java如何调用rest接口

在Java中调用REST接口通常使用HttpURLConnection或HttpClient来发送HTTP请求并接收响应。以下是一个简单的示例代码：

使用HttpURLConnection：

import java.io.BufferedReader; import java.io.InputStreamReader; import java.net.HttpURLConnection; import java.net.URL;  public class RestClient {      public static void main(String[] args) {         try {             URL url = new URL("http://example.com/api/resource");             HttpURLConnection conn = (HttpURLConnection) url.openConnection();             conn.setRequestMethod("GET");             conn.setRequestProperty("Content-Type", "application/json");              BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));             String inputLine;             StringBuffer response = new StringBuffer();              while ((inputLine = in.readLine()) != null) {                 response.append(inputLine);             }             in.close();              System.out.println(response.toString());         } catch (Exception e) {             e.printStackTrace();         }     } } 

使用HttpClient：

import org.apache.http.HttpResponse; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpGet; import org.apache.http.impl.client.HttpClientBuilder; import org.apache.http.util.EntityUtils;  public class RestClient {      public static void main(String[] args) {         HttpClient httpClient = HttpClientBuilder.create().build();         HttpGet request = new HttpGet("http://example.com/api/resource");         request.addHeader("Content-Type", "application/json");          try {             HttpResponse response = httpClient.execute(request);             String responseBody = EntityUtils.toString(response.getEntity());             System.out.println(responseBody);         } catch (Exception e) {             e.printStackTrace();         }     } } 

上述代码示例使用GET方法调用REST接口，并输出响应内容。根据实际情况，您可能需要修改HTTP方法、请求头或请求体等参数。