title: Instantiate generic type
body: <p>I'm trying to instantiate a new object by Class clazz like this:</p>
  
  <p><strong>Code:</strong></p>
  
  <pre><code>public class EntityType {
      private Map json = null;
      public EntityType(Map json){
          this.json = json;
      }
      public &lt;T&gt; T getAs(Class&lt;T&gt; clazz){
          final Class&lt;T&gt; clz = clazz;
          T obj = null;
          try {
              if (checkMap(json)){
                  obj = clz.newInstance();
              }
          } catch (Exception e){
              if (e instanceof InstantiationException){
                  e.printStackTrace();
              } else if (e instanceof IllegalAccessException){
                  e.printStackTrace();
              } else {
                  e.printStackTrace();
              }
          }
          return obj;
      }
  }
  </code></pre>
  
  <p>This is how I use the code:</p>
  
  <pre><code>EntityType type = new EntityType(map); // map contains values 
  User user = type.getAs(User.class);
  </code></pre>
  
  <p><code>java.lang.InstantiationException</code> is thrown for the above code.</p>
  
  <p>What could be wrong in my code?</p>
  
  <p><strong>Update:</strong></p>
  
  <pre><code>    @Entity(name = "user")
      public class User { 
          @Id 
          private String id;
          @Column
          private String name;
          @Column
          private Long age;
          public User() {}
         // Setters and getter 
     }
  </code></pre>
  
  <p>Full stack trace:</p>
  
  <pre><code>java.lang.InstantiationException: org.goo.AnnotationTest$User
      at java.lang.Class.newInstance0(Class.java:357)
      at java.lang.Class.newInstance(Class.java:325)
      at org.goodb.client.Goo$EntityType.getAs(Goo.java:90)
      at org.goo.AnnotationTest.doTest(AnnotationTest.java:97)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:601)
      at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
      at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
      at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
      at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
      at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
      at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74)
      at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31)
      at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:83)
      at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72)
      at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:231)
      at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
      at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
      at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
      at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
      at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
      at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
      at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
      at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71)
      at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
      at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:174)
      at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
      at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
      at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
      at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
      at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
      at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
  </code></pre>