issue #74;

git commit -m issue

weixin-java-common/src/main/java/me/chanjar/weixin/common/util/crypto/SHA1.java

@@ -10,27 +10,49 @@ import java.util.Arrays;
 public class SHA1 {
 
   /**
-   * 生成SHA1签名
+   * 串接arr参数，生成sha1 digest
+   *
    * @param arr
    * @return
    */
   public static String gen(String... arr) throws NoSuchAlgorithmException {
     Arrays.sort(arr);
     StringBuilder sb = new StringBuilder();
-    for(String a : arr) {
+    for (String a : arr) {
       sb.append(a);
     }
+    return genStr(sb.toString());
+  }
 
+  /**
+   * 用&串接arr参数，生成sha1 digest
+   *
+   * @param arr
+   * @return
+   */
+  public static String genWithAmple(String... arr) throws NoSuchAlgorithmException {
+    Arrays.sort(arr);
+    StringBuilder sb = new StringBuilder();
+    for (int i = 0; i < arr.length; i++) {
+      String a = arr[i];
+      sb.append(a);
+      if (i != arr.length - 1) {
+        sb.append('&');
+      }
+    }
+    return genStr(sb.toString());
+  }
+
+  public static String genStr(String str) throws NoSuchAlgorithmException {
     MessageDigest sha1 = MessageDigest.getInstance("SHA1");
-    sha1.update(sb.toString().getBytes());
+    sha1.update(str.getBytes());
     byte[] output = sha1.digest();
     return bytesToHex(output);
   }
 
-
   protected static String bytesToHex(byte[] b) {
-    char hexDigit[] = {'0', '1', '2', '3', '4', '5', '6', '7',
-        '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
+    char hexDigit[] = { '0', '1', '2', '3', '4', '5', '6', '7',
+        '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
     StringBuffer buf = new StringBuffer();
     for (int j = 0; j < b.length; j++) {
       buf.append(hexDigit[(b[j] >> 4) & 0x0f]);