1、HttpClient:代码复杂,还得操心资源回收等。代码很复杂,冗余代码多,不建议直接使用。
2、RestTemplate: 是 Spring 提供的用于访问Rest服务的客户端, RestTemplate 提供了多种便捷访问远程Http服务的方法,能够大大提高客户端的编写效率。
引入jar包:
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency>
添加初始化配置(也可以不配,有默认的)–注意RestTemplate只有初始化配置,没有什么连接池
package com.itunion.config; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.http.client.ClientHttpRequestFactory; import org.springframework.http.client.SimpleClientHttpRequestFactory; import org.springframework.web.client.RestTemplate; @Configuration public class ApiConfig { @Bean public RestTemplate restTemplate(ClientHttpRequestFactory factory) { return new RestTemplate(factory); } @Bean public ClientHttpRequestFactory simpleClientHttpRequestFactory() { SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();//默认的是JDK提供http连接,需要的话可以//通过setRequestFactory方法替换为例如Apache HttpComponents、Netty或//OkHttp等其它HTTP library。 factory.setReadTimeout(5000);//单位为ms factory.setConnectTimeout(5000);//单位为ms return factory; } }
1)get请求(不带参的即把参数取消即可)
// 1-getForObject() User user1 = this.restTemplate.getForObject(uri, User.class); // 2-getForEntity() ResponseEntity<User> responseEntity1 = this.restTemplate.getForEntity(uri, User.class); HttpStatus statusCode = responseEntity1.getStatusCode(); HttpHeaders header = responseEntity1.getHeaders(); User user2 = responseEntity1.getBody(); // 3-exchange() RequestEntity requestEntity = RequestEntity.get(new URI(uri)).build(); ResponseEntity<User> responseEntity2 = this.restTemplate.exchange(requestEntity, User.class); User user3 = responseEntity2.getBody();
方式一:
Notice notice = restTemplate.getForObject("http://fantj.top/notice/list/{1}/{2}" , Notice.class,1,5);
方式二:
Map<String,String> map = new HashMap(); map.put("start","1"); map.put("page","5"); Notice notice = restTemplate.getForObject("http://fantj.top/notice/list/" , Notice.class,map);
2)post请求:
// 1-postForObject() User user1 = this.restTemplate.postForObject(uri, user, User.class); // 2-postForEntity() ResponseEntity<User> responseEntity1 = this.restTemplate.postForEntity(uri, user, User.class); // 3-exchange() RequestEntity<User> requestEntity = RequestEntity.post(new URI(uri)).body(user); ResponseEntity<User> responseEntity2 = this.restTemplate.exchange(requestEntity, User.class);
方式一:
String url = "http://demo/<i>本文来源gaodai$ma#com搞$$代**码网</i>api/book/"; HttpHeaders headers = new HttpHeaders(); MediaType type = MediaType.parseMediaType("application/json; charset=UTF-8"); headers.setContentType(type); String requestJson = "{...}"; HttpEntity<String> entity = new HttpEntity<String>(requestJson,headers); String result = restTemplate.postForObject(url, entity, String.class); System.out.println(result);