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/**
* commons - Various Java Utils
* Copyright (C) 2009 Adrian Cristian Ionescu - https://github.com/acionescu
*
* 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 net.segoia.util.strings;
import java.io.IOException;
import java.io.StringWriter;
import java.io.Writer;
import java.util.List;
import net.segoia.util.parser.ParseEventHandlerConfig;
import net.segoia.util.parser.ParseResponse;
import net.segoia.util.parser.Parser;
import net.segoia.util.parser.ParserException;
import net.segoia.util.parser.ParserHandlerFactory;
import net.segoia.util.parser.event.ConfigurableParseEventHandler;
import net.segoia.util.parser.event.DefaultParseEventHandler;
public class StringUtil {
private static Parser unescapeHtmlParser;
private static Parser htmlSanitizer;
static {
unescapeHtmlParser = new Parser();
try {
unescapeHtmlParser
.addSymbols("[,DOC_START:IGNORE_EMPTY,doc_start,true],[&,GROUP_START:SEPARATE,html_escape_start,true,html_escape_end,html_escaper],[;,GROUP_END:UNGROUP,html_escape_end],['{}',WORKER:STRING_CONCAT,string_concat],['{lt=<,gt=>,amp=&,quot=\\\\\\\",apos=\\'}',WORKER:MAPPER,html_escaper]");
} catch (ParserException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
unescapeHtmlParser.setHandlerFactory(new ParserHandlerFactory(new DefaultParseEventHandler()));
unescapeHtmlParser.getParseContextConfig().getNestedSymbols().setCaseInsensitive(true);
htmlSanitizer = new Parser();
try {
htmlSanitizer
.addSymbols("[,DOC_START:IGNORE_EMPTY,doc_start,true],[,GROUP_END,es1],[,GROUP_END,end_tag]");
} catch (ParserException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
htmlSanitizer.setHandlerFactory(new ParserHandlerFactory(new DefaultParseEventHandler()));
htmlSanitizer.getParseContextConfig().getNestedSymbols().setCaseInsensitive(true);
}
/**
*
* Escapes the characters in a String using JavaScript String rules to a Writer.
*
*
*
* A null string input has no effect.
*
*
* @see #escapeJavaScript(java.lang.String)
* @param out
* Writer to write escaped string into
* @param str
* String to escape values in, may be null
* @throws IllegalArgumentException
* if the Writer is null
* @throws IOException
* if error occurs on underlying Writer
**/
public static void escapeJavaScript(Writer out, String str) throws IOException {
escapeJavaStyleString(out, str, true);
}
/**
*
* Worker method for the {@link #escapeJavaScript(String)} method.
*
*
* @param str
* String to escape values in, may be null
* @param escapeSingleQuotes
* escapes single quotes if true
* @return the escaped string
*/
private static String escapeJavaStyleString(String str, boolean escapeSingleQuotes) {
if (str == null) {
return null;
}
try {
StringWriter writer = new StringWriter(str.length() * 2);
escapeJavaStyleString(writer, str, escapeSingleQuotes);
return writer.toString();
} catch (IOException ioe) {
// this should never ever happen while writing to a StringWriter
ioe.printStackTrace();
return null;
}
}
/**
*
* Worker method for the {@link #escapeJavaScript(String)} method.
*
*
* @param out
* write to receieve the escaped string
* @param str
* String to escape values in, may be null
* @param escapeSingleQuote
* escapes single quotes if true
* @throws IOException
* if an IOException occurs
*/
private static void escapeJavaStyleString(Writer out, String str, boolean escapeSingleQuote) throws IOException {
if (out == null) {
throw new IllegalArgumentException("The Writer must not be null");
}
if (str == null) {
return;
}
int sz;
sz = str.length();
for (int i = 0; i < sz; i++) {
char ch = str.charAt(i);
// handle unicode
if (ch > 0xfff) {
out.write("\\u" + hex(ch));
} else if (ch > 0xff) {
out.write("\\u0" + hex(ch));
} else if (ch > 0x7f) {
out.write("\\u00" + hex(ch));
} else if (ch < 32) {
switch (ch) {
case '\b':
out.write('\\');
out.write('b');
break;
case '\n':
out.write('\\');
out.write('n');
break;
case '\t':
out.write('\\');
out.write('t');
break;
case '\f':
out.write('\\');
out.write('f');
break;
case '\r':
out.write('\\');
out.write('r');
break;
default:
if (ch > 0xf) {
out.write("\\u00" + hex(ch));
} else {
out.write("\\u000" + hex(ch));
}
break;
}
} else {
switch (ch) {
case '\'':
if (escapeSingleQuote) {
out.write('\\');
}
out.write('\'');
break;
case '"':
out.write('\\');
out.write('"');
break;
case '\\':
out.write('\\');
out.write('\\');
break;
case '/':
out.write('\\');
out.write('/');
break;
default:
out.write(ch);
break;
}
}
}
}
/**
*
* Unescapes any Java literals found in the String. For example, it will turn a sequence of
* '\' and 'n' into a newline character, unless the '\' is preceded by
* another '\'.
*
*
* @param str
* the String to unescape, may be null
* @return a new unescaped String, null if null string input
*/
public static String unescapeJava(String str) {
if (str == null) {
return null;
}
try {
StringWriter writer = new StringWriter(str.length());
unescapeJava(writer, str);
return writer.toString();
} catch (IOException ioe) {
// this should never ever happen while writing to a StringWriter
ioe.printStackTrace();
return null;
}
}
/**
*
* Unescapes any Java literals found in the String to a Writer.
*
*
*
* For example, it will turn a sequence of '\' and 'n' into a newline character, unless
* the '\' is preceded by another '\'.
*
*
*
* A null string input has no effect.
*
*
* @param out
* the Writer used to output unescaped characters
* @param str
* the String to unescape, may be null
* @throws IllegalArgumentException
* if the Writer is null
* @throws IOException
* if error occurs on underlying Writer
*/
public static void unescapeJava(Writer out, String str) throws IOException {
if (out == null) {
throw new IllegalArgumentException("The Writer must not be null");
}
if (str == null) {
return;
}
int sz = str.length();
StringBuffer unicode = new StringBuffer(4);
boolean hadSlash = false;
boolean inUnicode = false;
for (int i = 0; i < sz; i++) {
char ch = str.charAt(i);
if (inUnicode) {
// if in unicode, then we're reading unicode
// values in somehow
unicode.append(ch);
if (unicode.length() == 4) {
// unicode now contains the four hex digits
// which represents our unicode character
try {
int value = Integer.parseInt(unicode.toString(), 16);
out.write((char) value);
unicode.setLength(0);
inUnicode = false;
hadSlash = false;
} catch (NumberFormatException nfe) {
throw new IOException("Unable to parse unicode value: " + unicode, nfe);
}
}
continue;
}
if (hadSlash) {
// handle an escaped value
hadSlash = false;
switch (ch) {
case '\\':
out.write('\\');
break;
case '\'':
out.write('\'');
break;
case '\"':
out.write('"');
break;
case 'r':
out.write('\r');
break;
case 'f':
out.write('\f');
break;
case 't':
out.write('\t');
break;
case 'n':
out.write('\n');
break;
case 'b':
out.write('\b');
break;
case 'u': {
// uh-oh, we're in unicode country....
inUnicode = true;
break;
}
default:
out.write(ch);
break;
}
continue;
} else if (ch == '\\') {
hadSlash = true;
continue;
}
out.write(ch);
}
if (hadSlash) {
// then we're in the weird case of a \ at the end of the
// string, let's output it anyway.
out.write('\\');
}
}
/**
*
* Returns an upper case hexadecimal String for the given character.
*
*
* @param ch
* The character to convert.
* @return An upper case hexadecimal String
*/
private static String hex(char ch) {
return Integer.toHexString(ch).toUpperCase();
}
public static String escapeString(String input, String outputCharsToBeEscaped, String outputEscapeChar) {
StringBuffer in = new StringBuffer(input);
for (int i = 0; i < outputCharsToBeEscaped.length(); i++) {
char c = outputCharsToBeEscaped.charAt(i);
StringBuffer out = new StringBuffer();
replace(in, c, outputEscapeChar + c, out);
in = out;
}
return in.toString();
}
public static void replace(StringBuffer input, char what, String with, StringBuffer sb) {
for (int i = 0; i < input.length(); i++) {
char c = input.charAt(i);
if (c == what) {
sb.append(with);
} else {
sb.append(c);
}
}
}
public static String escapeHtml(String input) {
StringBuffer sb = new StringBuffer();
for (int i = 0; i < input.length(); i++) {
char c = input.charAt(i);
switch (c) {
case '<':
sb.append("<");
break;
case '>':
sb.append(">");
break;
case '&':
sb.append("&");
break;
default:
sb.append(c);
break;
}
}
return sb.toString();
}
public static String unescapeHtml(String input) {
try {
ParseResponse result = unescapeHtmlParser.parse(input);
StringBuffer resp = new StringBuffer();
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