Spring启动控制器内容协商 [英] Spring boot controller content negotiation

问题描述

我在Spring-boot应用程序中编写了一个简单的REST控制器，但我不确定如何实现内容协商，使其根据请求标头中的Content-Type参数返回JSON或XML。有人可以向我解释一下，我做错了什么？

I have a simple REST controller written in a Spring-boot application but I am not sure how to implement the content negotiation to make it return JSON or XML based on the Content-Type parameter in the request header. Could someone explain to me, what am I doing wrong?

控制器方法：

@RequestMapping(value = "/message", method = RequestMethod.GET, produces = { MediaType.APPLICATION_JSON_VALUE, MediaType.APPLICATION_XML_VALUE })
  public Message getMessageXML(@RequestParam("text") String text) throws Exception {
    Message message = new Message();
    message.setDate(new Date());
    message.setName("Test");
    message.setAge(99);
    message.setMessage(text);

    return message;
  }

调用此方法时我总是得到JSON（即使我指定 Content-Type 为 application / xml 或 text / xml ） 。

I always get JSON when calling this method (even if I specify the Content-Type to be application/xml or text/xml).

当我实现两个方法，每个方法具有不同的映射和不同的内容类型时，我能够从xml获取XML但是如果我指定两个mediaTypes则它不起作用在单个方法中（如提供的示例）。

When I implement two methods each with different mapping and different content type, I am able to get XML from the xml one but it does not work if I specify two mediaTypes in a single method (like the provided example).

我想要的是调用 \message 当GET请求的Content-Type设置为application / xml时，端点和接收

What I would like is to call the \message endpoint and receive

• XML


• 当Content-Type是application / json时的JSON

感谢任何帮助。

编辑：
我更新了我的控制器以接受所有媒体类型

I updated my controller to accept all media types

@RequestMapping(value = "/message", method = RequestMethod.GET, produces = { MediaType.APPLICATION_JSON_VALUE, MediaType.APPLICATION_XML_VALUE }, consumes = MediaType.ALL_VALUE)
  public Message getMessageXML(@RequestParam("text") String text) throws Exception {
    Message message = new Message();
    message.setDate(new Date());
    message.setName("Vladimir");
    message.setAge(35);
    message.setMessage(text);

    return message;
  }

推荐答案

你可以找到一些提示博客文章 @RequestMapping with Produces and Consumes at point 6。

You can find some hints in the blog post @RequestMapping with Produces and Consumes at point 6.

请注意有关Content-Type和Accept标题的部分：

Pay attention to the section about Content-Type and Accept headers:

@RequestMapping with Produces and Consumes：我们可以使用header
Content-Type和Accept查找请求内容以及
mime消息是什么想要回应。为清楚起见，@ RequestMapping
提供了生成和使用变量，我们可以在其中指定将调用哪个方法的
请求内容类型以及响应
内容类型。例如：

@RequestMapping with Produces and Consumes: We can use header Content-Type and Accept to find out request contents and what is the mime message it wants in response. For clarity, @RequestMapping provides produces and consumes variables where we can specify the request content-type for which method will be invoked and the response content type. For example:

@RequestMapping(value="/method6", produces={"application/json","application/xml"}, consumes="text/html")
@ResponseBody
public String method6(){
    return "method6";
}

以上方法只能使用Content-Type作为text / html $ b消费消息$ b并且能够生成类型为application / json和
application / xml的消息。

Above method can consume message only with Content-Type as text/html and is able to produce messages of type application/json and application/xml.

您也可以尝试< a href =http://www.byteslounge.com/tutorials/spring-mvc-requestmapping-consumes-condition-example\"rel =noreferrer>这种不同的方法（使用ResponseEntity对象）允许你找出传入的消息类型并生成相应的消息（同时展开@ResponseBody注释）

You can also try this different approach (using ResponseEntity object) that allows you to find out the incoming message type and produce the corresponding message (also expoliting the @ResponseBody annotation)

这篇关于Spring启动控制器内容协商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！