/* | |
* Licensed to the Apache Software Foundation (ASF) under one | |
* or more contributor license agreements. See the NOTICE file | |
* distributed with this work for additional information | |
* regarding copyright ownership. The ASF licenses this file | |
* to you 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 org.apache.axis2.datasource.jaxb; | |
import java.io.FilterOutputStream; | |
import java.io.IOException; | |
import java.io.OutputStream; | |
import org.apache.commons.logging.Log; | |
import org.apache.commons.logging.LogFactory; | |
/** | |
* Strip off the BOM when serializing an embedded JAXB object. | |
*/ | |
public class BOMOutputStreamFilter extends FilterOutputStream { | |
private static final Log log = LogFactory.getLog(BOMOutputStreamFilter.class); | |
int count = 0; | |
int bomLength = 2; | |
/** | |
* Create a BOMOutputStreamFilter to remove the BOM (Byte Order Mark) | |
* @param encoding | |
* @param out | |
*/ | |
public BOMOutputStreamFilter(String encoding, OutputStream out) { | |
super(out); | |
if (encoding == null || encoding.equalsIgnoreCase("UTF-8")) { | |
bomLength = 0; | |
} else if (encoding.equalsIgnoreCase("UTF-16")) { | |
// UTF-16LE and UTF-16BE shouldn't have a BOM | |
bomLength = 2; // FF FE or FE FF | |
} else { | |
bomLength = 0; | |
if (log.isDebugEnabled()) { | |
log.debug("Don't know the BOM length for " + encoding + ". assuming zero."); | |
} | |
} | |
if (log.isDebugEnabled()) { | |
log.debug("encoding = " + encoding); | |
log.debug("expected BOM length = " + bomLength); | |
} | |
} | |
@Override | |
public void write(int b) throws IOException { | |
// Don't write the first two characters because they represent the BOM | |
if (count >= bomLength) { | |
out.write(b); | |
} else { | |
if (b == -1 || // 0xFF | |
b == -2) { // 0xFE | |
// skip...this is a BOM character | |
if (log.isDebugEnabled()) { | |
log.debug("Skipping BOM character " + b + " at position " + count); | |
} | |
} else { | |
out.write(b); | |
} | |
} | |
count++; | |
} | |
@Override | |
public void write(byte[] b) throws IOException { | |
// Delegate to our 3 argument write method | |
this.write(b, 0, b.length); | |
} | |
@Override | |
public void write(byte[] b, int off, int len) throws IOException { | |
// Delegate the first couple of bytes to our | |
// single argument write constructor | |
while (count < bomLength && len > 0) { | |
this.write(b[off]); | |
off++; | |
len--; | |
} | |
// Delegate the remaining bytes to the target output stream | |
if (len > 0) { | |
out.write(b, off, len); | |
count = count + len; | |
} | |
} | |
} | |