Change svn project to java project in Eclipse

I checked out a project from subversion repository using Eclipse (3.4.1 ganymede). I chose to check it out into a new Eclipse project, but it turned out to be a non-java, svn project was created. In the project properties, there is no associated builder. Its .project file looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<projectDescription>
 <name>project1</name>
 <comment>project1</comment>
 <projects>
 </projects>
 <buildSpec>
 </buildSpec>
 <natures>
 </natures>
</projectDescription>

Now I want to turn it into a java project so it can be built with a java builder. I tried a few menus and other places inside Eclipse to no avail. Then I found I can just edit .project file, and that did the trick. Close Eclipse before doing these manual editing.

$HOME/workspace/project1/.project:
----------------------------------
<?xml version="1.0" encoding="UTF-8"?>
<projectDescription>
 <name>project1</name>
 <comment>project1</comment>
 <projects>
 </projects>
 <buildSpec>
  <buildCommand>
   <name>org.eclipse.jdt.core.javabuilder</name>
   <arguments>
   </arguments>
  </buildCommand>
 </buildSpec>
 <natures>
  <nature>org.eclipse.jdt.core.javanature</nature>
 </natures>
</projectDescription>

I also added a .classpath file:

$HOME/workspace/project1/.classpath:
-----------------------------------
<?xml version="1.0" encoding="UTF-8"?>
<classpath>
 <classpathentry kind="src" path="src"/>
 <classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER"/>
       <!-- change the default bin directory to classes directory -->
 <classpathentry kind="output" path="classes"/>
</classpath>

Finally, start Eclipse, open project1, and modify its source path, libraries, and other project properties.