Java实现迅雷地址转成普通地址

原理分析：迅雷的thunder://地址就是将普通url地址加前缀‘AA’、后缀‘ZZ’，再base64编码后得到的字符串

实现：

步骤1，添加工具类Base64 编码和解码：Base64.java

package th;

import java.io.*;  

/** 
 * Base64 编码和解码。 
 *  
 * @author 宋立君 
 * @date 2014年07月03日 
 */  
public class Base64 {  
   
    public Base64() {  
    }  
   
    /** 
     * 功能：编码字符串 
     *  
     * @author 宋立君 
     * @date 2014年07月03日 
     * @param data 
     *      源字符串 
     * @return String 
     */  
    public static String encode(String data) {  
        return new String(encode(data.getBytes()));  
    }  
   
    /** 
     * 功能：解码字符串 
     *  
     * @author 宋立君 
     * @date 2014年07月03日 
     * @param data 
     *      源字符串 
     * @return String 
     */  
    public static String decode(String data) {  
        return new String(decode(data.toCharArray()));  
    }  
   
    /** 
     * 功能：编码byte[] 
     *  
     * @author 宋立君 
     * @date 2014年07月03日 
     * @param data 
     *      源 
     * @return char[] 
     */  
    public static char[] encode(byte[] data) {  
        char[] out = new char[((data.length + 2) / 3) * 4];  
        for (int i = 0, index = 0; i < data.length; i += 3, index += 4) {  
            boolean quad = false;  
            boolean trip = false;  
   
            int val = (0xFF & (int) data[i]);  
            val <<= 8;  
            if ((i + 1) < data.length) {  
                val |= (0xFF & (int) data[i + 1]);  
                trip = true;  
            }  
            val <<= 8;  
            if ((i + 2) < data.length) {  
                val |= (0xFF & (int) data[i + 2]);  
                quad = true;  
            }  
            out[index + 3] = alphabet[(quad ? (val & 0x3F) : 64)];  
            val >>= 6;  
            out[index + 2] = alphabet[(trip ? (val & 0x3F) : 64)];  
            val >>= 6;  
            out[index + 1] = alphabet[val & 0x3F];  
            val >>= 6;  
            out[index + 0] = alphabet[val & 0x3F];  
        }  
        return out;  
    }  
   
    /** 
     * 功能：解码 
     *  
     * @author 宋立君 
     * @date 2014年07月03日 
     * @param data 
     *      编码后的字符数组 
     * @return byte[] 
     */  
    public static byte[] decode(char[] data) {  
   
        int tempLen = data.length;  
        for (int ix = 0; ix < data.length; ix++) {  
            if ((data[ix] > 255) || codes[data[ix]] < 0) {  
                --tempLen; // ignore non-valid chars and padding  
            }  
        }  
        // calculate required length:  
        // -- 3 bytes for every 4 valid base64 chars  
        // -- plus 2 bytes if there are 3 extra base64 chars,  
        // or plus 1 byte if there are 2 extra.  
   
        int len = (tempLen / 4) * 3;  
        if ((tempLen % 4) == 3) {  
            len += 2;  
        }  
        if ((tempLen % 4) == 2) {  
            len += 1;  
   
        }  
        byte[] out = new byte[len];  
   
        int shift = 0; // # of excess bits stored in accum  
        int accum = 0; // excess bits  
        int index = 0;  
   
        // we now go through the entire array (NOT using the 'tempLen' value)  
        for (int ix = 0; ix < data.length; ix++) {  
            int value = (data[ix] > 255) ? -1 : codes[data[ix]];  
   
            if (value >= 0) { // skip over non-code  
                accum <<= 6; // bits shift up by 6 each time thru  
                shift += 6; // loop, with new bits being put in  
                accum |= value; // at the bottom.  
                if (shift >= 8) { // whenever there are 8 or more shifted in,  
                    shift -= 8; // write them out (from the top, leaving any  
                    out[index++] = // excess at the bottom for next iteration.  
                    (byte) ((accum >> shift) & 0xff);  
                }  
            }  
        }  
   
        // if there is STILL something wrong we just have to throw up now!  
        if (index != out.length) {  
            throw new Error("Miscalculated data length (wrote " + index  
                    + " instead of " + out.length + ")");  
        }  
   
        return out;  
    }  
   
    /** 
     * 功能：编码文件 
     *  
     * @author 宋立君 
     * @date 2014年07月03日 
     * @param file 
     *      源文件 
     */  
    public static void encode(File file) throws IOException {  
        if (!file.exists()) {  
            System.exit(0);  
        }  
   
        else {  
            byte[] decoded = readBytes(file);  
            char[] encoded = encode(decoded);  
            writeChars(file, encoded);  
        }  
        file = null;  
    }  
   
    /** 
     * 功能：解码文件。 
     *  
     * @author 宋立君 
     * @date 2014年07月03日 
     * @param file 
     *      源文件 
     * @throws IOException 
     */  
    public static void decode(File file) throws IOException {  
        if (!file.exists()) {  
            System.exit(0);  
        } else {  
            char[] encoded = readChars(file);  
            byte[] decoded = decode(encoded);  
            writeBytes(file, decoded);  
        }  
        file = null;  
    }  
   
    //  
    // code characters for values 0..63  
    //  
    private static char[] alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="  
            .toCharArray();  
   
    //  
    // lookup table for converting base64 characters to value in range 0..63  
    //  
    private static byte[] codes = new byte[256];  
    static {  
        for (int i = 0; i < 256; i++) {  
            codes[i] = -1;  
            // LoggerUtil.debug(i + "&" + codes[i] + " ");  
        }  
        for (int i = 'A'; i <= 'Z'; i++) {  
            codes[i] = (byte) (i - 'A');  
            // LoggerUtil.debug(i + "&" + codes[i] + " ");  
        }  
   
        for (int i = 'a'; i <= 'z'; i++) {  
            codes[i] = (byte) (26 + i - 'a');  
            // LoggerUtil.debug(i + "&" + codes[i] + " ");  
        }  
        for (int i = '0'; i <= '9'; i++) {  
            codes[i] = (byte) (52 + i - '0');  
            // LoggerUtil.debug(i + "&" + codes[i] + " ");  
        }  
        codes['+'] = 62;  
        codes['/'] = 63;  
    }  
   
    private static byte[] readBytes(File file) throws IOException {  
        ByteArrayOutputStream baos = new ByteArrayOutputStream();  
        byte[] b = null;  
        InputStream fis = null;  
        InputStream is = null;  
        try {  
            fis = new FileInputStream(file);  
            is = new BufferedInputStream(fis);  
            int count = 0;  
            byte[] buf = new byte[16384];  
            while ((count = is.read(buf)) != -1) {  
                if (count > 0) {  
                    baos.write(buf, 0, count);  
                }  
            }  
            b = baos.toByteArray();  
   
        } finally {  
            try {  
                if (fis != null)  
                    fis.close();  
                if (is != null)  
                    is.close();  
                if (baos != null)  
                    baos.close();  
            } catch (Exception e) {  
                System.out.println(e);  
            }  
        }  
   
        return b;  
    }  
   
    private static char[] readChars(File file) throws IOException {  
        CharArrayWriter caw = new CharArrayWriter();  
        Reader fr = null;  
        Reader in = null;  
        try {  
            fr = new FileReader(file);  
            in = new BufferedReader(fr);  
            int count = 0;  
            char[] buf = new char[16384];  
            while ((count = in.read(buf)) != -1) {  
                if (count > 0) {  
                    caw.write(buf, 0, count);  
                }  
            }  
   
        } finally {  
            try {  
                if (caw != null)  
                    caw.close();  
                if (in != null)  
                    in.close();  
                if (fr != null)  
                    fr.close();  
            } catch (Exception e) {  
                System.out.println(e);  
            }  
        }  
   
        return caw.toCharArray();  
    }  
   
    private static void writeBytes(File file, byte[] data) throws IOException {  
        OutputStream fos = null;  
        OutputStream os = null;  
        try {  
            fos = new FileOutputStream(file);  
            os = new BufferedOutputStream(fos);  
            os.write(data);  
   
        } finally {  
            try {  
                if (os != null)  
                    os.close();  
                if (fos != null)  
                    fos.close();  
            } catch (Exception e) {  
                System.out.println(e);  
            }  
        }  
    }  
   
    private static void writeChars(File file, char[] data) throws IOException {  
        Writer fos = null;  
        Writer os = null;  
        try {  
            fos = new FileWriter(file);  
            os = new BufferedWriter(fos);  
            os.write(data);  
   
        } finally {  
            try {  
                if (os != null)  
                    os.close();  
                if (fos != null)  
                    fos.close();  
            } catch (Exception e) {  
                e.printStackTrace();  
            }  
        }  
    }  
   
}  

步骤2,编写迅雷地址转普通地址的类及方法：ThunderSiteConverUtil.java

package th;

/**
 * 迅雷地址转普通地址
 * <p>Title: ThunderSiteConverUtil</p>
 * <p>Description: </p>
 * <p>Company: www.itcast.com</p> 
 * @author	入云龙
 * @date	2017年3月6日下午2:11:32
 * @version 1.0
 */
public   class ThunderSiteConverUtil {

	/**
	 *  迅雷thunder://地址与普通url地址转换
		其实迅雷的thunder://地址就是将普通url地址加前缀‘AA’、后缀‘ZZ’，再base64编码后得到的字符串
	 * <p>Title: t1</p>
	 * <p>Description: </p>
	 * @param url
	 * @return
	 */
		public String conver(String url){
			String newUrl="";
			//s＝s.substring(int begin，int end);截取s中从begin开始至end结束时的字符串，并将其赋值给s;
			//去掉迅雷地址前缀
			url=url.substring(10, url.length());
			//解密
			newUrl=Base64.decode(url);
			//去掉头AA，尾ZZ
			newUrl=newUrl.substring(2, newUrl.length()-2);
			return newUrl;
		}
}

步骤3，建立测试类：TestTh.java

package th;

import org.junit.Test;

/*
 * 迅雷地址转普通地址测试
 */
public class TestTh {
	
	@Test
	public void test1(){
		 String url="thunder://QUFodHRwOi8vdG9vbC5sdS90ZXN0LnppcFpa";
		 System.out.println("迅雷地址："+url);
		 url=new ThunderSiteConverUtil().conver(url);
		 System.out.println("普通地址："+url);
	}
}

 运行Junit测试test1，控制台输出：

迅雷地址：thunder://QUFodHRwOi8vdG9vbC5sdS90ZXN0LnppcFpa
普通地址：http://tool.lu/test.zip