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/*
* util4J - ObjectUtils.java, Oct 4, 2012 6:01:21 PM
*
* Copyright 2012 Varra Ltd, Inc. All rights reserved.
* Varra proprietary/confidential. Use is subject to license terms.
*/
package com.varra.util;
import java.beans.XMLDecoder;
import java.beans.XMLEncoder;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.lang.reflect.Array;
import java.util.Arrays;
import java.util.Collection;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Map;
import com.varra.io.FastByteArrayOutputStream;
/**
* Various object utilities.
*
* @author Rajakrishna V. Reddy
* @version 1.0
*/
public class ObjectUtils
{
/**
* Safely compares two objects just like equals() would, except
* it allows any of the 2 objects to be null.
*
* @param obj1
* the obj1
* @param obj2
* the obj2
* @return true if arguments are equal, otherwise
* false
*/
public static boolean equals(Object obj1, Object obj2)
{
return (obj1 != null) ? (obj1.equals(obj2)) : (obj2 == null);
}
/**
* Compares two objects or two object arrays. Useful for
* {@link Object#equals(Object)}.
*
* @param obj1
* the obj1
* @param obj2
* the obj2
* @return true, if successful
* @see #equals(Object, Object)
*/
public static boolean equalsEx(Object obj1, Object obj2)
{
if (obj1 == null)
{
return (obj2 == null);
}
if (obj2 == null)
{
return false;
}
if (obj1.getClass().isArray())
{
if (obj2.getClass().isArray() == false)
{
return false;
}
return Arrays.equals((Object[]) obj1, (Object[]) obj2);
}
else
{
return obj1.equals(obj2);
}
}
/**
* Non-symmetric utility for comparing the types of two objects. Might be
* useful for {@link Object#equals(Object)} if instanceOf is
* not used.
*
* @param object
* equals() argument
* @param thiz
* current class that overrides equals()
* @return true, if successful
*/
public static boolean equalsType(Object object, Object thiz)
{
return (object != null && thiz != null) && (object.getClass().equals(thiz.getClass()));
}
// ---------------------------------------------------------------- clone
/**
* Clone an object by invoking it's clone() method, even if it
* is not overridden.
*
* @param source
* the source
* @return the object
* @throws CloneNotSupportedException
* the clone not supported exception
*/
public static Object clone(Object source) throws CloneNotSupportedException
{
if (source == null)
{
return null;
}
try
{
return ReflectUtil.invokeDeclared(source, "clone", new Class[] {}, new Object[] {});
}
catch (Exception ex)
{
throw new CloneNotSupportedException("Can't invoke clone() on object due to: " + ex.getMessage());
}
}
/**
* Create object copy using serialization mechanism.
*
* @param obj
* the obj
* @return the object
* @throws IOException
* Signals that an I/O exception has occurred.
* @throws ClassNotFoundException
* the class not found exception
*/
public static Object cloneViaSerialization(Serializable obj) throws IOException, ClassNotFoundException
{
final FastByteArrayOutputStream bytes = new FastByteArrayOutputStream();
ObjectOutputStream out = null;
ObjectInputStream in = null;
Object objCopy = null;
try
{
out = new ObjectOutputStream(bytes);
out.writeObject(obj);
in = new ObjectInputStream(new ByteArrayInputStream(bytes.toByteArray()));
objCopy = in.readObject();
}
finally
{
StreamUtils.close(out);
StreamUtils.close(in);
}
return objCopy;
}
// ----------------------------------------------------------------
// serialization to file
/**
* Write object.
*
* @param dest
* the dest
* @param object
* the object
* @throws IOException
* Signals that an I/O exception has occurred.
* @see #writeObject(java.io.File, Object)
*/
public static void writeObject(String dest, Object object) throws IOException
{
writeObject(new File(dest), object);
}
/**
* Writes serializable object to a file. Existing file will be overwritten.
*
* @param dest
* the dest
* @param object
* the object
* @throws IOException
* Signals that an I/O exception has occurred.
*/
public static void writeObject(File dest, Object object) throws IOException
{
FileOutputStream fos = null;
ObjectOutputStream oos = null;
try
{
fos = new FileOutputStream(dest);
oos = new ObjectOutputStream(new BufferedOutputStream(fos));
oos.writeObject(object);
}
finally
{
StreamUtils.close(fos);
StreamUtils.close(oos);
}
}
/**
* Writes serializable object to a XML file. Existing file will be
* overwritten.
*
* @param dest
* the dest
* @param object
* the object
* @throws IOException
* Signals that an I/O exception has occurred.
*/
public static void writeObjectAsXml(File dest, Object object) throws IOException
{
FileOutputStream fos = null;
XMLEncoder xmlenc = null;
try
{
fos = new FileOutputStream(dest);
xmlenc = new XMLEncoder(new BufferedOutputStream(fos));
xmlenc.writeObject(object);
}
finally
{
StreamUtils.close(fos);
if (xmlenc != null)
{
xmlenc.close();
}
}
}
/**
* Write object as xml.
*
* @param dest
* the dest
* @param object
* the object
* @throws IOException
* Signals that an I/O exception has occurred.
* @see #writeObjectAsXml(java.io.File, Object)
*/
public static void writeObjectAsXml(String dest, Object object) throws IOException
{
writeObjectAsXml(new File(dest), object);
}
/**
* Read object.
*
* @param source
* the source
* @return the object
* @throws IOException
* Signals that an I/O exception has occurred.
* @throws ClassNotFoundException
* the class not found exception
* @see #readObject(java.io.File)
*/
public static Object readObject(String source) throws IOException, ClassNotFoundException
{
return readObject(new File(source));
}
/**
* Reads serialized object from the file.
*
* @param source
* the source
* @return the object
* @throws IOException
* Signals that an I/O exception has occurred.
* @throws ClassNotFoundException
* the class not found exception
*/
public static Object readObject(File source) throws IOException, ClassNotFoundException
{
Object result = null;
FileInputStream fis = null;
ObjectInputStream ois = null;
try
{
fis = new FileInputStream(source);
ois = new ObjectInputStream(new BufferedInputStream(fis));
result = ois.readObject();
}
finally
{
StreamUtils.close(fis);
StreamUtils.close(ois);
}
return result;
}
/**
* Reads serialized object from the XML file.
*
* @param source
* the source
* @return the object
* @throws IOException
* Signals that an I/O exception has occurred.
*/
public static Object readObjectAsXml(File source) throws IOException
{
Object result = null;
FileInputStream fis = null;
XMLDecoder xmldec = null;
try
{
fis = new FileInputStream(source);
xmldec = new XMLDecoder(new BufferedInputStream(fis));
result = xmldec.readObject();
}
finally
{
StreamUtils.close(fis);
if (xmldec != null)
{
xmldec.close();
}
}
return result;
}
/**
* Read object as xml.
*
* @param source
* the source
* @return the object
* @throws IOException
* Signals that an I/O exception has occurred.
* @see #readObjectAsXml(java.io.File)
*/
public static Object readObjectAsXml(String source) throws IOException
{
return readObjectAsXml(new File(source));
}
// ----------------------------------------------------------------
// serialization to byte array
/**
* Serialize an object to byte array.
*
* @param obj
* the obj
* @return the byte[]
* @throws IOException
* Signals that an I/O exception has occurred.
*/
public static byte[] objectToByteArray(Object obj) throws IOException
{
FastByteArrayOutputStream bos = new FastByteArrayOutputStream();
ObjectOutputStream oos = null;
try
{
oos = new ObjectOutputStream(bos);
oos.writeObject(obj);
oos.flush();
}
finally
{
StreamUtils.close(oos);
}
return bos.toByteArray();
}
/**
* De-serialize an object from byte array.
*
* @param data
* the data
* @return the object
* @throws IOException
* Signals that an I/O exception has occurred.
* @throws ClassNotFoundException
* the class not found exception
*/
public static Object byteArrayToObject(byte[] data) throws IOException, ClassNotFoundException
{
Object retObj = null;
final ByteArrayInputStream bais = new ByteArrayInputStream(data);
ObjectInputStream ois = null;
try
{
ois = new ObjectInputStream(bais);
retObj = ois.readObject();
}
finally
{
StreamUtils.close(ois);
}
return retObj;
}
// ---------------------------------------------------------------- misc
/**
* Returns length of the object.
*
* @param obj
* the obj
* @return the int
*/
@SuppressWarnings("rawtypes")
public static int length(Object obj)
{
if (obj == null)
{
return 0;
}
if (obj instanceof String)
{
return ((String) obj).length();
}
if (obj instanceof Collection)
{
return ((Collection) obj).size();
}
if (obj instanceof Map)
{
return ((Map) obj).size();
}
int count;
if (obj instanceof Iterator)
{
Iterator iter = (Iterator) obj;
count = 0;
while (iter.hasNext())
{
count++;
iter.next();
}
return count;
}
if (obj instanceof Enumeration)
{
Enumeration enumeration = (Enumeration) obj;
count = 0;
while (enumeration.hasMoreElements())
{
count++;
enumeration.nextElement();
}
return count;
}
if (obj.getClass().isArray() == true)
{
return Array.getLength(obj);
}
return -1;
}
/**
* Returns true if first argument contains provided element. s
*
* @param obj
* the obj
* @param element
* the element
* @return true, if successful
*/
@SuppressWarnings("rawtypes")
public static boolean containsElement(Object obj, Object element)
{
if (obj == null)
{
return false;
}
if (obj instanceof String)
{
if (element == null)
{
return false;
}
return ((String) obj).indexOf(element.toString()) != -1;
}
if (obj instanceof Collection)
{
return ((Collection) obj).contains(element);
}
if (obj instanceof Map)
{
return ((Map) obj).values().contains(element);
}
if (obj instanceof Iterator)
{
Iterator iter = (Iterator) obj;
while (iter.hasNext())
{
Object o = iter.next();
if (equals(o, element))
{
return true;
}
}
return false;
}
if (obj instanceof Enumeration)
{
Enumeration enumeration = (Enumeration) obj;
while (enumeration.hasMoreElements())
{
Object o = enumeration.nextElement();
if (equals(o, element))
{
return true;
}
}
return false;
}
if (obj.getClass().isArray() == true)
{
int len = Array.getLength(obj);
for (int i = 0; i < len; i++)
{
Object o = Array.get(obj, i);
if (equals(o, element))
{
return true;
}
}
}
return false;
}
/**
*
* Checks if an Object is null.
*
*
*
* {@link ObjectUtils}.isNull(null) = true
*
*
* @param object
* the Object to check, may be null
* @return true if the object is null
*/
public static boolean isNull(Object object)
{
return object == null ? true : false;
}
/**
*
* Checks if an Object is not null.
*
*
*
* {@link ObjectUtils}.isNotNull(null) = false
*
*
* @param object
* the Object to check, may be null
* @return true if the object is not null.
*/
public static boolean isNotNull(Object object)
{
return !isNull(object);
}
/**
*
* Checks if an Object is an instance of the given class.
*
*
*
* {@link ObjectUtils}.isInstanceOf(object, class) = false
*
*
* @param object
* the Object to check, may be instance of class
* @param klass
* the class
* @return true if the object is an instance of the given
* class.
*/
public static boolean isInstanceOf(Object object, Class klass)
{
if (isNotNull(object))
{
return klass.isInstance(object);
}
return false;
}
/**
*
* Checks if an Object is not an instance of the given class.
*
*
*
* {@link ObjectUtils}.isNotInstanceOf(object, class) = false
*
*
* @param object
* the Object to check, may be not an instance of class
* @param klass
* the class
* @return true if the object is an instance of the given
* class.
*/
public static boolean isNotInstanceOf(Object object, Class klass)
{
return !isInstanceOf(object, klass);
}
}