RestTemplate对象，进行get和post简单用法

如果只是针对纯Rest接口处理的话，我们可以使用restTemplate对象来操作，简单方便，可以不需要手写httpClient代码了。

我们看下基本的用法，如下：

1.getForObject

client:
@RestController
@RequestMapping("restTemp")
public class RestTemplateController {
    @GetMapping("getTest1")
    public void getTest1(){
        String url = "http://具体iP地址/demo/demoTest?name={name}&email={email}";
        Map<String,String> params = new HashMap<>();
        params.put("name","yyc");
        params.put("email","12306");
        RestTemplate restTemplate = new RestTemplate();
        String request = restTemplate.getForObject(url,String.class,params);
        //String request = restTemplate.getForObject(url,String.class,"yyc","email");
        System.out.println(request);
    }
}

server:

@GetMapping(value = "demoTest", produces = MediaType.APPLICATION_JSON_VALUE)
public String demoTest(@RequestParam String name,@RequestParam String email){
        System.out.println(name);
        System.out.println(email);
        return "success";
}

2.getForEntity

client:

@GetMapping("getTest2")
    public void getTest2(){
        String url = "http://具体iP地址:8080/demo/demoTest?name={name}&email={email}";
        HttpHeaders headers = new HttpHeaders();
        headers.set("phone","123456");
        Map<String,Object> params = new HashMap<>();
        params.put("name","yyc");
        params.put("email","12306");
        RestTemplate restTemplate = new RestTemplate();
        HttpEntity httpEntity = new HttpEntity(headers);
        ResponseEntity<String> request = restTemplate.getForEntity(url,String.class,httpEntity,params);
        System.out.println(request.getBody());
    }

server:

@GetMapping(value = "demoTest1", produces = MediaType.APPLICATION_JSON_VALUE)
    public String demoTest1(@RequestParam String name, @RequestParam String email, @RequestHeader String phone){
        System.out.println(name);
        System.out.println(email);
        System.out.println(phone);
        return "success";
    }

3.postForObject

这里的User类是实体类，在此本人不写了，请自行创建 User Entity。

server:

@PostMapping(value = "demoTest2", consumes = MediaType.APPLICATION_JSON_VALUE,produces = MediaType.APPLICATION_JSON_VALUE)
    public String demoTest2(@RequestBody User user, @RequestHeader String phone){
        System.out.println(user.getName());
        System.out.println(user.getEmail());
        System.out.println(phone);
        return "success";
    }

client:

@PostMapping("postTest1")
    public void postTest1() {
        String url = "http://IP:8080/demo/demoTest2";
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);
        headers.set("phone", "123456");
        Map<String, Object> params = new HashMap<>();
        params.put("name", "yyc");
        params.put("email", "12306");
        RestTemplate restTemplate = new RestTemplate();
        HttpEntity httpEntity = new HttpEntity(params,headers);
        ResponseEntity<String> request = restTemplate.postForEntity(url, httpEntity,String.class);
        System.out.println(request.getBody());
    }

当所有传递的数据类型为复杂数据类型： headers.setContentType(MediaType.MULTIPART_FORM_DATA);

并且需要接受的参数不再实体类中进行映射。

MultiValueMap来进行传递。

server:

@PostMapping(value = "demoTest3",produces = MediaType.APPLICATION_JSON_VALUE)
    public String demoTest3(@RequestParam String  name,String email, @RequestHeader String phone){
        System.out.println(name);
        System.out.println(email);
        System.out.println(phone);
        return "success";
    }

client:

@PostMapping("postTest2")
    public void postTest2() {
        String url = "http://ip:8080/demo/demoTest3";
        HttpHeaders headers = new HttpHeaders();
        headers.set("phone", "1234567");
        MultiValueMap<String, Object> params = new LinkedMultiValueMap<>();
        params.add("name", "yyc");
        params.add("email", "123067");
        RestTemplate restTemplate = new RestTemplate();
        HttpEntity httpEntity = new HttpEntity(params, headers);
        ResponseEntity<String> request = restTemplate.postForEntity(url, httpEntity, String.class);
        System.out.println(request.getBody());
    }

既有实体类，又有普通的参数
server:

@PostMapping(value = "demoTest4",produces = MediaType.APPLICATION_JSON_VALUE)
    public String demoTest4(@RequestBody User user,String sex, @RequestHeader String phone){
        System.out.println(user.getName());
        System.out.println(user.getEmail());
        System.out.println(sex);
        System.out.println(phone);
        return "success";
    }

client:

@PostMapping("postTest3")
    public void postTest3() {
        String url = "http://ip:8080/demo/demoTest4?sex={sex}";
        HttpHeaders headers = new HttpHeaders();
        headers.set("phone", "1234567");
        Map<String, Object> params = new HashMap<>();
        params.put("name", "yyc");
        params.put("email", "123067");
        Map<String,Object> other = new HashMap<>();
        other.put("sex","男");
        RestTemplate restTemplate = new RestTemplate();
        HttpEntity httpEntity = new HttpEntity(params, headers);
        ResponseEntity<String> request = restTemplate.postForEntity(url, httpEntity, String.class,other);
        System.out.println(request.getBody());
    }