java获取文件MD5值代码实例说明，以下是java源码说明，在复制过程中有可能需要将中文状态的双引号全部替换为英文输入状态的双引号：

package com.topcheer;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
public class GetFileMD5 {
/**
* 获取压缩文件MD5值
* David 2012-10-12
*
*/
protected static char hexDigits[] = { ’0′, ’1′,’2′, ’3′, ’4′, ’5′, ’6′, ’7′, ’8′, ’9′,’a', ‘b’, ‘c’, ‘d’, ‘e’, ‘f’};
protected static MessageDigest messagedigest = null;
static{
try {
messagedigest = MessageDigest.getInstance(“MD5″);
} catch (NoSuchAlgorithmException e) {

//System.err.println(GetFileMD5.class.getName()+”初始化失败，MessageDigest不支持MD5Util。”);
e.printStackTrace();
}
}

public static String getFileMD5String(File file) throws IOException{
FileInputStream in = new FileInputStream(file);
FileChannel ch =in.getChannel();
MappedByteBuffer byteBuffer =ch.map(FileChannel.MapMode.READ_ONLY, 0, file.length());
messagedigest.update(byteBuffer);
return bufferToHex(messagedigest.digest());
}

public static String getMD5String(String s){
return getMD5String(s.getBytes());
}

public static String getMD5String(byte[] bytes){
messagedigest.update(bytes);
return bufferToHex(messagedigest.digest());
}

private static String bufferToHex(byte bytes[]){
return bufferToHex(bytes, 0,bytes.length);
}

private static String bufferToHex(byte bytes[], int m, int n){
StringBuffer stringbuffer =new StringBuffer(2 * n);
int k = m + n;
for (int l = m; l< k; l++) {
appendHexPair(bytes[l], stringbuffer);
}
return stringbuffer.toString();
}

private static void appendHexPair(byte bt, StringBuffer stringbuffer) {
char c0 = hexDigits[(bt& 0xf0) >> 4];
char c1 = hexDigits[bt& 0xf];
stringbuffer.append(c0);
stringbuffer.append(c1);
}
public static boolean checkPassword(String password, String md5PwdStr) {
String s =getMD5String(password);
return s.equals(md5PwdStr);
}

//
public static void main(String[] args) throws IOException{
long beginTime =System.currentTimeMillis();
File fileZIP = new File(“D:/TEST/IMG_0004.zip”);
String md5=getFileMD5String(fileZIP);
long endTime =System.currentTimeMillis();
System.out.println(“md5:”+md5+”\n time:”+((endTime-beginTime)/1000)+”s”);
}
} 本文链接地址: java获取文件MD5值代码实例说明