来源(null)

一个进行Base64编码的类

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源作者:sonymusic                   人气:16345

package sony.utils;
import java.io.*;
import java.net.*;
public final class Codes {
    public final static byte[] base64Encode(byte[] byteData) {
        if (byteData == null)
        return null;
        int iSrcIdx; // index into source (byteData)
        int iDestIdx; // index into destination (byteDest)
        byte byteDest[] = new byte[((byteData.length + 2) / 3) * 4];
        for (iSrcIdx = 0, iDestIdx = 0; iSrcIdx < byteData.length - 2; iSrcIdx += 3) {
            byteDest[iDestIdx++] = (byte) ((byteData[iSrcIdx] >>> 2) & 077);
            byteDest[iDestIdx++] =
            (byte) ((byteData[iSrcIdx + 1] >>> 4) & 017 | (byteData[iSrcIdx] << 4) & 077);
            byteDest[iDestIdx++] =
            (byte) ((byteData[iSrcIdx + 2] >>> 6)
                & 003
                | (byteData[iSrcIdx + 1] << 2)
            & 077);
            byteDest[iDestIdx++] = (byte) (byteData[iSrcIdx + 2] & 077);
        }
        if (iSrcIdx < byteData.length) {
            byteDest[iDestIdx++] = (byte) ((byteData[iSrcIdx] >>> 2) & 077);
            if (iSrcIdx < byteData.length - 1) {
                byteDest[iDestIdx++] =
                (byte) ((byteData[iSrcIdx + 1] >>> 4) & 017 | (byteData[iSrcIdx] << 4) & 077);
                byteDest[iDestIdx++] = (byte) ((byteData[iSrcIdx + 1] << 2) & 077);
            } else
            byteDest[iDestIdx++] = (byte) ((byteData[iSrcIdx] << 4) & 077);
        }
        for (iSrcIdx = 0; iSrcIdx < iDestIdx; iSrcIdx++) {
            if (byteDest[iSrcIdx] < 26)
            byteDest[iSrcIdx] = (byte) (byteDest[iSrcIdx] + &acute;A&acute;);
            else
            if (byteDest[iSrcIdx] < 52)
            byteDest[iSrcIdx] = (byte) (byteDest[iSrcIdx] + &acute;a&acute; - 26);
            else
            if (byteDest[iSrcIdx] < 62)
            byteDest[iSrcIdx] = (byte) (byteDest[iSrcIdx] + &acute;0&acute; - 52);
            else
            if (byteDest[iSrcIdx] < 63)
            byteDest[iSrcIdx] = (byte) &acute;+&acute;;
            else
            byteDest[iSrcIdx] = (byte) &acute;/&acute;;
        }
        for (; iSrcIdx < byteDest.length; iSrcIdx++)
        byteDest[iSrcIdx] = (byte) &acute;=&acute;;
        return byteDest;
    }
    public final static String base64Encode(String strInput) {
        if (strInput == null)
        return null;
        return base64Encode(strInput,"GB2312");
    }
    public final static String base64Encode(String strInput,String charSet) {
        if (strInput == null)
        return null;
        String strOutput=null;
        byte byteData[] = new byte[strInput.length()];
        try {
            //strInput.getBytes(0, strInput.length(), byteData, 0);
            byteData = strInput.getBytes(charSet);
            strOutput=new String(base64Encode(byteData),charSet);
            //strOutput=new String(base64Encode(byteData),0);
        } catch (UnsupportedEncodingException e) {
            return null;
        }
        return strOutput;
    }
    /**
    * 此处插入方法说明。
    * 创建日期:(2000-11-4 18:27:35)
    * @param steam java.io.InputStream
    * @param charSet java.lang.String
    */
    public final static String base64Encode(InputStream in, String charSet) {
        try {
            int c;
            byte[] buff = new byte[1024];
            ByteArrayOutputStream out = new ByteArrayOutputStream(2048);
            while ((c = in.read(buff, 0, 1024)) != -1) {
                out.write(buff, 0, c);
                //index+=1024;
                //out.write(c);
                //attachContent+=ss;
            }
            in.close();
            out.flush();
            byte[] tmp2 = Codes.base64Encode(out.toByteArray());
            out.close();
            return new String(tmp2,charSet);
        }
        catch (IOException e) {
            return "";
        }
    }/**
    * 此处插入方法说明。
    * 创建日期:(2000-11-3 23:31:04)
    * @return java.lang.String
    * @param strIn java.lang.String
    */
    public final static String chunkSplit(String strIn) {
        return chunkSplit(strIn,76);
    }/**
    * 此处插入方法说明。
    * 创建日期:(2000-11-3 23:31:04)
    * @return java.lang.String
    * @param strIn java.lang.String
    */
    public final static String chunkSplit(String strIn,int splitLen) {
        int index=0;
        String strOut="";
        while(index+splitLen<strIn.length()){
            strOut+=strIn.substring(index,index+splitLen)+"\n";
            index+=splitLen;
        }
        if(index<strIn.length()){
            strOut+=strIn.substring(index);
        }
        return strOut;
    }
}

Link: http://www.asm32.net/article_details.aspx?id=191