/* * 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.regexp;import org.apache.regexp.RECompiler;import org.apache.regexp.RESyntaxException;/** * 'recompile' is a command line tool that pre-compiles one or more regular expressions * for use with the regular expression matcher class 'RE'.  For example, the command * <code>java org.apache.regexp.recompile re1 "a*b"</code> produces output like this: * * <pre> * *    // Pre-compiled regular expression 'a*b' *    private static final char[] re1Instructions = *    { *        0x002a, 0x0000, 0x0007, 0x0041, 0x0001, 0xfffd, 0x0061, *        0x0041, 0x0001, 0x0004, 0x0062, 0x0045, 0x0000, 0x0000, *    }; * *    private static final REProgram re1 = new REProgram(re1Instructions); * * </pre> * * By pasting this output into your code, you can construct a regular expression matcher * (RE) object directly from the pre-compiled data (the character array re1), thus avoiding * the overhead of compiling the expression at runtime.  For example: * * <pre> * *    RE r = new RE(re1); * * </pre> * * @see RE * @see RECompiler * * @author <a href="mailto:jonl@muppetlabs.com">Jonathan Locke</a> * @version $Id: recompile.java 518156 2007-03-14 14:31:26Z vgritsenko $ */public class recompile{    /**     * Main application entrypoint.     *     * @param arg Command line arguments     */    static public void main(String[] arg)    {        // Create a compiler object        RECompiler r = new RECompiler();        // Print usage if arguments are incorrect        if (arg.length <= 0 || arg.length % 2 != 0)        {            System.out.println("Usage: recompile <patternname> <pattern>");            System.exit(0);        }        // Loop through arguments, compiling each        for (int i = 0; i < arg.length; i += 2)        {            try            {                // Compile regular expression                String name         = arg[i];                String pattern      = arg[i+1];                String instructions = name + "Instructions";                // Output program as a nice, formatted character array                System.out.print("\n    // Pre-compiled regular expression '" + pattern + "'\n"                                 + "    private static final char[] " + instructions + " = \n    {");                // Compile program for pattern                REProgram program = r.compile(pattern);                // Number of columns in output                int numColumns = 7;                // Loop through program                char[] p = program.getInstructions();                for (int j = 0; j < p.length; j++)                {                    // End of column?                    if ((j % numColumns) == 0)                    {                        System.out.print("\n        ");                    }                    // Print character as padded hex number                    String hex = Integer.toHexString(p[j]);                    while (hex.length() < 4)                    {                        hex = "0" + hex;                    }                    System.out.print("0x" + hex + ", ");                }                // End of program block                System.out.println("\n    };");                System.out.println("\n    private static final REProgram " + name + " = new REProgram(" + instructions + ");");            }            catch (RESyntaxException e)            {                System.out.println("Syntax error in expression \"" + arg[i] + "\": " + e.toString());            }            catch (Exception e)            {                System.out.println("Unexpected exception: " + e.toString());            }            catch (Error e)            {                System.out.println("Internal error: " + e.toString());            }        }    }}