springboot中RestTemplate的用法

配置RestTemplate用于get请求携带multipart/form-data数据

原生的RestTemplate在发送get请求时，无法携带body数据，但是有时候咱们的业务场景需要这样做，所以我们可以对RestTemplate重新配置达到该目的。

 1 package com.syx.config;
 2 
 3 import org.apache.http.client.methods.HttpEntityEnclosingRequestBase;
 4 import org.apache.http.client.methods.HttpUriRequest;
 5 import org.apache.http.config.Registry;
 6 import org.apache.http.config.RegistryBuilder;
 7 import org.apache.http.conn.socket.ConnectionSocketFactory;
 8 import org.apache.http.conn.socket.PlainConnectionSocketFactory;
 9 import org.apache.http.impl.client.HttpClientBuilder;
10 import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
11 import org.springframework.context.annotation.Bean;
12 import org.springframework.context.annotation.Configuration;
13 import org.springframework.http.HttpMethod;
14 import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
15 import org.springframework.web.client.RestTemplate;
16 
17 import java.net.URI;
18 
19 /**
20  * @author:whh
21  * @date: 2022-11-07 20:42
22  * <p></p>
23  */
24 @Configuration
25 public class RestTemplateConfig {
26 
27     @Bean
28     public RestTemplate restTemplate(){
29         RestTemplate restTemplate = new RestTemplate();
30         HttpComponentsClientHttpRequestFactory requestFactory = new HttpComponentsClientHttpRequestFactory() {
31             @Override
32             protected HttpUriRequest createHttpUriRequest(HttpMethod httpMethod, URI uri) {
33                 if (httpMethod == HttpMethod.GET) {
34                     return new HttpGetRequestWithEntity(uri);
35                 }
36                 return super.createHttpUriRequest(httpMethod, uri);
37             }
38         };
39 
40         /**
41          * 使用客户端类API调用远程交易时必须设置相应的超时时间，如果远程交易有问题如长时间未响应，若未设置超时时间，则会耗尽客户端所在服务器的资源
42          */
43         // 连接超时
44         requestFactory.setConnectTimeout(5000);
45         //读超时
46         requestFactory.setReadTimeout(10000);
47         //连接池获取连接超时时间
48         requestFactory.setConnectionRequestTimeout(5000);
49 
50         HttpClientBuilder httpClientBuilder = HttpClientBuilder.create();
51         //Httpclient连接池的方式，同时支持netty，okHttp以及其他http框架
52         PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager();
53         // 最大连接数
54         connectionManager.setMaxTotal(200);
55         // 同路由并发数
56         connectionManager.setDefaultMaxPerRoute(50);
57         //配置连接池
58         httpClientBuilder.setConnectionManager(connectionManager);
59 
60         // 最大连接数
61         connectionManager.setMaxTotal(500);
62         // 同路由并发数（每个主机的并发）
63         connectionManager.setDefaultMaxPerRoute(100);
64         httpClientBuilder.setConnectionManager(connectionManager);
65         requestFactory.setHttpClient(httpClientBuilder.build());
66         restTemplate.setRequestFactory(requestFactory);
67         return restTemplate;
68     }
69 
70     private static final class HttpGetRequestWithEntity extends HttpEntityEnclosingRequestBase {
71         public HttpGetRequestWithEntity(final URI uri) {
72             super.setURI(uri);
73         }
74         @Override
75         public String getMethod() {
76             return HttpMethod.GET.name();
77 
78         }
79     }
80 }

重写一下HttpComponentsClientHttpRequestFactory 的createHttpUriRequest方法在请求方式为get的时候使用我们自定义的HttpGetRequestWithEntity 类

 1  @Test
 2     public void func2() {
 3         HttpHeaders headers = new HttpHeaders();
 4         headers.setContentType(MediaType.MULTIPART_FORM_DATA);
 5         MultiValueMap<String, String> form = new LinkedMultiValueMap<>();
 6         form.add("id", "1");
 7         form.add("name", "张三");
 8         form.add("sex","男");
 9         String uri = "http://localhost:8888/user/test";
10         HttpEntity< MultiValueMap<String, String>> entity = new HttpEntity<>(form,headers);
11         ResponseEntity<String> response = restTemplate.exchange(uri, HttpMethod.GET, entity, String.class);
12         System.out.println(response.getBody());
13 
14     }

服务端代码：

1  @RequestMapping(value = "/test",method = RequestMethod.GET)
2     public User query(User user){
3         return user;
4     }