import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.Map;
import java.util.Optional;import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.lang.Nullable;
import org.springframework.web.client.RestTemplate;import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.NoArgsConstructor;
import lombok.extern.slf4j.Slf4j;/*** Rest客户端* * @author heaven**/
@Builder
@Slf4j
@NoArgsConstructor
@AllArgsConstructor
public class RestClient {/*** 请求方法*/HttpMethod httpMethod;@Builder.DefaultRestTemplate restTemplate = new RestTemplate();public void setCharsets() {List<HttpMessageConverter<?>> list = restTemplate.getMessageConverters();for (HttpMessageConverter<?> httpMessageConverter : list) {if(httpMessageConverter instanceof StringHttpMessageConverter) {((StringHttpMessageConverter) httpMessageConverter).setDefaultCharset(StandardCharsets.UTF_8);}}}/*** 发起rest请求* @param url 请求地址* @param body 请求体，对post，put，delete等有请求体有效，对get无效* @param responseType 设置相应结果绑定对象* @param uriVariables 请求变量，用于组装请求url* @return 响应结果*/public <T> Optional<T> restRequest(String url, @Nullable Object body, Class<T> responseType,Map<String, ?> uriVariables) {T response = null;switch (httpMethod) {case GET:response = restTemplate.getForObject(url, responseType, uriVariables);break;case POST:response = restTemplate.postForObject(url, body, responseType, uriVariables);break;default:log.error("not support method");}return Optional.ofNullable(response);}public String restRequest(String url, String request) {String result = null;/*** 添加headers* 所有请求必须携带* */HttpHeaders requestHeaders = new HttpHeaders();requestHeaders.add("需要携带的头文件", "不需要，可以不写");HttpEntity<String> requestEntity = new HttpEntity<String>(null, requestHeaders);if("post".equals(request)) {result = restTemplate.exchange(url, HttpMethod.POST, requestEntity, String.class).getBody();}if("get".equals(request)) {result = restTemplate.exchange(url, HttpMethod.GET, requestEntity, String.class).getBody();}return result;}
}