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import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.security.MessageDigest;
import org.apache.commons.codec.binary.Hex;
import org.apache.commons.codec.digest.DigestUtils;
/**
*MD5计算工具
*/
public class Md5CaculateUtil {
/**
* 获取一个文件的md5值(可处理大文件)
* @return md5 value
*/
public static String getMD5(File file) {
FileInputStream fileInputStream = null;
try {
MessageDigest MD5 = MessageDigest.getInstance("MD5");
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(Hex.encodeHex(MD5.digest()));
} catch (Exception e) {
e.printStackTrace();
return null;
} finally {
try {
if (fileInputStream != null){
fileInputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
/**
* 求一个字符串的md5值
* @param target 字符串
* @return md5 value
*/
public static String MD5(String target) {
return DigestUtils.md5Hex(target);
}
public static void main(String[] args) {
long beginTime = System.currentTimeMillis();
File file = new File("D:/1/pdi-ce-7.0.0.0-24.zip");
String md5 = getMD5(file);
long endTime = System.currentTimeMillis();
System.out.println("MD5:" + md5 + "\n 耗时:" + ((endTime - beginTime) / 1000) + "s");
}
}
修改的一个utils方法： package hanwl.FileDemo; 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 = "0123456789ABCDEF".toCharArray(); public static void main(String[] args) { long beginTime = System.currentTimeMillis(); File file = new File("E:/云舒测试文件/20180628-北大社-中国古文字学通论.pdf"); //File file = new File("E:/拉鲁斯法汉双解词典(12新)/制作文件库/其他/SJ00040936 拉鲁斯法汉双解词典(内文排版).zip"); String md5 = calcMD5(file); long endTime = System.currentTimeMillis(); System.out.println("MD5:" + md5 + "\n 耗时:" + ((endTime - beginTime) / 1000) + "s"); } /** * 计算文件 MD5 * @param file * @return 返回文件的md5字符串，如果计算过程中任务的状态变为取消或暂停，返回null， 如果有其他异常，返回空字符串 */ protected static String calcMD5(File file) { try (InputStream stream = Files.newInputStream(file.toPath(), StandardOpenOption.READ)) { MessageDigest digest = MessageDigest.getInstance("MD5"); byte[] buf = new byte[8192]; int len; while ((len = 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 = new StringBuilder(data.length * 2); for (byte b : data) { r.append(hexCode[(b >> 4) & 0xF]); r.append(hexCode[(b & 0xF)]); } return r.toString(); } }
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