Spring @RequestParam Map< String，String>在POST方法中不起作用 [英] Spring @RequestParam Map<String, String> does not work in POST method

问题描述

从Spring文档中我采取了以下内容：

from the Spring documentation I took the following:

public @interface RequestParam

注释，表示方法参数应绑定到Web请求参数。支持Servlet和Portlet环境中带注释的处理程序方法。

Annotation which indicates that a method parameter should be bound to a web request parameter. Supported for annotated handler methods in Servlet and Portlet environments.

...

如果方法参数是Map或者未指定MultiValueMap和参数名称，然后使用所有请求参数名称和值填充map参数。

If the method parameter is Map or MultiValueMap and a parameter name is not specified, then the map parameter is populated with all request parameter names and values.

现在我有为测试目的创建了一个控制器。它有一个GET和一个POST方法，每个都使用 @RequestParam java.util.Map 作为唯一参数。在方法体中，我只是尝试打印地图的大小。当我仅在GET方法中发送请求（GET / POST）时，映射包含任何键/值对。我正在使用Firefox中的Poster插件，我正在发送三个参数。

Now I have created a controller for test purposes. It has a GET and a POST method and each uses a @RequestParam java.util.Map as only parameter. In the method body I am only trying to print the size of the map. When I send requests (GET/POST) only in the GET method the map contains any key/value pairs. I am using the Poster add-on in Firefox and I am sending three parameters.

import java.util.Map;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class TestController {

    @RequestMapping(value="test/method", method = RequestMethod.GET)
    @ResponseBody
    public String testmethodGet(@RequestParam Map<String, String> params) {

        System.out.println("GET: " + params.size()); // prints GET: 3   
        return "";

    }

    @RequestMapping(value="test/method", method = RequestMethod.POST)
    @ResponseBody
    public String testmethodPost(@RequestParam Map<String, String> params) {

        System.out.println("POST: " + params.size()); // prints POST: 0
        return "";

    }

}

任何一个你们知道为什么@RequestParam Map不能用于POST请求，或者我是否需要更改某些内容以使其正常工作？

Would any of you guys know why @RequestParam Map would not work with a POST request or whether I need to change something to make it work?

谢谢。

推荐答案

实际上，它适用于GET和POST方法。这完全是我的错。当您实际将参数传递给POST请求时，最初给定的代码将起作用。

Actually, it works on GET and POST method. It was solely my fault. The initially given code will work, when you actually pass parameters to the POST request.

考虑以下JS（jQuery）代码作为如何发送有效请求：

Consider the following JS ( jQuery ) code as how to send a valid request:

$.ajax({
    type: "POST",
    url: "test/method",
    data: { param1: param1, param2: param2, param3: param3 },
    success: function(data) {
        console.log("testPost successful!");
    },    
    dataType: "html", // expected return value type
    error: function(data, status, error) {
        console.log("testPost with errors!");
    }
});

这篇关于Spring @RequestParam Map< String，String>在POST方法中不起作用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！