Spring/spring-framework
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Moved REST HTTP Method Conversion to View chapter.

Browse Source
This commit is contained in:
Arjen Poutsma
2009-06-16 14:31:42 +00:00
parent 06777c8123
commit e9ac4bc0ad
2 changed files with 52 additions and 45 deletions
Download Patch File Download Diff File Expand all files Collapse all files

53
spring-framework-reference/src/view.xml
View File

@@ -737,6 +737,57 @@ productList.url=/WEB-INF/jsp/productlist.jsp</programlisting>
&lt;/tr&gt;
&lt;/form&gt;</programlisting>
</section>
<section id="rest-method-conversion">
<title>HTTP Method Conversion</title>
<para>A key principle of REST is the use of the Uniform Interface.
This means that all resources (URLs) can be manipulated using the same
four HTTP methods: GET, PUT, POST, and DELETE. For each methods, the
HTTP specification defines the exact semantics. For instance, a GET
should always be a safe operation, meaning that is has no side
effects, and a PUT or DELETE should be idempotent, meaning that you
can repeat these operations over and over again, but the end result
should be the same. While HTTP defines these four methods, HTML only
supports two: GET and POST. Fortunately, there are two possible
workarounds: you can either use JavaScript to do your PUT or DELETE,
or simply do a POST with the 'real' method as an additional parameter
(modeled as a hidden input field in an HTML form). This latter trick
is what Spring's <classname>HiddenHttpMethodFilter</classname> does.
This filter is a plain Servlet Filter and therefore it can be used in
combination with any web framework (not just Spring MVC). Simply add
this filter to your web.xml, and a POST with a hidden _method
parameter will be converted into the corresponding HTTP method
request.</para>
<para>To support HTTP method conversion the Spring MVC form tag was
updated to support setting the HTTP method. For example, the following
snippet taken from the updated Petclinic sample</para>
<programlisting language="xml">&lt;form:form method="delete"&gt;
&lt;p class="submit"&gt;&lt;input type="submit" value="Delete Pet"/&gt;&lt;/p&gt;
&lt;/form:form&gt;</programlisting>
<para>This will actually perform an HTTP POST, with the 'real' DELETE
method hidden behind a request parameter, to be picked up by the
<classname>HiddenHttpMethodFilter</classname>, as defined in web.xml:</para>
<programlisting language="java">&lt;filter&gt;
&lt;filter-name&gt;httpMethodFilter&lt;/filter-name&gt;
&lt;filter-class&gt;org.springframework.web.filter.HiddenHttpMethodFilter&lt;/filter-class&gt;
&lt;/filter&gt;
&lt;filter-mapping&gt;
&lt;filter-name&gt;httpMethodFilter&lt;/filter-name&gt;
&lt;servlet-name&gt;petclinic&lt;/servlet-name&gt;
&lt;/filter-mapping&gt;</programlisting><para>The corresponding @Controller method
is shown below:</para>
<programlisting language="java">@RequestMapping(method = RequestMethod.DELETE)
public String deletePet(@PathVariable int ownerId, @PathVariable int petId) {
this.clinic.deletePet(petId);
return "redirect:/owners/" + ownerId;
}</programlisting>
</section>
</section>
</section>
@@ -2435,7 +2486,7 @@ simpleReport.reportDataKey=myBeanData</programlisting>
</section>
</section>
<section id="rest-feedview">
<section id="view-feeds">
<title>Feed Views</title>
<para>Both <classname>AbstractAtomFeedView</classname> and