详解Spring cloud使用Ribbon进行Restful请求

    org.springframework.bootspring-boot-maven-plugin org.apache.maven.pluginsmaven-compiler-plugin 1.81.8

 package com.cnblogs.hellxz; /** * 用于测试的pojo */ public class User { private String name; private String sex; private String phone; public User(){} public User(String name, String sex, String phone) { this.name = name; this.sex = sex; this.phone = phone; } public String toString(){ return "user:{" +"name: " + name + ", " +"sex: " + sex + ", " +"phone: " + phone +" }"; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public String getPhone() { return phone; } public void setPhone(String phone) { this.phone = phone; } } 

 package com.cnblogs.hellxz; import org.apache.log4j.Logger; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.cloud.client.ServiceInstance; import org.springframework.cloud.client.discovery.DiscoveryClient; import org.springframework.web.bind.annotation.*; /** * @Author : Hellxz * @Description: 服务提供者 * @Date : 2018/4/18 11:36 */ @RestController public class GetRequestController { @Autowired private DiscoveryClient client; //注入发现客户端 private final Logger logger = Logger.getLogger(GetRequestController.class); /** * go straight test */ @GetMapping(value = "/hello") public String hello(){ //获取服务实例，作用为之后console显示效果 ServiceInstance serviceInstance = client.getLocalServiceInstance(); logger.info("/hello host:"+serviceInstance.getHost()+" service_id:" +serviceInstance.getServiceId()); return "hello"; } /** * parameter test */ @GetMapping(value = "/greet/{dd}") public String greet(@PathVariable String dd){ ServiceInstance serviceInstance = client.getLocalServiceInstance(); logger.info("/hello host:"+serviceInstance.getHost()+" service_id:" +serviceInstance.getServiceId()); return "hello "+dd; } /** * 返回测试对象 */ @GetMapping("/user") public User getUser(){ ServiceInstance serviceInstance = client.getLocalServiceInstance(); logger.info("/user "+serviceInstance.getHost()+" port:"+serviceInstance.getPort()+" serviceInstanceid:"+serviceInstance.getServiceId()); return new User("hellxz","male", "123456789"); } /** * 根据名称返回对象，这里模拟查数据库操作 */ @GetMapping("/user/{name}") public User getUserSelect(@PathVariable String name){ ServiceInstance serviceInstance = client.getLocalServiceInstance(); logger.info("/user "+serviceInstance.getHost()+" port:"+serviceInstance.getPort()+" serviceInstanceid:"+serviceInstance.getServiceId()); if(name.isEmpty()){ return new User(); }else if(name.equals("hellxz")){ return new User("hellxz","male", "123456789"); }else{ return new User("随机用户","male", "987654321"); } } } 

 package com.cnblogs.hellxz; import org.apache.log4j.Logger; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.http.ResponseEntity; import org.springframework.web.bind.annotation.*; import org.springframework.web.client.RestTemplate; import org.springframework.web.util.UriComponents; import org.springframework.web.util.UriComponentsBuilder; import java.net.URI; import java.util.HashMap; import java.util.Map; /** * @Author : Hellxz * @Description: ribbon消费者应用Controller，get请求 * @Date : 2018/4/16 15:54 */ @RestController public class GetRequestController { private Logger logger = Logger.getLogger(GetRequestController.class); @Autowired //注入restTemplate private RestTemplate restTemplate; /** * ResponseEntity getForEntity(String url, Class responseType) * T getBody() 以下此方法相同 */ @GetMapping(value="/entity/noparam") public String noParamGetForEntity(){ //这里注释掉，因为之前想当然使用了直链访问服务提供者的接口，这样是不会返回结果的，而且会报错 //return restTemplate.getForEntity("http://localhost:8080/hello",String.class).getBody(); //使用restTemplate调用微服务接口 return restTemplate.getForEntity("http://hello-service/hello", String.class).getBody(); } /** * ResponseEntity getForEntity(String url, Class responseType, Object... uriVariables) */ @GetMapping("/entity/type") public User getForEntityIdentifyByType(){ //不传参返回指定类型结果 ResponseEntity entity = restTemplate.getForEntity("http://hello-service/user", User.class); User body = entity.getBody(); logger.info("user:"+body); return body; //以上可简写为 //    return restTemplate.getForEntity("http://hello-service/user", User.class).getBody(); } /** * ResponseEntity getForEntity(String url, Class responseType, Object... uriVariables) * 使用占位符对参数进行替换，内部使用String.format方法实现 */ @GetMapping(value="/entity") //如果接收的参数是使用参数没有使用?有则使用@PathVariable，否则用@RequestParam public String getForEntityByQuestionMarkParam(@RequestParam("name") String name){ //主要测试getEntity方法，这里测试直接传参 return restTemplate.getForEntity("http://hello-service/greet/{1}", String.class, name).getBody(); } /** * getForEntity方法内部会提取map中，以占位符为key的值作为参数回填入url中 * ResponseEntity getForEntity(String url, Class responseType, Map uriVariables) */ @GetMapping(value="/entity/map/{name}") //如果接收的参数是使用参数没有使用?有则使用@PathVariable，否则用@RequestParam public String getForEntityByMap(@PathVariable("name") String name){ //主要测试getEntity方法，这里测试map传参 Map reqMap = new HashMap(); reqMap.put("name",name); return restTemplate.getForEntity("http://hello-service/greet/{name}", String.class,reqMap).getBody(); } /** * ResponseEntity getForObject(URI url, Class responseType) */ @GetMapping("/entity/uri") public String getForEntityByURI(){ //使用uri进行传参并访问 UriComponents uriComponents = UriComponentsBuilder.fromUriString("http://hello-service/greet/{name}").build().expand("laozhang").encode(); URI uri = uriComponents.toUri(); return restTemplate.getForEntity(uri, String.class).getBody(); } /** * T getForObject(String url, Class responseType) */ @GetMapping("/object") public User getForObjectWithNoParam(){ //相比getForEntity方法，获取对象可以省去调用getBody return restTemplate.getForObject("http://hello-service/user", User.class); } /** * T getForObject(String url, Class responseType, Map uriVariables) */ @GetMapping("/object/map") public User getForObjectByMap(){ //使用map传参 Map paramMap = new HashMap<>(); paramMap.put("name","hellxz"); return restTemplate.getForObject("http://hello-service/user", User.class, paramMap); } /** * T getForObject(String url, Class responseType, Object... uriVariables) */ @GetMapping("/object/param/{name}") public User getForObjectByParam(@PathVariable String name){ return restTemplate.getForObject("http://hello-service/user/{name}",User.class, name); } /** * T getForObject(URI url, Class responseType) */ @GetMapping("/object/uri/{name}") public User getForObjectByURI(@PathVariable String name){ UriComponents uriComponents = UriComponentsBuilder.fromUriString("http://hello-service/user/{name}") .build().expand(name).encode(); URI uri = uriComponents.toUri(); return restTemplate.getForObject(uri,User.class); } } 

 package com.shunneng.springcloudhelloworld; import org.apache.log4j.Logger; import org.springframework.web.bind.annotation.*; import org.springframework.web.util.UriComponents; import org.springframework.web.util.UriComponentsBuilder; import java.net.URI; /** * @Author : Hellxz * @Description: * @Date : 2018/4/18 10:21 */ @RestController public class PostRequestController { private Logger logger = Logger.getLogger(PostRequestController.class); /** * 接收一个对象再返回回去,postForEntity/postForObject方法通用 */ @PostMapping("/user") public User returnUserByPost(@RequestBody User user){ logger.info("/use接口 "+user); if(user == null) return new User("这是一个空对象","",""); return user; } /** * 测试PostForEntity方法的参数，可以直接看输出判断结果了 */ @PostMapping("/user/{str}") public User returnUserByPost(@PathVariable String str, @RequestBody User user){ logger.info("/user/someparam 接口传参 name："+str +" "+user); if(user == null) return new User("这是一个空对象","",""); return user; } /** * 为postForLocation方法返回URI */ @PostMapping("/location") public URI returnURI(@RequestBody User user){ //这里模拟一个url，真实资源位置不一定是这里 UriComponents uriComponents = UriComponentsBuilder.fromUriString("http://hello-service/location") .build().expand(user).encode(); URI toUri = uriComponents.toUri(); //这里不知道是什么问题，明明生成uri了，返回之后好像并没有被获取到 logger.info("/location uri:"+toUri); return toUri; } } 

 package com.cnblogs.hellxz; import org.apache.log4j.Logger; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.http.ResponseEntity; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RestController; import org.springframework.web.client.RestTemplate; import org.springframework.web.util.UriComponents; import org.springframework.web.util.UriComponentsBuilder; import java.net.URI; /** * @Author : Hellxz * @Description: Ribbon消费者post请求controller * @Date : 2018/4/18 9:47 */ @RestController public class PostRequestController { private Logger logger = Logger.getLogger(PostRequestController.class); @Autowired private RestTemplate restTemplate; /** * ResponseEntity postForEntity(String url, Object request, Class responseType) * 其中参数url不多说，Object request如果是不是一个HttpEntity对象，会自动转换为HttpEntity对象，视作完整的body来处理; * 如果是HttpEntity对象，那么会被直接当做body处理并且包含header内容。 * 以下对于重写的方法就不多说了，使用方法大体同getForEntity，如果仅是简单post对象，那么使用不带Object...variables或Map variables的方法即可。 * postForEntity(String url, Object request, Class responseType, Object... uriVariables) * postForEntity(String url, Object request, Class responseType, Map uriVariables) * * 这里详细说下我遇到的坑： * 1、其他几个重载方法的最后边的Object...variables和Map variables都是对之前的url进行操作的， *   也就是说，在post请求的url中使用占位符进行传参，而如果在url中没有使用占位符，那么这些最后传的参数是无效的！ * 2、方法中Object request这个对象如果和服务提供者的接收参数类型相同，那么服务提供者仅需使用@RequestBody接收参数即可。 * 3、如果二者都使用了，这就比较有趣了，需要一边通过@PathVariable注解接收uri中的参数，一边还需要@RequestBody接收对象或RequestParam按字段接收参数！ * 4、如果报错了，请仔细看看我上边写的三条，并注意服务提供者的参数接收注解的使用等。 */ @PostMapping("/entity") public User postForEntity(){ User user = new User("hellxz1","1","678912345"); ResponseEntity entity = restTemplate.postForEntity("http://hello-service/user/{str}", user, User.class, "测试参数"); User body = entity.getBody(); //所有restTemplate.*ForEntity方法都是包装类，body为返回类型对象 return body; } /** * 使用URI传参，测试结果会显示在服务提供者的终端中 * ResponseEntity postForEntity(URI url, Object request, Class responseType) */ @PostMapping("/entity/uri") public User postForEntityByURI(){ User user = new User("老张","1","678912345"); //这里只是将url转成URI，并没有添加参数 UriComponents uriComponents = UriComponentsBuilder.fromUriString("http://hello-service/user") .build().encode(); URI toUri = uriComponents.toUri(); //使用user传参 User object = restTemplate.postForObject(toUri, user, User.class); return object; } /** * 这里测试postForObject方法，需要注意的参数如上述方法的描述，区别只是不需要getBody了，这里就不再累述了 * postForObject(String url, Object request, Class responseType, Object... uriVariables) * postForObject(String url, Object request, Class responseType, Map uriVariables) */ @PostMapping("/object") public User postForObject(){ User user = new User("hellxz2","1","123654987"); //这里url传1是为了调用服务者项目中的一个接口 User responseBody = restTemplate.postForObject("http://hello-service/user/1", user, User.class); return responseBody; } /** * post请求还有一种：postForLocation，这里也同样有三种重载，除了无需指定返回类型外，用法相同，返回类型均为URI，也就不累述了 * postForLocation(String url, Object request, Object... uriVariables) * postForLocation(String url, Object request, Map uriVariables) * postForLocation(URI url, Object request) */ @PostMapping("/location") public URI postForLocation(){ User user = new User("hellxz3","1","987654321"); URI uri = restTemplate.postForLocation("http://hello-service/location", user); //不知道为什么返回来是空，这个方法仅供参考吧，如果知道是什么情况，我会回来改的 logger.info("/location uri:"+uri); return uri; } } 

 package com.cnblogs.hellxz; import org.apache.log4j.Logger; import org.springframework.web.bind.annotation.*; /** * @Author : Hellxz * @Description: 服务提供者 put&delete请求controller * @Date : 2018/4/19 14:11 */ @RestController public class PutAndDeleteRequestController { private Logger logger = Logger.getLogger(PutAndDeleteRequestController.class); @PutMapping("/put") public void put(@RequestBody User user){ logger.info("/put "+user); } @DeleteMapping("/delete/{id}") public void delete(@PathVariable Long id){ logger.info("/delete id:"+id); } } 

 package com.cnblogs.hellxz; import org.apache.log4j.Logger; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.*; import org.springframework.web.client.RestTemplate; /** * @Author : Hellxz * @Description: put请求、delete请求，重载的参数与上述demo基本相同，不予列出 * @Date : 2018/4/19 13:43 */ @RestController public class PutRequestController { private Logger logger = Logger.getLogger(PostRequestController.class); @Autowired private RestTemplate restTemplate; /** * put请求示例，一般put请求多用作修改 */ @PutMapping("/put") public void put(@RequestBody User user){ restTemplate.put("http://hello-service/put",user); } /** * delete请求示例 */ @DeleteMapping("/del/{id}") public void delete(@PathVariable Long id){ restTemplate.delete("http://hello-service/delete/{1}", id); } }