1. 说明
android自带的MD5校验类
2. 例程
1) 功能
对文件/init.rc做MD5计算，并以字串的方式显示
2) 可从此处下载可独立运行的代码
http://download.csdn.net/source/2660824
3) 使用linux命令得到MD5值
$ md5sum init.rc
4) 核心代码及说明
import java.security.MessageDigest;
import java.io.FileInputStream;
import java.io.InputStream;
public class MD5 {
private static final char HEX_DIGITS[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'A', 'B', 'C', 'D', 'E', 'F' };
public static void main(String[] args)
{
System.out.println(md5sum("/init.rc"));
}
public static String toHexString(byte[] b) {
StringBuilder sb = new StringBuilder(b.length * 2);
for (int i = 0; i < b.length; i++) {
sb.append(HEX_DIGITS[(b[i] & 0xf0) >>> 4]);
sb.append(HEX_DIGITS[b[i] & 0x0f]);
}
return sb.toString();
}
public static String md5sum(String filename) {
InputStream fis;
byte[] buffer = new byte[1024];
int numRead = 0;
MessageDigest md5;
try{
fis = new FileInputStream(filename);
md5 = MessageDigest.getInstance("MD5");
while((numRead=fis.read(buffer)) > 0) {
md5.update(buffer,0,numRead);
}
fis.close();
return toHexString(md5.digest());
} catch (Exception e) {
System.out.println("error");
return null;
}
}
}