/*
* 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.commons.lang3;
import java.io.IOException;
import java.io.Writer;
import org.apache.commons.lang3.text.translate.AggregateTranslator;
import org.apache.commons.lang3.text.translate.CharSequenceTranslator;
import org.apache.commons.lang3.text.translate.EntityArrays;
import org.apache.commons.lang3.text.translate.LookupTranslator;
import org.apache.commons.lang3.text.translate.NumericEntityUnescaper;
import org.apache.commons.lang3.text.translate.OctalUnescaper;
import org.apache.commons.lang3.text.translate.UnicodeEscaper;
import org.apache.commons.lang3.text.translate.UnicodeUnescaper;
/**
* <p>Escapes and unescapes {@code String}s for
* Java, Java Script, HTML and XML.</p>
*
* <p>#ThreadSafe#</p>
* @since 2.0
* @version $Id: StringEscapeUtils.java 1148520 2011-07-19 20:53:23Z ggregory $
*/
public class StringEscapeUtils {
/* ESCAPE TRANSLATORS */
/**
* Translator object for escaping Java.
*
* While {@link #escapeJava(String)} is the expected method of use, this
* object allows the Java escaping functionality to be used
* as the foundation for a custom translator.
*
* @since 3.0
*/
public static final CharSequenceTranslator ESCAPE_JAVA =
new LookupTranslator(
new String[][] {
{"\"", "\\\""},
{"\\", "\\\\"},
}).with(
new LookupTranslator(EntityArrays.JAVA_CTRL_CHARS_ESCAPE())
).with(
UnicodeEscaper.outsideOf(32, 0x7f)
);
/**
* Translator object for escaping EcmaScript/JavaScript.
*
* While {@link #escapeEcmaScript(String)} is the expected method of use, this
* object allows the EcmaScript escaping functionality to be used
* as the foundation for a custom translator.
*
* @since 3.0
*/
public static final CharSequenceTranslator ESCAPE_ECMASCRIPT =
new AggregateTranslator(
new LookupTranslator(
new String[][] {
{"'", "\\'"},
{"\"", "\\\""},
{"\\", "\\\\"},
{"/", "\\/"}
}),
new LookupTranslator(EntityArrays.JAVA_CTRL_CHARS_ESCAPE()),
UnicodeEscaper.outsideOf(32, 0x7f)
);
/**
* Translator object for escaping XML.
*
* While {@link #escapeXml(String)} is the expected method of use, this
* object allows the XML escaping functionality to be used
* as the foundation for a custom translator.
*
* @since 3.0
*/
public static final CharSequenceTranslator ESCAPE_XML =
new AggregateTranslator(
new LookupTranslator(EntityArrays.BASIC_ESCAPE()),
new LookupTranslator(EntityArrays.APOS_ESCAPE())
);
/**
* Translator object for escaping HTML version 3.0.
*
* While {@link #escapeHtml3(String)} is the expected method of use, this
* object allows the HTML escaping functionality to be used
* as the foundation for a custom translator.
*
* @since 3.0
*/
public static final CharSequenceTranslator ESCAPE_HTML3 =
new AggregateTranslator(
new LookupTranslator(EntityArrays.BASIC_ESCAPE()),
new LookupTranslator(EntityArrays.ISO8859_1_ESCAPE())
);
/**
* Translator object for escaping HTML version 4.0.
*
* While {@link #escapeHtml4(String)} is the expected method of use, this
* object allows the HTML escaping functionality to be used
* as the foundation for a custom translator.
*
* @since 3.0
*/
public static final CharSequenceTranslator ESCAPE_HTML4 =
new AggregateTranslator(
new LookupTranslator(EntityArrays.BASIC_ESCAPE()),
new LookupTranslator(EntityArrays.ISO8859_1_ESCAPE()),
new LookupTranslator(EntityArrays.HTML40_EXTENDED_ESCAPE())
);
/**
* Translator object for escaping individual Comma Separated Values.
*
* While {@link #escapeCsv(String)} is the expected method of use, this
* object allows the CSV escaping functionality to be used
* as the foundation for a custom translator.
*
* @since 3.0
*/
public static final CharSequenceTranslator ESCAPE_CSV = new CsvEscaper();
// TODO: Create a parent class - 'SinglePassTranslator' ?
// It would handle the index checking + length returning,
// and could also have an optimization check method.
static class CsvEscaper extends CharSequenceTranslator {
private static final char CSV_DELIMITER = ',';
private static final char CSV_QUOTE = '"';
private static final String CSV_QUOTE_STR = String.valueOf(CSV_QUOTE);
private static final char[] CSV_SEARCH_CHARS =
new char[] {CSV_DELIMITER, CSV_QUOTE, CharUtils.CR, CharUtils.LF};
@Override
public int translate(CharSequence input, int index, Writer out) throws IOException {
if(index != 0) {
throw new IllegalStateException("CsvEscaper should never reach the [1] index");
}
if (StringUtils.containsNone(input.toString(), CSV_SEARCH_CHARS)) {
out.write(input.toString());
} else {
out.write(CSV_QUOTE);
out.write(StringUtils.replace(input.toString(), CSV_QUOTE_STR, CSV_QUOTE_STR + CSV_QUOTE_STR));
out.write(CSV_QUOTE);
}
return input.length();
}
}
/* UNESCAPE TRANSLATORS */
/**
* Translator object for unescaping escaped Java.
*
* While {@link #unescapeJava(String)} is the expected method of use, this
* object allows the Java unescaping functionality to be used
* as the foundation for a custom translator.
*
* @since 3.0
*/
// TODO: throw "illegal character: \92" as an Exception if a \ on the end of the Java (as per the compiler)?
public static final CharSequenceTranslator UNESCAPE_JAVA =
new AggregateTranslator(
new OctalUnescaper(), // .between('\1', '\377'),
new UnicodeUnescaper(),
new LookupTranslator(EntityArrays.JAVA_CTRL_CHARS_UNESCAPE()),
new LookupTranslator(
new String[][] {
{"\\\\", "\\"},
{"\\\"", "\""},
{"\\'", "'"},
{"\\", ""}
})
);
/**
* Translator object for unescaping escaped EcmaScript.
*
* While {@link #unescapeEcmaScript(String)} is the expected method of use, this
* object allows the EcmaScript unescaping functionality to be used
* as the foundation for a custom translator.
*
* @since 3.0
*/
public static final CharSequenceTranslator UNESCAPE_ECMASCRIPT = UNESCAPE_JAVA;
/**
* Translator object for unescaping escaped HTML 3.0.
*
* While {@link #unescapeHtml3(String)} is the expected method of use, this
* object allows the HTML unescaping functionality to be used
* as the foundation for a custom translator.
*
* @since 3.0
*/
public static final CharSequenceTranslator UNESCAPE_HTML3 =
new AggregateTranslator(
new LookupTranslator(EntityArrays.BASIC_UNESCAPE()),
new LookupTranslator(EntityArrays.ISO8859_1_UNESCAPE()),
new NumericEntityUnescaper()
);
/**
* Translator object for unescaping escaped HTML 4.0.
*
* While {@link #unescapeHtml4(String)} is the expected method of use, this
* object allows the HTML unescaping functionality to be used
* as the foundation for a custom translator.
*
* @since 3.0
*/
public static final CharSequenceTranslator UNESCAPE_HTML4 =
new AggregateTranslator(
new LookupTranslator(EntityArrays.BASIC_UNESCAPE()),
new LookupTranslator(EntityArrays.ISO8859_1_UNESCAPE()),
new LookupTranslator(EntityArrays.HTML40_EXTENDED_UNESCAPE()),
new NumericEntityUnescaper()
);
/**
* Translator object for unescaping escaped XML.
*
* While {@link #unescapeXml(String)} is the expected method of use, this
* object allows the XML unescaping functionality to be used
* as the foundation for a custom translator.
*
* @since 3.0
*/
public static final CharSequenceTranslator UNESCAPE_XML =
new AggregateTranslator(
new LookupTranslator(EntityArrays.BASIC_UNESCAPE()),
new LookupTranslator(EntityArrays.APOS_UNESCAPE()),
new NumericEntityUnescaper()
);
/**
* Translator object for unescaping escaped Comma Separated Value entries.
*
* While {@link #unescapeCsv(String)} is the expected method of use, this
* object allows the CSV unescaping functionality to be used
* as the foundation for a custom translator.
*
* @since 3.0
*/
public static final CharSequenceTranslator UNESCAPE_CSV = new CsvUnescaper();
static class CsvUnescaper extends CharSequenceTranslator {
private static final char CSV_DELIMITER = ',';
private static final char CSV_QUOTE = '"';
private static final String CSV_QUOTE_STR = String.valueOf(CSV_QUOTE);
private static final char[] CSV_SEARCH_CHARS =
new char[] {CSV_DELIMITER, CSV_QUOTE, CharUtils.CR, CharUtils.LF};
@Override
public int translate(CharSequence input, int index, Writer out) throws IOException {
if(index != 0) {
throw new IllegalStateException("CsvUnescaper should never reach the [1] index");
}
if ( input.charAt(0) != CSV_QUOTE || input.charAt(input.length() - 1) != CSV_QUOTE ) {
out.write(input.toString());
return input.length();
}
// strip quotes
String quoteless = input.subSequence(1, input.length() - 1).toString();
if ( StringUtils.containsAny(quoteless, CSV_SEARCH_CHARS) ) {
// deal with escaped quotes; ie) ""
out.write(StringUtils.replace(quoteless, CSV_QUOTE_STR + CSV_QUOTE_STR, CSV_QUOTE_STR));
} else {
out.write(input.toString());
}
return input.length();
}
}
/* Helper functions */
/**
* <p>{@code StringEscapeUtils} instances should NOT be constructed in
* standard programming.</p>
*
* <p>Instead, the class should be used as:
* <pre>StringEscapeUtils.escapeJava("foo");</pre></p>
*
* <p>This constructor is public to permit tools that require a JavaBean
* instance to operate.</p>
*/
public StringEscapeUtils() {
super();
}
// Java and JavaScript
//--------------------------------------------------------------------------
/**
* <p>Escapes the characters in a {@code String} using Java String rules.</p>
*
* <p>Deals correctly with quotes and control-chars (tab, backslash, cr, ff, etc.) </p>
*
* <p>So a tab becomes the characters {@code '\\'} and
* {@code 't'}.</p>
*
* <p>The only difference between Java strings and JavaScript strings
* is that in JavaScript, a single quote and forward-slash (/) are escaped.</p>
*
* <p>Example:
* <pre>
* input string: He didn't say, "Stop!"
* output string: He didn't say, \"Stop!\"
* </pre>
* </p>
*
* @param input String to escape values in, may be null
* @return String with escaped values, {@code null} if null string input
*/
public static final String escapeJava(String input) {
return ESCAPE_JAVA.translate(input);
}
/**
* <p>Escapes the characters in a {@code String} using EcmaScript String rules.</p>
* <p>Escapes any values it finds into their EcmaScript String form.
* Deals correctly with quotes and control-chars (tab, backslash, cr, ff, etc.) </p>
*
* <p>So a tab becomes the characters {@code '\\'} and
* {@code 't'}.</p>
*
* <p>The only difference between Java strings and EcmaScript strings
* is that in EcmaScript, a single quote and forward-slash (/) are escaped.</p>
*
* <p>Note that EcmaScript is best known by the JavaScript and ActionScript dialects. </p>
*
* <p>Example:
* <pre>
* input string: He didn't say, "Stop!"
* output string: He didn\'t say, \"Stop!\"
* </pre>
* </p>
*
* @param input String to escape values in, may be null
* @return String with escaped values, {@code null} if null string input
*
* @since 3.0
*/
public static final String escapeEcmaScript(String input) {
return ESCAPE_ECMASCRIPT.translate(input);
}
/**
* <p>Unescapes any Java literals found in the {@code String}.
* For example, it will turn a sequence of {@code '\'} and
* {@code 'n'} into a newline character, unless the {@code '\'}
* is preceded by another {@code '\'}.</p>
*
* @param input the {@code String} to unescape, may be null
* @return a new unescaped {@code String}, {@code null} if null string input
*/
public static final String unescapeJava(String input) {
return UNESCAPE_JAVA.translate(input);
}
/**
* <p>Unescapes any EcmaScript literals found in the {@code String}.</p>
*
* <p>For example, it will turn a sequence of {@code '\'} and {@code 'n'}
* into a newline character, unless the {@code '\'} is preceded by another
* {@code '\'}.</p>
*
* @see #unescapeJava(String)
* @param input the {@code String} to unescape, may be null
* @return A new unescaped {@code String}, {@code null} if null string input
*
* @since 3.0
*/
public static final String unescapeEcmaScript(String input) {
return UNESCAPE_ECMASCRIPT.translate(input);
}
// HTML and XML
//--------------------------------------------------------------------------
/**
* <p>Escapes the characters in a {@code String} using HTML entities.</p>
*
* <p>
* For example:
* </p>
* <p><code>"bread" & "butter"</code></p>
* becomes:
* <p>
* <code>"bread" & "butter"</code>.
* </p>
*
* <p>Supports all known HTML 4.0 entities, including funky accents.
* Note that the commonly used apostrophe escape character (')
* is not a legal entity and so is not supported). </p>
*
* @param input the {@code String} to escape, may be null
* @return a new escaped {@code String}, {@code null} if null string input
*
* @see <a href="http://hotwired.lycos.com/webmonkey/reference/special_characters/">ISO Entities</a>
* @see <a href="http://www.w3.org/TR/REC-html32#latin1">HTML 3.2 Character Entities for ISO Latin-1</a>
* @see <a href="http://www.w3.org/TR/REC-html40/sgml/entities.html">HTML 4.0 Character entity references</a>
* @see <a href="http://www.w3.org/TR/html401/charset.html#h-5.3">HTML 4.01 Character References</a>
* @see <a href="http://www.w3.org/TR/html401/charset.html#code-position">HTML 4.01 Code positions</a>
*
* @since 3.0
*/
public static final String escapeHtml4(String input) {
return ESCAPE_HTML4.translate(input);
}
/**
* <p>Escapes the characters in a {@code String} using HTML entities.</p>
* <p>Supports only the HTML 3.0 entities. </p>
*
* @param input the {@code String} to escape, may be null
* @return a new escaped {@code String}, {@code null} if null string input
*
* @since 3.0
*/
public static final String escapeHtml3(String input) {
return ESCAPE_HTML3.translate(input);
}
//-----------------------------------------------------------------------
/**
* <p>Unescapes a string containing entity escapes to a string
* containing the actual Unicode characters corresponding to the
* escapes. Supports HTML 4.0 entities.</p>
*
* <p>For example, the string "<Français>"
* will become "<Français>"</p>
*
* <p>If an entity is unrecognized, it is left alone, and inserted
* verbatim into the result string. e.g. ">&zzzz;x" will
* become ">&zzzz;x".</p>
*
* @param input the {@code String} to unescape, may be null
* @return a new unescaped {@code String}, {@code null} if null string input
*
* @since 3.0
*/
public static final String unescapeHtml4(String input) {
return UNESCAPE_HTML4.translate(input);
}
/**
* <p>Unescapes a string containing entity escapes to a string
* containing the actual Unicode characters corresponding to the
* escapes. Supports only HTML 3.0 entities.</p>
*
* @param input the {@code String} to unescape, may be null
* @return a new unescaped {@code String}, {@code null} if null string input
*
* @since 3.0
*/
public static final String unescapeHtml3(String input) {
return UNESCAPE_HTML3.translate(input);
}
//-----------------------------------------------------------------------
/**
* <p>Escapes the characters in a {@code String} using XML entities.</p>
*
* <p>For example: <tt>"bread" & "butter"</tt> =>
* <tt>"bread" & "butter"</tt>.
* </p>
*
* <p>Supports only the five basic XML entities (gt, lt, quot, amp, apos).
* Does not support DTDs or external entities.</p>
*
* <p>Note that Unicode characters greater than 0x7f are as of 3.0, no longer
* escaped. If you still wish this functionality, you can achieve it
* via the following:
* {@code StringEscapeUtils.ESCAPE_XML.with( NumericEntityEscaper.between(0x7f, Integer.MAX_VALUE) );}</p>
*
* @param input the {@code String} to escape, may be null
* @return a new escaped {@code String}, {@code null} if null string input
* @see #unescapeXml(java.lang.String)
*/
public static final String escapeXml(String input) {
return ESCAPE_XML.translate(input);
}
//-----------------------------------------------------------------------
/**
* <p>Unescapes a string containing XML entity escapes to a string
* containing the actual Unicode characters corresponding to the
* escapes.</p>
*
* <p>Supports only the five basic XML entities (gt, lt, quot, amp, apos).
* Does not support DTDs or external entities.</p>
*
* <p>Note that numerical \\u Unicode codes are unescaped to their respective
* Unicode characters. This may change in future releases. </p>
*
* @param input the {@code String} to unescape, may be null
* @return a new unescaped {@code String}, {@code null} if null string input
* @see #escapeXml(String)
*/
public static final String unescapeXml(String input) {
return UNESCAPE_XML.translate(input);
}
//-----------------------------------------------------------------------
/**
* <p>Returns a {@code String} value for a CSV column enclosed in double quotes,
* if required.</p>
*
* <p>If the value contains a comma, newline or double quote, then the
* String value is returned enclosed in double quotes.</p>
* </p>
*
* <p>Any double quote characters in the value are escaped with another double quote.</p>
*
* <p>If the value does not contain a comma, newline or double quote, then the
* String value is returned unchanged.</p>
* </p>
*
* see <a href="http://en.wikipedia.org/wiki/Comma-separated_values">Wikipedia</a> and
* <a href="http://tools.ietf.org/html/rfc4180">RFC 4180</a>.
*
* @param input the input CSV column String, may be null
* @return the input String, enclosed in double quotes if the value contains a comma,
* newline or double quote, {@code null} if null string input
* @since 2.4
*/
public static final String escapeCsv(String input) {
return ESCAPE_CSV.translate(input);
}
/**
* <p>Returns a {@code String} value for an unescaped CSV column. </p>
*
* <p>If the value is enclosed in double quotes, and contains a comma, newline
* or double quote, then quotes are removed.
* </p>
*
* <p>Any double quote escaped characters (a pair of double quotes) are unescaped
* to just one double quote. </p>
*
* <p>If the value is not enclosed in double quotes, or is and does not contain a
* comma, newline or double quote, then the String value is returned unchanged.</p>
* </p>
*
* see <a href="http://en.wikipedia.org/wiki/Comma-separated_values">Wikipedia</a> and
* <a href="http://tools.ietf.org/html/rfc4180">RFC 4180</a>.
*
* @param input the input CSV column String, may be null
* @return the input String, with enclosing double quotes removed and embedded double
* quotes unescaped, {@code null} if null string input
* @since 2.4
*/
public static final String unescapeCsv(String input) {
return UNESCAPE_CSV.translate(input);
}
}