在springboot项目中，可以直接注入RestTemplate使用，也可进行简单配置
基础配置
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@Configurationpublic 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; }} |
以下为进阶配置和使用
1 场景
java开发中，使用http连接，访问第三方网络接口，通常使用的连接工具为HttpClient和OKHttp。
这两种连接工具，使用起来比较复杂，新手容易出问题。如果使用spring框架，可以使用restTemplate来进行http连接请求。
restTemplate默认的连接方式是java中的HttpConnection，可以使用ClientHttpRequestFactory指定不同的HTTP连接方式。
2 依赖
maven依赖如下：
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<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> |
3 配置
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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;@Configurationpublic 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; } } |
4 使用
使用到的实体类如下：
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@Data@ToStringpublic class TempUser implements Serializable { private String userName; private Integer age;} |
4.1 GET请求
后台接口代码：
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@RequestMapping("getUser")public TempUser getUser(TempUser form) { TempUser tempUser = new TempUser(); tempUser.setUserName(form.getUserName()); tempUser.setAge(form.getAge()); return tempUser;} |
4.1.1 普通访问
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TempUser result = restTemplate.getForObject("http://localhost:8080/cs-admin/rest/getUser?userName=张三&age=18", TempUser.class); |
4.1.2 返回HTTP状态
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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headersHttpHeaders httpHeaders = responseEntity.getHeaders();// 获取bodyTempUser result = responseEntity.getBody(); |
4.1.3 映射请求参数
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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); |
4.2 POST请求
4.2.1 普通访问
后台接口代码：
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RequestMapping("getPostUser") public TempUser getPostUser(@RequestBody TempUser form) { TempUser tempUser = new TempUser(); tempUser.setUserName(form.getUserName()); tempUser.setAge(form.getAge()); return tempUser;} |
（1）普通访问接口
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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); |
（2）带HEAD访问接口
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// 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); |
4.2.2 无请求体的访问
仅method为post，传参方式仍然为get的param方式
后台接口代码：
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@RequestMapping("getPostUserNoBody")public TempUser getPostUserNoBody(TempUser form) { TempUser tempUser = new TempUser(); tempUser.setUserName(form.getUserName()); tempUser.setAge(form.getAge()); return tempUser;} |
访问方式：
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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); |
4.3 上传文件
后台接口代码：
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@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;} |
访问方式：
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// 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); |
以上为个人经验，希望能给大家一个参考，也希望大家多多支持服务器之家。
原文链接：https://blog.csdn.net/weixin_43702146/article/details/116567707
