juneau-doc/docs/Topics/07.juneau-rest-server/14.Parsers.html

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Parsers

<p>
	REST resources use the {@link oaj.parser.Parser} API for defining parsers for parsing request
	body content and converting them into POJOs.
</p>
<p>
	The servlet will pick which parser to use by matching the request <l>Content-Type</l> header with the
	media types defined through the {@link oaj.parser.Parser#getMediaTypes()} method.
</p>
<p>
	Parsers can be associated with REST servlets in the following ways:
</p>
<ul>
	<li class='ja'>
		{@link oajr.annotation.RestResource#parsers() RestResource(parsers)} 
		- Annotation on resource Java class.
	<li class='ja'>
		{@link oajr.annotation.RestMethod#parsers() RestMethod(parsers)} 
		- Annotation on resource Java method.
	<li class='jm'>
		{@link oajr.RestContextBuilder#parsers(Class[])} 
		- Programmatic.
</ul>
<p>
	The following are all equivalent ways of defining parsers used by a resource:
</p>
<p class='bpcode w800'>
	<jc>// Option #1 - Defined via annotation.</jc>
	<ja>@RestResource</ja>(parsers={JsonParser.<jk>class</jk>, XmlParser.<jk>class</jk>})
	<jk>public class</jk> MyResource {
		
		<jc>// Option #2 - Defined via builder passed in through resource constructor.</jc>
		<jk>public</jk> MyResource(RestContextBuilder builder) <jk>throws</jk> Exception {
			
			<jc>// Using method on builder.</jc>
			builder.parsers(JsonParser.<jk>class</jk>, XmlParser.<jk>class</jk>);

			<jc>// Same, but use pre-instantiated parsers.</jc>
			builder.parsers(JsonParser.<jsf>DEFAULT</jsf>, XmlParser.<jsf>DEFAULT</jsf>);

			<jc>// Same, but using property.</jc>
			builder.set(<jsf>REST_parsers</jsf>, JsonParser.<jk>class</jk>, XmlParser.<jk>class</jk>);
		}

		<jc>// Option #3 - Defined via builder passed in through init method.</jc>
		<ja>@RestHook</ja>(<jsf>INIT</jsf>)
		<jk>public void</jk> init(RestContextBuilder builder) <jk>throws</jk> Exception {
			builder.parsers(JsonParser.<jk>class</jk>, XmlParser.<jk>class</jk>);
		}

		<jc>// Override at the method level.</jc>
		<ja>@RestMethod</ja>(parsers={HtmlParser.<jk>class</jk>})
		<jk>public</jk> Object myMethod(<ja>@Body</ja> MyPojo myPojo) {
			<jc>// Do something with your parsed POJO.</jc>
		}
	}
</p>
<h5 class='section'>See Also:</h5>
<ul class='doctree'>
	<li class='jf'>{@link oajr.RestContext#REST_parsers}
</ul>