一、示例依赖
<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>com.alibaba.fastjson2</groupId> <artifactId>fastjson2</artifactId> <version>2.0.3.android</version> </dependency> </dependencies>
二、将RestTemplate加入spring管理
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 BeanConfig { @Bean public RestTemplate restTemplate(ClientHttpRequestFactory factory) { RestTemplate restTemplate = new RestTemplate(factory); return restTemplate; } @Bean public ClientHttpRequestFactory simpleClientHttpRequestFactory() { SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory(); //建⽴连接所⽤的时间，适⽤于⽹络状况正常的情况下，两端连接所⽤的时间。单位毫秒 factory.setConnectTimeout(15000); //建⽴连接后从服务器读取到可⽤资源所⽤的时间。单位毫秒 factory.setReadTimeout(5000); return factory; } }
三、请求基础数据
server.port=8089
import lombok.Data; @Data public class Student { private String name; private Integer age; }
import lombok.Data; @Data public class Teacher { private String name; private String phone; }
准备两个请求，一个get一个post
#get地址 http://localhost:8089/test/getTeacherByStudnetId #post地址 http://localhost:8089/test/saveStudent http://localhost:8089/test/saveStudent2
import com.minos.resttemplete.bean.Student; import com.minos.resttemplete.bean.Teacher; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RequestBody; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController @RequestMapping("/test") public class TestController { /*普通get请求*/ @GetMapping("/getTeacherByStudnetId") public Teacher getTeacher(Long studentId) { System.out.println("根据学生:" + studentId + "查询老师"); Teacher teacher = new Teacher(); teacher.setName("xxx老师"); teacher.setPhone("13113113152"); return teacher; } /*普通post请求*/ @PostMapping("/saveStudent") public Student addStudnet(Student student) { System.out.println(student.toString()); return student; } /*@RequestBody形势post请求*/ @PostMapping("/saveStudent2") public Student addStudnet2(@RequestBody Student student) { System.out.println(student.toString()); return student; } }
四、RestTemplate之get请求
1、getForObject
@Autowired RestTemplate restTemplate; @Test void testGetForObject() { String url = "http://localhost:8089/test/getTeacherByStudnetId"; Map<String, Long> paramMap = new HashMap<>(); paramMap.put("studentId", 5L); //只能返回响应体 Teacher teacher = restTemplate.getForObject(url, Teacher.class, paramMap); System.out.println(JSON.toJSONString(teacher)); // {"name":"xxx老师","phone":"13113113152"} }
2、 getForEntity
@Autowired RestTemplate restTemplate; @Test void testGetForEntity() { String url = "http://localhost:8089/test/getTeacherByStudnetId?studentId=1"; Map<String, Long> paramMap = new HashMap<>(); paramMap.put("studentId", 5L); //返回形体、http头信息、http状态 ResponseEntity<Teacher> forEntity = restTemplate.getForEntity(url, Teacher.class, paramMap); HttpStatus statusCode = forEntity.getStatusCode(); int statusCodeValue = forEntity.getStatusCodeValue(); Teacher teacher = forEntity.getBody(); HttpHeaders headers = forEntity.getHeaders(); System.out.println(JSON.toJSONString(statusCode)); System.out.println(JSON.toJSONString(statusCodeValue)); System.out.println(JSON.toJSONString(teacher)); System.out.println(JSON.toJSONString(headers)); // "OK" //200 //{"name":"xxx老师","phone":"13113113152"} //{"Content-Type":["application/json"],"Transfer-Encoding":["chunked"],"Date":["Wed, 18 May 2022 01:39:01 GMT"],"Keep-Alive":["timeout=60"],"Connection":["keep-alive"]} }
五、RestTemplate之post请求
@Autowired RestTemplate restTemplate; @Test void testPosttForObject1_1() { String url = "http://localhost:8089/test/saveStudent"; Student stu = new Student(); stu.setName("zhangsan"); stu.setAge(50); //只能返回响应体 Student student = restTemplate.postForObject(url, stu, Student.class); System.out.println(JSON.toJSONString(student)); // {} } @Test void testPosttForObject1_2() { String url = "http://localhost:8089/test/saveStudent"; MultiValueMap<String, Object> paramMap = new LinkedMultiValueMap<>(); paramMap.add("name", "zhangsan2"); paramMap.add("age", 15); //只能返回响应体 Student student = restTemplate.postForObject(url, paramMap, Student.class); System.out.println(JSON.toJSONString(student)); // {"age":15,"name":"zhangsan2"} } @Test void testPostForEntity1() { String url = "http://localhost:8089/test/saveStudent"; MultiValueMap<String, Object> paramMap = new LinkedMultiValueMap<>(); paramMap.add("name", "zhangsan2"); paramMap.add("age", 15); //返回形体、http头信息、http状态 ResponseEntity<Student> studentResponseEntity = restTemplate.postForEntity(url, paramMap, Student.class); System.out.println(JSON.toJSONString(studentResponseEntity.getStatusCode())); System.out.println(JSON.toJSONString(studentResponseEntity.getStatusCodeValue())); System.out.println(JSON.toJSONString(studentResponseEntity.getHeaders())); System.out.println(JSON.toJSONString(studentResponseEntity.getBody())); // "OK" //200 //{"Content-Type":["application/json"],"Transfer-Encoding":["chunked"],"Date":["Wed, 18 May 2022 01:37:01 GMT"],"Keep-Alive":["timeout=60"],"Connection":["keep-alive"]} //{"age":15,"name":"zhangsan2"} } @Test void testPosttForObject2_1() { String url = "http://localhost:8089/test/saveStudent2"; Student stu = new Student(); stu.setName("zhangsan"); stu.setAge(50); //只能返回响应体 Student student = restTemplate.postForObject(url, stu, Student.class); System.out.println(JSON.toJSONString(student)); } @Test void testPosttForObject2_2() { String url = "http://localhost:8089/test/saveStudent2"; HttpHeaders headers = new HttpHeaders(); //设置请求头为json headers.setContentType(MediaType.APPLICATION_JSON); Student stu = new Student(); stu.setName("zhangsan"); stu.setAge(50); HttpEntity<Student> request = new HttpEntity<>(stu, headers); //只能返回响应体 Student student = restTemplate.postForObject(url, request, Student.class); System.out.println(JSON.toJSONString(student)); // {"age":50,"name":"zhangsan"} } @Test void testPostForEntity2() { String url = "http://localhost:8089/test/saveStudent2"; HttpHeaders headers = new HttpHeaders(); //设置请求头为json headers.setContentType(MediaType.APPLICATION_JSON); Student stu = new Student(); stu.setName("zhangsan"); stu.setAge(50); HttpEntity<Student> request = new HttpEntity<>(stu, headers); //返回形体、http头信息、http状态 ResponseEntity<Student> studentResponseEntity = restTemplate.postForEntity(url, request, Student.class); System.out.println(JSON.toJSONString(studentResponseEntity.getStatusCode())); System.out.println(JSON.toJSONString(studentResponseEntity.getStatusCodeValue())); System.out.println(JSON.toJSONString(studentResponseEntity.getHeaders())); System.out.println(JSON.toJSONString(studentResponseEntity.getBody())); //"OK" //200 //{"Content-Type":["application/json"],"Transfer-Encoding":["chunked"],"Date":["Wed, 18 May 2022 01:38:00 GMT"],"Keep-Alive":["timeout=60"],"Connection":["keep-alive"]} //{"age":50,"name":"zhangsan"} }
六、RestTemplatelUtil工具类
可以返回泛型参数
@Component public class RestTemplatelUtil { @Autowired RestTemplate restTemplate; /** * * @param url 请求的参数 * @param method 请求的方法 HttpMethod.POST GET, HEAD, POST, PUT, PATCH, DELETE, OPTIONS，TRACE; * @param responseBodyType 返回的数据结构 * @param requestBody 请求的数据 * @param <T> 返回的数据泛型 * @param <A> 请求的数据 * @return */ public <T, A> T exchange(String url, HttpMethod method, ParameterizedTypeReference<T> responseBodyType, A requestBody) { RestTemplate restTemplate = new RestTemplate(); // 请求头 HttpHeaders headers = new HttpHeaders(); MimeType mimeType = MimeTypeUtils.parseMimeType("application/json"); MediaType mediaType = new MediaType(mimeType.getType(), mimeType.getSubtype(), Charset.forName("UTF-8")); // 请求体 headers.setContentType(mediaType); // 发送请求 HttpEntity<A> entity = new HttpEntity<>(requestBody, headers); ResponseEntity<T> resultEntity = restTemplate.exchange(url, method, entity, responseBodyType); return resultEntity.getBody(); } }
使用方法
public ResponseToken getToken() { //构造请求参数数据 RequestData requestData = new RequestData(); RequestLogin login = new RequestLogin(); requestData.setData(login); //URL String url = RequestConstantsUrl.thloginUrl; //发起请求 ResponseData<ResponseToken> exchange = restTemplatelUtil.exchange(url, HttpMethod.POST, new ParameterizedTypeReference<ResponseData<ResponseToken>>() { }, requestData); //获取数据 return exchange.getReturnData(); }
总结：
1、xxForObject和xxForEntity区别：xxForObject返回返回体，xxForEntity返回http头部信息、http状态码、返回体。一般使用xxForEntity，判断getStatusCodeValue()为200时候，再getBody；
2、post请求和get请求，第一个参数都是URL，第二个参数post是请求的参数，get是返回接受的类；第三个参数post是返回接受的类，get是请求的参数。
restTemplate.postForEntity(url, request, Student.class); restTemplate.getForEntity(url, Teacher.class, paramMap);
