package com.webservices;
public class Base64_Encode { //对应php里的 base64_decode 方法
private static final String base64code = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+ "abcdefghijklmnopqrstuvwxyz" + "0123456789" + "+/";
private static final int splitLinesAt = 76;
public static byte[] zeroPad(int length, byte[] bytes) {
// initialized to zero by JVM
byte[] padded = new byte[length];
System.arraycopy(bytes, 0, padded, 0, bytes.length);
return padded;
}
public static String encode(String string) {
String encoded = "";
byte[] stringArray;
try {
// use appropriate encoding string!
stringArray = string.getBytes("UTF-8");
} catch (Exception ignored) {
// use locale default rather than croak
stringArray = string.getBytes();
}
// determine how many padding bytes to add to the output
int paddingCount = (3 - (stringArray.length % 3)) % 3;
// add any necessary padding to the input
stringArray = zeroPad(stringArray.length + paddingCount, stringArray);
// process 3 bytes at a time, churning out 4 output bytes
// worry about CRLF insertions later
for (int i = 0; i < stringArray.length; i += 3) {
int j = ((stringArray[i] & 0xff) << 16) +
((stringArray[i + 1] & 0xff) << 8) +
(stringArray[i + 2] & 0xff);
encoded = encoded + base64code.charAt((j >> 18) & 0x3f) +
base64code.charAt((j >> 12) & 0x3f) +
base64code.charAt((j >> 6) & 0x3f) +
base64code.charAt(j & 0x3f);
}
// replace encoded padding nulls with "="
return splitLines(encoded.substring(0, encoded.length() -
paddingCount) + "==".substring(0, paddingCount));
}
public static String splitLines(String string) {
String lines = "";
for (int i = 0; i < string.length(); i += splitLinesAt) {
lines += string.substring(i, Math.min(string.length(), i + splitLinesAt));
lines += "/r/n";
}
return lines;
}
}