计算文件md5java_Java计算文件MD5值(支持大文件)

【实例简介】

【实例截图】

【核心代码】

import java.io.File;

import java.io.IOException;

import java.io.InputStream;

import java.nio.file.Files;

import java.nio.file.StandardOpenOption;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

public class CalcMD5 {

private static final char[] hexCode &＃61; "0123456789ABCDEF".toCharArray();

public static void main(String[] args) {

long beginTime &＃61; System.currentTimeMillis();

File file &＃61; new File("C:/Users/Administrator/Downloads/OpenCVSharp-Samples.rar");

String md5 &＃61; calcMD5(file);

long endTime &＃61; System.currentTimeMillis();

System.out.println("MD5:" md5 "\n 耗时:" ((endTime - beginTime) / 1000) "s");

}

/**

* 计算文件 MD5

* &＃64;param file

* &＃64;return 返回文件的md5字符串&＃xff0c;如果计算过程中任务的状态变为取消或暂停&＃xff0c;返回null&＃xff0c; 如果有其他异常&＃xff0c;返回空字符串

*/

protected static String calcMD5(File file) {

try (InputStream stream &＃61; Files.newInputStream(file.toPath(), StandardOpenOption.READ)) {

MessageDigest digest &＃61; MessageDigest.getInstance("MD5");

byte[] buf &＃61; new byte[8192];

int len;

while ((len &＃61; stream.read(buf)) > 0) {

digest.update(buf, 0, len);

}

return toHexString(digest.digest());

} catch (IOException e) {

e.printStackTrace();

return "";

} catch (NoSuchAlgorithmException e) {

e.printStackTrace();

return "";

}

}

public static String toHexString(byte[] data) {

StringBuilder r &＃61; new StringBuilder(data.length * 2);

for (byte b : data) {

r.append(hexCode[(b >> 4) & 0xF]);

r.append(hexCode[(b & 0xF)]);

}

return r.toString().toLowerCase();

}

}