发送GET请求
<T> ResponseEntity<T> getForEntity(URI var1, Class<T> var2)
/*client*/@Testpublic void testRest(){ RestTemplate restTemplate = new RestTemplate(); String getUrl = "http://localhost:8083/mock/test/get" + "/" + "helloworld"; ResponseEntity<Student> entity = restTemplate.getForEntity(getUrl,Student.class); log.info(entity.toString()); log.info(entity.getHeaders().toString()); log.info(entity.getBody().toString());}客户端输出日志：
2020-05-27 09:14:44 [main] INFO AppTest -<200,Student(name=王杰, age=28),[Content-Type:"application/json", Transfer-Encoding:"chunked", Date:"Wed, 27 May 2020 01:14:44 GMT", Keep-Alive:"timeout=60", Connection:"keep-alive"]>
2020-05-27 09:14:44 [main] INFO AppTest -[Content-Type:"application/json", Transfer-Encoding:"chunked", Date:"Wed, 27 May 2020 01:14:44 GMT", Keep-Alive:"timeout=60", Connection:"keep-alive"]
2020-05-27 09:14:44 [main] INFO AppTest -Student(name=王杰, age=28)
/*server*/@RestController@Slf4jpublic class Demo { @GetMapping("/test/get/{name}") public JSONObject get(@PathVariable("name") String username){ log.debug("get server被调用"); log.info(username); JSONObject result = new JSONObject(); result.put("name","王杰"); result.put("age",28); return result; }}服务端输出日志：
2020-05-27 09:14:44 [http-nio-8083-exec-3] DEBUG com.ai.mock.rests.Demo -get server被调用
2020-05-27 09:14:44 [http-nio-8083-exec-3] INFO com.ai.mock.rests.Demo -helloworld
<T> ResponseEntity<T> getForEntity(String url, Class<T> responseType, Map<String, ?> uriVariables)
/*client*/@Testpublic void testRest2(){ RestTemplate restTemplate = new RestTemplate(); String getUrl = "http://localhost:8083/mock/test/get2?name={name}&age={age}"; Map<String,Object> map = new HashMap<>(); map.put("name","皮皮虾"); map.put("age",3); ResponseEntity<Student> entity = restTemplate.getForEntity(getUrl,Student.class,map); log.info(entity.toString()); log.info(entity.getHeaders().toString()); log.info(entity.getBody().toString()); /*验证entity中放的就是Student对象*/ Student s = entity.getBody(); log.info(s.getName()); log.info(s.getAge().toString());}客户端输出日志：
2020-05-27 09:26:34 [main] INFO AppTest -<200,Student(name=王杰, age=28),[Content-Type:"application/json", Transfer-Encoding:"chunked", Date:"Wed, 27 May 2020 01:26:34 GMT", Keep-Alive:"timeout=60", Connection:"keep-alive"]>
2020-05-27 09:26:34 [main] INFO AppTest -[Content-Type:"application/json", Transfer-Encoding:"chunked", Date:"Wed, 27 May 2020 01:26:34 GMT", Keep-Alive:"timeout=60", Connection:"keep-alive"]
2020-05-27 09:26:34 [main] INFO AppTest -Student(name=王杰, age=28)
2020-05-27 09:26:34 [main] INFO AppTest -王杰
2020-05-27 09:26:34 [main] INFO AppTest -28
/*server*/@GetMapping("/test/get2")public JSONObject get2(@RequestParam("name") String username,@RequestParam("age") Integer age){ log.debug("get server被调用"); log.info("username=" + username); log.info("age=" + age); JSONObject result = new JSONObject(); result.put("name","王杰"); result.put("age",28); return result;}服务端输出日志：
2020-05-27 09:26:34 [http-nio-8083-exec-2] DEBUG com.ai.mock.rests.Demo -get server被调用
2020-05-27 09:26:34 [http-nio-8083-exec-2] INFO com.ai.mock.rests.Demo -username=皮皮虾
2020-05-27 09:26:34 [http-nio-8083-exec-2] INFO com.ai.mock.rests.Demo -age=3
<T> ResponseEntity<T> getForEntity(String url, Class<T> responseType, Object... uriVariables)
/*client*/ @Test public void testRest3(){ RestTemplate restTemplate = new RestTemplate(); String getUrl = "http://localhost:8083/mock/test/get3?name={name}"; String name = "hello world"; ResponseEntity<Student> entity = restTemplate.getForEntity(getUrl,Student.class,name); Student s = entity.getBody(); log.info(s.getName()); log.info(entity.toString()); log.info(entity.getHeaders().toString()); log.info(entity.getBody().toString()); }客户端日志输出：
2020-05-27 09:39:54 [main] INFO AppTest -<200,Student(name=王杰, age=28),[Content-Type:"application/json", Transfer-Encoding:"chunked", Date:"Wed, 27 May 2020 01:39:54 GMT", Keep-Alive:"timeout=60", Connection:"keep-alive"]>
2020-05-27 09:39:54 [main] INFO AppTest -[Content-Type:"application/json", Transfer-Encoding:"chunked", Date:"Wed, 27 May 2020 01:39:54 GMT", Keep-Alive:"timeout=60", Connection:"keep-alive"]
2020-05-27 09:39:54 [main] INFO AppTest -Student(name=王杰, age=28)
/*server*/ @GetMapping("/test/get3") public JSONObject get3(@RequestParam("name") String username){ log.debug("get server被调用"); log.info(username); JSONObject result = new JSONObject(); result.put("name","王杰"); result.put("age",28); return result; }服务端日志输出：
2020-05-27 09:39:54 [http-nio-8083-exec-10] DEBUG com.ai.mock.rests.Demo -get server被调用
2020-05-27 09:39:54 [http-nio-8083-exec-10] INFO com.ai.mock.rests.Demo -hello world
如果Object为一个java对象，想像Map一样传参，行不通！在这里我特么想极力吐槽一波。如果想传java对象，得这样传：
/*client*/ @Test public void testRest4(){ RestTemplate restTemplate = new RestTemplate(); String getUrl = "http://localhost:8083/mock/test/get4?name={student}"; Student student = new Student("皮皮虾",3); ResponseEntity<Student> entity = restTemplate.getForEntity(getUrl,Student.class,student); log.info(entity.toString()); log.info(entity.getHeaders().toString()); log.info(entity.getBody().toString()); }客户端日志输出：
2020-05-27 09:48:35 [main] INFO AppTest -<200,Student(name=王杰, age=28),[Content-Type:"application/json", Transfer-Encoding:"chunked", Date:"Wed, 27 May 2020 01:48:34 GMT", Keep-Alive:"timeout=60", Connection:"keep-alive"]>
2020-05-27 09:48:35 [main] INFO AppTest -[Content-Type:"application/json", Transfer-Encoding:"chunked", Date:"Wed, 27 May 2020 01:48:34 GMT", Keep-Alive:"timeout=60", Connection:"keep-alive"]
2020-05-27 09:48:35 [main] INFO AppTest -Student(name=王杰, age=28)
/*server*/ @GetMapping("/test/get4") public JSONObject get4(@RequestParam("name") String name){ log.debug("get server被调用"); log.info(name); JSONObject result = new JSONObject(); result.put("name","王杰"); result.put("age",28); return result; }服务端日志输出：
2020-05-27 09:48:34 [http-nio-8083-exec-5] DEBUG com.ai.mock.rests.Demo -get server被调用
2020-05-27 09:48:34 [http-nio-8083-exec-5] INFO com.ai.mock.rests.Demo -Student(name=皮皮虾, age=3)
<T> T getForObject(URI url, Class<T> responseType)
/*client*/ @Test public void testRest5(){ RestTemplate restTemplate = new RestTemplate(); String getUrl = "http://localhost:8083/mock/test/get5/helloworld"; Student stu = restTemplate.getForObject(getUrl,Student.class); log.info(stu.toString()); }客户端输出日志：
2020-05-27 10:10:52 [main] INFO AppTest -Student(name=王杰, age=28)
/*server*/ @GetMapping("/test/get5/{name}") public JSONObject get5(@PathVariable("name") String username){ log.debug("get server被调用"); log.info(username); JSONObject result = new JSONObject(); result.put("name","王杰"); result.put("age",28); return result; }服务端输出日志：
2020-05-27 10:10:52 [http-nio-8083-exec-1] DEBUG com.ai.mock.rests.Demo -get server被调用
2020-05-27 10:10:52 [http-nio-8083-exec-1] INFO com.ai.mock.rests.Demo -helloworld
/*client*/ @Test public void testRest6(){ RestTemplate restTemplate = new RestTemplate(); String getUrl = "http://localhost:8083/mock/test/get6?name={name}&age={age}"; Map<String,Object> map = new HashMap<>(); map.put("name","皮皮虾"); map.put("age",3); Student s = restTemplate.getForObject(getUrl,Student.class,map); log.info(s.toString()); }客户端输出日志：
2020-05-27 10:14:47 [main] INFO AppTest -Student(name=王杰, age=28)
/*server*/ @GetMapping("/test/get6") public JSONObject get6(@RequestParam("name") String username,@RequestParam("age") Integer age){ log.debug("get server被调用"); log.info("username=" + username); log.info("age=" + age); JSONObject result = new JSONObject(); result.put("name","王杰"); result.put("age",28); return result; }服务端输出日志：
2020-05-27 10:14:47 [http-nio-8083-exec-2] DEBUG com.ai.mock.rests.Demo -get server被调用
2020-05-27 10:14:47 [http-nio-8083-exec-2] INFO com.ai.mock.rests.Demo -username=皮皮虾
2020-05-27 10:14:47 [http-nio-8083-exec-2] INFO com.ai.mock.rests.Demo -age=3
<T> T getForObject(String url, Class<T> responseType, Object... uriVariables)
/*client*/ @Test public void testRest7(){ RestTemplate restTemplate = new RestTemplate(); String getUrl = "http://localhost:8083/mock/test/get7?name={stu}"; Student stu = new Student("皮皮虾",3); Student s = restTemplate.getForObject(getUrl,Student.class,stu); log.info(s.toString()); }客户端日志输出：
2020-05-27 10:22:29 [main] INFO AppTest -Student(name=王杰, age=28)
/*server*/ @GetMapping("/test/get7") public JSONObject get7(@RequestParam("name") String name){ log.debug("get server被调用"); log.info(name); JSONObject result = new JSONObject(); result.put("name","王杰"); result.put("age",28); return result; }服务端日志输出：
2020-05-27 10:25:50 [http-nio-8083-exec-3] DEBUG com.ai.mock.rests.Demo -get server被调用
2020-05-27 10:25:50 [http-nio-8083-exec-3] INFO com.ai.mock.rests.Demo -Student(name=皮皮虾, age=3)
GET小结
看了前面的一堆测试代码，不禁提问：你怎么这么唇笔啊？server端不会用JSONObject来接受MAP 或者 java对象吗？
答案是：不可以！特么的设计者的思想就是GET方式 传参 就从URL里面取值。不管你是从path还是从url参数里面都可以。就是不可以从body里面取。
getForEntity与getForObject的区别是 getForEntity返回的数据中包含了请求头、请求体，而getForObject只有体。
发送POST请求
POST提交方式主要有两种：form表单提交、payload提交。
这里给出鄙人的一点浅薄的见解：
- form表单提交:无论是后端通过restTemplate还是前端人员通过ajax发送的请求，请求头中Content-Type: application/x-www-form-urlencoded; charset=UTF-8。server端获取参数值，需要使用RequestParmas,不能使用RequestBody获取到。
- payload提交：无论是后端通过restTemplate还是前端人员通过ajax发送的请求，请求头中Content-Type: application/json;charset=UTF-8。server端获取参数值，需要使用RequestBody,不能使用RequestParams获取到。
<T> ResponseEntity<T> postForEntity(URI url, @Nullable Object request, Class<T> responseType)
<T> ResponseEntity<T> postForEntity(URI url, @Nullable Object request, Class<T> responseType) form提交
/*client*/ /*表单提交 Form Data服务端只能用RequestParams取值 不能用RequestBody*/ /*Content-Type: application/x-www-form-urlencoded; charset=UTF-8*/ @Test public void testRest8(){ RestTemplate restTemplate = new RestTemplate(); String url = "http://localhost:8083/mock/test/post"; MultiValueMap params = new LinkedMultiValueMap(); params.add("name","皮皮虾"); params.add("age",3); HttpHeaders headers = new HttpHeaders(); headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED); HttpEntity<MultiValueMap> entity = new HttpEntity<>(params,headers); ResponseEntity<String> responseEntity = restTemplate.postForEntity(url,entity,String.class); log.info(responseEntity.getBody()); }客户端日志：
2020-05-28 16:06:54 [main] INFO AppTest -{"name":"王杰","age":28}
/*server*/ @PostMapping("/test/post") public JSONObject post(@RequestParam("name") String name,@RequestParam("age") Integer age){ log.debug("post server被调用"); log.info(name); log.info(age.toString()); JSONObject result = new JSONObject(); result.put("name","王杰"); result.put("age",28); return result; }服务端日志：
2020-05-28 16:06:54 [http-nio-8083-exec-4] DEBUG com.ai.mock.rests.Demo -post server被调用
2020-05-28 16:06:54 [http-nio-8083-exec-4] INFO com.ai.mock.rests.Demo -皮皮虾
2020-05-28 16:06:54 [http-nio-8083-exec-4] INFO com.ai.mock.rests.Demo -3
<T> ResponseEntity<T> postForEntity(URI url, @Nullable Object request, Class<T> responseType) payload提交
/*<T> ResponseEntity<T> postForEntity(URI url, @Nullable Object request, Class<T> responseType)*/ /*payload提交*/ /*参数放在body requestParams 取不到*/ /*Content-Type: application/json;charset=UTF-8*/ @Test public void testRest9(){ RestTemplate restTemplate = new RestTemplate(); String url = "http://localhost:8083/mock/test/post2"; MultiValueMap params = new LinkedMultiValueMap(); params.add("name","皮皮虾"); params.add("age",3); /*此处注销的代码块 也可以作为请求体参数传递*/ /*Map<String,Object> params = new HashMap<>(); params.put("name","皮皮虾"); params.put("age",3);*/ HttpHeaders headers = new HttpHeaders(); headers.setContentType(MediaType.APPLICATION_JSON_UTF8); HttpEntity<Map> entity = new HttpEntity<>(params,headers); ResponseEntity<String> responseEntity = restTemplate.postForEntity(url,entity,String.class); log.info(responseEntity.getBody()); }客户端日志：
2020-05-28 16:12:35 [main] INFO AppTest -{"name":"王杰","age":28}
/*server*/ @PostMapping("/test/post2") public JSONObject post2(@RequestBody JSONObject jsonObject){ log.debug("post server被调用"); log.info(jsonObject.toJSONString()); JSONObject result = new JSONObject(); result.put("name","王杰"); result.put("age",28); return result; }服务端日志：
2020-05-28 16:12:35 [http-nio-8083-exec-6] DEBUG com.ai.mock.rests.Demo -post server被调用
2020-05-28 16:12:35 [http-nio-8083-exec-6] INFO com.ai.mock.rests.Demo -{"name":["皮皮虾"],"age":[3]}
<T> ResponseEntity<T> postForEntity(String url, @Nullable Object request, Class<T> responseType, Map<String, ?> uriVariables)
这里就基于payload方式举例子了，也可以基于form data 方式。
/*除了请求头里面传值 还可以在 请求参数里面传值 需要显示申明 请求体用RequestBody获取 请求头用RequestParam获取*/ @Test public void testRest10(){ RestTemplate restTemplate = new RestTemplate(); String url = "http://localhost:8083/mock/test/post3?sex={sex}"; MultiValueMap params = new LinkedMultiValueMap(); params.add("name","皮皮虾"); params.add("age",3); Map<String,Object> uriParam = new HashMap<>(); uriParam.put("sex","man"); HttpHeaders headers = new HttpHeaders(); headers.setContentType(MediaType.APPLICATION_JSON_UTF8); HttpEntity<Map> entity = new HttpEntity<>(params,headers); ResponseEntity<String> responseEntity = restTemplate.postForEntity(url,entity,String.class,uriParam); log.info(responseEntity.getBody()); }客户端日志：
2020-05-28 16:18:32 [main] INFO AppTest -{"name":"王杰","age":28}
@PostMapping("/test/post3") public JSONObject post2(@RequestBody JSONObject jsonObject,@RequestParam("sex") String sex){ log.debug("post server被调用"); log.info(jsonObject.toJSONString()); log.info(sex); JSONObject result = new JSONObject(); result.put("name","王杰"); result.put("age",28); return result; }server端日志：
2020-05-28 16:18:32 [http-nio-8083-exec-7] DEBUG com.ai.mock.rests.Demo -post server被调用
2020-05-28 16:18:32 [http-nio-8083-exec-7] INFO com.ai.mock.rests.Demo -{"name":["皮皮虾"],"age":[3]}
2020-05-28 16:18:32 [http-nio-8083-exec-7] INFO com.ai.mock.rests.Demo -man
<T> ResponseEntity<T> postForEntity(String url, @Nullable Object request, Class<T> responseType, Object... uriVariables)
这里就基于payload方式举例子了，也可以基于form data 方式。
@Test public void testRest11(){ RestTemplate restTemplate = new RestTemplate(); String url = "http://localhost:8083/mock/test/post4?stu={stu}"; MultiValueMap params = new LinkedMultiValueMap(); params.add("name","皮皮虾"); params.add("age",3); Student stu = new Student("王杰",20); HttpHeaders headers = new HttpHeaders(); headers.setContentType(MediaType.APPLICATION_JSON_UTF8); HttpEntity<Map> entity = new HttpEntity<>(params,headers); ResponseEntity<String> responseEntity = restTemplate.postForEntity(url,entity,String.class,stu); log.info(responseEntity.getBody()); }客户端日志：
2020-05-28 16:22:16 [main] INFO AppTest -{"name":"王杰","age":28}
@PostMapping("/test/post4") public JSONObject post4(@RequestBody JSONObject jsonObject,@RequestParam("stu") String stu){ log.debug("post server被调用"); log.info(jsonObject.toJSONString()); log.info(stu); JSONObject result = new JSONObject(); result.put("name","王杰"); result.put("age",28); return result; }服务端日志：
2020-05-28 16:22:16 [http-nio-8083-exec-10] DEBUG com.ai.mock.rests.Demo -post server被调用
2020-05-28 16:22:16 [http-nio-8083-exec-10] INFO com.ai.mock.rests.Demo -{"name":["皮皮虾"],"age":[3]}
2020-05-28 16:22:16 [http-nio-8083-exec-10] INFO com.ai.mock.rests.Demo -Student(name=王杰, age=20)
postForEntity小结：如果是form data请求 需要设置请求头的ContentType为MediaType.APPLICATION_JSON_UTF8 且将参数 放入MultiValueMap中 不可以使用普通Map，同时需要将请求体 请求头放入HttpEntity中之后，发起请求。服务端接受参数使用RequestParam。
如果是payload请求 普通Map也可以，需要将CententType设置为MediaType.APPLICATION_JSON_UTF8。服务端接受参数使用ReuqestBody.
<T> T postForObject(URI url, @Nullable Object request, Class<T> responseType)
/*默认 payload方式*/ @Test public void testRest12(){ RestTemplate restTemplate = new RestTemplate(); String url = "http://localhost:8083/mock/test/post2"; Map<String,Object> params = new HashMap<>(); params.put("name","皮皮虾"); params.put("age",3); String result = restTemplate.postForObject(url,params,String.class); log.info(result); }客户端日志：
2020-05-28 16:26:08 [main] INFO AppTest -{"name":"王杰","age":28}
@PostMapping("/test/post2") public JSONObject post2(@RequestBody JSONObject jsonObject){ log.debug("post server被调用"); log.info(jsonObject.toJSONString()); JSONObject result = new JSONObject(); result.put("name","王杰"); result.put("age",28); return result; }服务端日志：
2020-05-28 16:26:08 [http-nio-8083-exec-2] DEBUG com.ai.mock.rests.Demo -post server被调用
2020-05-28 16:26:08 [http-nio-8083-exec-2] INFO com.ai.mock.rests.Demo -{"name":"皮皮虾","age":3}
<T> T postForObject(String url, @Nullable Object request, Class<T> responseType, Map<String, ?> uriVariables)
@Test public void testRest13(){ RestTemplate restTemplate = new RestTemplate(); String url = "http://localhost:8083/mock/test/post3?sex={sex}"; Map<String,Object> params = new HashMap<>(); params.put("name","皮皮虾"); params.put("age",3); Map<String,Object> uriParam = new HashMap<>(); uriParam.put("sex","man"); String result = restTemplate.postForObject(url,params,String.class,uriParam); log.info(result); }客户端日志：
2020-05-28 16:28:51 [main] INFO AppTest -{"name":"王杰","age":28}
@PostMapping("/test/post3") public JSONObject post2(@RequestBody JSONObject jsonObject,@RequestParam("sex") String sex){ log.debug("post server被调用"); log.info(jsonObject.toJSONString()); log.info(sex); JSONObject result = new JSONObject(); result.put("name","王杰"); result.put("age",28); return result; }服务端日志：
2020-05-28 16:28:51 [http-nio-8083-exec-4] DEBUG com.ai.mock.rests.Demo -post server被调用
2020-05-28 16:28:51 [http-nio-8083-exec-4] INFO com.ai.mock.rests.Demo -{"name":"皮皮虾","age":3}
2020-05-28 16:28:51 [http-nio-8083-exec-4] INFO com.ai.mock.rests.Demo -man
<T> T postForObject(String url, @Nullable Object request, Class<T> responseType, Object... uriVariables)
@Test public void testRest14(){ RestTemplate restTemplate = new RestTemplate(); String url = "http://localhost:8083/mock/test/post4?stu={stu}"; Map<String,Object> params = new HashMap<>(); params.put("name","皮皮虾"); params.put("age",3); Student stu = new Student("王杰",20); String result = restTemplate.postForObject(url,params,String.class,stu); log.info(result); }客户端日志：
2020-05-28 16:29:42 [main] INFO AppTest -{"name":"王杰","age":28}
@PostMapping("/test/post4") public JSONObject post4(@RequestBody JSONObject jsonObject,@RequestParam("stu") String stu){ log.debug("post server被调用"); log.info(jsonObject.toJSONString()); log.info(stu); JSONObject result = new JSONObject(); result.put("name","王杰"); result.put("age",28); return result; }服务端日志：
2020-05-28 16:29:42 [http-nio-8083-exec-6] DEBUG com.ai.mock.rests.Demo -post server被调用
2020-05-28 16:29:42 [http-nio-8083-exec-6] INFO com.ai.mock.rests.Demo -{"name":"皮皮虾","age":3}
2020-05-28 16:29:42 [http-nio-8083-exec-6] INFO com.ai.mock.rests.Demo -Student(name=王杰, age=20)
exchange
至于exchange如果知道上面的用法之后 ，只需要在参数请求方法中 添加一个HttpMethod就OK。不再赘述。