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POWhy grails throwing null pointer exception while accessing hasMany relationship first time?
 

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    <p>I have a strange problem.<br> I have two domain classes <code>User</code> and <code>Post</code> with fields: </p> <pre><code>class User { String name static hasMany = [posts: Post] static constraints = { } } </code></pre> <p>and</p> <pre><code>class Post { String content long date = System.getTimeInMillis() static constraints = { } static belongsTo = [user: User] static mapping = { version: 'false' } } </code></pre> <p>and controller code is: </p> <pre><code>class UserController { def addUser = { def user if (User.count() == 0) { user = new User() user.name = "Manish Zedwal" user.save(flush: true) } else { user = User.get(1) } println "Posts count: " + user.posts.size() render "post count: " + user.posts.size() } } </code></pre> <p>For the first time while accessing url <code>http://localhost:8080/test/user/addUser</code>, it throws null pointer exception, but after this works fine.<br> This is the exception I am getting</p> <pre><code>2011-08-04 15:41:25,847 [http-8080-1] ERROR errors.GrailsExceptionResolver - Exception occurred when processing request: [GET] /test/user/addUser Stacktrace follows: java.lang.NullPointerException: Cannot invoke method size() on null object at test.UserController$_closure2.doCall(UserController.groovy:18) at test.UserController$_closure2.doCall(UserController.groovy) at java.lang.Thread.run(Thread.java:636) </code></pre> <p>and for second time, it prints and renders fine like charm</p> <pre><code>Posts count: 0 </code></pre> <p>In user domain class, coz of <code>hasMany</code> relationship for <code>posts</code>, <code>posts</code> is a list of <code>Post</code> objects then there shouldn't be null pointer exception on getting the size of empty list, rather it should be zero.</p> <p>Any help appreciated </p>
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