[Java] Springboot之restTemplate的配置及使用方式

• 基础配置
  
• 以下为进阶配置和使用
  
  
  
  • 1 场景
    
  • 2 依赖
    
  • 3 配置
    
  • 4 使用
    
    
    
    • 4.1 GET请求
      
    • 4.2 POST请求
      
    • 4.3 上传文件
      
    
    
  
  

@Configuration
public class RestTemplateConfig {
   @Bean
   public RestTemplate restTemplate(ClientHttpRequestFactory factory) {
     return new RestTemplate(factory);
   }
   @Bean
   public ClientHttpRequestFactory simpleClientHttpRequestFactory() {
     SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
     factory.setReadTimeout(150000); // ms
     factory.setConnectTimeout(150000); // ms
     return factory;
   }
}

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-web</artifactId>
  <version>5.2.2.RELEASE</version>
</dependency>
<dependency>
  <groupId>org.apache.httpcomponents</groupId>
  <artifactId>httpclient</artifactId>
  <version>4.5.7</version>
</dependency>

import org.apache.http.client.HttpClient;
import org.apache.http.conn.HttpClientConnectionManager;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.ClientHttpRequestFactory;
import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;
@Configuration
public class RestTemplateConfig {
  
  /**
   * http连接管理器
   * @return
   */
  @Bean
  public HttpClientConnectionManager poolingHttpClientConnectionManager() {
    /*// 注册http和https请求
    Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory>create()
        .register("http", PlainConnectionSocketFactory.getSocketFactory())
        .register("https", SSLConnectionSocketFactory.getSocketFactory())
        .build();
    PoolingHttpClientConnectionManager poolingHttpClientConnectionManager = new PoolingHttpClientConnectionManager(registry);*/
    
    PoolingHttpClientConnectionManager poolingHttpClientConnectionManager = new PoolingHttpClientConnectionManager();
    // 最大连接数
    poolingHttpClientConnectionManager.setMaxTotal(500);
    // 同路由并发数（每个主机的并发）
    poolingHttpClientConnectionManager.setDefaultMaxPerRoute(100);
    return poolingHttpClientConnectionManager;
  }
  
  /**
   * HttpClient
   * @param poolingHttpClientConnectionManager
   * @return
   */
  @Bean
  public HttpClient httpClient(HttpClientConnectionManager poolingHttpClientConnectionManager) {
    HttpClientBuilder httpClientBuilder = HttpClientBuilder.create();
    // 设置http连接管理器
    httpClientBuilder.setConnectionManager(poolingHttpClientConnectionManager);
    
    /*// 设置重试次数
    httpClientBuilder.setRetryHandler(new DefaultHttpRequestRetryHandler(3, true));*/
    
    // 设置默认请求头
    /*List<Header> headers = new ArrayList<>();
    headers.add(new BasicHeader("Connection", "Keep-Alive"));
    httpClientBuilder.setDefaultHeaders(headers);*/     
    return httpClientBuilder.build();
  }
  
  /**
   * 请求连接池配置
   * @param httpClient
   * @return
   */
  @Bean
  public ClientHttpRequestFactory clientHttpRequestFactory(HttpClient httpClient) {
    HttpComponentsClientHttpRequestFactory clientHttpRequestFactory = new HttpComponentsClientHttpRequestFactory();
    // httpClient创建器
    clientHttpRequestFactory.setHttpClient(httpClient);
    // 连接超时时间/毫秒（连接上服务器(握手成功)的时间，超出抛出connect timeout）
    clientHttpRequestFactory.setConnectTimeout(5 * 1000);
    // 数据读取超时时间(socketTimeout)/毫秒（务器返回数据(response)的时间，超过抛出read timeout）
    clientHttpRequestFactory.setReadTimeout(10 * 1000);
    // 连接池获取请求连接的超时时间，不宜过长，必须设置/毫秒（超时间未拿到可用连接，会抛出org.apache.http.conn.ConnectionPoolTimeoutException: Timeout waiting for connection from pool）
    clientHttpRequestFactory.setConnectionRequestTimeout(10 * 1000);
    return clientHttpRequestFactory;
  }
  
  /**
   * rest模板
   * @return
   */
  @Bean
  public RestTemplate restTemplate(ClientHttpRequestFactory clientHttpRequestFactory) {
    // boot中可使用RestTemplateBuilder.build创建
    RestTemplate restTemplate = new RestTemplate();
    // 配置请求工厂
    restTemplate.setRequestFactory(clientHttpRequestFactory);
    return restTemplate;
  }  
}

@Data
@ToString
public class TempUser implements Serializable {
  private String userName;   
  private Integer age;
}

@RequestMapping("getUser")
public TempUser getUser(TempUser form) {
  TempUser tempUser = new TempUser();
  tempUser.setUserName(form.getUserName());
  tempUser.setAge(form.getAge());
  return tempUser;
}

TempUser result = restTemplate.getForObject("http://localhost:8080/cs-admin/rest/getUser?userName=张三&age=18", TempUser.class);

ResponseEntity<TempUser> responseEntity = restTemplate.getForEntity("http://localhost:8080/cs-admin/rest/getUser?userName=张三&age=18", TempUser.class);
// 获取状态对象
HttpStatus httpStatus = responseEntity.getStatusCode();
// 获取状态码
int statusCodeValue = responseEntity.getStatusCodeValue();
// 获取headers
HttpHeaders httpHeaders = responseEntity.getHeaders();
// 获取body
TempUser result = responseEntity.getBody();

Map<String, Object> paramMap = new HashMap<>();
paramMap.put("userName", "张三");
paramMap.put("age", 18);
TempUser result = restTemplate.getForObject("http://localhost:8080/cs-admin/rest/getUser?userName={userName}&age={age}", TempUser.class, paramMap);

RequestMapping("getPostUser")
  public TempUser getPostUser(@RequestBody TempUser form) {
  TempUser tempUser = new TempUser();
  tempUser.setUserName(form.getUserName());
  tempUser.setAge(form.getAge());
  return tempUser;
}

TempUser param = new TempUser();
param.setUserName("张三");
param.setAge(18);
TempUser result = restTemplate.postForObject("http://localhost:8080/cs-admin/rest/getPostUser", param, TempUser.class);

// 请求头信息
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.valueOf("application/json;charset=UTF-8"));
//headers.add("headParam1", "headParamValue");
// 请求体内容
TempUser param = new TempUser();
param.setUserName("张三");
param.setAge(18);
// 组装请求信息
HttpEntity<TempUser> httpEntity=new HttpEntity<>(param,headers);
TempUser result = restTemplate.postForObject("http://localhost:8080/cs-admin/rest/getPostUser", httpEntity, TempUser.class);

@RequestMapping("getPostUserNoBody")
public TempUser getPostUserNoBody(TempUser form) {
  TempUser tempUser = new TempUser();
  tempUser.setUserName(form.getUserName());
  tempUser.setAge(form.getAge());
  return tempUser;
}

Map<String, Object> paramMap = new HashMap<>();
paramMap.put("userName", "张三");
paramMap.put("age", 18);
TempUser result = restTemplate.postForObject("http://localhost:8080/cs-admin/rest/getPostUserNoBody?userName={userName}&age={age}", null, TempUser.class, paramMap);
System.out.println(result);

@RequestMapping("uploadFile")
public TempUser uploadFile(HttpServletRequest request, TempUser form) {
 MultipartHttpServletRequest multipartHttpServletRequest = (MultipartHttpServletRequest) request;
 //获取文件信息
 MultipartFile multipartFile = multipartHttpServletRequest.getFile("file");
 TempUser tempUser = new TempUser();
 if (multipartFile != null) {
   tempUser.setUserName(form.getUserName()+" "+multipartFile.getOriginalFilename());
 }
 if(form!=null){
   tempUser.setAge(form.getAge());
 }
 return tempUser;
}

// 文件
FileSystemResource file=new FileSystemResource("D:\\Elasticsearch权威指南（中文版）.pdf");
// 设置请求内容
MultiValueMap<String, Object> param=new LinkedMultiValueMap<>();
param.add("file", file);
// 其他参数
param.add("userName", "张三");
param.add("age", 18);
// 组装请求信息
HttpEntity<MultiValueMap<String, Object>> httpEntity=new HttpEntity<>(param);
// 发送请求
TempUser result = restTemplate.postForObject("http://localhost:8080/cs-admin/rest/uploadFile", httpEntity, TempUser.class);