/* Copyright 2004 The Apache Software Foundation | |
* | |
* Licensed under the Apache License, Version 2.0 (the "License"); | |
* you may not use this file except in compliance with the License. | |
* You may obtain a copy of the License at | |
* | |
* http://www.apache.org/licenses/LICENSE-2.0 | |
* | |
* Unless required by applicable law or agreed to in writing, software | |
* distributed under the License is distributed on an "AS IS" BASIS, | |
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
* See the License for the specific language governing permissions and | |
* limitations under the License. | |
*/ | |
package org.apache.xmlbeans.impl.jam; | |
import java.lang.reflect.Constructor; | |
import java.lang.reflect.Field; | |
import java.lang.reflect.Method; | |
import java.util.Arrays; | |
import java.util.Comparator; | |
/** | |
* <p>Singleton collection of utility methods which can be very useful in | |
* some samples, but not often enough to warrant inclusion in the main | |
* APIs. </p> | |
* | |
* <p>Most of these are here to help you jump from the JClass | |
* hierarchy to the java.lang.reflect hierarchy. This is primarily | |
* useful when you find yourself, for example, wanting to actually invoke | |
* a method represented by a JMethod.</p> | |
* | |
* @author Patrick Calahan <email: pcal-at-bea-dot-com> | |
*/ | |
public class JamUtils { | |
// ======================================================================== | |
// Singleton | |
public static final JamUtils getInstance() { return INSTANCE; } | |
private JamUtils() {} | |
private static final JamUtils INSTANCE = new JamUtils(); | |
// ======================================================================== | |
// Public methods | |
/** | |
* <p>Returns the java.lang.Method on a given | |
* java.lang.Class which is represented by a given JMethod.</p> | |
* | |
* @param containedin Class to be searched for the method. | |
* @return | |
* @throws ClassNotFoundException if one of the paramType classes specified | |
* for this MethodName cannot be loaded from the given class' classloader. | |
* @throws NoSuchMethodException If the named method does not exist on | |
* this class. | |
* @throws IllegalArgumentException if any argument is null | |
*/ | |
public Method getMethodOn(JMethod method, Class containedin) | |
throws NoSuchMethodException, ClassNotFoundException | |
{ | |
if (containedin == null) throw new IllegalArgumentException("null class"); | |
if (method == null) throw new IllegalArgumentException("null method"); | |
Class[] types = null; | |
JParameter[] params = method.getParameters(); | |
if (params != null && params.length > 0) { | |
types = new Class[params.length]; | |
for (int i = 0; i < types.length; i++) { | |
types[i] = loadClass(params[i].getType(),containedin.getClassLoader()); | |
} | |
} | |
return containedin.getMethod(method.getSimpleName(), types); | |
} | |
/** | |
* <p>Returns the java.lang.Method on a given | |
* java.lang.Class which is represented by a given JMethod.</p> | |
* | |
* @param containedin Class to be searched for the ctor. | |
* @return | |
* @throws ClassNotFoundException if one of the paramType classes specified | |
* for this MethodName cannot be loaded from the given class' classloader. | |
* @throws NoSuchMethodException If the named ctor does not exist on | |
* this class. | |
* @throws IllegalArgumentException if any argument is null | |
*/ | |
public Constructor getConstructorOn(JConstructor ctor, Class containedin) | |
throws NoSuchMethodException, ClassNotFoundException | |
{ | |
if (containedin == null) throw new IllegalArgumentException("null class"); | |
if (ctor == null) throw new IllegalArgumentException("null ctor"); | |
Class[] types = null; | |
JParameter[] params = ctor.getParameters(); | |
if (params != null && params.length > 0) { | |
types = new Class[params.length]; | |
for (int i = 0; i < types.length; i++) { | |
types[i] = loadClass(params[i].getType(),containedin.getClassLoader()); | |
} | |
} | |
return containedin.getConstructor(types); | |
} | |
/** | |
* <p>Returns the java.lang.Method on a given | |
* java.lang.Class which is represented by a given JMethod.</p> | |
* | |
* @param containedin Class to be searched for the method. | |
* @return | |
* @throws NoSuchFieldException if the field does not exist on the class. | |
* @throws IllegalArgumentException if any argument is null | |
*/ | |
public Field getFieldOn(JField field, Class containedin) | |
throws NoSuchFieldException | |
{ | |
if (containedin == null) throw new IllegalArgumentException("null class"); | |
if (field == null) throw new IllegalArgumentException("null field"); | |
return containedin.getField(field.getSimpleName()); | |
} | |
/** | |
* <p>Loads the java.lang.Class represented by a given JClass out of a given | |
* classloader.</p> | |
* @return | |
* @throws ClassNotFoundException If the class is not found in the classloader | |
*/ | |
public Class loadClass(JClass clazz, ClassLoader inThisClassloader) | |
throws ClassNotFoundException | |
{ | |
return inThisClassloader.loadClass(clazz.getQualifiedName()); | |
} | |
/** | |
* Sorts the given array in place so that the elements are ordered by | |
* their sourcePosition's line numbers. | |
*/ | |
public void placeInSourceOrder(JElement[] elements) { | |
if (elements == null) throw new IllegalArgumentException("null elements"); | |
Arrays.sort(elements,SOURCE_POSITION_COMPARATOR); | |
} | |
// ======================================================================== | |
// Private | |
private static Comparator SOURCE_POSITION_COMPARATOR = new Comparator() { | |
public int compare(Object o, Object o1) { | |
JSourcePosition p1 = ((JElement)o).getSourcePosition(); | |
JSourcePosition p2 = ((JElement)o1).getSourcePosition(); | |
if (p1 == null) return (p2 == null) ? 0 : -1; | |
if (p2 == null) return 1; | |
return (p1.getLine() < p2.getLine()) ? -1 : | |
(p1.getLine() > p2.getLine()) ? 1 : 0; | |
} | |
}; | |
} |