标签：android style class blog code java
Android腾讯微博开发入门之随机字符串与签名实现
直接上代码
1、Utils类，包括签名和随机字符串
import java.util.Random;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
/**
*
* @author mrlixirong
*
* 2011-11-16
*/
public class Utils {
//签名
public static String getSignature(String baseString,String
key){
String returnStr="";
Mac mac = null;
byte[] byteHMAC = null;
try {
mac =
Mac.getInstance("HmacSHA1");
SecretKeySpec spec = new
SecretKeySpec(key.getBytes(), "HmacSHA1");
mac.init(spec);
byteHMAC =
mac.doFinal(baseString.getBytes());
returnStr =
Base64Encoder.encode(byteHMAC);
//returnStr=URLEncoder.encode(returnStr,ENCODING);
} catch (Exception e1) {
returnStr="error";
e1.printStackTrace();
}
return returnStr;
}
/*
* 获取随机字符串
* 实现方法很多，也很简单，但是对这种简单的东西，开发者有时候就是不想去敲键盘
* 但是不敲就做不下去，本来在此愿意成全和我一样有此烦恼的开发者
*/
public static String getRandomString(int len){
String returnStr="";
char[] ch=new char[len];
Random rd=new Random();
for(int i=0;i<len;i++){
ch[i]=(char)(rd.nextInt(9)+97);
}
returnStr=new String(ch);
return returnStr;
}
}
2、Base64Encoder
public class Base64Encoder {
private static final char last2byte = (char)
Integer.parseInt("00000011", 2);
private static final char last4byte = (char)
Integer.parseInt("00001111", 2);
private static final char last6byte = (char)
Integer.parseInt("00111111", 2);
private static final char lead6byte = (char)
Integer.parseInt("11111100", 2);
private static final char lead4byte = (char)
Integer.parseInt("11110000", 2);
private static final char lead2byte = (char)
Integer.parseInt("11000000", 2);
private static final char[] encodeTable = 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‘, ‘+‘,
‘/‘};
public static String encode(byte[] from) {
StringBuffer to = new StringBuffer((int)
(from.length * 1.34) + 3);
int num = 0;
char currentByte = 0;
for (int i = 0; i < from.length; i++)
{
num = num % 8;
while (num < 8) {
switch (num)
{
case
0:
currentByte = (char) (from[i] & lead6byte);
currentByte = (char) (currentByte >>> 2);
break;
case
2:
currentByte = (char) (from[i] & last6byte);
break;
case
4:
currentByte = (char) (from[i] & last4byte);
currentByte = (char) (currentByte << 2);
if ((i + 1) < from.length) {
currentByte |= (from[i + 1] & lead2byte)
>>> 6;
}
break;
case
6:
currentByte = (char) (from[i] & last2byte);
currentByte = (char) (currentByte << 4);
if ((i + 1) < from.length) {
currentByte |= (from[i + 1] & lead4byte)
>>> 4;
}
break;
}
to.append(encodeTable[currentByte]);
num += 6;
}
}
if (to.length() % 4 != 0) {
for (int i = 4 - to.length() % 4;
i > 0; i--) {
to.append("=");
}
}
return to.toString();
}
}
