生成sha1签名时，加入参数判断

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

@@ -1,6 +1,7 @@
 package me.chanjar.weixin.common.util.crypto;
 
 import org.apache.commons.codec.digest.DigestUtils;
+import org.apache.commons.lang3.StringUtils;
 
 import java.util.Arrays;
 
@@ -13,6 +14,10 @@ public class SHA1 {
    * 串接arr参数，生成sha1 digest
    */
   public static String gen(String... arr) {
+    if (StringUtils.isAnyEmpty(arr)) {
+      throw new IllegalArgumentException("非法请求参数，有部分参数为空 : " + Arrays.toString(arr));
+    }
+
     Arrays.sort(arr);
     StringBuilder sb = new StringBuilder();
     for (String a : arr) {

weixin-java-common/src/test/java/me/chanjar/weixin/common/util/crypto/SHA1Test.java

@@ -0,0 +1,36 @@
+package me.chanjar.weixin.common.util.crypto;
+
+import org.testng.annotations.Test;
+
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertNotNull;
+
+/**
+ * <pre>
+ *  Created by BinaryWang on 2017/6/10.
+ * </pre>
+ *
+ * @author <a href="https://github.com/binarywang">binarywang(Binary Wang)</a>
+ */
+public class SHA1Test {
+  @Test
+  public void testGen() throws Exception {
+    final String result = SHA1.gen("123", "345");
+    assertNotNull(result);
+    assertEquals(result,"9f537aeb751ec72605f57f94a2f6dc3e3958e1dd");
+  }
+
+  @Test(expectedExceptions = {IllegalArgumentException.class})
+  public void testGen_illegalArguments() {
+    final String result = SHA1.gen(null, "", "345");
+    assertNotNull(result);
+  }
+
+  @Test
+  public void testGenWithAmple() throws Exception {
+    final String result = SHA1.genWithAmple("123", "345");
+    assertNotNull(result);
+    assertEquals(result,"20b896ccbd5a72dde5dbe0878ff985e4069771c6");
+  }
+
+}