org.apache.sling.scripting.sightly.java.compiler.JavaEscapeUtils 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.sling.scripting.sightly.java.compiler;
import java.util.HashSet;
import java.util.Set;
import org.apache.commons.lang3.StringUtils;
/**
* The {@code JavaEscapeUtils} provides useful methods for escaping or transforming invalid Java tokens to valid ones that could be used in
* generated Java source code.
*/
public class JavaEscapeUtils {
private static final Set javaKeywords = new HashSet() {{
add("abstract");
add("assert");
add("boolean");
add("break");
add("byte");
add("case");
add("catch");
add("char");
add("class");
add("const");
add("continue");
add("default");
add("do");
add("double");
add("else");
add("enum");
add("extends");
add("final");
add("finally");
add("float");
add("for");
add("goto");
add("if");
add("implements");
add("import");
add("instanceof");
add("int");
add("interface");
add("long");
add("native");
add("new");
add("package");
add("private");
add("protected");
add("public");
add("return");
add("short");
add("static");
add("strictfp");
add("super");
add("switch");
add("synchronized");
add("this");
add("throw");
add("throws");
add("transient");
add("try");
add("void");
add("volatile");
add("while");
}};
/**
* Converts the given identifier to a legal Java identifier
*
* @param identifier the identifier to convert
* @return legal Java identifier corresponding to the given identifier
*/
public static String makeJavaIdentifier(String identifier) {
StringBuilder modifiedIdentifier = new StringBuilder(identifier.length());
if (!Character.isJavaIdentifierStart(identifier.charAt(0))) {
modifiedIdentifier.append('_');
}
for (int i = 0; i < identifier.length(); i++) {
char ch = identifier.charAt(i);
if (Character.isJavaIdentifierPart(ch)) {
modifiedIdentifier.append(ch);
} else if (ch == '.') {
modifiedIdentifier.append('_');
} else {
modifiedIdentifier.append(mangleChar(ch));
}
}
if (isJavaKeyword(modifiedIdentifier.toString())) {
modifiedIdentifier.append('_');
}
return modifiedIdentifier.toString();
}
/**
* Mangle the specified character to create a legal Java class name.
*
* @param ch the character to mangle
* @return the mangled
*/
public static String mangleChar(char ch) {
return String.format("__%04x__", (int) ch);
}
/**
* Provided a mangled string (obtained by calling {@link #mangleChar(char)}) it will will return the character that was mangled.
*
* @param mangled the mangled string
* @return the original character
*/
public static char unmangle(String mangled) {
String toProcess = mangled.replaceAll("__", "");
return (char) Integer.parseInt(toProcess, 16);
}
/**
* Converts the given scriptName to a Java package or fully-qualified class name
*
* @param scriptName the scriptName to convert
* @return Java package corresponding to the given scriptName
*/
public static String makeJavaPackage(String scriptName) {
String classNameComponents[] = StringUtils.split(scriptName, "/\\");
StringBuilder legalClassNames = new StringBuilder();
for (int i = 0; i < classNameComponents.length; i++) {
legalClassNames.append(makeJavaIdentifier(classNameComponents[i]));
if (i < classNameComponents.length - 1) {
legalClassNames.append('.');
}
}
return legalClassNames.toString();
}
/**
* Test whether the argument is a Java keyword.
*
* @param key the String to test
* @return {@code true} if the String is a Java keyword, {@code false} otherwise
*/
public static boolean isJavaKeyword(String key) {
return javaKeywords.contains(key);
}
}