Reading files from Amazon S3 directly in a java.net.URL object.

Handler.java

package sun.net.www.protocol.s3;

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLStreamHandler;

import org.jets3t.service.ServiceException;
import org.jets3t.service.impl.rest.httpclient.RestS3Service;
import org.jets3t.service.model.S3Object;
import org.jets3t.service.security.AWSCredentials;

public class Handler extends URLStreamHandler {
	
	protected URLConnection openConnection(URL url) throws IOException {
		
		return new URLConnection(url) {
									
			@Override
			public InputStream getInputStream() throws IOException {

				//aws credentials
				String accessKey = null;
				String secretKey = null;
			
				if (url.getUserInfo() != null) {
					String[] credentials = url.getUserInfo().split("[:]");
					accessKey = credentials[0];
					secretKey = credentials[1];
				}
			
				//bucket
				String bucket = url.getHost().substring(0, url.getHost().indexOf("."));
			
				//key
				String key = url.getPath().substring(1);
				
				try {
					RestS3Service s3Service = new RestS3Service(new AWSCredentials(accessKey, secretKey));
					S3Object s3obj = s3Service.getObject(bucket, key);
					return s3obj.getDataInputStream();
					
				} catch (ServiceException e) {
					throw new IOException(e);
				}
			}
			
			@Override
			public void connect() throws IOException { }

		};		
	}
}

TestS3Url.java

package main;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;
import java.net.URL;
import java.net.URLConnection;

public class TestUrl {
	
	public static void main(String[] args) throws IOException {

		URL url = new URL("s3://<access-key>:<secret-key>@<bucket>.s3.amazonaws.com/<filename>");
		
		URLConnection conn = url.openConnection();
		InputStream is = conn.getInputStream();
		
		if (is != null) {
			
			Writer writer = new StringWriter();
			char[] buffer = new char[1024];
			try {
				Reader reader = new BufferedReader(new InputStreamReader(is, "UTF-8"));
				int n;
				while ((n = reader.read(buffer)) != -1) {
					writer.write(buffer, 0, n);
				}
			} finally {
				is.close();
			}
			
			System.out.println("connected");
			System.out.println(writer.toString());
			
		} else {        
			System.out.println("no-connection");
		}
	}
}