src/java.base/share/classes/java/lang/String.java

rev 52979 : 8215281: Use String.isEmpty() when applicable in java.base
Reviewed-by: TBD

*** 662,672 ****
       *
       * @return  the length of the sequence of characters represented by this
       *          object.
       */
      public int length() {
!         return value.length >> coder();
      }
  
      /**
       * Returns {@code true} if, and only if, {@link #length()} is {@code 0}.
       *
--- 662,672 ----
       *
       * @return  the length of the sequence of characters represented by this
       *          object.
       */
      public int length() {
!         return isLatin1() ? value.length : value.length >> UTF16;
      }
  
      /**
       * Returns {@code true} if, and only if, {@link #length()} is {@code 0}.
       *
*** 1941,1952 ****
       *                of this {@code String}.
       * @return  a string that represents the concatenation of this object's
       *          characters followed by the string argument's characters.
       */
      public String concat(String str) {
!         int olen = str.length();
!         if (olen == 0) {
              return this;
          }
          if (coder() == str.coder()) {
              byte[] val = this.value;
              byte[] oval = str.value;
--- 1941,1951 ----
       *                of this {@code String}.
       * @return  a string that represents the concatenation of this object's
       *          characters followed by the string argument's characters.
       */
      public String concat(String str) {
!         if (str.isEmpty()) {
              return this;
          }
          if (coder() == str.coder()) {
              byte[] val = this.value;
              byte[] oval = str.value;
*** 1954,1963 ****
--- 1953,1963 ----
              byte[] buf = Arrays.copyOf(val, len);
              System.arraycopy(oval, 0, buf, val.length, oval.length);
              return new String(buf, coder);
          }
          int len = length();
+         int olen = str.length();
          byte[] buf = StringUTF16.newBytesFor(len + olen);
          getBytes(buf, 0, UTF16);
          str.getBytes(buf, len, UTF16);
          return new String(buf, UTF16);
      }
*** 2314,2324 ****
                  list.add(substring(off, length()));
  
              // Construct result
              int resultSize = list.size();
              if (limit == 0) {
!                 while (resultSize > 0 && list.get(resultSize - 1).length() == 0) {
                      resultSize--;
                  }
              }
              String[] result = new String[resultSize];
              return list.subList(0, resultSize).toArray(result);
--- 2314,2324 ----
                  list.add(substring(off, length()));
  
              // Construct result
              int resultSize = list.size();
              if (limit == 0) {
!                 while (resultSize > 0 && list.get(resultSize - 1).isEmpty()) {
                      resultSize--;
                  }
              }
              String[] result = new String[resultSize];
              return list.subList(0, resultSize).toArray(result);