RestTemplate:exchange() vs postForEntity() vs execute() [英] RestTemplate: exchange() vs postForEntity() vs execute()

问题描述

我正在使用 Spring Boot 处理 Rest API，我必须访问应用程序的端点.我使用了 RestTemplate.我能够使用两种方法来做到这一点，

I am working on Rest API using Spring boot and I had to access an application's endpoint. I used RestTemplate for it. I was able to do it using 2 methods,

• postForEntity():

responseEntity = 
    restTemplate.postForEntity(uri, httpEntity, ResponseClass.class);

exchange():

responseEntity = 
    restTemplate.exchange(uri, HttpMethod.POST, httpEntity, ResponseClass.class);

我想知道这两种方法的用法和区别.

I would like to know the usage and differences of these two methods.

我还看到了另一个方法 execute().请解释一下.如何以及何时使用它.

I also see another method execute(). Please shed some light on it. How and when to use it.

推荐答案

RestTemplate 是一个非常通用的对象.

The RestTemplate is a very versatile object.

让我们从 execute 开始，因为它是最通用的方法:

Let's start with execute, since it's the most generic method:

execute(String url, HttpMethod method, @Nullable RequestCallback requestCallback,
        @Nullable ResponseExtractor<T> responseExtractor, Object... uriVariables)

注意 uriVariables 也可以作为 Map 传递.

Note the uriVariables can be passed as a Map too.

execute 旨在适用于尽可能多的场景:

execute is designed to be applicable in the highest variety of scenarios possible:

• 第一个和第二个参数允许 URL 和方法的任何有效组合.
• 通过传递自定义的RequestCallback(一个@FunctionalInterface，只有一个方法doWithRequest(ClientHttpRequest request)) 发送之前.
• 可以通过传递自定义 ResponseExtractor 以任何必要的方式反序列化从远程资源返回的响应.

• The first and second parameters allow any valid combination of URL and method.
• The request can be modified in a myriad of different ways by passing a custom RequestCallback (a @FunctionalInterface with just one method doWithRequest(ClientHttpRequest request)) before sending it.
• The response returned from the remote resource can be deserialized in any way necessary by passing a custom ResponseExtractor.

将此与 exchange 进行比较:

Compare this with exchange:

exchange(String url, HttpMethod method, @Nullable HttpEntity<?> requestEntity,
         Class<T> responseType, Object... uriVariables)

这里有两个主要区别:

• 您现在可以直接传递 HttpEntity，而在此之前需要使用 RequestCallback 手动设置.
• 通过传递所需的响应类型 Class 来提供开箱即用的反序列化机制.

• You can now pass an HttpEntity directly, whereas before it needed to be set manually using the RequestCallback.
• Deserialization mechanics are provided out of the box by passing the desired response type Class.

如您所见，这对于日常使用来说更加方便.

As you can see, this is much more convenient for everyday use.

像 getForEntity 和 postForEntity 这样的方法更短、更容易理解:

Methods like getForEntity and postForEntity are even shorter, easier to understand versions of this:

getForEntity(String url, Class<T> responseType, Object... uriVariables)

postForEntity(String url, @Nullable Object request, Class<T> responseType,
              Object... uriVariables)

注意 postForEntity 现在允许您直接 POST 任何 Object 而无需包装器.使用这些代替 execute 没有性能优势或损害，因为它们在幕后调用 execute - 这只是一个方便的问题.

Notice postForEntity now allows you to POST any Object directly without a wrapper. There is no performance benefit or detriment to using these instead of execute, as they call execute themselves under the hood - it's simply a matter of convenience.

这篇关于RestTemplate:exchange() vs postForEntity() vs execute()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！