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.*;
public class base64 {
public base64() {
}
public static String encode(String data) {
return new String(encode(data.getBytes()));
}
public static String decode(String data) {
return new String(decode(data.toCharArray()));
}
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;
}
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;
}
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;
}
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;
public class ThunderSiteConverUtil {
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;
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
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持考高分网。
