Native2Ascii文件转换 -- 待完善

摘自：https://www.oschina.net/code/snippet_87799_1612 

Native2Ascii文件转换 -- 待完善

package com.xxx.xxx.Util;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;

/**
 * 类、接口等说明
 *
 * @Date 
 * @version v1.0
 * @author 　　
 */
public class ConvertFileNative2ASCIIUtil {

    public static boolean native2Ascii(String srcFileName, String srcFilecharsetName, String dstFileName,
            String dstFilecharsetName) throws IOException {

        File srcFileNameFile = new File(srcFileName);

        if (!srcFileNameFile.exists()) {
            throw new IOException(" File(" + srcFileName + ") Parameter does not reference a file that exists");
        } else if (!srcFileNameFile.isFile()) {
            throw new IOException("File(" + srcFileName + ") Parameter exists, but does not reference a file");
        } else if (!srcFileNameFile.canRead()) {
            throw new IOException("File(" + srcFileName + ") exists and is a file, but cannot be read.");
        } else {
            String content = readFile(srcFileName, srcFilecharsetName);
            String ascii = Native2ASCIIUtil.native2Ascii(content);
            writeFile(dstFileName, ascii, dstFilecharsetName);
        }

        return true;
    }

    public static boolean ascii2Native(String srcFileName, String srcFilecharsetName, String dstFileName,
            String dstFilecharsetName) throws IOException {

        File srcFileNameFile = new File(srcFileName);

        if (!srcFileNameFile.exists()) {
            throw new IOException(" File(" + srcFileName + ") Parameter does not reference a file that exists");
        } else if (!srcFileNameFile.isFile()) {
            throw new IOException("File(" + srcFileName + ") Parameter exists, but does not reference a file");
        } else if (!srcFileNameFile.canRead()) {
            throw new IOException("File(" + srcFileName + ") exists and is a file, but cannot be read.");
        } else {
            String content = readFile(srcFileName, srcFilecharsetName);
            String nativeString = Native2ASCIIUtil.ascii2Native(content);
            writeFile(dstFileName, nativeString, dstFilecharsetName);
        }

        return true;
    }

    public static void writeFile(String path, String content, String encoding) throws IOException {
        File file = new File(path);
        file.delete();
        file.createNewFile();
        BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file), encoding));
        writer.write(content);
        writer.close();
    }

    public static String readFile(String path, String encoding) throws IOException {
        String content = "";
        File file = new File(path);
        BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(file), encoding));
        String line = null;
        while ((line = reader.readLine()) != null) {
            content += line + "
";
        }
        reader.close();
        return content;
    }
}

package com.xxx.xxx.Util;

/**
 * 类、接口等说明
 *
 * @Date 
 * @version v1.0
 * @author 
 */
public class Native2ASCIIUtil {

    /** 
     * prefix of ascii string of native character 
     */
    private static String PREFIX = "\u";

    /** 
     * Native to ascii string. It's same as execut native2ascii.exe. 
     * @param str native string 
     * @return ascii string 
     */
    public static String native2Ascii(String str) {
        char[] chars = str.toCharArray();
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < chars.length; i++) {
            sb.append(char2Ascii(chars[i]));
        }
        return sb.toString();
    }

    /** 
     * Native character to ascii string. 
     * @param c native character 
     * @return ascii string 
     */
    private static String char2Ascii(char c) {
        if (c > 255) {
            StringBuilder sb = new StringBuilder();
            sb.append(PREFIX);
            int code = (c >> 8);
            String tmp = Integer.toHexString(code);
            if (tmp.length() == 1) {
                sb.append("0");
            }
            sb.append(tmp);
            code = (c & 0xFF);
            tmp = Integer.toHexString(code);
            if (tmp.length() == 1) {
                sb.append("0");
            }
            sb.append(tmp);
            return sb.toString();
        } else {
            return Character.toString(c);
        }
    }

    /** 
     * Ascii to native string. It's same as execut native2ascii.exe -reverse. 
     * @param str ascii string 
     * @return native string 
     */
    public static String ascii2Native(String str) {
        StringBuilder sb = new StringBuilder();
        int begin = 0;
        int index = str.indexOf(PREFIX);
        while (index != -1) {
            sb.append(str.substring(begin, index));
            sb.append(ascii2Char(str.substring(index, index + 6)));
            begin = index + 6;
            index = str.indexOf(PREFIX, begin);
        }
        sb.append(str.substring(begin));
        return sb.toString();
    }

    /** 
     * Ascii to native character. 
     * @param str ascii string 
     * @return native character 
     */
    private static char ascii2Char(String str) {
        if (str.length() != 6) {
            throw new IllegalArgumentException("Ascii string of a native character must be 6 character.");
        }
        if (!PREFIX.equals(str.substring(0, 2))) {
            throw new IllegalArgumentException("Ascii string of a native character must start with "\u".");
        }
        String tmp = str.substring(2, 4);
        int code = Integer.parseInt(tmp, 16) << 8;
        tmp = str.substring(4, 6);
        code += Integer.parseInt(tmp, 16);
        return (char) code;
    }
}