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。