Home » Author Archives: Gerard Davison

Author Archives: Gerard Davison

Converting string configuration properties to other types, with a bit of Optional

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Somedays you come across some code and think that’s pretty, why didn’t I think of that? So my long time colleague Mark Warner has a nice twist on the standard name/value store pattern using method references to deal with converting from a String. int size = store.getProperty("cache.limit", 500, Integer::parseInt); boolean enabled = store.getProperty("cache.enabled", true, Boolean::getBoolean); I took his example and ...

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Lambda of Lambda, if/else from an Optional

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So I got frustrated with two limitations of the Optional interface in JDK 8. The first problem is that there is no obvious way to perform an else operation in a block as there is only a isPresent method unless you are using an old school if statement. The second problem is of course the old chestnut that even if ...

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Per client cookie handling with Jersey

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A lot of REST services will use cookies as part of the authentication / authorisation scheme. This is a problem because by default the old Jersey client will use the singleton CookieHandler.getDefault which is most cases will be null and if not null will not likely work in a multithreaded server environment. (This is because in the background the default ...

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Declarative Linking in Jersey 2.9 and up

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A couple of weeks ago A couple of months ago I was looking how I was going to engineers new REST API for an Oracle Cloud project. Once of the things I had planned to do was to use the declarative link injection created in Jersey 1.x by Marc Hadley. Sadly this hadn’t been forwarded ported yet, so a quick ...

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Transparent PATCH support in JAX-RS 2.0

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The PATCH method is one the the less well loved HTTP methods simple because until recently there really wasn’t a standard PATCH format. This has been standardized for JSON for a while now so there are quite a few libraries that will do the heavy lifting for you. For the purposes of this blog I am going to use json-patch ...

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