Simplify the code of StringUtils to make it more graceful. (apache#2740

)

* Simplify the code of StringUtils to make it more graceful.

* Add Apache license

dubbo-common/src/main/java/org/apache/dubbo/common/utils/ArrayUtils.java

@@ -0,0 +1,47 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.dubbo.common.utils;
+
+/**
+ * Contains some methods to check array.
+ */
+public final class ArrayUtils {
+
+    private ArrayUtils() {
+    }
+
+    /**
+     * <p>Checks if the array is null or empty. <p/>
+     *
+     * @param array th array to check
+     * @return {@code true} if the array is null or empty.
+     */
+    public static boolean isEmpty(final Object[] array) {
+        return array == null || array.length == 0;
+    }
+
+    /**
+     * <p>Checks if the array is not null or empty. <p/>
+     *
+     * @param array th array to check
+     * @return {@code true} if the array is not null or empty.
+     */
+    public static boolean isNotEmpty(final Object[] array) {
+        return !isEmpty(array);
+    }
+}

dubbo-common/src/main/java/org/apache/dubbo/common/utils/StringUtils.java

@@ -174,7 +174,7 @@ public static String repeat(final String str, final String separator, final int
      *  {@code null} if null String input
      */
     public static String removeEnd(final String str, final String remove) {
-        if (isEmpty(str) || isEmpty(remove)) {
+        if (isAnyEmpty(str, remove)) {
             return str;
         }
         if (str.endsWith(remove)) {
@@ -314,7 +314,7 @@ public static String replace(final String text, final String searchString, final
      *  {@code null} if null String input
      */
     public static String replace(final String text, final String searchString, final String replacement, int max) {
-        if (isEmpty(text) || isEmpty(searchString) || replacement == null || max == 0) {
+        if (isAnyEmpty(text, searchString) || replacement == null || max == 0) {
             return text;
         }
         int start = 0;
@@ -340,10 +340,7 @@ public static String replace(final String text, final String searchString, final
     }
 
     public static boolean isBlank(String str) {
-        if (str == null || str.length() == 0) {
-            return true;
-        }
-        return false;
+        return isEmpty(str);
     }
 
     /**
@@ -353,10 +350,57 @@ public static boolean isBlank(String str) {
      * @return is empty.
      */
     public static boolean isEmpty(String str) {
-        if (str == null || str.length() == 0) {
-            return true;
+        return str == null || str.isEmpty();
+    }
+
+    /**
+     * <p>Checks if the strings contain empty or null elements. <p/>
+     *
+     * <pre>
+     * StringUtils.isNoneEmpty(null)            = false
+     * StringUtils.isNoneEmpty("")              = false
+     * StringUtils.isNoneEmpty(" ")             = true
+     * StringUtils.isNoneEmpty("abc")           = true
+     * StringUtils.isNoneEmpty("abc", "def")    = true
+     * StringUtils.isNoneEmpty("abc", null)     = false
+     * StringUtils.isNoneEmpty("abc", "")       = false
+     * StringUtils.isNoneEmpty("abc", " ")      = true
+     * </pre>
+     *
+     * @param ss the strings to check
+     * @return {@code true} if all strings are not empty or null
+     */
+    public static boolean isNoneEmpty(final String... ss) {
+        if (ArrayUtils.isEmpty(ss)) {
+            return false;
         }
-        return false;
+        for (final String s : ss){
+            if (isEmpty(s)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    /**
+     * <p>Checks if the strings contain at least on empty or null element. <p/>
+     *
+     * <pre>
+     * StringUtils.isAnyEmpty(null)            = true
+     * StringUtils.isAnyEmpty("")              = true
+     * StringUtils.isAnyEmpty(" ")             = false
+     * StringUtils.isAnyEmpty("abc")           = false
+     * StringUtils.isAnyEmpty("abc", "def")    = false
+     * StringUtils.isAnyEmpty("abc", null)     = true
+     * StringUtils.isAnyEmpty("abc", "")       = true
+     * StringUtils.isAnyEmpty("abc", " ")      = false
+     * </pre>
+     *
+     * @param ss the strings to check
+     * @return {@code true} if at least one in the strings is empty or null
+     */
+    public static boolean isAnyEmpty(final String... ss) {
+        return !isNoneEmpty(ss);
     }
 
     /**
@@ -366,7 +410,7 @@ public static boolean isEmpty(String str) {
      * @return is not empty.
      */
     public static boolean isNotEmpty(String str) {
-        return str != null && str.length() > 0;
+        return !isEmpty(str);
     }
 
     /**
@@ -391,25 +435,19 @@ public static boolean isEquals(String s1, String s2) {
      * @return is integer
      */
     public static boolean isInteger(String str) {
-        if (str == null || str.length() == 0) {
-            return false;
-        }
-        return INT_PATTERN.matcher(str).matches();
+        return isNotEmpty(str) && INT_PATTERN.matcher(str).matches();
     }
 
     public static int parseInteger(String str) {
-        if (!isInteger(str)) {
-            return 0;
-        }
-        return Integer.parseInt(str);
+        return isInteger(str) ? Integer.parseInt(str) : 0;
     }
 
     /**
      * Returns true if s is a legal Java identifier.<p>
      * <a href="http://www.exampledepot.com/egs/java.lang/IsJavaId.html">more info.</a>
      */
     public static boolean isJavaIdentifier(String s) {
-        if (s.length() == 0 || !Character.isJavaIdentifierStart(s.charAt(0))) {
+        if (isEmpty(s) || !Character.isJavaIdentifierStart(s.charAt(0))) {
             return false;
         }
         for (int i = 1; i < s.length(); i++) {
@@ -421,10 +459,7 @@ public static boolean isJavaIdentifier(String s) {
     }
 
     public static boolean isContains(String values, String value) {
-        if (values == null || values.length() == 0) {
-            return false;
-        }
-        return isContains(Constants.COMMA_SPLIT_PATTERN.split(values), value);
+        return isNotEmpty(values) && isContains(Constants.COMMA_SPLIT_PATTERN.split(values), value);
     }
 
     /**
@@ -433,7 +468,7 @@ public static boolean isContains(String values, String value) {
      * @return contains
      */
     public static boolean isContains(String[] values, String value) {
-        if (value != null && value.length() > 0 && values != null && values.length > 0) {
+        if (isNotEmpty(value) && ArrayUtils.isNotEmpty(values)) {
             for (String v : values) {
                 if (value.equals(v)) {
                     return true;
@@ -449,7 +484,7 @@ public static boolean isNumeric(String str) {
         }
         int sz = str.length();
         for (int i = 0; i < sz; i++) {
-            if (Character.isDigit(str.charAt(i)) == false) {
+            if (!Character.isDigit(str.charAt(i))) {
                 return false;
             }
         }
@@ -494,14 +529,14 @@ public static String toString(String msg, Throwable e) {
     }
 
     /**
-     * translat.
+     * translate.
      *
      * @param src  source string.
      * @param from src char table.
      * @param to   target char table.
      * @return String.
      */
-    public static String translat(String src, String from, String to) {
+    public static String translate(String src, String from, String to) {
         if (isEmpty(src)) {
             return src;
         }
@@ -561,8 +596,8 @@ public static String[] split(String str, char ch) {
      * @return String.
      */
     public static String join(String[] array) {
-        if (array.length == 0) {
-            return "";
+        if (ArrayUtils.isEmpty(array)) {
+            return EMPTY;
         }
         StringBuilder sb = new StringBuilder();
         for (String s : array) {
@@ -579,8 +614,8 @@ public static String join(String[] array) {
      * @return String.
      */
     public static String join(String[] array, char split) {
-        if (array.length == 0) {
-            return "";
+        if (ArrayUtils.isEmpty(array)) {
+            return EMPTY;
         }
         StringBuilder sb = new StringBuilder();
         for (int i = 0; i < array.length; i++) {
@@ -600,8 +635,8 @@ public static String join(String[] array, char split) {
      * @return String.
      */
     public static String join(String[] array, String split) {
-        if (array.length == 0) {
-            return "";
+        if (ArrayUtils.isEmpty(array)) {
+            return EMPTY;
         }
         StringBuilder sb = new StringBuilder();
         for (int i = 0; i < array.length; i++) {
@@ -614,8 +649,8 @@ public static String join(String[] array, String split) {
     }
 
     public static String join(Collection<String> coll, String split) {
-        if (coll.isEmpty()) {
-            return "";
+        if (CollectionUtils.isEmpty(coll)) {
+            return EMPTY;
         }
 
         StringBuilder sb = new StringBuilder();
@@ -643,7 +678,7 @@ private static Map<String, String> parseKeyValuePair(String str, String itemSepa
         Map<String, String> map = new HashMap<String, String>(tmp.length);
         for (int i = 0; i < tmp.length; i++) {
             Matcher matcher = KVP_PATTERN.matcher(tmp[i]);
-            if (matcher.matches() == false) {
+            if (!matcher.matches()) {
                 continue;
             }
             map.put(matcher.group(1), matcher.group(2));
@@ -663,7 +698,7 @@ public static String getQueryStringValue(String qs, String key) {
      * @return Parameters instance.
      */
     public static Map<String, String> parseQueryString(String qs) {
-        if (qs == null || qs.length() == 0) {
+        if (isEmpty(qs)) {
             return new HashMap<String, String>();
         }
         return parseKeyValuePair(qs, "\\&");
@@ -672,12 +707,12 @@ public static Map<String, String> parseQueryString(String qs) {
     public static String getServiceKey(Map<String, String> ps) {
         StringBuilder buf = new StringBuilder();
         String group = ps.get(Constants.GROUP_KEY);
-        if (group != null && group.length() > 0) {
+        if (isNotEmpty(group)) {
             buf.append(group).append("/");
         }
         buf.append(ps.get(Constants.INTERFACE_KEY));
         String version = ps.get(Constants.VERSION_KEY);
-        if (version != null && version.length() > 0) {
+        if (isNotEmpty(group)) {
             buf.append(":").append(version);
         }
         return buf.toString();
@@ -689,8 +724,7 @@ public static String toQueryString(Map<String, String> ps) {
             for (Map.Entry<String, String> entry : new TreeMap<String, String>(ps).entrySet()) {
                 String key = entry.getKey();
                 String value = entry.getValue();
-                if (key != null && key.length() > 0
-                        && value != null && value.length() > 0) {
+                if (isNoneEmpty(key, value)) {
                     if (buf.length() > 0) {
                         buf.append("&");
                     }
@@ -704,7 +738,7 @@ public static String toQueryString(Map<String, String> ps) {
     }
 
     public static String camelToSplitName(String camelName, String split) {
-        if (camelName == null || camelName.length() == 0) {
+        if (isEmpty(camelName)) {
             return camelName;
         }
         StringBuilder buf = null;

dubbo-common/src/test/java/org/apache/dubbo/common/utils/ArrayUtilsTest.java

@@ -0,0 +1,41 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.dubbo.common.utils;
+
+import static junit.framework.TestCase.assertFalse;
+import static junit.framework.TestCase.assertTrue;
+
+import org.junit.Test;
+
+public class ArrayUtilsTest {
+
+    @Test
+    public void isEmpty() throws Exception {
+        assertTrue(ArrayUtils.isEmpty(null));
+        assertTrue(ArrayUtils.isEmpty(new Object[0]));
+        assertFalse(ArrayUtils.isEmpty(new Object[]{"abc"}));
+    }
+
+    @Test
+    public void isNotEmpty() throws Exception {
+        assertFalse(ArrayUtils.isNotEmpty(null));
+        assertFalse(ArrayUtils.isNotEmpty(new Object[0]));
+        assertTrue(ArrayUtils.isNotEmpty(new Object[]{"abc"}));
+    }
+
+}

dubbo-common/src/test/java/org/apache/dubbo/common/utils/StringUtilsTest.java

@@ -111,6 +111,30 @@ public void testIsEmpty() throws Exception {
         assertFalse(StringUtils.isEmpty("abc"));
     }
 
+    @Test
+    public void testIsNoneEmpty() throws Exception {
+        assertFalse(StringUtils.isNoneEmpty(null));
+        assertFalse(StringUtils.isNoneEmpty(""));
+        assertTrue(StringUtils.isNoneEmpty(" "));
+        assertTrue(StringUtils.isNoneEmpty("abc"));
+        assertTrue(StringUtils.isNoneEmpty("abc", "def"));
+        assertFalse(StringUtils.isNoneEmpty("abc", null));
+        assertFalse(StringUtils.isNoneEmpty("abc", ""));
+        assertTrue(StringUtils.isNoneEmpty("abc", " "));
+    }
+
+    @Test
+    public void testIsAnyEmpty() throws Exception {
+        assertTrue(StringUtils.isAnyEmpty(null));
+        assertTrue(StringUtils.isAnyEmpty(""));
+        assertFalse(StringUtils.isAnyEmpty(" "));
+        assertFalse(StringUtils.isAnyEmpty("abc"));
+        assertFalse(StringUtils.isAnyEmpty("abc", "def"));
+        assertTrue(StringUtils.isAnyEmpty("abc", null));
+        assertTrue(StringUtils.isAnyEmpty("abc", ""));
+        assertFalse(StringUtils.isAnyEmpty("abc", " "));
+    }
+
     @Test
     public void testIsNotEmpty() throws Exception {
         assertFalse(StringUtils.isNotEmpty(null));
@@ -200,10 +224,10 @@ public void testSplit() throws Exception {
     }
 
     @Test
-    public void testTranslat() throws Exception {
+    public void testTranslate() throws Exception {
         String s = "16314";
-        assertEquals(StringUtils.translat(s, "123456", "abcdef"), "afcad");
-        assertEquals(StringUtils.translat(s, "123456", "abcd"), "acad");
+        assertEquals(StringUtils.translate(s, "123456", "abcdef"), "afcad");
+        assertEquals(StringUtils.translate(s, "123456", "abcd"), "acad");
     }
 
     @Test