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Archive for June 2010

Introducing the GAE-AWS SDK for Java

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I’m making what I hope will be a useful release today — a version of the Amazon Web Services SDK for Java that will run from inside of Google App Engine. This wouldn’t work if you simply included the JAR that AWS provides directly into GAE’s WAR, because GAE’s security model doesn’t allow the Apache Commons HTTP Client to create the sockets and low-level networking primitives it requires to establish an HTTP connection; instead, Google requires you to make all connections through its URLFetch utility. This version of the SDK does exactly that, swapping out the Apache HTTP Connection Manager for one that returns URLFetchHttpConnections.

With it, you can make use of the multitude of powerful AWS services (excepting S3, which requires more work before it will integrate properly) from within Google App Engine, making both of these tools significantly more useful. In fact, AWS seems to nicely complement several of Google App Engine’s deficiencies; for example, my original motivation for creating this was to be able to make SimpleDB requests from GAE for a school project I’m working on.

Using it is very simple — just download the full package from its GitHub page, and add all of the JAR files in the package (including the third-party/ directory) to Google App Engine’s war/WEB-INF/lib/ directory, and add them to your build path in Eclipse. Then just use the SDK in the usual fashion! For example, the following lines of code:

		AmazonSimpleDB sdb = new AmazonSimpleDBClient(new PropertiesCredentials("AWSCredentials.properties"));
		sdb.setEndpoint("http://sdb.amazonaws.com");

		String serverInfo = getServletContext().getServerInfo();
		String userAgent = getThreadLocalRequest().getHeader("User-Agent");
		return "Hello, " + input + "!<br><br>I am running " + serverInfo
				+ ".<br><br>It looks like you are using:<br>" + userAgent
				+ ".<br><br>You have " + sdb.listDomains().getDomainNames().size() + " SDB domains.";

turns the usual GWT welcome page into this:

Notice the last line there!

I intend to merge in all upstream changes from the real AWS SDK for Java, of which this is simply a GitHub fork. Please post any issues or questions you have in the GitHub page!

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Written by Adrian Petrescu

June 22, 2010 at 9:38 am

Posted in Development

Tagged with ,

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