RestTemplate

依赖注入

	@Bean
	// 开启负载均衡
	@LoadBalanced
	RestTemplate restTemplate() {
		return new RestTemplate();
	}

接下来便可以使用资源地址调用服务

String url ="http://provider/getHi";
String respStr = restTemplate.getForObject(url, String.class);
		

get 请求处理

getForEntity

getForEntity方法的返回值是一个ResponseEntity，ResponseEntity是Spring对HTTP请求响应的封装，包括了几个重要的元素，如响应码、contentType、contentLength、响应消息体等。

<200,Hi,[Content-Type:"text/plain;charset=UTF-8", Content-Length:"8", Date:"Fri, 10 Apr 2020 09:58:44 GMT", Keep-Alive:"timeout=60", Connection:"keep-alive"]>

返回一个Map

调用方

		String url ="http://provider/getMap";
		   
		ResponseEntity<Map> entity = restTemplate.getForEntity(url, Map.class);
		   
		System.out.println("respStr: "  + entity.getBody() );

生产方

	@GetMapping("/getMap")
	public Map<String, String> getMap() {
		
		HashMap<String, String> map = new HashMap<>();
		map.put("name", "500");
		return map; 
	}

返回对象

调用方

		ResponseEntity<Person> entity = restTemplate.getForEntity(url, Person.class);
		   
		System.out.println("respStr: "  + ToStringBuilder.reflectionToString(entity.getBody() ));

生产方

	@GetMapping("/getObj")
	public Person getObj() {


		Person person = new Person();
		person.setId(100);
		person.setName("xiaoming");
		return person; 
	}

Person类

	private int id;
	private String name;

传参调用

使用占位符

	String url ="http://provider/getObjParam?name={1}";
	   
	ResponseEntity<Person> entity = restTemplate.getForEntity(url, Person.class,"hehehe...");

使用map

		String url ="http://provider/getObjParam?name={name}";
		   
		Map<String, String> map = Collections.singletonMap("name", " memeda");
		ResponseEntity<Person> entity = restTemplate.getForEntity(url, Person.class,map);

返回对象

Person person = restTemplate.getForObject(url, Person.class,map);

post 请求处理

调用方

	
		String url ="http://provider/postParam";
		   
		Map<String, String> map = Collections.singletonMap("name", " memeda");
		 ResponseEntity<Person> entity = restTemplate.postForEntity(url, map, Person.class);

生产方

	@PostMapping("/postParam")
	public Person postParam(@RequestBody String name) {

		System.out.println("name:" + name);

		Person person = new Person();
		person.setId(100);
		person.setName("xiaoming" + name);
		return person; 
	}

postForLocation

调用方

		String url ="http://provider/postParam";
		   
		Map<String, String> map = Collections.singletonMap("name", " memeda");
		URI location = restTemplate.postForLocation(url, map, Person.class);
		
		System.out.println(location);

生产方

需要设置头信息，不然返回的是null

	public URI postParam(@RequestBody Person person,HttpServletResponse response) throws Exception {

	URI uri = new URI("https://www.baidu.com/s?wd="+person.getName());
	response.addHeader("Location", uri.toString());

exchange

可以自定义http请求的头信息，同时保护get和post方法

拦截器

需要实现ClientHttpRequestInterceptor接口

拦截器

public class LoggingClientHttpRequestInterceptor implements ClientHttpRequestInterceptor {

	@Override
	public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution)
			throws IOException {

		System.out.println("拦截啦！！！");
		System.out.println(request.getURI());

		ClientHttpResponse response = execution.execute(request, body);

		System.out.println(response.getHeaders());
		return response;
	}

添加到resttemplate中

	@Bean
	@LoadBalanced
	RestTemplate restTemplate() {
		RestTemplate restTemplate = new RestTemplate();
		restTemplate.getInterceptors().add(new LoggingClientHttpRequestInterceptor());
		return restTemplate;
	}