org.apache.tomcat.util.buf.UEncoder Maven / Gradle / Ivy
/*
* 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.tomcat.util.buf;
import java.io.CharArrayWriter;
import java.io.IOException;
import java.io.Writer;
import java.util.BitSet;
/** Efficient implementation for encoders.
* This class is not thread safe - you need one encoder per thread.
* The encoder will save and recycle the internal objects, avoiding
* garbage.
*
* You can add extra characters that you want preserved, for example
* while encoding a URL you can add "/".
*
* @author Costin Manolache
*/
public final class UEncoder {
private static final org.apache.juli.logging.Log log=
org.apache.juli.logging.LogFactory.getLog(UEncoder.class );
// Not static - the set may differ ( it's better than adding
// an extra check for "/", "+", etc
private BitSet safeChars=null;
private C2BConverter c2b=null;
private ByteChunk bb=null;
private String encoding="UTF8";
public UEncoder() {
initSafeChars();
}
/**
* @deprecated Unused. Will be removed in Tomcat 8.0.x onwards.
*/
@Deprecated
public void setEncoding( String s ) {
encoding=s;
}
public void addSafeCharacter( char c ) {
safeChars.set( c );
}
/** URL Encode string, using a specified encoding.
*
* @param buf The writer
* @param s string to be encoded
* @throws IOException If an I/O error occurs
*/
public void urlEncode( Writer buf, String s )
throws IOException {
if( c2b==null ) {
bb=new ByteChunk(16); // small enough.
c2b=new C2BConverter( bb, encoding );
}
for (int i = 0; i < s.length(); i++) {
int c = s.charAt(i);
if( safeChars.get( c ) ) {
if(log.isDebugEnabled()) {
log.debug("Encoder: Safe: " + (char)c);
}
buf.write((char)c);
} else {
if(log.isDebugEnabled()) {
log.debug("Encoder: Unsafe: " + (char)c);
}
c2b.convert( (char)c );
// "surrogate" - UTF is _not_ 16 bit, but 21 !!!!
// ( while UCS is 31 ). Amazing...
if (c >= 0xD800 && c <= 0xDBFF) {
if ( (i+1) < s.length()) {
int d = s.charAt(i+1);
if (d >= 0xDC00 && d <= 0xDFFF) {
if(log.isDebugEnabled()) {
log.debug("Encoder: Unsafe: " + c);
}
c2b.convert( (char)d);
i++;
}
}
}
c2b.flushBuffer();
urlEncode( buf, bb.getBuffer(), bb.getOffset(),
bb.getLength() );
bb.recycle();
}
}
}
/**
*/
public void urlEncode( Writer buf, byte bytes[], int off, int len)
throws IOException {
for( int j=off; j< len; j++ ) {
buf.write( '%' );
char ch = Character.forDigit((bytes[j] >> 4) & 0xF, 16);
if(log.isDebugEnabled()) {
log.debug("Encoder: Encode: " + ch);
}
buf.write(ch);
ch = Character.forDigit(bytes[j] & 0xF, 16);
if(log.isDebugEnabled()) {
log.debug("Encoder: Encode: " + ch);
}
buf.write(ch);
}
}
/**
* Utility function to re-encode the URL.
* Still has problems with charset, since UEncoder mostly
* ignores it.
*/
public String encodeURL(String uri) {
String outUri=null;
try {
// XXX optimize - recycle, etc
CharArrayWriter out = new CharArrayWriter();
urlEncode(out, uri);
outUri=out.toString();
} catch (IOException iex) {
}
return outUri;
}
// -------------------- Internal implementation --------------------
private void initSafeChars() {
safeChars=new BitSet(128);
int i;
for (i = 'a'; i <= 'z'; i++) {
safeChars.set(i);
}
for (i = 'A'; i <= 'Z'; i++) {
safeChars.set(i);
}
for (i = '0'; i <= '9'; i++) {
safeChars.set(i);
}
//safe
safeChars.set('$');
safeChars.set('-');
safeChars.set('_');
safeChars.set('.');
// Dangerous: someone may treat this as " "
// RFC1738 does allow it, it's not reserved
// safeChars.set('+');
//extra
safeChars.set('!');
safeChars.set('*');
safeChars.set('\'');
safeChars.set('(');
safeChars.set(')');
safeChars.set(',');
}
}