SpringBoot RestTemplate的几种请求调用

心已赠人 2022-05-21 09:49 200阅读 0赞

## **1.用统一的方法模板进行四种请求：POST,PUT,DELETE,GET** ##

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1 restTemplate.exchange(
    2         String url, 
    3         HttpMethod method,
    4         HttpEntity requestEntity, 
    5         Class responseType, 
    6         Object uriVariables[]
    7     )

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说明：
    1）url: 请求地址；
    2）method: 请求类型(如：POST,PUT,DELETE,GET)；
    3）requestEntity: 请求实体，封装请求头，请求内容
    4）responseType: 响应类型，根据服务接口的返回类型决定
    5）uriVariables: url中参数变量值

例如：

(1)POST请求

1 String reqJsonStr = "{\"code\":\"testCode\", \"group\":\"testGroup\",\"content\":\"testContent\", \"order\":1}";
    2 HttpHeaders headers = new HttpHeaders(); headers.setContentType(MediaType.APPLICATION_JSON);
    3 HttpEntity<String> entity = new HttpEntity<String>(reqJsonStr,headers);
    4 ResponseEntity<Map> resp = restTemplate.exchange(DIC_DATA_URL, HttpMethod.POST, entity, Map.class);

(2)PUT请求

String reqJsonStr = "{\"id\":227,\"code\":\"updateCC\", \"group\":\"UPDATE\",\"content\":\"updateCT\", \"order\":9}";
    HttpHeaders headers = new HttpHeaders();
    headers.setContentType(MediaType.APPLICATION_JSON);
    HttpEntity<String> entity = new HttpEntity<String>(reqJsonStr,headers);
    ResponseEntity<Map> resp = restTemplate.exchange(DIC_DATA_URL, HttpMethod.PUT, entity, Map.class);

(3)DELETE请求

ResponseEntity<Map> resp = restTemplate.exchange(DIC_DATA_URL + "?id={id}", HttpMethod.DELETE, null, Map.class, 227);

(4)GET请求

ResponseEntity<String> results = restTemplate.exchange(url,HttpMethod.GET, null, String.class, params);

## **2.用各种请求对应的专一接口** ##

(1)POST请求

postForObject(String url, Object request, Class responseType, Object uriVariables[]):

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返回数据对象Object，例如：
            DicData data = new DicData();
            data.setCode("cd123"); data.setGroup("TEST"); data.setContent("测试数据"); data.setOrder(5);    
            DicData obj = restTemplate.postForObject(DIC_DATA_URL, data, DicData.class);
    
    
    > 或者
    
    
    
    postForEntity:(String url, Object request, Class responseType, Object uriVariables[])

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返回封装了数据对象的ResponseEntity对象，例如：
     DicData data = new DicData();
     data.setCode("cd123"); data.setGroup("TEST"); data.setContent("测试数据"); data.setOrder(5); 
     ResponseEntity<Map> respEntity = restTemplate.postForEntity(DIC_DATA_URL, data, Map.class);

(2)PUT请求     put(String url, Object request, Object urlVariables[])

例如：
        DicData data = new DicData();
        data.setId(226L); data.setCode("updateCode"); data.setGroup("UPDATE"); 
        data.setContent("测试数据"); data.setOrder(9);      
        restTemplate.put(DIC_DATA_URL, data);

(3)DELETE请求  
  
    delete(String url, Object urlVariables\[\])

例如：
        restTemplate.delete(DIC_DATA_URL + "?id={id}", 222);

(4)GET请求  
  
    getForObject(String url, Class responseType, Object urlVariables\[\])：

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返回请求的结果对象，例如
        Order o = restTemplate.getForObject(Constants.SERVER_URL+"/order?orderCode={orderCode}",
                            Order.class,order.getOrderCode());
    getForEntity(String url, Class responseType, Object urlVariables[])：
    返回封装了数据对象的ResponseEntity对象，例如：
    ResponseEntity<EBTUser> ebtuserResponse = restTemplate.getForEntity(url,EBTUser.class);
    EBTUser user = ebtuserResponse.getBody();

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## **3.GET请求,要返回一些复合数据类型时的处理** ##

(1)返回List类型数据
    
        DicData[] dicResult = restTemplate.getForObject( Constants.SERVER_URL + "/dicDatas/dicData?"
                    + "group={group}", DicData[].class, group);
        List<DicData> list = Arrays.asList(dicResult);

`  或者`

// pass generic information to resttemplate; ParameterizedTypeReference为spring3.2版本后引进的类
        ParameterizedTypeReference<List<DicData>> responseType = new ParameterizedTypeReference<List<DicData>>();
        ResponseEntity<List<DicData>> resp = restTemplate.exchange(Constants.SERVER_URL + "/dicDatas/dicData?group={group}", 
                HttpMethod.GET, null, responseType);
        List<DicData> list = resp.getBody();

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> (2)返回属性中有范型数据的复合对象
    
        比如，分页对象
        ResponseEntity<String> results = restTemplate.exchange(url,HttpMethod.GET, null, String.class, params);
        // 借助com.fasterxml.jackson.databind.ObjectMapper 对象来解析嵌套的json字符串    
        ObjectMapper mapper = new ObjectMapper(); mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        PageInfo<Product> page = mapper.readValue(results.getBody(), new TypeReference<PageInfo<Product>>() { });

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[copycode.gif]: /images/20220521/f9f668d92b6c4621a40100638a47cbc8.png