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BaseCharset.java
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BaseCharset.java
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/**
* Copyright (C) 2011 Twitter, Inc.
*
* 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 com.cloudhopper.commons.charset;
import java.util.Arrays;
/**
* Base Charset class implementing common functionality.
*
* @author jlauer
* @author John Woolf (twitter: @jwoolf330 or <a href="http://twitter.com/jwoolf330" target=window>http://twitter.com/jwoolf330</a>)
*/
public abstract class BaseCharset implements Charset {
protected abstract byte[] encodeCharSequence(CharSequence str0);
protected abstract void decodeToBuffer(byte[] bytes, StringBuilder buffer);
/** {@inheritDoc} */
@Deprecated
@Override
public String normalize(CharSequence str0) {
return normalize(false, str0);
}
/** {@inheritDoc} */
@Override
public String normalize(boolean udh, CharSequence str0) {
byte[] bytes = this.encode(udh, str0);
// normalizing a string should never be result in a longer string
StringBuilder buf = new StringBuilder(str0.length());
this.decode(udh, bytes, buf);
return buf.toString();
}
/** {@inheritDoc} */
@Deprecated
@Override
public final void decode(byte[] bytes, StringBuilder buffer) {
decode(false, bytes, buffer);
}
/** {@inheritDoc} */
@Override
public void decode(boolean udh, byte[] bytes, StringBuilder buffer) {
if (bytes == null) {
// append nothing
return;
}
if (udh) {
int udhl = bytes[0] + 1;
buffer.append(new String(Arrays.copyOfRange(bytes, 0, udhl)));
byte[] messageBytes = new byte[bytes.length - udhl];
System.arraycopy(bytes, udhl, messageBytes, 0, messageBytes.length);
decodeToBuffer(messageBytes, buffer);
} else {
decodeToBuffer(bytes, buffer);
}
}
/** {@inheritDoc} */
@Deprecated
@Override
public final byte[] encode(CharSequence str0) {
return encode(false, str0);
}
/** {@inheritDoc} */
@Override
public byte[] encode(boolean udh, CharSequence str0) {
//public final byte[] encode(boolean udh, CharSequence str0) {
if (str0 == null) {
return null;
}
if (udh) {
int udhl = str0.charAt(0) + 1;
CharSequence udhChars = str0.subSequence(0, udhl);
byte[] udhBytes = udhChars.toString().getBytes();
CharSequence message = str0.subSequence(udhl, str0.length());
byte[] messageBytes = encodeCharSequence(message);
byte[] bytes = concatByteArrays(udhBytes, messageBytes);
return bytes;
} else {
return encodeCharSequence(str0);
}
}
private byte[] concatByteArrays(byte[] udhBytes, byte[] messageBytes) {
byte[] bytes = new byte[udhBytes.length + messageBytes.length];
System.arraycopy(udhBytes, 0, bytes, 0, udhBytes.length);
System.arraycopy(messageBytes, 0, bytes, udhBytes.length, messageBytes.length);
return bytes;
}
}