fix circular dependency between ReflectHelpers and remove all dependencies.

git-svn-id: https://svn.jboss.org/repos/hibernate/core/trunk@16438 1b8cb986-b30d-0410-93ca-fae66ebed9b2

commons-annotations/src/main/java/org/hibernate/annotations/common/util/ReflectHelper.java

@@ -23,8 +23,12 @@
  */
 package org.hibernate.annotations.common.util;
 
-import java.lang.reflect.Method;
 import java.lang.reflect.Member;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+
+import org.hibernate.AssertionFailure;
+import org.hibernate.util.StringHelper;
 
 /**
  * Complete duplication of {@link org.hibernate.util.ReflectHelper}.
@@ -32,47 +36,198 @@ import java.lang.reflect.Member;
  * @author Emmanuel Bernard
  */
 public final class ReflectHelper {
-	public static boolean overridesEquals(Class clazz) {
-		return org.hibernate.util.ReflectHelper.overridesEquals( clazz );
-	}
 
-	public static boolean overridesHashCode(Class clazz) {
+	public static final Class[] NO_PARAM_SIGNATURE = new Class[0];
-		return org.hibernate.util.ReflectHelper.overridesHashCode( clazz );
+	public static final Object[] NO_PARAMS = new Object[0];
-	}
 
-	public static Class classForName(String name) throws ClassNotFoundException {
+	public static final Class[] SINGLE_OBJECT_PARAM_SIGNATURE = new Class[] { Object.class };
-		return ReflectHelper.classForName( name );
-	}
 
-	public static Class classForName(String name, Class caller) throws ClassNotFoundException {
+	private static final Method OBJECT_EQUALS;
-		return org.hibernate.util.ReflectHelper.classForName( name, caller );
+	private static final Method OBJECT_HASHCODE;
-	}
 
-	public static boolean isPublic(Class clazz, Member member) {
+	static {
-		return org.hibernate.util.ReflectHelper.isPublic( clazz, member );
+		Method eq;
+		Method hash;
+		try {
+			eq = extractEqualsMethod( Object.class );
+			hash = extractHashCodeMethod( Object.class );
 		}
-
+		catch ( Exception e ) {
-	public static Object getConstantValue(String name) {
+			throw new AssertionFailure( "Could not find Object.equals() or Object.hashCode()", e );
-		return org.hibernate.util.ReflectHelper.getConstantValue( name );
 		}
-
+		OBJECT_EQUALS = eq;
-	public static boolean isAbstractClass(Class clazz) {
+		OBJECT_HASHCODE = hash;
-		return org.hibernate.util.ReflectHelper.isAbstractClass( clazz );
-	}
-
-	public static boolean isFinalClass(Class clazz) {
-		return org.hibernate.util.ReflectHelper.isFinalClass( clazz );
-	}
-
-	public static Method getMethod(Class clazz, Method method) {
-		return org.hibernate.util.ReflectHelper.getMethod( clazz, method );
 	}
 
 	/**
-	 * Direct instantiation of ReflectHelper disallowed.
+	 * Disallow instantiation of ReflectHelper.
 	 */
 	private ReflectHelper() {
 	}
 
+	/**
+	 * Encapsulation of getting hold of a class's {@link Object#equals equals}  method.
+	 *
+	 * @param clazz The class from which to extract the equals method.
+	 * @return The equals method reference
+	 * @throws NoSuchMethodException Should indicate an attempt to extract equals method from interface.
+	 */
+	public static Method extractEqualsMethod(Class clazz) throws NoSuchMethodException {
+		return clazz.getMethod( "equals", SINGLE_OBJECT_PARAM_SIGNATURE );
+	}
+
+	/**
+	 * Encapsulation of getting hold of a class's {@link Object#hashCode hashCode} method.
+	 *
+	 * @param clazz The class from which to extract the hashCode method.
+	 * @return The hashCode method reference
+	 * @throws NoSuchMethodException Should indicate an attempt to extract hashCode method from interface.
+	 */
+	public static Method extractHashCodeMethod(Class clazz) throws NoSuchMethodException {
+		return clazz.getMethod( "hashCode", NO_PARAM_SIGNATURE );
+	}
+
+	/**
+	 * Determine if the given class defines an {@link Object#equals} override.
+	 *
+	 * @param clazz The class to check
+	 * @return True if clazz defines an equals override.
+	 */
+	public static boolean overridesEquals(Class clazz) {
+		Method equals;
+		try {
+			equals = extractEqualsMethod( clazz );
+		}
+		catch ( NoSuchMethodException nsme ) {
+			return false; //its an interface so we can't really tell anything...
+		}
+		return !OBJECT_EQUALS.equals( equals );
+	}
+
+	/**
+	 * Determine if the given class defines a {@link Object#hashCode} override.
+	 *
+	 * @param clazz The class to check
+	 * @return True if clazz defines an hashCode override.
+	 */
+	public static boolean overridesHashCode(Class clazz) {
+		Method hashCode;
+		try {
+			hashCode = extractHashCodeMethod( clazz );
+		}
+		catch ( NoSuchMethodException nsme ) {
+			return false; //its an interface so we can't really tell anything...
+		}
+		return !OBJECT_HASHCODE.equals( hashCode );
+	}
+
+	/**
+	 * Perform resolution of a class name.
+	 * <p/>
+	 * Here we first check the context classloader, if one, before delegating to
+	 * {@link Class#forName(String, boolean, ClassLoader)} using the caller's classloader
+	 *
+	 * @param name The class name
+	 * @param caller The class from which this call originated (in order to access that class's loader).
+	 * @return The class reference.
+	 * @throws ClassNotFoundException From {@link Class#forName(String, boolean, ClassLoader)}.
+	 */
+	public static Class classForName(String name, Class caller) throws ClassNotFoundException {
+		try {
+			ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader();
+			if ( contextClassLoader != null ) {
+				return contextClassLoader.loadClass( name );
+			}
+		}
+		catch ( Throwable ignore ) {
+		}
+		return Class.forName( name, true, caller.getClassLoader() );
+	}
+
+	/**
+	 * Perform resolution of a class name.
+	 * <p/>
+	 * Same as {@link #classForName(String, Class)} except that here we delegate to
+	 * {@link Class#forName(String)} if the context classloader lookup is unsuccessful.
+	 *
+	 * @param name The class name
+	 * @return The class reference.
+	 * @throws ClassNotFoundException From {@link Class#forName(String)}.
+	 */
+	public static Class classForName(String name) throws ClassNotFoundException {
+		try {
+			ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader();
+			if ( contextClassLoader != null ) {
+				return contextClassLoader.loadClass(name);
+			}
+		}
+		catch ( Throwable ignore ) {
+		}
+		return Class.forName( name );
+	}
+
+	/**
+	 * Is this member publicly accessible.
+	 *
+	 * @param clazz The class which defines the member
+	 * @param member The memeber.
+	 * @return True if the member is publicly accessible, false otherwise.
+	 */
+	public static boolean isPublic(Class clazz, Member member) {
+		return Modifier.isPublic( member.getModifiers() ) && Modifier.isPublic( clazz.getModifiers() );
+	}
+
+	/**
+	 * Resolve a constant to its actual value.
+	 *
+	 * @param name The name
+	 * @return The value
+	 */
+	public static Object getConstantValue(String name) {
+		Class clazz;
+		try {
+			clazz = classForName( org.hibernate.util.StringHelper.qualifier( name ) );
+		}
+		catch ( Throwable t ) {
+			return null;
+		}
+		try {
+			return clazz.getField( StringHelper.unqualify( name ) ).get( null );
+		}
+		catch ( Throwable t ) {
+			return null;
+		}
+	}
+
+	/**
+	 * Determine if the given class is declared abstract.
+	 *
+	 * @param clazz The class to check.
+	 * @return True if the class is abstract, false otherwise.
+	 */
+	public static boolean isAbstractClass(Class clazz) {
+		int modifier = clazz.getModifiers();
+		return Modifier.isAbstract(modifier) || Modifier.isInterface(modifier);
+	}
+
+	/**
+	 * Determine is the given class is declared final.
+	 *
+	 * @param clazz The class to check.
+	 * @return True if the class is final, flase otherwise.
+	 */
+	public static boolean isFinalClass(Class clazz) {
+		return Modifier.isFinal( clazz.getModifiers() );
+	}
+
+	public static Method getMethod(Class clazz, Method method) {
+		try {
+			return clazz.getMethod( method.getName(), method.getParameterTypes() );
+		}
+		catch (Exception e) {
+			return null;
+		}
+	}
+
 }