Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/**
 * 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.lang.reflect.Method;
import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main {
    private static final Pattern CHARSET_NAME_PATTERN = Pattern.compile("[ \\\"]*([^ >,;\\\"]+).*");
    private static final Pattern ISO_NAME_PATTERN = Pattern.compile(".*8859-(\\d+)");
    private static final Pattern CP_NAME_PATTERN = Pattern.compile("cp-(\\d+)");
    private static final Pattern WIN_NAME_PATTERN = Pattern.compile("win-?(\\d+)");
    private static final Map<String, Charset> COMMON_CHARSETS = new HashMap<String, Charset>();
    private static Method getCharsetICU = null;

    /** Returns Charset impl, if one exists.  This method
     *  optionally uses ICU4J's CharsetICU.forNameICU,
     *  if it is found on the classpath, else only uses
     *  JDK's builtin Charset.forName. */
    public static Charset forName(String name) {
        if (name == null) {
            throw new IllegalArgumentException();
        }

        // Get rid of cruft around names, like <>, trailing commas, etc.
        Matcher m = CHARSET_NAME_PATTERN.matcher(name);
        if (!m.matches()) {
            throw new IllegalCharsetNameException(name);
        }
        name = m.group(1);

        String lower = name.toLowerCase(Locale.ENGLISH);
        Charset charset = COMMON_CHARSETS.get(lower);
        if (charset != null) {
            return charset;
        } else if ("none".equals(lower) || "no".equals(lower)) {
            throw new IllegalCharsetNameException(name);
        } else {
            Matcher iso = ISO_NAME_PATTERN.matcher(lower);
            Matcher cp = CP_NAME_PATTERN.matcher(lower);
            Matcher win = WIN_NAME_PATTERN.matcher(lower);
            if (iso.matches()) {
                // Handle "iso 8859-x" error
                name = "iso-8859-" + iso.group(1);
                charset = COMMON_CHARSETS.get(name);
            } else if (cp.matches()) {
                // Handle "cp-xxx" error
                name = "cp" + cp.group(1);
                charset = COMMON_CHARSETS.get(name);
            } else if (win.matches()) {
                // Handle "winxxx" and "win-xxx" errors
                name = "windows-" + win.group(1);
                charset = COMMON_CHARSETS.get(name);
            }
            if (charset != null) {
                return charset;
            }
        }

        if (getCharsetICU != null) {
            try {
                Charset cs = (Charset) getCharsetICU.invoke(null, name);
                if (cs != null) {
                    return cs;
                }
            } catch (Exception e) {
                // ignore
            }
        }

        return Charset.forName(name);
    }
}