package com.lzy.tool
;
import java.io.File
;
import java.io.FileInputStream
;
import java.io.FileNotFoundException
;
import java.io.IOException
;
import java.security.MessageDigest
;
import java.security.NoSuchAlgorithmException
;
/**
* 计算文件MD5值工具类.
*
* @author linzhiyong
* @time 2015年11月4日10:27:29
* @email wflinzhiyong@163.com
*/
public class MD5Util {
/**
* The M d5.
*/
static MessageDigest
MD5 =
null;
/**
* The Constant HEX_DIGITS.
*/
private static final char HEX_DIGITS[] = {
'0', '1', '2', '3', '4', '5',
'6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'}
;
static {
try {
MD5 = MessageDigest.
getInstance(
"MD5")
;
}
catch (NoSuchAlgorithmException ne) {
ne.printStackTrace()
;
}
}
/**
* 获取文件md5值.
*
* @param file the file
* @return md5串
* @throws IOException
*/
public static String
getFileMD5String(File file)
throws IOException {
FileInputStream fileInputStream =
null;
try {
fileInputStream =
new FileInputStream(file)
;
byte[] buffer =
new byte[
8192]
;
int length
;
while ((length = fileInputStream.read(buffer)) != -
1) {
MD5.update(buffer
, 0, length)
;
}
return new String(
encodeHex(
MD5.digest()))
;
}
catch (FileNotFoundException e) {
throw e
;
}
catch (IOException e) {
throw e
;
}
finally {
try {
if (fileInputStream !=
null)
fileInputStream.close()
;
}
catch (IOException e) {
throw e
;
}
}
}
/**
* 获取文件md5值.
*
* @param data the byte[] data
* @return md5串
* @throws IOException
*/
public static String
getFileMD5String(
byte[] data)
throws IOException {
MD5.update(data)
;
return new String(
encodeHex(
MD5.digest()))
;
}
/**
* Encode hex.
*
* @param bytes the bytes
* @return the string
*/
public static String
encodeHex(
byte bytes[]) {
return bytesToHex(bytes
, 0, bytes.
length)
;
}
/**
* Bytes to hex.
*
* @param bytes the bytes
* @param start the start
* @param end the end
* @return the string
*/
public static String
bytesToHex(
byte bytes[]
, int start
, int end) {
StringBuilder sb =
new StringBuilder()
;
for (
int i = start
; i < start + end
; i++) {
sb.append(
byteToHex(bytes[i]))
;
}
return sb.toString()
;
}
/**
* Byte to hex.
*
* @param bt the bt
* @return the string
*/
public static String
byteToHex(
byte bt) {
return HEX_DIGITS[(bt &
0xf0) >>
4] +
"" +
HEX_DIGITS[bt &
0xf]
;
}
/**
* 获取md5值.
*
* @param str the string
* @return md5串
* @throws IOException
*/
public static String
getStringMD5(String str) {
StringBuilder sb =
new StringBuilder()
;
try {
byte[] data = str.getBytes(
"utf-8")
;
MessageDigest MD5 = MessageDigest.
getInstance(
"MD5")
;
MD5.update(data)
;
data = MD5.digest()
;
for (
int i =
0; i < data.
length; i++) {
sb.append(
HEX_DIGITS[(data[i] &
0xf0) >>
4] +
"" +
HEX_DIGITS[data[i] &
0xf])
;
}
}
catch (Exception e) {
}
return sb.toString()
;
}
/**
* The main method.
*
* @param args the arguments
*/
public static void main(String[] args) {
long beginTime = System.
currentTimeMillis()
;
File fileZIP =
new File(
"E:/android-sdk-windows.7z")
;
String md5 =
"";
try {
md5 =
getFileMD5String(fileZIP)
;
}
catch (IOException e) {
e.printStackTrace()
;
}
long endTime = System.
currentTimeMillis()
;
System.
out.println(
"MD5:" + md5 +
"\n time:" + ((endTime - beginTime)) +
"ms")
;
}
}
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