md5 java 工具类_javamd5工具类

import java.io.UnsupportedEncodingException;

import java.security.MessageDigest;

import java.util.HashMap;

import java.util.Map;

import java.util.concurrent.locks.ReentrantLock;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

//import sun.security.provider.MD5;

/**

* 简单计算MD5

*

* @author agapple 2015年3月26日 下午8:45:47

* @since 5.1.19

*/

public class MD5Utils {

private static final Log log = LogFactory.getLog(MD5Utils.class);

private static char[] digits = { ‘0’, ‘1’, ‘2’, ‘3’, ‘4’, ‘5’, ‘6’, ‘7’, ‘8’, ‘9’, ‘a’, ‘b’, ‘c’,

‘d’, ‘e’, ‘f’ };

private static Map rDigits = new HashMap(16);

static {

for (int i = 0; i < digits.length; ++i) {

rDigits.put(digits[i], i);

}

}

private static MD5Utils me = new MD5Utils();

private MessageDigest mHasher;

private ReentrantLock opLock = new ReentrantLock();

private MD5Utils(){

try {

mHasher = MessageDigest.getInstance(“md5”);

} catch (Exception e) {

throw new RuntimeException(e);

}

}

public static MD5Utils getInstance() {

return me;

}

public String getMD5String(String content) {

return bytes2string(hash(content));

}

public String getMD5String(byte[] content) {

return bytes2string(hash(content));

}

public byte[] getMD5Bytes(byte[] content) {

return hash(content);

}

/**

* 对字符串进行md5

*

* @param str

* @return md5 byte[16]

*/

public byte[] hash(String str) {

opLock.lock();

try {

byte[] bt = mHasher.digest(str.getBytes(“UTF-8”));

if (null == bt || bt.length != 16) {

throw new IllegalArgumentException(“md5 need”);

}

return bt;

} catch (UnsupportedEncodingException e) {

throw new RuntimeException(“unsupported utf-8 encoding”, e);

} finally {

opLock.unlock();

}

}

/**

* 对二进制数据进行md5

*

* @param str

* @return md5 byte[16]

*/

public byte[] hash(byte[] data) {

opLock.lock();

try {

byte[] bt = mHasher.digest(data);

if (null == bt || bt.length != 16) {

throw new IllegalArgumentException(“md5 need”);

}

return bt;

} finally {

opLock.unlock();

}

}

/**

* 将一个字节数组转化为可见的字符串

*

* @param bt

* @return

*/

public String bytes2string(byte[] bt) {

int l = bt.length;

char[] out = new char[l << 1];

for (int i = 0, j = 0; i < l; i++) {

out[j++] = digits[(0xF0 & bt[i]) >>> 4];

out[j++] = digits[0x0F & bt[i]];

}

if (log.isDebugEnabled()) {

log.debug(“[hash]” + (new String(out)));

}

return new String(out);

}

/**

* 将字符串转换为bytes

*

* @param str

* @return byte[]

*/

public byte[] string2bytes(String str) {

if (null == str) {

throw new IllegalArgumentException(“str is null”);

}

if (str.length() != 32) {

throw new IllegalArgumentException(“str.length() != 32”);

}

byte[] data = new byte[16];

char[] chs = str.toCharArray();

for (int i = 0; i < 16; ++i) {

int h = rDigits.get(chs[i * 2]).intValue();

int l = rDigits.get(chs[i * 2 + 1]).intValue();

data[i] = (byte) ((h & 0x0F) << 4 | (l & 0x0F));

}

return data;

}

}

以上代码就是用于md5的算法