一)RestTemplate简介
RestTemplate是HTTP客户端库提供了一个更高水平的API。主要用于Rest服务调用。
RestTemplate方法:
方法组 | 描述 |
---|---|
getForObject |
通过GET检索表示形式。 |
getForEntity |
ResponseEntity通过使用GET 检索(即状态,标头和正文)。 |
headForHeaders |
通过使用HEAD检索资源的所有标头。 |
postForLocation |
通过使用POST创建新资源,并Location从响应中返回标头。 |
postForObject |
通过使用POST创建新资源,并从响应中返回表示形式。 |
postForEntity |
通过使用POST创建新资源,并从响应中返回表示形式。 |
put |
通过使用PUT创建或更新资源。 |
patchForObject |
通过使用PATCH更新资源,并从响应中返回表示形式。请注意,JDK HttpURLConnection不支持PATCH,但是Apache HttpComponents和其他支持。 |
delete |
使用DELETE删除指定URI处的资源。 |
optionsForAllow |
通过使用ALLOW检索资源的允许的HTTP方法。 |
exchange |
前述方法的通用性强(且意见少的版本),在需要时提供了额外的灵活性。它接受RequestEntity(包括HTTP方法,URL,标头和正文作为输入)并返回ResponseEntity。 这些方法允许使用ParameterizedTypeReference而不是Class使用泛型来指定响应类型。 |
execute |
执行请求的最通用方法,完全控制通过回调接口进行的请求准备和响应提取。 |
二)RestTemplate案例
第一步:创建一个maven项目,在pom.xml引入一个springboot的版本
pom.xml内容:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.oysept</groupId> <artifactId>spring_resttemplate</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.4.RELEASE</version> <relativePath/> </parent> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <configuration> <mainClass>com.oysept.RestTemplateApplication</mainClass> </configuration> </plugin> <plugin> <groupId>org.apache.tomcat.maven</groupId> <artifactId>tomcat7-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
application.yml配置:该配置就一个默认端口
server:
port: 8080
创建一个springboot启动类RestTemplateApplication
package com.oysept; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.boot.builder.SpringApplicationBuilder; @SpringBootApplication public class RestTemplateApplication { public static void main(String[] args) { new SpringApplicationBuilder(RestTemplateApplication.class).run(args); } }
到此步骤时,可以先运行RestTemplateApplication中的main方法,检验springboot启动是否正常。
第二步:创建一个RestTemplate配置类并注入,因为在使用时,不提前注入ResttTemplate,在通过@Autowired使用会报RestTemplate找不到
package com.oysept.config; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.web.client.RestTemplate; /** * 注册一个RestTemplate Bean, 否则直接通过@Autowired使用会报RestTemplate找不到 * @author ouyangjun */ @Configuration public class RestTemplateConfig { /** * 方式一: 默认是使用JDK原生java.net.HttpURLConnection请求 * @return */ @Bean(name = "restTemplate") public RestTemplate restTemplate() { return new RestTemplate(); } /** * 方式二: 使用apache http内置请求, 需要在pom.xml中引入相应的apache jar * 可以使用HttpClient,设置一些http连接池等信息 * @return * @Bean(name = "restTemplate") public RestTemplate restTemplate() { return new RestTemplate(new HttpComponentsClientHttpRequestFactory()); } */ /** * 方式三: 使用OkHttp内置请求, 需要在pom.xml中引入相应的OkHttp3 jar * 可以使用OkHttpClient,设置一些http连接池信息 * @return * @Bean(name = "restTemplate") public RestTemplate restTemplate() { return new RestTemplate(new OkHttp3ClientHttpRequestFactory()); } */ }
第三步:创建一个VO类,用于测试入参和出参
package com.oysept.vo; public class MsgVO { private String msgKey; private String msgValue; public String getMsgKey() {return msgKey;} public void setMsgKey(String msgKey) {this.msgKey = msgKey;} public String getMsgValue() {return msgValue;} public void setMsgValue(String msgValue) {this.msgValue = msgValue;} public String toString() { return "MsgVO [msgKey: "+this.msgKey+", msgValue: "+this.msgValue+"]"; } }
第四步:创建一个服务端接口,用于测试
package com.oysept.controller; import java.util.ArrayList; import java.util.List; import org.springframework.http.MediaType; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestBody; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.RestController; import com.oysept.vo.MsgVO; /** * 服务端, 提供接口被调用 * @author ouyangjun */ @RestController public class ServerController { // 无参GET请求: http://localhost:8080/server/get @RequestMapping(value = "/server/get", method = RequestMethod.GET) public String get() { return "/server/get"; } // 带参GET请求: http://localhost:8080/server/get/param?param=111222333444 @RequestMapping(value = "/server/get/param", method = RequestMethod.GET) public String getParam(@RequestParam(value = "param") String param) { return "/server/get/param," + param; } // 路径中带参GET请求: http://localhost:8080/server/get/url/AAAA/BBBB @RequestMapping(value = "/server/get/url/{one}/{two}", method = RequestMethod.GET) public String getUrl(@PathVariable("one") String one, @PathVariable("two") String two) { return "/get/url/{one}/{two}," + one + "," + two; } // 无参GET请求, 返回List: http://localhost:8080/server/get/list @RequestMapping(value = "/server/get/list", method = RequestMethod.GET) public List<Object> getList() { List<Object> list = new ArrayList<Object>(); list.add(11); list.add("AA"); return list; } // 无参GET请求, 返回对象: http://localhost:8080/server/get/MsgVO @RequestMapping(value = "/server/get/MsgVO", method = RequestMethod.GET) public MsgVO getMsgVO() { MsgVO vo = new MsgVO(); vo.setMsgKey("keyAAA"); vo.setMsgValue("valueBBB"); return vo; } // POST请求, 表单参数, application/x-www-form-urlencoded @RequestMapping(value = "/server/post/form", method = RequestMethod.POST, consumes = MediaType.APPLICATION_FORM_URLENCODED_VALUE) public MsgVO postForm(MsgVO msgVO) { System.out.println("msgKey: " + msgVO.getMsgKey() + ", msgValue: " + msgVO.getMsgValue()); return msgVO; } // POST请求, JSON参数, application/json @RequestMapping(value = "/server/post/json", method = RequestMethod.POST, consumes = MediaType.APPLICATION_JSON_UTF8_VALUE, produces = MediaType.APPLICATION_JSON_UTF8_VALUE) public MsgVO postJson(@RequestBody MsgVO msgVO) { System.out.println("msgKey: " + msgVO.getMsgKey() + ", msgValue: " + msgVO.getMsgValue()); return msgVO; } }
第五步:创建一个测试服务端接口的API
import的类和注入的RestTemplate:
package com.oysept.controller; import java.net.URI; import java.util.HashMap; import java.util.List; import java.util.Map; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.http.HttpEntity; import org.springframework.http.HttpHeaders; import org.springframework.http.MediaType; import org.springframework.http.RequestEntity; import org.springframework.http.ResponseEntity; import org.springframework.util.LinkedMultiValueMap; import org.springframework.util.MultiValueMap; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RestController; import org.springframework.web.client.RestTemplate; import org.springframework.web.util.UriComponentsBuilder; import com.oysept.vo.MsgVO; /** * 客户端, 调用服务端提供的接口 * @author ouyangjun */ @RestController public class ClientController { // 使用默认请求方式 @Autowired @Qualifier(value = "restTemplate") private RestTemplate restTemplate; // 在此处添加客户端测试代码 }
1、GET请求
// 直接在浏览中输入访问地址: http://localhost:8080/client/get @RequestMapping(value = "/client/get", method = RequestMethod.GET) public String get() { // 无参GET请求 String get = restTemplate.getForObject("http://localhost:8080/server/get", String.class); System.out.println("==>/server/get return: " + get); // 带参GET请求 String getParam = restTemplate.getForObject("http://localhost:8080/server/get/param?param=111222333444", String.class); System.out.println("==>/server/get/param return: " + getParam); // 带参GET url请求 String getUrlParam = restTemplate.getForObject("http://localhost:8080/server/get/url/{one}/{two}", String.class, "AAAA", "BBBB"); System.out.println("==>/server/get/url/{one}/{two} return: " + getUrlParam); // 带参GET url请求 Map<String, String> vars = new HashMap<String, String>(); vars.put("one", "HHHH"); vars.put("two", "EEEE"); String getUrlVars = restTemplate.getForObject("http://localhost:8080/server/get/url/{one}/{two}", String.class, vars); System.out.println("==>/server/get/url/{one}/{two} return: " + getUrlVars); // 无参GET请求, 返回List @SuppressWarnings("unchecked") List<String> getList = restTemplate.getForObject("http://localhost:8080/server/get/list", List.class); System.out.println("==>/server/get/list return: " + getList); // GET请求, 返回对象 ResponseEntity<MsgVO> entity = restTemplate.getForEntity("http://localhost:8080/server/get/MsgVO", MsgVO.class); System.out.println("==>/server/get/list return: " + entity.getBody()); return "GET SUCCESS"; }
2、GET url中传参请求
// 直接在浏览中输入访问地址: http://localhost:8080/client/get/request // GET请求, url参数, 在表头中添加参数 @RequestMapping(value = "/client/get/request", method = RequestMethod.GET) public String getRequest() { // url中参数 Map<String, String> vars = new HashMap<String, String>(); vars.put("one", "HHHH"); vars.put("two", "EEEE"); // 请求地址 String uriTemplate = "http://localhost:8080/server/get/url/{one}/{two}"; // 给URL地址encode转码 URI uri = UriComponentsBuilder.fromUriString(uriTemplate).buildAndExpand(vars).toUri(); // GET请求参数 RequestEntity<Void> requestEntity = RequestEntity.get(uri) .header("MyHeader", "aaabbbcccddd") .build(); // 响应 ResponseEntity<String> response = restTemplate.exchange(requestEntity, String.class); // 结果 System.out.println("==>/get/request header: " + response.getHeaders().getFirst("MyHeader")); System.out.println("==>/get/request body: " + response.getBody()); return "POST SUCCESS"; }
3、POST application/x-www-form-urlencoded表单传参请求
// 直接在浏览中输入访问地址: http://localhost:8080/client/postForm // POST请求, form表单入参 @RequestMapping(value = "/client/postForm", method = RequestMethod.GET) public String postForm() { // uri String uriTemplate = "http://localhost:8080/server/post/form"; // 设置请求头为form形式: application/x-www-form-urlencoded HttpHeaders headers = new HttpHeaders(); headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED); // 设置参数, 和MsgVO中变量名对应 MultiValueMap<String, String> map = new LinkedMultiValueMap<String, String>(); map.add("msgKey", "1234"); map.add("msgValue", "TestTest"); // 封装请求参数 HttpEntity<MultiValueMap<String, String>> requestb = new HttpEntity<MultiValueMap<String, String>>(map, headers); ResponseEntity<String> response = restTemplate.postForEntity(uriTemplate, requestb, String.class); System.out.println("==>/server/post/form return: " + response.getBody()); return "POST SUCCESS"; }
4、POST application/json JSON传参请求
// 直接在浏览中输入访问地址: http://localhost:8080/client/postJson // POST请求, JSON入参 @RequestMapping(value = "/client/postJson", method = RequestMethod.GET) public String postJson() { // json入参 MsgVO vo = new MsgVO(); vo.setMsgKey("TTT"); vo.setMsgValue("KKK"); String uriTemplate = "http://localhost:8080/server/post/json"; URI uri = UriComponentsBuilder.fromUriString(uriTemplate).buildAndExpand().toUri(); RequestEntity<MsgVO> requestEntity = RequestEntity.post(uri) .header("Content-Type", "application/json; charset=UTF-8") .body(vo); ResponseEntity<MsgVO> response = restTemplate.exchange(requestEntity, MsgVO.class); System.out.println("==>/server/post/json return: " + response.getBody()); return "POST SUCCESS"; }
项目结构图:
以上这篇SpringBoot RestTemplate GET POST请求的实例讲解就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持亿速云。
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