Springboot 使用RestTemplate

2023年2月25日07:55:54

最近项目中springboot使用了RestTemplate，在此了解和学习了一下，有问题请指正

创建RestTemplate 

//自创建RestTemplate 
public static RestTemplate restTemplate() {
        SimpleClientHttpRequestFactory requestFactory = new SimpleClientHttpRequestFactory();
        requestFactory.setConnectTimeout(30000);// 设置连接超时，单位毫秒
        requestFactory.setReadTimeout(30000);  //设置读取超时
        RestTemplate restTemplate = new RestTemplate();
        restTemplate.setRequestFactory(requestFactory);
        logger.info("RestTemplate初始化完成");
        return restTemplate;
    }



//使用注解注入
@Autowired
private  RestTemplate restTemplate;

引用的是spring-web-4.3.6.RELEASE.jar

设置请求头HttpHeaders

请求头中常设置的参数是Content-Type，一般用setContentType(MediaType mediaType)方式添加MediaType类中存在的值，或者用add(name，value)的方式添加所需要的值

MediaType类关于具体值的源码如下：

public static final MediaType ALL = valueOf("*/*");
    public static final String ALL_VALUE = "*/*";
    public static final MediaType APPLICATION_ATOM_XML = valueOf("application/atom+xml");
    public static final String APPLICATION_ATOM_XML_VALUE = "application/atom+xml";
    public static final MediaType APPLICATION_FORM_URLENCODED = valueOf("application/x-www-form-urlencoded");
    public static final String APPLICATION_FORM_URLENCODED_VALUE = "application/x-www-form-urlencoded";
    public static final MediaType APPLICATION_JSON = valueOf("application/json");
    public static final String APPLICATION_JSON_VALUE = "application/json";
    public static final MediaType APPLICATION_JSON_UTF8 = valueOf("application/json;charset=UTF-8");
    public static final String APPLICATION_JSON_UTF8_VALUE = "application/json;charset=UTF-8";
    public static final MediaType APPLICATION_OCTET_STREAM = valueOf("application/octet-stream");
    public static final String APPLICATION_OCTET_STREAM_VALUE = "application/octet-stream";
    public static final MediaType APPLICATION_PDF = valueOf("application/pdf");
    public static final String APPLICATION_PDF_VALUE = "application/pdf";
    public static final MediaType APPLICATION_RSS_XML = valueOf("application/rss+xml");
    public static final String APPLICATION_RSS_XML_VALUE = "application/rss+xml";
    public static final MediaType APPLICATION_XHTML_XML = valueOf("application/xhtml+xml");
    public static final String APPLICATION_XHTML_XML_VALUE = "application/xhtml+xml";
    public static final MediaType APPLICATION_XML = valueOf("application/xml");
    public static final String APPLICATION_XML_VALUE = "application/xml";
    public static final MediaType IMAGE_GIF = valueOf("image/gif");
    public static final String IMAGE_GIF_VALUE = "image/gif";
    public static final MediaType IMAGE_JPEG = valueOf("image/jpeg");
    public static final String IMAGE_JPEG_VALUE = "image/jpeg";
    public static final MediaType IMAGE_PNG = valueOf("image/png");
    public static final String IMAGE_PNG_VALUE = "image/png";
    public static final MediaType MULTIPART_FORM_DATA = valueOf("multipart/form-data");
    public static final String MULTIPART_FORM_DATA_VALUE = "multipart/form-data";
    public static final MediaType TEXT_EVENT_STREAM = valueOf("text/event-stream");
    public static final String TEXT_EVENT_STREAM_VALUE = "text/event-stream";
    public static final MediaType TEXT_HTML = valueOf("text/html");
    public static final String TEXT_HTML_VALUE = "text/html";
    public static final MediaType TEXT_MARKDOWN = valueOf("text/markdown");
    public static final String TEXT_MARKDOWN_VALUE = "text/markdown";
    public static final MediaType TEXT_PLAIN = valueOf("text/plain");
    public static final String TEXT_PLAIN_VALUE = "text/plain";
    public static final MediaType TEXT_XML = valueOf("text/xml");
    public static final String TEXT_XML_VALUE = "text/xml";
    private static final String PARAM_QUALITY_FACTOR = "q";

 具体写法如下：

HttpHeaders headers = new HttpHeaders();
//相当于headers.add("Content-Type","application/json;charset=UTF-8");
headers.setContentType(MediaType.APPLICATION_JSON_UTF8);
或者添加MediaType类没有的值
headers.add("Content-Type","application/x-www-form-urlencoded; charset=UTF-8");

post请求

postForEntity

如果请求参数是form-data类型的可以如下写法：

String url = "http://127.0.0.1:8080/login";
LinkedMultiValueMap<String, Object> paramMap = new LinkedMultiValueMap<>();
paramMap.add("username", "zhangsan");
paramMap.add("password", "123456");
paramMap.add("randomStr",String.valueOf(System.currentTimeMillis()));
HttpEntity<LinkedMultiValueMap<String, Object>> httpEntity = new HttpEntity<>(paramMap, requestHeaders);

ResponseEntity<String> exchange = restTemplate.postForEntity(url, httpEntity, String.class);

String resultRemote = exchange.getBody();//得到返回的值

具体的请求参数和返回的参数样例如下：

参数：

｛

username: 张三

password: 123456

randomStr: 1597300142432

｝

返回：

{

"code": 200,

"msg": "操作成功",

"data": {

"token": "dfghjkl",

"username": "张三",

},

"timestamp": 1597299860

}

如果请求参数是json，而且里面还有json数组

Map<String,Object> jsonMap = new HashMap<>();
jsonMap.put("com","ty");
Map<String,Object> deMap = new HashMap<>();
deMap.put("name", "设备");
List<Object> list = new ArrayList<>();
list.add(deMap);
jsonMap.put("des",list);
logger.info("----"+JSONObject.toJSONString(jsonMap));

HttpEntity<String>  httpEntitys = new HttpEntity<>(JSONObject.toJSONString(jsonMap),requestHeader);
ResponseEntity<String> exchanges = restTemplate.postForEntity(url, httpEntitys, String.class);

String resultRemote = exchanges.getBody();
Map stringToMap = JSONObject.parseObject(resultRemote);

例子：

{

    des": [{

            "name": "设备"

         }],

"com": "ty"

}

返回：

{

"code": 200,

"msg": "操作成功",

"data": "567897890-090",

"timestamp": 2367301740

}

 

Get请求

getForEntity请求不带参数，默认请求头

//请求不带参数，默认请求头
String url = "xxx.xx.xx";
ResponseEntity<String> result = restTemplate.getForEntity(url,String.class);

getForEntity请求带参数

//URL作为String
String url = "http://127.0.0.1:8080/login?name={name}";
Map<String,String> map = new HashMap<>();
map.put("name","张三");
ResponseEntity<String> result = restTemplate.getForEntity(url,String.class,map);

//URL作为URI,参数存进URI中
UriComponents uriComponents = UriComponentsBuilder.fromUriString(url).build().expand("李四").encode();
URI uri = uriComponents.toUri();
ResponseEntity<String> result = restTemplate.getForEntity(uri,String.class);


//返回参数也可以是自定义对象例如User
String url = "http://127.0.0.1:8080/login?name={name}";
Map<String,String> map = new HashMap<>();
map.put("name","张三");
ResponseEntity<User> result = restTemplate.getForEntity(url,User.class,map);

get请求带请求头 exchange

HttpHeaders resultRequestHeader = new HttpHeaders();
resultRequestHeader.add("Authorization", "wetyuigyihjj");
resultRequestHeader.add("charset", "UTF-8");
resultRequestHeader.setContentType(MediaType.APPLICATION_JSON);
LinkedMultiValueMap<String, Object> resultParamMap = new LinkedMultiValueMap<>();

HttpEntity<String>  resultHttpEntity = new HttpEntity<>(null, resultRequestHeader);
ResponseEntity<String> exchange = restTemplate.exchange(resultUrl, HttpMethod.GET,resultHttpEntity,String.class);

resultRemote = exchange.getBody();
logger.info("结果resultRemote:"+resultRemote);
Map stringToMap = JSONObject.parseObject(resultRemote);

PUT请求

//put方法的参数和postForEntity方法的参数基本一致
String url = "http://127.0.0.1:8080/login";
Map<String,Object> jsonMap = new HashMap<>();
jsonMap.put("username","admin");
jsonMap.put("password","123456");
HttpEntity<String>  httpEntitys = new HttpEntity<>(JSONObject.toJSONString(jsonMap),requestHeaders);

restTemplate.put(url,httpEntitys,String.class);

 

DELETE 请求

String url = "http://127.0.0.1:8080/get?name={name}";
restTemplate.delete(url,"张三");

 

exchange方法

post请求

String url = "http://127.0.0.1:8080/login";
LinkedMultiValueMap<String, Object> paramMap = new LinkedMultiValueMap<>();
paramMap.add("username", "zhangsan");
paramMap.add("password", "123456");
paramMap.add("randomStr",String.valueOf(System.currentTimeMillis()));
HttpEntity<LinkedMultiValueMap<String, Object>> httpEntity = new HttpEntity<>(paramMap, requestHeaders);

ResponseEntity<String> result = restTemplate.exchange(url, HttpMethod.POST,httpEntitys,String.class);

String resultRemote = exchange.getBody();//得到返回的值
 

get请求

ResponseEntity<String> exchange = restTemplate.exchange(resultUrl, HttpMethod.GET,resultHttpEntity,String.class);

或者

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

 

put请求

String url = "http://127.0.0.1:8080/login";
LinkedMultiValueMap<String, Object> paramMap = new LinkedMultiValueMap<>();
paramMap.add("username", "zhangsan");
paramMap.add("password", "123456");
paramMap.add("randomStr",String.valueOf(System.currentTimeMillis()));
HttpEntity<LinkedMultiValueMap<String, Object>> httpEntity = new HttpEntity<>(paramMap, requestHeaders);

ResponseEntity<String> result = restTemplate.exchange(url, HttpMethod.PUT,httpEntitys,String.class);

delete请求

String url = "http://127.0.0.1:8080/get";
ResponseEntity<String> result = restTemplate.exchange(url + "?id={id}", HttpMethod.DELETE, null, String.class, 56789);

  • 作者：醇醛酸酯
  • 原文链接：https://blog.csdn.net/qq_30938705/article/details/109804221
    更新时间：2023年2月25日07:55:54 ，共 8014 字。