eva2/src/eva2/tools/SerializedObject.java

136 lines
4.0 KiB
Java

package eva2.tools;
import java.io.*;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
/**
* This class stores an object serialized in memory. It allows compression,
* to be used to conserve memory (for example, when storing large strings
* in memory), or can be used as a mechanism for deep copying objects.
*
* @author Holger Ulmer, Felix Streichert, Hannes Planatscher
*/
public class SerializedObject implements Serializable {
/**
* Stores the serialized object
*/
private byte[] serializedBytes;
/**
* True if the object has been compressed during storage
*/
private boolean isCompressed;
/**
* Serializes the supplied object into a byte array without compression.
*
* @param obj the Object to serialize.
* @throws IOException
*/
public SerializedObject(Object obj) throws IOException {
this(obj, false);
}
/**
* Serializes the supplied object into a byte array.
*
* @param obj the Object to serialize.
* @param compress true if the object should be stored compressed.
* @throws IOException
*/
public SerializedObject(Object obj, boolean compress) throws IOException {
isCompressed = compress;
serializedBytes = toByteArray(obj, isCompressed);
}
/**
* Serializes the supplied object to a byte array.
*
* @param obj the Object to serialize
* @param compress true if the object should be compressed.
* @return the byte array containing the serialized object.
* @throws IOException if the object is not Serializable.
*/
protected static byte[] toByteArray(Object obj, boolean compress) throws IOException {
ByteArrayOutputStream bo = new ByteArrayOutputStream();
OutputStream os = bo;
if (compress) {
os = new GZIPOutputStream(os);
}
os = new BufferedOutputStream(os);
ObjectOutputStream oo = new ObjectOutputStream(os);
oo.writeObject(obj);
oo.close();
return bo.toByteArray();
}
/**
* Gets the object stored in this SerializedObject. The object returned
* will be a deep copy of the original stored object.
*
* @return the deserialized Object.
* @throws IOException
* @throws ClassNotFoundException
*/
public Object getObject() throws IOException, ClassNotFoundException {
// try {
InputStream is = new ByteArrayInputStream(serializedBytes);
if (isCompressed) {
is = new GZIPInputStream(is);
}
is = new BufferedInputStream(is);
ObjectInputStream oi = new ObjectInputStream(is);
Object result = oi.readObject();
oi.close();
return result;
}
/**
* Compares this object with another for equality.
*
* @param other the other Object.
* @return true if the objects are equal.
*/
@Override
public final boolean equals(Object other) {
// Check class type
if ((other == null) || !(other.getClass().equals(this.getClass()))) {
return false;
}
// Check serialized length
byte[] os = ((SerializedObject) other).serializedBytes;
if (os.length != serializedBytes.length) {
return false;
}
// Check serialized contents
for (int i = 0; i < serializedBytes.length; i++) {
if (serializedBytes[i] != os[i]) {
return false;
}
}
return true;
}
/**
* Returns a hashcode for this object.
*
* @return the hashcode for this object.
*/
@Override
public final int hashCode() {
return serializedBytes.length;
}
/**
* Returns a text representation of the state of this object.
*
* @return a String representing this object.
*/
@Override
public String toString() {
return (isCompressed ? "Compressed object: " : "Uncompressed object: ")
+ serializedBytes.length + " bytes";
}
}