1 files changed, 99 insertions, 0 deletions
diff --git a/src/com/nis/nmsclient/util/MD5Util.java b/src/com/nis/nmsclient/util/MD5Util.java
new file mode 100644
index 0000000..7d2ac4f
--- /dev/null
+++ b/src/com/nis/nmsclient/util/MD5Util.java
@@ -0,0 +1,99 @@
+package com.nis.nmsclient.util;
+
+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 MD5Util {
+	/**
+	 * 默认的密码字符串组合，apache校验下载的文件的正确性用的就是默认的这个组合
+	 */
+	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 nsaex) {
+			System.err.println(MD5Util.class.getName()
+					+ "初始化失败，MessageDigest不支持MD5Util。");
+			nsaex.printStackTrace();
+		}
+	}
+
+	public static void main(String[] args) throws IOException {
+		long begin = System.currentTimeMillis();
+
+		// 2EA3E66AC37DF7610F5BD322EC4FFE48 670M 11s kuri双核1.66G 2G内存
+		File big = new File("I:/大型安装程序的压缩版本/Rational rose 2003.rar");
+
+		String md5 = getFileMD5String(big);
+
+		long end = System.currentTimeMillis();
+		System.out.println("md5:" + md5 + " time:" + ((end - begin) / 1000)
+				+ "s");
+	}
+
+	/**
+	 * 适用于上G大的文件
+	 * 
+	 * @param file
+	 * @return
+	 * @throws IOException
+	 */
+	public static String getFileMD5String(File file) throws IOException {
+		FileInputStream in = null;
+		try {
+			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());
+		} catch (Exception e) {
+			throw new IOException(e.getCause());
+		}finally{
+			if(in!=null){
+				in.close();
+			}
+		}
+	}
+
+	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);
+	}
+}