Docjar: org/hibernate/bytecode/javassist/ProxyFactoryFactoryImpl.java

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Source code: org/hibernate/bytecode/javassist/ProxyFactoryFactoryImpl.java

1   package org.hibernate.bytecode.javassist;
2   
3   import org.hibernate.bytecode.ProxyFactoryFactory;
4   import org.hibernate.bytecode.BasicProxyFactory;
5   import org.hibernate.proxy.ProxyFactory;
6   import org.hibernate.proxy.pojo.javassist.JavassistProxyFactory;
7   import org.hibernate.AssertionFailure;
8   import org.hibernate.HibernateException;
9   import javassist.util.proxy.MethodFilter;
10  import javassist.util.proxy.ProxyObject;
11  import javassist.util.proxy.MethodHandler;
12  
13  import java.lang.reflect.Method;
14  import java.util.HashMap;
15  
16  /**
17   * A factory for Javassist-based {@link ProxyFactory} instances.
18   *
19   * @author Steve Ebersole
20   */
21  public class ProxyFactoryFactoryImpl implements ProxyFactoryFactory {
22  
23    /**
24     * Builds a Javassist-based proxy factory.
25     *
26     * @return a new Javassist-based proxy factory.
27     */
28    public ProxyFactory buildProxyFactory() {
29      return new JavassistProxyFactory();
30    }
31  
32    public BasicProxyFactory buildBasicProxyFactory(Class superClass, Class[] interfaces) {
33      return new BasicProxyFactoryImpl( superClass, interfaces );
34    }
35  
36    private static class BasicProxyFactoryImpl implements BasicProxyFactory {
37      private final Class proxyClass;
38  
39      public BasicProxyFactoryImpl(Class superClass, Class[] interfaces) {
40        if ( superClass == null && ( interfaces == null || interfaces.length < 1 ) ) {
41          throw new AssertionFailure( "attempting to build proxy without any superclass or interfaces" );
42        }
43        javassist.util.proxy.ProxyFactory factory = new javassist.util.proxy.ProxyFactory();
44        factory.setFilter( FINALIZE_FILTER );
45        if ( superClass != null ) {
46          factory.setSuperclass( superClass );
47        }
48        if ( interfaces != null && interfaces.length > 0 ) {
49          factory.setInterfaces( interfaces );
50        }
51        proxyClass = factory.createClass();
52      }
53  
54      public Object getProxy() {
55        try {
56          ProxyObject proxy = ( ProxyObject ) proxyClass.newInstance();
57          proxy.setHandler( new PassThroughHandler( proxy, proxyClass.getName() ) );
58          return proxy;
59        }
60        catch ( Throwable t ) {
61          throw new HibernateException( "Unable to instantiated proxy instance" );
62        }
63      }
64  
65      public boolean isInstance(Object object) {
66        return proxyClass.isInstance( object );
67      }
68    }
69  
70    private static final MethodFilter FINALIZE_FILTER = new MethodFilter() {
71      public boolean isHandled(Method m) {
72        // skip finalize methods
73        return !( m.getParameterTypes().length == 0 && m.getName().equals( "finalize" ) );
74      }
75    };
76  
77    private static class PassThroughHandler implements MethodHandler {
78      private HashMap data = new HashMap();
79      private final Object proxiedObject;
80      private final String proxiedClassName;
81  
82      public PassThroughHandler(Object proxiedObject, String proxiedClassName) {
83        this.proxiedObject = proxiedObject;
84        this.proxiedClassName = proxiedClassName;
85      }
86  
87      public Object invoke(
88          Object object,
89              Method method,
90              Method method1,
91              Object[] args) throws Exception {
92        String name = method.getName();
93        if ( "toString".equals( name ) ) {
94          return proxiedClassName + "@" + System.identityHashCode( object );
95        }
96        else if ( "equals".equals( name ) ) {
97          return proxiedObject == object ? Boolean.TRUE : Boolean.FALSE;
98        }
99        else if ( "hashCode".equals( name ) ) {
100         return new Integer( System.identityHashCode( object ) );
101       }
102       boolean hasGetterSignature = method.getParameterTypes().length == 0 && method.getReturnType() != null;
103       boolean hasSetterSignature = method.getParameterTypes().length == 1 && ( method.getReturnType() == null || method.getReturnType() == void.class );
104       if ( name.startsWith( "get" ) && hasGetterSignature ) {
105         String propName = name.substring( 3 );
106         return data.get( propName );
107       }
108       else if ( name.startsWith( "is" ) && hasGetterSignature ) {
109         String propName = name.substring( 2 );
110         return data.get( propName );
111       }
112       else if ( name.startsWith( "set" ) && hasSetterSignature) {
113         String propName = name.substring( 3 );
114         data.put( propName, args[0] );
115         return null;
116       }
117       else {
118         // todo : what else to do here?
119         return null;
120       }
121     }
122   }
123 }