个对象的数组，即

[
  {
    "name" : "object1",
    "prop1" : "foo",
    "prop2" : "bar"
  },
  {
    "name" : "object2",
    "prop1" : "hello",
    "prop2" : "world"
  }
]

然后，在控制器方法中，将请求主体作为一个对象接收，并提取两个包含的对象。即：

@RequestMapping(value="/handlePost", method = RequestMethod.POST, 
                consumes = {      "application/json" })
public void doPost(@RequestBody WrapperObject wrapperObj) { 
     Object obj1 = wrapperObj.getObj1;
     Object obj2 = wrapperObj.getObj2;

     //Do what you want with the objects...


}

包装对象看起来像...

public class WrapperObject {    
private Object obj1;
private Object obj2;

public Object getObj1() {
    return obj1;
}
public void setObj1(Object obj1) {
    this.obj1 = obj1;
}
public Object getObj2() {
    return obj2;
}
public void setObj2(Object obj2) {
    this.obj2 = obj2;
}   

}