content: /*
   * 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 com.alipay.remoting.util;
  
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * Created by zhangg on 2016/7/14 21:07.
   *
   * @author <a href=mailto:zhanggeng.zg@antfin.com>GengZhang</a>
   */
  public class StringUtils {
  
      public static final String   EMPTY              = "";
  
      public static final String[] EMPTY_STRING_ARRAY = new String[0];
  
      // Empty checks
      //-----------------------------------------------------------------------
      public static boolean isEmpty(CharSequence cs) {
          return cs == null || cs.length() == 0;
      }
  
      public static boolean isNotEmpty(CharSequence cs) {
          return !StringUtils.isEmpty(cs);
      }
  
      public static boolean isBlank(CharSequence cs) {
          int strLen;
          if (cs == null || (strLen = cs.length()) == 0) {
              return true;
          }
          for (int i = 0; i < strLen; i++) {
              if (!Character.isWhitespace(cs.charAt(i))) {
                  return false;
              }
          }
          return true;
      }
  
      public static boolean isNotBlank(CharSequence cs) {
          return !StringUtils.isBlank(cs);
      }
  
      // Splitting
      //-----------------------------------------------------------------------
  
      public static String[] split(final String str, final char separatorChar) {
          return splitWorker(str, separatorChar, false);
      }
  
      private static String[] splitWorker(final String str, final char separatorChar,
                                          final boolean preserveAllTokens) {
          // Performance tuned for 2.0 (JDK1.4)
  
          if (str == null) {
              return null;
          }
          final int len = str.length();
          if (len == 0) {
              return EMPTY_STRING_ARRAY;
          }
          final List<String> list = new ArrayList<String>();
          int i = 0, start = 0;
          boolean match = false;
          boolean lastMatch = false;
          while (i < len) {
              if (str.charAt(i) == separatorChar) {
                  if (match || preserveAllTokens) {
                      list.add(str.substring(start, i));
                      match = false;
                      lastMatch = true;
                  }
                  start = ++i;
                  continue;
              }
              lastMatch = false;
              match = true;
              i++;
          }
          if (match || preserveAllTokens && lastMatch) {
              list.add(str.substring(start, i));
          }
          return list.toArray(new String[list.size()]);
      }
  
      public static boolean isNumeric(String str) {
          if (str == null) {
              return false;
          } else {
              int sz = str.length();
  
              for (int i = 0; i < sz; ++i) {
                  if (!Character.isDigit(str.charAt(i))) {
                      return false;
                  }
              }
  
              return true;
          }
      }
  
      public static boolean equals(String str1, String str2) {
          return str1 == null ? str2 == null : str1.equals(str2);
      }
  }
  