添加 md5

4dkankan-common-utils/src/main/java/com/fdkankan/common/util/MD5.java

@@ -0,0 +1,86 @@
+package com.fdkankan.common.util;
+
+import java.io.UnsupportedEncodingException;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+public class MD5 {
+
+    public static String md5Str(String str) {
+        if (str == null) return "";
+        return md5Str(str, 0);
+    }
+
+
+    public static String md5Str(String str, int offset) {
+        try {
+            MessageDigest md5 = MessageDigest.getInstance("MD5");
+            byte[] b = str.getBytes("UTF8");
+            md5.update(b, offset, b.length);
+            return byteArrayToHexString(md5.digest());
+        } catch (NoSuchAlgorithmException ex) {
+            ex.printStackTrace();
+            return null;
+        } catch (UnsupportedEncodingException ex) {
+            ex.printStackTrace();
+            return null;
+        }
+    }
+
+    /**
+     * @param b byte[]
+     * @return String
+     */
+    public static String byteArrayToHexString(byte[] b) {
+        String result = "";
+        for (int i = 0; i < b.length; i++) {
+            result += byteToHexString(b[i]);
+        }
+        return result;
+    }
+
+    private static String[] hexDigits =
+            {
+                    "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b",
+                    "c", "d", "e", "f"};
+
+    public static String byteToHexString(byte b) {
+        int n = b;
+        if (n < 0) {
+            n = 256 + n;
+        }
+        int d1 = n / 16;
+        int d2 = n % 16;
+        return hexDigits[d1] + hexDigits[d2];
+    }
+
+    public static void main(String[] args) {
+        System.out.println(byteToHexString((byte) -99));
+        String str =
+                "eeeeeeeeeeeeeewrw213123122222222222222222222222213123213213213erwer";
+        String ened = MD5.md5Str(str);
+        System.out.println(ened.length());
+        System.out.println(ened);
+    }
+
+
+    public final static String getMessageDigest(byte[] buffer) {
+        char hexDigits[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
+        try {
+            MessageDigest mdTemp = MessageDigest.getInstance("MD5");
+            mdTemp.update(buffer);
+            byte[] md = mdTemp.digest();
+            int j = md.length;
+            char str[] = new char[j * 2];
+            int k = 0;
+            for (int i = 0; i < j; i++) {
+                byte byte0 = md[i];
+                str[k++] = hexDigits[byte0 >>> 4 & 0xf];
+                str[k++] = hexDigits[byte0 & 0xf];
+            }
+            return new String(str);
+        } catch (Exception e) {
+            return null;
+        }
+    }
+}