一个简单的java对象序列化工具类

/**
* serialized or compressed data.
*
* @author dongjian
*/
@SuppressWarnings("unchecked")
public final class Transcoder {

private static Log log = LogFactory.getLog(Transcoder.class);

protected static String charset = "UTF-8";

private Transcoder() { }

public static <T> T decodeObject(byte[] b) {
return (T) deserialize(decompress(b));
}

public static byte[] encodeObject(Object o) {
byte[] b = serialize(o);
return compress(b);
}

/**
* Decode the string with the current character set.
*/
public static String decodeString(byte[] data) {
String rv = null;
try {
if (data != null) {
rv = new String(data, charset);
}
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
return rv;
}

/**
* Encode a string into the current character set.
*/
public static byte[] encodeString(String in) {
byte[] rv = null;
try {
rv = in.getBytes(charset);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
return rv;
}

/**
* Get the bytes representing the given serialized object.
*/
private static byte[] serialize(Object o) {
if (o == null) {
throw new NullPointerException("Can't serialize null");
}
byte[] rv = null;
ByteArrayOutputStream bos = null;
ObjectOutputStream os = null;
try {
bos = new ByteArrayOutputStream();
os = new ObjectOutputStream(bos);
os.writeObject(o);
os.close();
bos.close();
rv = bos.toByteArray();
} catch (IOException e) {
throw new IllegalArgumentException("Non-serializable object", e);
} finally {
CloseUtil.close(os);
CloseUtil.close(bos);
}
return rv;
}

/**
* Get the object represented by the given serialized bytes.
*/
private static Object deserialize(byte[] in) {
Object rv = null;
ByteArrayInputStream bis = null;
ObjectInputStream is = null;
try {
if (in != null) {
bis = new ByteArrayInputStream(in);
is = new ObjectInputStream(bis);
rv = is.readObject();
is.close();
bis.close();
}
} catch (IOException e) {
log.warn("Caught IOException decoding "
+ (in == null ? 0 : in.length) + " bytes of data", e);
} catch (ClassNotFoundException e) {
log.warn("Caught CNFE decoding " + (in == null ? 0 : in.length)
+ " bytes of data", e);
} finally {
CloseUtil.close(is);
CloseUtil.close(bis);
}
return rv;
}

/**
* Compress the given array of bytes.
*/
private static byte[] compress(byte[] in) {
if (in == null) {
throw new NullPointerException("Can't compress null");
}
ByteArrayOutputStream bos = new ByteArrayOutputStream();
GZIPOutputStream gz = null;
try {
gz = new GZIPOutputStream(bos);
gz.write(in);
} catch (IOException e) {
throw new RuntimeException("IO exception compressing data", e);
} finally {
CloseUtil.close(gz);
CloseUtil.close(bos);
}
byte[] rv = bos.toByteArray();
log.debug("Compressed " + in.length + " bytes to " + rv.length);
return rv;
}

/**
* Decompress the given array of bytes.
*
* @return null if the bytes cannot be decompressed
*/
private static byte[] decompress(byte[] in) {
ByteArrayOutputStream bos = null;
if (in != null) {
ByteArrayInputStream bis = new ByteArrayInputStream(in);
bos = new ByteArrayOutputStream();
GZIPInputStream gis = null;
try {
gis = new GZIPInputStream(bis);

byte[] buf = new byte[8192];
int r = -1;
while ((r = gis.read(buf)) > 0) {
bos.write(buf, 0, r);
}
} catch (IOException e) {
log.warn("Failed to decompress data", e);
bos = null;
} finally {
CloseUtil.close(gis);
CloseUtil.close(bis);
CloseUtil.close(bos);
}
}
return bos == null ? null : bos.toByteArray();
}

private static final class CloseUtil {
private CloseUtil() { }
public static void close(Closeable closeable) {
if (closeable != null) {
try {
closeable.close();
} catch (Exception e) {
log.warn("Unable to close " + e.getMessage(), e);
}
}
}
}

}