Optimisation from Ortwin Glueck (#SANDBOX-166) in which empty String arrays are replaced with constants.

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/sandbox/csv/trunk@430240 13f79535-47bb-0310-9956-ffa450edef68

Author: hen

src/java/org/apache/commons/csv/CSVUtils.java

@@ -24,6 +24,9 @@
  */
 public class CSVUtils {
 
+    private static final String[] EMPTY_STRING_ARRAY = new String[0];
+    private static final String[][] EMPTY_DOUBLE_STRING_ARRAY = new String[0][0];
+
     /**
      * <p><code>CSVUtils</code> instances should NOT be constructed in
      * standard programming. 
@@ -86,7 +89,7 @@ public static String[][] parse(String s) throws IOException {
     if (result == null) {
       // since CSVStrategy ignores empty lines an empty array is returned
       // (i.e. not "result = new String[][] {{""}};")
-      result = new String[0][0];
+      result = EMPTY_DOUBLE_STRING_ARRAY;
     }
     return result;
   }
@@ -108,7 +111,7 @@ public static String[] parseLine(String s) throws IOException {
     }
     // uh,jh: make sure that parseLine("").length == 0
     if (s.length() == 0) {
-      return new String[0];
+      return EMPTY_STRING_ARRAY;
     }
     return (new CSVParser(new StringReader(s))).getLine();
   }