Java Tutorial/Reflection/Class
Содержание
- 1 Class comparator: compare and sort classes and their superclasses.
- 2 Create new instance
- 3 Demonstrates Dynamic class type checking
- 4 Demonstrates fetching nested class info from a Class object
- 5 Demonstrates getting immediate superclass info
- 6 Demonstrates how to get declaration information on a Class
- 7 Demonstrates how to set public field objects
- 8 Demonstrates the use of getDeclaringClass()
- 9 Demonstrates the use of instance comparisons
- 10 Demonstrates usage of various class information methods
- 11 Demonstration of how to obtain instances of java.lang.Class
- 12 Determine whether the supplied string represents a well-formed fully-qualified Java classname.
- 13 Get Canonical Name for a class
- 14 get class from an object
- 15 Get class name for various object
- 16 Is the Same Signature
- 17 Is Type Compatible
- 18 Returns the name of a class without the package name
Class comparator: compare and sort classes and their superclasses.
<source lang="java">
/*
* JCommon : a free general purpose class library for the Java(tm) platform * * * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors. * * Project Info: http://www.jfree.org/jcommon/index.html * * This library is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 of the License, or * (at your option) any later version. * * This library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public * License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, * USA. * * [Java is a trademark or registered trademark of Sun Microsystems, Inc. * in the United States and other countries.] * * -------------------- * ClassComparator.java * -------------------- * (C)opyright 2003-2005, by Thomas Morgner and Contributors. * * Original Author: Thomas Morgner (taquera@sherito.org); * Contributor(s): David Gilbert (for Object Refinery Limited); * * $Id: ClassComparator.java,v 1.3 2005/10/18 13:24:19 mungady Exp $ * * Changes * ------- * 02-May-2003 : Initial version * */
import java.io.Serializable; import java.util.ruparator; /**
* The class comparator can be used to compare and sort classes and their * superclasses. The comparator is not able to compare classes which have no * relation... * * @author Thomas Morgner */
public class ClassComparator implements Comparator, Serializable {
/** For serialization. */
private static final long serialVersionUID = -5225335361837391120L;
/**
* Defaultconstructor.
*/
public ClassComparator() {
super();
}
/**
* Compares its two arguments for order. Returns a negative integer, zero, or
* a positive integer as the first argument is less than, equal to, or greater
* than the second.
*
*
* Note: throws ClassCastException if the arguments" types prevent them from
* being compared by this Comparator. And IllegalArgumentException if the
* classes share no relation.
*
* The implementor must ensure that sgn(compare(x, y)) ==
* -sgn(compare(y, x))
* for all x and y. (This implies that
* compare(x, y) must throw an exception if and only if
* compare(y, x) throws an exception.)
*
*
* The implementor must also ensure that the relation is transitive:
* ((compare(x, y)>0) && (compare(y, z)>0)) implies
* compare(x, z)>0.
*
*
* Finally, the implementer must ensure that compare(x, y)==0
* implies that sgn(compare(x, z))==sgn(compare(y, z)) for all
* z.
*
*
* It is generally the case, but not strictly required that
* (compare(x, y)==0) == (x.equals(y)). Generally speaking, any
* comparator that violates this condition should clearly indicate this fact.
* The recommended language is "Note: this comparator imposes orderings that
* are inconsistent with equals."
*
* @param o1
* the first object to be compared.
* @param o2
* the second object to be compared.
* @return a negative integer, zero, or a positive integer as the first
* argument is less than, equal to, or greater than the second.
*/
public int compare(final Object o1, final Object o2) {
final Class c1 = (Class) o1;
final Class c2 = (Class) o2;
if (c1.equals(o2)) {
return 0;
}
if (c1.isAssignableFrom(c2)) {
return -1;
} else {
if (!c2.isAssignableFrom(c2)) {
throw new IllegalArgumentException("The classes share no relation");
}
return 1;
}
}
/**
* Checks, whether the given classes are comparable. This method will return
* true, if one of the classes is assignable from the other class.
*
* @param c1
* the first class to compare
* @param c2
* the second class to compare
* @return true, if the classes share a direct relation, false otherwise.
*/
public boolean isComparable(final Class c1, final Class c2) {
return (c1.isAssignableFrom(c2) || c2.isAssignableFrom(c1));
}
}</source>
Create new instance
<source lang="java">
public class StringTest {
public static void main(String[] args) {
try {
String pc = String.class.newInstance();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
}</source>
Demonstrates Dynamic class type checking
<source lang="java">
/*
* file: DynamicTypeChecking.java * package: oreilly.hcj.reflection * * This software is granted under the terms of the Common Public License, * CPL, which may be found at the following URL: * http://www-124.ibm.ru/developerworks/oss/CPLv1.0.htm * * Copyright(c) 2003-2005 by the authors indicated in the @author tags. * All Rights are Reserved by the various authors. * ########## DO NOT EDIT ABOVE THIS LINE ########## */
import java.io.Serializable; import java.util.HashSet; import java.util.Iterator; import java.util.Set; /**
* Demonstrates Dynamic class type checking. * * @author * @version $Revision: 1.3 $ */
public class DynamicTypeChecking {
/**
* Demonstrates usage of isAssignableFrom on a class object.
*
* @param dataType
* The data type to check.
*
* @return The value true if the class is a descendant of
* java.lang.Number or false if it isnt.
*/
public static boolean isNumber(final Class dataType) {
return Number.class.isAssignableFrom(dataType);
}
/**
* Demonstration Method.
*
* @param args
* Command Line arguments.
*/
public static void main(final String[] args) {
final Set classes = new HashSet();
classes.add(Class.class);
classes.add(Comparable.class);
classes.add(Serializable.class);
classes.add(Integer.class);
classes.add(int.class);
classes.add(Float[].class);
classes.add(String.class);
classes.add(double[].class);
classes.add(boolean.class);
System.out.println("Using isAssignableFrom:");
useAssignable(classes);
System.out.println("\nUsing isInstance:");
useIsInstance(classes);
}
/**
* Demonstrates use of isAssignableFrom on objects in a set.
*
* @param inputSet
* The set to check.
*/
public static void useAssignable(final Set inputSet) {
final Iterator iter = inputSet.iterator();
Object obj = null;
while (iter.hasNext()) {
obj = iter.next();
if (obj != null) {
if (Number.class.isAssignableFrom(obj.getClass())) {
System.out.println(obj);
}
}
}
}
/**
* Demonstrates usage of isInstance on objects in a set.
*
* @param inputSet
* The set to check.
*/
public static void useIsInstance(final Set inputSet) {
final Iterator iter = inputSet.iterator();
Object obj = null;
while (iter.hasNext()) {
obj = iter.next();
if (Number.class.isInstance(obj)) {
System.out.println(obj);
}
}
}
/**
* Demonstration method for class comparison based on passed class and object.
*
* @param dataType
* The data type to check.
* @param inputSet
* The input set to check.
*
* @throws NullPointerException
* If the data type given is null.
*/
public static void useIsInstance2(final Class dataType, final Set inputSet) {
if (dataType == null) {
throw new NullPointerException();
}
final Iterator iter = inputSet.iterator();
Object obj = null;
while (iter.hasNext()) {
obj = iter.next();
if (dataType.isInstance(obj)) {
System.out.println(obj);
}
}
}
/**
* A bad version of useInstance. If you uncomment this method you will get a
* compiler error.
*/
// public static void useIsInstance3(final Class dataType, final Set inputSet)
// {
// final Iterator iter = inputSet.iterator();
// Object obj = null;
// while (iter.hasNext()) {
// obj = iter.next();
// if (obj instanceof dataType) {
// System.out.println(obj);
// }
// }
// }
} /* ########## End of File ########## */</source>
Demonstrates fetching nested class info from a Class object
<source lang="java">
/*
* file: NestedInfoDemo.java * package: oreilly.hcj.reflection * * This software is granted under the terms of the Common Public License, * CPL, which may be found at the following URL: * http://www-124.ibm.ru/developerworks/oss/CPLv1.0.htm * * Copyright(c) 2003-2005 by the authors indicated in the @author tags. * All Rights are Reserved by the various authors. *
- DO NOT EDIT ABOVE THIS LINE ########## */
import java.util.Arrays; import javax.swing.JTable; /**
* Demonstrates fetching nested class info from a Class object. * * @author * @version $Revision: 1.3 $ */
public class NestedInfoDemo {
/**
* Demo method.
*
* @param args Command line arguments.
*/
public static void main(final String[] args) {
printMemberClasses(JTable.class);
}
/**
* Printo out member information for a class.
*
* @param dataType The class to work with.
*/
public static void printMemberClasses(final Class dataType) {
final Class[] nestedClasses = dataType.getClasses();
final Class[] declaredNestedClasses = dataType.getDeclaredClasses();
final Class[] nestedInterfaces = dataType.getInterfaces();
final Class declaringClass = dataType.getDeclaringClass();
// --
System.out.println("Member Class infor for: " + dataType.getName());
System.out.println("Nested Classes: " + Arrays.asList(nestedClasses));
System.out.println("Declared Nested Classes: "
+ Arrays.asList(declaredNestedClasses));
System.out.println("Interfaces: " + Arrays.asList(nestedInterfaces));
System.out.println("Declaring Class: " + declaringClass);
System.out.println();
}
} /* ########## End of File ########## */</source>
Demonstrates getting immediate superclass info
<source lang="java">
/*
* file: SuperclassInfoDemo.java * package: oreilly.hcj.reflection * * This software is granted under the terms of the Common Public License, * CPL, which may be found at the following URL: * http://www-124.ibm.ru/developerworks/oss/CPLv1.0.htm * * Copyright(c) 2003-2005 by the authors indicated in the @author tags. * All Rights are Reserved by the various authors. *
- DO NOT EDIT ABOVE THIS LINE ########## */
import java.util.Set; import javax.swing.JDialog; /**
* Demonstrates getting immediate superclass info. * * @author * @version $Revision: 1.3 $ */
public class SuperclassInfoDemo {
/**
* Demon method.
*
* @param args Command line arguments.
*/
public static void main(final String[] args) {
System.out.println("JDialog --|> " + JDialog.class.getSuperclass());
System.out.println("Integer --|> " + Integer.class.getSuperclass());
System.out.println("Object --|> " + Object.class.getSuperclass());
System.out.println("int --|> " + int.class.getSuperclass());
System.out.println("int[] --|> " + int[].class.getSuperclass());
System.out.println("Set --|> " + Set.class.getSuperclass());
System.out.println("Comparable --|> " + Comparable.class.getSuperclass());
}
} /* ########## End of File ########## */</source>
Demonstrates how to get declaration information on a Class
<source lang="java">
/*
* file: DeclarationInfoDemo.java * package: oreilly.hcj.reflection * * This software is granted under the terms of the Common Public License, * CPL, which may be found at the following URL: * http://www-124.ibm.ru/developerworks/oss/CPLv1.0.htm * * Copyright(c) 2003-2005 by the authors indicated in the @author tags. * All Rights are Reserved by the various authors. *
- DO NOT EDIT ABOVE THIS LINE ########## */
import java.lang.reflect.Modifier; import java.util.Collection;
/**
* Demonstrates how to get declaration information on a Class. * * @author * @version $Revision: 1.3 $ */
public class DeclarationInfoDemo {
/**
* Demonstration Method.
*
* @param args Command line arguments.
*/
public static void main(final String[] args) {
printModifiers(Object.class);
printModifiers(Float.class);
printModifiers(Collection.class);
printModifiers(int.class);
printModifiers(String.class);
}
/**
* Prints out the modifiers for a class.
*
* @param dataType The class for which to print out modifiers.
*/
public static void printModifiers(final Class dataType) {
final int modifiers = dataType.getModifiers();
if (Modifier.isPrivate(modifiers)) {
System.out.print("private ");
}
if (Modifier.isPrivate(modifiers)) {
System.out.print("private ");
}
if (Modifier.isPublic(modifiers)) {
System.out.print("private ");
}
if (Modifier.isAbstract(modifiers)) {
System.out.print("abstract ");
}
if (Modifier.isFinal(modifiers)) {
System.out.print("final ");
}
if (Modifier.isNative(modifiers)) {
System.out.print("native ");
}
if (Modifier.isInterface(modifiers)) {
System.out.print("interface ");
}
if (Modifier.isStatic(modifiers)) {
System.out.print("static ");
}
if (Modifier.isStrict(modifiers)) {
System.out.print("strict ");
}
if (Modifier.isSynchronized(modifiers)) {
System.out.print("synchronized ");
}
if (Modifier.isTransient(modifiers)) {
System.out.print("transient ");
}
if (Modifier.isVolatile(modifiers)) {
System.out.print("volatile ");
}
System.out.println(dataType.getName());
}
} /* ########## End of File ########## */</source>
Demonstrates how to set public field objects
<source lang="java">
/*
* file: HiddenFieldModification.java * package: oreilly.hcj.reflection * * This software is granted under the terms of the Common Public License, * CPL, which may be found at the following URL: * http://www-124.ibm.ru/developerworks/oss/CPLv1.0.htm * * Copyright(c) 2003-2005 by the authors indicated in the @author tags. * All Rights are Reserved by the various authors. * ########## DO NOT EDIT ABOVE THIS LINE ########## */
import java.lang.reflect.Field; /**
* Demonstrates how to set public field objects. * * @author * @version $Revision: 1.3 $ */
public class HiddenFieldModification {
/**
* Sets all int fields in an object to 0.
*
* @param obj
* The object to operate on.
*
* @throws RuntimeException
* If there is a reflection problem.
*/
public static void initIntFields(final Object obj) {
try {
Field[] fields = obj.getClass().getDeclaredFields();
for (int idx = 0; idx < fields.length; idx++) {
if (fields[idx].getType() == int.class) {
fields[idx].setAccessible(true);
fields[idx].setInt(obj, 0);
}
}
} catch (final IllegalAccessException ex) {
throw new RuntimeException(ex);
}
}
/**
* Demo Method.
*
* @param args
* Command line arguments.
*/
public static final void main(final String[] args) {
Integer value = new Integer("123");
System.out.println("Before: " + value);
initIntFields(value);
System.out.println("After: " + value);
}
} /* ########## End of File ########## */</source>
Demonstrates the use of getDeclaringClass()
<source lang="java">
/*
* file: DeclaringClassDemo.java * package: oreilly.hcj.reflection * * This software is granted under the terms of the Common Public License, * CPL, which may be found at the following URL: * http://www-124.ibm.ru/developerworks/oss/CPLv1.0.htm * * Copyright(c) 2003-2005 by the authors indicated in the @author tags. * All Rights are Reserved by the various authors. *
- DO NOT EDIT ABOVE THIS LINE ########## */
//package oreilly.hcj.reflection; import java.lang.reflect.Method; /**
* Demonstrates the use of getDeclaringClass(). * * @author * @version $Revision: 1.3 $ */
public class DeclaringClassDemo {
/**
* Demo method.
*
* @param args Command line arguments.
*/
public static void main(final String[] args) {
Method[] methods = String.class.getMethods();
for (int idx = 0; idx < methods.length; idx++) {
System.out.println(methods[idx] + " declared by "
+ methods[idx].getDeclaringClass());
}
}
} /* ########## End of File ########## */</source>
Demonstrates the use of instance comparisons
<source lang="java">
/*
* file: InstanceOfDemo.java * package: oreilly.hcj.reflection * * This software is granted under the terms of the Common Public License, * CPL, which may be found at the following URL: * http://www-124.ibm.ru/developerworks/oss/CPLv1.0.htm * * Copyright(c) 2003-2005 by the authors indicated in the @author tags. * All Rights are Reserved by the various authors. * ########## DO NOT EDIT ABOVE THIS LINE ########## */
import java.util.ArrayList; import java.util.Collections; import java.util.HashSet; import java.util.Iterator; import java.util.Set; import javax.swing.JPanel; /**
* Demonstrates the use of instance comparisons. * * @author * @version $Revision: 1.3 $ */
public class InstanceOfDemo {
/** A set of demon objects. */
public static final Set OBJECT_SET;
static {
Set objectSet = new HashSet();
objectSet.add(new Integer(5));
objectSet.add(new String("Hardcore Java"));
objectSet.add(new Float(22.5f));
objectSet.add(new JPanel());
objectSet.add(new Character("x"));
objectSet.add(new ArrayList());
objectSet.add(new Double(354.5676));
objectSet.add(null);
OBJECT_SET = Collections.unmodifiableSet(objectSet);
}
/**
* Demo method.
*
* @param args
* Command Line arguments.
*/
public static void main(final String[] args) {
final Iterator iter = OBJECT_SET.iterator();
Object obj = null;
while (iter.hasNext()) {
obj = iter.next();
if (obj instanceof Number) {
System.out.println(obj);
}
}
}
} /* ########## End of File ########## */</source>
Demonstrates usage of various class information methods
<source lang="java">
/*
* file: ClassInfoDemo.java * package: oreilly.hcj.reflection * * This software is granted under the terms of the Common Public License, * CPL, which may be found at the following URL: * http://www-124.ibm.ru/developerworks/oss/CPLv1.0.htm * * Copyright(c) 2003-2005 by the authors indicated in the @author tags. * All Rights are Reserved by the various authors. *
- DO NOT EDIT ABOVE THIS LINE ########## */
import java.io.Serializable; import java.util.HashSet; import java.util.Iterator; import java.util.Set; /**
* Demonstrates usage of various class information methods. * * @author * @version $Revision: 1.3 $ */
public class ClassInfoDemo {
/**
* Demonstration Method
*
* @param args Demonstration Method.
*/
public static void main(final String[] args) {
final Set classes = new HashSet();
classes.add(Class.class);
classes.add(Comparable.class);
classes.add(Serializable.class);
classes.add(Integer.class);
classes.add(int.class);
classes.add(Float[].class);
classes.add(String.class);
classes.add(double[].class);
classes.add(boolean.class);
// --
System.out.println("Finding interface Class objects in the set.");
Iterator iter = classes.iterator();
while (iter.hasNext()) {
useIsInterface((Class)iter.next());
}
System.out.println("\nFinding primitive Class objects in the set.");
iter = classes.iterator();
while (iter.hasNext()) {
useIsPrimitive((Class)iter.next());
}
System.out.println("\nFinding array Class objects in the set.");
iter = classes.iterator();
while (iter.hasNext()) {
useIsArray((Class)iter.next());
}
}
/**
* Demonstrates usage of isArray from Class.
*
* @param dataType The data type to check.
*
* @throws NullPointerException If the user passes null for dataType.
*/
public static void useIsArray(final Class dataType) {
if (dataType == null) {
throw new NullPointerException();
}
if (dataType.isArray()) {
System.out.print(dataType.getName());
System.out.println("\t ==> " + dataType.getComponentType());
}
}
/**
* Demonstrates usage of isInterface from Class.
*
* @param dataType The data type to check.
*
* @throws NullPointerException If the user passes null for dataType.
*/
public static void useIsInterface(final Class dataType) {
if (dataType == null) {
throw new NullPointerException();
}
if (dataType.isInterface()) {
System.out.println(dataType.getName());
}
}
/**
* Demonstrates usage of isPrimitive from Class.
*
* @param dataType The data type to check.
*
* @throws NullPointerException If the user passes null for dataType.
*/
public static void useIsPrimitive(final Class dataType) {
if (dataType == null) {
throw new NullPointerException();
}
if (dataType.isPrimitive()) {
System.out.println(dataType.getName());
}
}
} /* ########## End of File ########## */</source>
Demonstration of how to obtain instances of java.lang.Class
<source lang="java">
/*
* file: ObtainingClassInstances.java * package: oreilly.hcj.reflection * * This software is granted under the terms of the Common Public License, * CPL, which may be found at the following URL: * http://www-124.ibm.ru/developerworks/oss/CPLv1.0.htm * * Copyright(c) 2003-2005 by the authors indicated in the @author tags. * All Rights are Reserved by the various authors. *
- DO NOT EDIT ABOVE THIS LINE ########## */
/**
* Demonstration of how to obtain instances of java.lang.Class. * * @author * @version $Revision: 1.3 $ */
public class ObtainingClassInstances {
/** An Integer object */
protected static Integer someInteger = new Integer(10);
/** A generic object. */
protected static Object someObject = null;
/** A String. */
protected static String someString = new String("Hardcore Java");
/** An int. */
protected static int someInt = 15;
/** An array of ints. */
protected static int[] intArray = new int[] { 4, 5, 7, 9 };
/**
* Main method.
*
* @param args Command line arguments.
*/
public static void main(final String[] args) {
// -- Print out the Class instances.
System.out.println(someInteger.getClass());
System.out.println(someString.getClass());
System.out.println(intArray.getClass());
System.out.println(Object.class);
System.out.println(Integer.class);
System.out.println(int.class);
System.out.println(String.class);
System.out.println(Comparable.class);
System.out.println(Object[].class);
// -- Things that WON"T work
// System.out.println(someObject.getClass()); // <= Exception
// System.out.println(someInt.getClass()); // <= Compiler errror
}
/**
* Demonstration of a method that doesnt check for null.
*
* @param obj The object passed.
*/
public void writeClass(final Object obj) {
System.out.println(obj.getClass());
}
} /* ########## End of File ########## */</source>
Determine whether the supplied string represents a well-formed fully-qualified Java classname.
<source lang="java">
/*
* JBoss DNA (http://www.jboss.org/dna) * See the COPYRIGHT.txt file distributed with this work for information * regarding copyright ownership. Some portions may be licensed * to Red Hat, Inc. under one or more contributor license agreements. * See the AUTHORS.txt file in the distribution for a full listing of * individual contributors. * * JBoss DNA is free software. Unless otherwise indicated, all code in JBoss DNA * is licensed to you under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * JBoss DNA is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this software; if not, write to the Free * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA, or see the FSF site: http://www.fsf.org. */
import java.text.CharacterIterator; import java.text.StringCharacterIterator;
public class Utils {
/**
* Determine whether the supplied string represents a well-formed fully-qualified Java classname. This utility method enforces
* no conventions (e.g., packages are all lowercase) nor checks whether the class is available on the classpath.
*
* @param classname
* @return true if the string is a fully-qualified class name
*/
public static boolean isFullyQualifiedClassname( String classname ) {
if (classname == null) return false;
String[] parts = classname.split("[\\.]");
if (parts.length == 0) return false;
for (String part : parts) {
CharacterIterator iter = new StringCharacterIterator(part);
// Check first character (there should at least be one character for each part) ...
char c = iter.first();
if (c == CharacterIterator.DONE) return false;
if (!Character.isJavaIdentifierStart(c) && !Character.isIdentifierIgnorable(c)) return false;
c = iter.next();
// Check the remaining characters, if there are any ...
while (c != CharacterIterator.DONE) {
if (!Character.isJavaIdentifierPart(c) && !Character.isIdentifierIgnorable(c)) return false;
c = iter.next();
}
}
return true;
}
}</source>
Get Canonical Name for a class
<source lang="java">
public class GetCanonicalName {
public static void main(String[] args) {
System.out.println(Person.class.getCanonicalName());
}
} //// import javax.ejb.Entity; import javax.ejb.AccessType; import javax.ejb.Id; import javax.ejb.GeneratorType; import java.io.Serializable; @Entity(access = AccessType.FIELD) public class Person implements Serializable {
@Id(generate = GeneratorType.AUTO) Integer id; String name;
}</source>
get class from an object
<source lang="java">
// ClassInfoDemo1.java class ClassInfoDemo1 {
public static void main (String [] args)
{
String s = "";
Class c = s.getClass ();
System.out.println (c.getName ());
c = new ClassInfoDemo1 ().getClass ();
System.out.println (c.getName ());
}
}</source>
Get class name for various object
<source lang="java">
public class GetName {
public static void main(String[] args) {
System.out.println(GetName.class.getName());
System.out.println(int[].class.getName());
System.out.println(GetName[].class.getName());
System.out.println(GetName.class.getPackage());
}
}</source>
Is the Same Signature
<source lang="java">
// //$Id: IntrospectionUtil.java 1540 2007-01-19 12:24:10Z janb $ //Copyright 2006 Mort Bay Consulting Pty. Ltd. //------------------------------------------------------------------------ //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. //
import java.lang.reflect.Method; import java.util.Arrays; import java.util.List; public class Utils {
public static boolean isSameSignature(Method methodA, Method methodB) {
if (methodA == null)
return false;
if (methodB == null)
return false;
List parameterTypesA = Arrays.asList(methodA.getParameterTypes());
List parameterTypesB = Arrays.asList(methodB.getParameterTypes());
if (methodA.getName().equals(methodB.getName()) && parameterTypesA.containsAll(parameterTypesB))
return true;
return false;
}
}</source>
Is Type Compatible
<source lang="java">
// //$Id: IntrospectionUtil.java 1540 2007-01-19 12:24:10Z janb $ //Copyright 2006 Mort Bay Consulting Pty. Ltd. //------------------------------------------------------------------------ //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. //
import java.lang.reflect.Method; import java.util.Arrays; import java.util.List; public class Utils {
public static boolean isTypeCompatible(Class formalType, Class actualType, boolean strict) {
if (formalType == null && actualType != null)
return false;
if (formalType != null && actualType == null)
return false;
if (formalType == null && actualType == null)
return true;
if (strict)
return formalType.equals(actualType);
else
return formalType.isAssignableFrom(actualType);
}
}</source>
Returns the name of a class without the package name
<source lang="java">
public class Utils {
/**
* Returns the name of a class without the package name. For example: if
* input = "java.lang.Object" , then output = "Object".
* @param fully qualified classname
* @return the unqualified classname
*/
public static String getShortClassName(final String className) {
if (className != null) {
final int index = className.lastIndexOf(".");
return className.substring(index + 1);
}
return null;
}
}</source>
