This operation retrieves all or some of the objects in a bucket from QueryIO server.
Following code is used to retrieve object from the bucket.
HttpURLConnection object is used to create a GET request with bucketName appended at the end of the URL.
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import org.apache.http.HttpStatus;
public class BucketOperations {
/**
* This program gets objects from the bucket
* @param serverURL: URL of S3 Compatible REST server(http://<S3 server IP> : <S3 server port> /queryio/). For example: http://192.168.0.1:5667/queryio/
* @param token: authorization token.
* @bucketName: Name of the bucket to be retrieved .
*/
public void getBucket(String serverURL, String token, String bucketName)
throws Exception {
URL url = null;
HttpURLConnection httpCon = null;
InputStream is = null;
try {
/* append "/" at end of serverURL */
if (!serverURL.endsWith("/")) {
serverURL = serverURL + "/";
}
url = new URL(serverURL + bucketName); //creates a URL with appending bucket name at end
//Returns a URLConnection object that represents a connection to the remote object referred to by the URL.
httpCon = (HttpURLConnection) url.openConnection();
httpCon.setDoOutput(true); // to use the URL connection for output
httpCon.setRequestMethod("GET"); //GET request is used.
httpCon.setRequestProperty("authorization", token); //Provides token for authorization
httpCon.connect(); //Opens a communications link to the resource reference by the URL
if (httpCon.getResponseCode() == HttpStatus.SC_OK) {
is = httpCon.getInputStream(); //response of GET bucket operation
// Process response here
StringWriter writer = new StringWriter();
IOUtils.copy(is, writer, "UTF-8");
System.out.println(writer.toString()); //Displaying response
}
} finally {
try {
if (is != null)
is.close();
} catch (IOException e) {
e.printStackTrace();
}
if (httpCon != null) {
httpCon.disconnect();
}
}
}
}