socket发送接收字段采用Base64加密笔记

首先，贴上Base64工具类【网上也有专门的base64第三方封装类库jar。我做过测试，在java环境下可用；可是当我在android项目中调用jar包工具类时，程序显示找不到指定方法的异常，问题在于android里面对第三方jar包不兼容，所以最后放弃调用外部jar包的方式，转而调用自己的工具类】

以下是base64可用工具类：

package com.sohan.util;
import java.io.UnsupportedEncodingException;
public class Base64Util {
    private static char[] base64EncodeChars = new char[] { 'A', 'B', 'C', 'D',
            'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q',
            'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',
            'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q',
            'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3',
            '4', '5', '6', '7', '8', '9', '+', '/' };

    private static byte[] base64DecodeChars = new byte[] { -1, -1, -1, -1, -1,
            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
            -1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59,
            60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
            10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1,
            -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,
            38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1,
            -1, -1 };

    public static String encode(byte[] data) {
        StringBuffer sb = new StringBuffer();
        int len = data.length;
        int i = 0;
        int b1, b2, b3;
        while (i < len) {
            b1 = data[i++] & 0xff;
            if (i == len) {
                sb.append(base64EncodeChars[b1 >>> 2]);
                sb.append(base64EncodeChars[(b1 & 0x3) << 4]);
                sb.append("==");
                break;
            }
            b2 = data[i++] & 0xff;
            if (i == len) {
                sb.append(base64EncodeChars[b1 >>> 2]);
                sb.append(base64EncodeChars[((b1 & 0x03) << 4)
                        | ((b2 & 0xf0) >>> 4)]);
                sb.append(base64EncodeChars[(b2 & 0x0f) << 2]);
                sb.append("=");
                break;
            }
            b3 = data[i++] & 0xff;
            sb.append(base64EncodeChars[b1 >>> 2]);
            sb.append(base64EncodeChars[((b1 & 0x03) << 4)
                    | ((b2 & 0xf0) >>> 4)]);
            sb.append(base64EncodeChars[((b2 & 0x0f) << 2)
                    | ((b3 & 0xc0) >>> 6)]);
            sb.append(base64EncodeChars[b3 & 0x3f]);
        }
        return sb.toString();
    }

    public static byte[] decode(String str) throws UnsupportedEncodingException {
        StringBuffer sb = new StringBuffer();
        byte[] data = str.getBytes("US-ASCII");
        int len = data.length;
        int i = 0;
        int b1, b2, b3, b4;
        while (i < len) {

            do {
                b1 = base64DecodeChars[data[i++]];
            } while (i < len && b1 == -1);
            if (b1 == -1)
                break;

            do {
                b2 = base64DecodeChars[data[i++]];
            } while (i < len && b2 == -1);
            if (b2 == -1)
                break;
            sb.append((char) ((b1 << 2) | ((b2 & 0x30) >>> 4)));

            do {
                b3 = data[i++];
                if (b3 == 61)
                    return sb.toString().getBytes("iso8859-1");
                b3 = base64DecodeChars[b3];
            } while (i < len && b3 == -1);
            if (b3 == -1)
                break;
            sb.append((char) (((b2 & 0x0f) << 4) | ((b3 & 0x3c) >>> 2)));

            do {
                b4 = data[i++];
                if (b4 == 61)
                    return sb.toString().getBytes("iso8859-1");
                b4 = base64DecodeChars[b4];
            } while (i < len && b4 == -1);
            if (b4 == -1)
                break;
            sb.append((char) (((b3 & 0x03) << 6) | b4));
        }
        return sb.toString().getBytes("iso8859-1");
    }




    /**
     * @param args
     * @throws UnsupportedEncodingException
     */
    public static void main(String[] args) throws UnsupportedEncodingException {
        // 自定义类库加密解密
        Base64Util bs = new Base64Util();
        String s = "110Action=APITest&";
        System.out.println("加密前：" + s);
        String x = bs.encode(s.getBytes());
        System.out.println("加密后：" + x);
        String x1 = new String(bs.decode(x));
        System.out.println("解密后：" + x1);
        
        //before:110Action=APITest&
        //base64:MTEwQWN0aW9uPUFQSVRlc3Qm
        //return:u7bTrcq508PLtrq6QVBJ
    }

}

然后，socket客户端代码如下：

    public String BaseSocket(Context con, String sendstr) {
        PrintWriter outw = null;
        DataInputStream dataIn = null;        Socket s = null;
        String servername ="127.0.0.1";
        String port = 55555;
        String readData = "";
        try {
            Log.d("log", "......BaseSocket Starting.....");
            
            s = new Socket(); // 实例化socket
            SocketAddress socketAddress = new InetSocketAddress(servername,
                    port); // 获取sockaddress对象
            s.connect(socketAddress, 8000); // 连接socket并设置连接超时为8秒，如果8秒后服务端还没有响应，则弹出异常信息。

            outw = new PrintWriter(new BufferedWriter(new OutputStreamWriter(
                    s.getOutputStream(), "GBK")), true);
                        String base64str = Base64Util.encode(sendstr.getBytes("gb2312"));//加密socket发送字段，注意编码的统一，防止中文乱码的出现

            base64str = base64str.replaceAll("\\r\\n", "");//注意转义字符的使用
            Log.d("log","send_before:" + sendstr);
            Log.d("log","send_encode:" + base64str);
            outw.println(base64str);
            Log.d("log", "服务器:" + s.getRemoteSocketAddress());
            dataIn = new DataInputStream(s.getInputStream());
            byte[] readByte = new byte[1024];
            int i = 0;
            while ((i = dataIn.read(readByte)) != -1) {
                readData += new String(readByte, 0, i, "gbk");
                if (readData.contains("\r") || readData.contains("\n"))//约定服务端发送的base64字段以换行符作为结束字符

                    break;
            }
            Log.d("log","return:" + readData);
            sockResultStr = new String(Base64Util.decode(readData), "gb2312");//解密socket返回base64字段,同样注意编码问题
            Log.d("log","redecode:" + sockResultStr);
        } catch (Exception e) {// 捕获异常
            sockResultStr = "fail";
            e.printStackTrace();
            Log.d("log", "连接服务器失败");
        } finally {
            try {
                if (dataIn != null) {
                    dataIn.close();
                    dataIn = null;
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            try {
                if (outw != null) {
                    outw.close();
                    outw = null;
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            try {
                if (s != null) {
                    s.close();
                    s = null;
                    Log.d("log", "......baseSocket finished.....");
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            return sockResultStr;
        }

    }