Example REST API with Java HTTP

펌 - https://www.ibm.com/support/knowledgecenter/SSBLQQ_8.7.1/com.ibm.rational.rit.ref.doc/topics/r_ritref_rest_api_ex.html

Example of calling REST API with Java HTTP

The following example uses Apache HttpClient v4 to call a REST API.

Example

import java.io.*;
import java.net.*;
import javax.xml.xpath.*;
import org.apache.http.*;
import org.apache.http.client.*;
import org.apache.http.client.methods.*;
import org.apache.http.client.utils.*;
import org.apache.http.entity.*;
import org.apache.http.impl.client.*;
import org.apache.http.util.*;
import org.xml.sax.*;

...

         String stubsApiBaseUri = "http://localhost:7819/RTCP/rest/stubs/";
         String domain = "default";
         String environment = "addNumbers";
         String stubName = "1+1=2";

         HttpClient client = HttpClients.createDefault();

         URIBuilder builder = new URIBuilder(stubsApiBaseUri);
         builder.addParameter("domain", domain);
         builder.addParameter("env", environment);
         builder.addParameter("stub", stubName);
         String listStubsUri = builder.build().toString();
         HttpGet getStubMethod = new HttpGet(listStubsUri);
         HttpResponse getStubResponse = client.execute(getStubMethod);
         int getStubStatusCode = getStubResponse.getStatusLine()
               .getStatusCode();
         if (getStubStatusCode < 200 || getStubStatusCode >= 300) {
            // Handle non-2xx status code
            return;
         }
         String responseBody = EntityUtils
               .toString(getStubResponse.getEntity());
         // Assuming only one stub matches
         String stubRelativeUri = XPathFactory
               .newInstance()
               .newXPath()
               .evaluate("/stubs/stub/@href",
                     new InputSource(new StringReader(responseBody)));
         String stubAbsoluteUri = new URI(stubsApiBaseUri).resolve(
               stubRelativeUri).toString();

         HttpPost startStubMethod = new HttpPost(stubAbsoluteUri);
         ContentType contentType = ContentType.APPLICATION_XML
               .withCharset("utf-8");
         String data = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
               + "<start-stub />";
         startStubMethod.setEntity(new ByteArrayEntity(data
               .getBytes(contentType.getCharset()), contentType));
         HttpResponse startStubResponse = client.execute(startStubMethod);
         int startStubStatusCode = startStubResponse.getStatusLine()
               .getStatusCode();
         if (startStubStatusCode < 200 || startStubStatusCode >= 300) {
            // Handle non-2xx status code
            return;
         }
         // If you want to check the status of the stub that is starting, you
         // can use the response data to get the stub instance URI and poll it
         // for updates
         System.out.println(startStubStatusCode);
         String startStubResponseBody = EntityUtils.toString(startStubResponse
               .getEntity());
         System.out.println(startStubResponseBody);

      } catch (URISyntaxException | IOException | XPathExpressionException e) {
         // Handle errors
      }