org.apache.maven.shared.utils.xml.XMLEncode Maven / Gradle / Ivy
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package org.apache.maven.shared.utils.xml;
/*
* 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.
*/
import java.io.IOException;
import java.io.StringWriter;
import java.io.Writer;
/**
* Collection of XML encoding/decoding helpers.
* This is all about the special characters & and <, and for attributes
* " and '. These must be encoded/decoded from/to XML.
*/
final class XMLEncode
{
private static final int CDATA_BLOCK_THRESHOLD_LENGTH = 12;
private static final char DEFAULT_QUOTE_CHAR = '"';
/**
* Checks if this text purely consists of the white space characters
* ' ', TAB, NEWLINE.
*/
public static boolean isWhiteSpace( String text )
{
for ( int i = 0; i < text.length(); i++ )
{
char c = text.charAt( i );
if ( !Character.isWhitespace( c ) )
{
return false;
}
}
return true;
}
/**
* Makes any text fit into XML attributes.
*/
public static String xmlEncodeTextForAttribute( String text, char quoteChar )
{
if ( text == null )
{
return null;
}
return xmlEncodeTextAsPCDATA( text, true, quoteChar );
}
/**
* Encodes text as XML in the most suitable way, either CDATA block or PCDATA.
*/
public static String xmlEncodeText( String text )
{
if ( text == null )
{
return null;
}
StringWriter writer = new StringWriter( text.length() * 2 );
xmlEncodeText( text, writer );
return writer.toString();
}
public static void xmlEncodeText( String text, Writer writer )
{
if ( text == null )
{
return;
}
try
{
if ( !needsEncoding( text ) )
{
writer.write( text );
return;
}
else
{
// only encode as cdata if is is longer than CDATA block overhead:
if ( text.length() > CDATA_BLOCK_THRESHOLD_LENGTH )
{
String cdata = xmlEncodeTextAsCDATABlock( text );
if ( cdata != null )
{
writer.write( cdata );
return;
}
}
}
}
catch ( IOException e )
{
throw new RuntimeException( e );
}
// if every thing else fails, do it the save way...
xmlEncodeTextAsPCDATA( text, false, DEFAULT_QUOTE_CHAR, writer );
}
/**
* Encodes any text as PCDATA.
*/
public static String xmlEncodeTextAsPCDATA( String text )
{
if ( text == null )
{
return null;
}
return xmlEncodeTextAsPCDATA( text, false );
}
/**
* Encodes any text as PCDATA.
*
* @param forAttribute if you want
* quotes and apostrophes specially treated for attributes
*/
public static String xmlEncodeTextAsPCDATA( String text, boolean forAttribute )
{
return xmlEncodeTextAsPCDATA( text, forAttribute, DEFAULT_QUOTE_CHAR );
}
/**
* Encodes any text as PCDATA.
*
* @param forAttribute if you want
* quotes and apostrophes specially treated for attributes
* @param quoteChar if this is for attributes this char is used to quote the attribute value
*/
public static String xmlEncodeTextAsPCDATA( String text, boolean forAttribute, char quoteChar )
{
if ( text == null )
{
return null;
}
StringWriter writer = new StringWriter( text.length() * 2 );
xmlEncodeTextAsPCDATA( text, forAttribute, quoteChar, writer );
return writer.toString();
}
public static void xmlEncodeTextAsPCDATA( String text, boolean forAttribute, char quoteChar, Writer n )
{
if ( text == null )
{
return;
}
try
{
char c;
int length = text.length();
if ( forAttribute )
{
n.append( quoteChar );
}
for ( int i = 0; i < length; i++ )
{
c = text.charAt( i );
switch ( c )
{
case '&':
n.append( "&" );
break;
case '<':
n.append( "<" );
break;
case '>': // FIX for sourceforge bug #802520 ("]]>" needs encoding)
n.append( ">" );
break;
case '"':
if ( forAttribute )
{
n.append( """ );
}
else
{
n.append( c );
}
break;
case '\'':
if ( forAttribute )
{
n.append( "'" );
}
else
{
n.append( c );
}
break;
case '\r':
if ( forAttribute )
{
if ( i == ( length - 1 ) || text.charAt( i + 1 ) != '\n' )
{
n.append( "
" );
}
}
else
{
n.append( c );
}
// but skip the \r in \r\n
break;
case '\n':
if ( forAttribute )
{
n.append( "
" );
}
break;
default:
n.append( c );
break;
}
}
if ( forAttribute )
{
n.append( quoteChar );
}
}
catch ( IOException e )
{
throw new RuntimeException( e );
}
}
/**
* Returns string as CDATA block if possible, otherwise null.
*/
public static String xmlEncodeTextAsCDATABlock( String text )
{
if ( text == null )
{
return null;
}
if ( isCompatibleWithCDATABlock( text ) )
{
return "";
}
else
{
return null;
}
}
/**
* Checks if this text needs encoding in order to be represented in XML.
*/
public static boolean needsEncoding( String text )
{
return needsEncoding( text, false );
}
/**
* Checks if this text needs encoding in order to be represented in XML.
*
* Set checkForAttr if you want to check for storability in
* an attribute.
*/
public static boolean needsEncoding( String data, boolean checkForAttr )
{
if ( data == null )
{
return false;
}
char c;
for ( int i = 0; i < data.length(); i++ )
{
c = data.charAt( i );
if ( c == '&' || c == '<' || ( checkForAttr && ( c == '"' || c == '\'' ) ) )
{
return true;
}
}
return false;
}
/**
* Can this text be stored into a CDATA block?
*/
public static boolean isCompatibleWithCDATABlock( String text )
{
return text != null && ( !text.contains( "]]>" ) );
}
/**
* Make CDATA out of possibly encoded PCDATA.
* E.g. make '&' out of '&'
*/
public static String xmlDecodeTextToCDATA( String pcdata )
{
if ( pcdata == null )
{
return null;
}
char c, c1, c2, c3, c4, c5;
StringBuilder n = new StringBuilder( pcdata.length() );
for ( int i = 0; i < pcdata.length(); i++ )
{
c = pcdata.charAt( i );
if ( c == '&' )
{
c1 = lookAhead( 1, i, pcdata );
c2 = lookAhead( 2, i, pcdata );
c3 = lookAhead( 3, i, pcdata );
c4 = lookAhead( 4, i, pcdata );
c5 = lookAhead( 5, i, pcdata );
if ( c1 == 'a' && c2 == 'm' && c3 == 'p' && c4 == ';' )
{
n.append( "&" );
i += 4;
}
else if ( c1 == 'l' && c2 == 't' && c3 == ';' )
{
n.append( "<" );
i += 3;
}
else if ( c1 == 'g' && c2 == 't' && c3 == ';' )
{
n.append( ">" );
i += 3;
}
else if ( c1 == 'q' && c2 == 'u' && c3 == 'o' && c4 == 't' && c5 == ';' )
{
n.append( "\"" );
i += 5;
}
else if ( c1 == 'a' && c2 == 'p' && c3 == 'o' && c4 == 's' && c5 == ';' )
{
n.append( "'" );
i += 5;
}
else
{
n.append( "&" );
}
}
else
{
n.append( c );
}
}
return n.toString();
}
private static char lookAhead( int la, int offset, String data )
{
try
{
return data.charAt( offset + la );
}
catch ( StringIndexOutOfBoundsException e )
{
return 0x0;
}
}
// combine multiple checks in one methods for speed
private static boolean contains( String text, char[] chars )
{
if ( text == null || chars == null || chars.length == 0 )
{
return false;
}
for ( int i = 0; i < text.length(); i++ )
{
char c = text.charAt( i );
for ( char aChar : chars )
{
if ( aChar == c )
{
return true;
}
}
}
return false;
}
}