8294397: Replace StringBuffer with StringBuilder within java.text

Reviewed-by: lancea, naoto, bchristi

Author: justin-curtis-lu

src/java.base/share/classes/java/text/CollationElementIterator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2022, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -776,7 +776,7 @@ private int prevContractChar(int ch)
     private NormalizerBase text = null;
     private int[] buffer = null;
     private int expIndex = 0;
-    private StringBuffer key = new StringBuffer(5);
+    private StringBuilder key = new StringBuilder(5);
     private int swapOrder = 0;
     private RBCollationTables ordering;
     private RuleBasedCollator owner;

src/java.base/share/classes/java/text/DigitList.java

@@ -161,12 +161,12 @@ public final double getDouble() {
             return 0.0;
         }
 
-        StringBuffer temp = getStringBuffer();
-        temp.append('.');
-        temp.append(digits, 0, count);
-        temp.append('E');
-        temp.append(decimalAt);
-        return Double.parseDouble(temp.toString());
+        return Double.parseDouble(getStringBuilder()
+                .append('.')
+                .append(digits, 0, count)
+                .append('E')
+                .append(decimalAt)
+                .toString());
     }
 
     /**
@@ -187,7 +187,7 @@ public final long getLong() {
             return Long.MIN_VALUE;
         }
 
-        StringBuffer temp = getStringBuffer();
+        StringBuilder temp = getStringBuilder();
         temp.append(digits, 0, count);
         for (int i = count; i < decimalAt; ++i) {
             temp.append('0');
@@ -736,7 +736,7 @@ public Object clone() {
             char[] newDigits = new char[digits.length];
             System.arraycopy(digits, 0, newDigits, 0, digits.length);
             other.digits = newDigits;
-            other.tempBuffer = null;
+            other.tempBuilder = null;
             return other;
         } catch (CloneNotSupportedException e) {
             throw new InternalError(e);
@@ -788,23 +788,24 @@ public String toString() {
         if (isZero()) {
             return "0";
         }
-        StringBuffer buf = getStringBuffer();
-        buf.append("0.");
-        buf.append(digits, 0, count);
-        buf.append("x10^");
-        buf.append(decimalAt);
-        return buf.toString();
+
+        return getStringBuilder()
+                .append("0.")
+                .append(digits, 0, count)
+                .append("x10^")
+                .append(decimalAt)
+                .toString();
     }
 
-    private StringBuffer tempBuffer;
+    private StringBuilder tempBuilder;
 
-    private StringBuffer getStringBuffer() {
-        if (tempBuffer == null) {
-            tempBuffer = new StringBuffer(MAX_COUNT);
+    private StringBuilder getStringBuilder() {
+        if (tempBuilder == null) {
+            tempBuilder = new StringBuilder(MAX_COUNT);
         } else {
-            tempBuffer.setLength(0);
+            tempBuilder.setLength(0);
         }
-        return tempBuffer;
+        return tempBuilder;
     }
 
     private void extendDigits(int len) {

src/java.base/share/classes/java/text/MergeCollation.java

@@ -101,18 +101,18 @@ public String getPattern(boolean withWhiteSpace) {
                     PatternEntry last = findLastWithNoExtension(i-1);
                     for (int j = extList.size() - 1; j >= 0 ; j--) {
                         tmp = extList.get(j);
-                        tmp.addToBuffer(result, false, withWhiteSpace, last);
+                        tmp.addToBuilder(result, false, withWhiteSpace, last);
                     }
                     extList = null;
                 }
-                entry.addToBuffer(result, false, withWhiteSpace, null);
+                entry.addToBuilder(result, false, withWhiteSpace, null);
             }
         }
         if (extList != null) {
             PatternEntry last = findLastWithNoExtension(i-1);
             for (int j = extList.size() - 1; j >= 0 ; j--) {
                 tmp = extList.get(j);
-                tmp.addToBuffer(result, false, withWhiteSpace, last);
+                tmp.addToBuilder(result, false, withWhiteSpace, last);
             }
             extList = null;
         }
@@ -151,7 +151,7 @@ public String emitPattern(boolean withWhiteSpace) {
         {
             PatternEntry entry = patterns.get(i);
             if (entry != null) {
-                entry.addToBuffer(result, true, withWhiteSpace, null);
+                entry.addToBuilder(result, true, withWhiteSpace, null);
             }
         }
         return result.toString();
@@ -211,7 +211,7 @@ public PatternEntry getItemAt(int index) {
 
     // This is really used as a local variable inside fixEntry, but we cache
     // it here to avoid newing it up every time the method is called.
-    private transient StringBuffer excess = new StringBuffer();
+    private transient StringBuilder excess = new StringBuilder();
 
     //
     // When building a MergeCollation, we need to do lots of searches to see
@@ -300,7 +300,7 @@ private final void fixEntry(PatternEntry newEntry) throws ParseException
     }
 
     private final int findLastEntry(PatternEntry entry,
-                              StringBuffer excessChars) throws ParseException
+                              StringBuilder excessChars) throws ParseException
     {
         if (entry == null)
             return 0;

src/java.base/share/classes/java/text/PatternEntry.java

@@ -84,7 +84,7 @@ public int hashCode() {
      */
     public String toString() {
         StringBuilder result = new StringBuilder();
-        addToBuffer(result, true, false, null);
+        addToBuilder(result, true, false, null);
         return result.toString();
     }
 
@@ -111,10 +111,10 @@ final String getChars() {
 
     // ===== privates =====
 
-    void addToBuffer(StringBuilder toAddTo,
-                     boolean showExtension,
-                     boolean showWhiteSpace,
-                     PatternEntry lastEntry)
+    void addToBuilder(StringBuilder toAddTo,
+                      boolean showExtension,
+                      boolean showWhiteSpace,
+                      PatternEntry lastEntry)
     {
         if (showWhiteSpace && toAddTo.length() > 0)
             if (strength == Collator.PRIMARY || lastEntry != null)
@@ -190,8 +190,8 @@ private static void appendQuoted(String chars, StringBuilder toAddTo) {
     //========================================================================
 
     PatternEntry(int strength,
-                 StringBuffer chars,
-                 StringBuffer extension)
+                 StringBuilder chars,
+                 StringBuilder extension)
     {
         this.strength = strength;
         this.chars = chars.toString();
@@ -287,8 +287,8 @@ public PatternEntry next() throws ParseException {
         }
 
         // We re-use these objects in order to improve performance
-        private StringBuffer newChars = new StringBuffer();
-        private StringBuffer newExtension = new StringBuffer();
+        private StringBuilder newChars = new StringBuilder();
+        private StringBuilder newExtension = new StringBuilder();
 
     }
 

test/jdk/sun/text/IntHashtable/Bug4170614TestRun.java

@@ -21,7 +21,7 @@
  * questions.
  */
 
-/**
+/*
  * @test
  * @bug 4705389
  * @summary Make sure to find removed slots, which test case will be timed out without the fix.

test/jdk/sun/text/IntHashtable/Bug4705389.java

@@ -21,11 +21,6 @@
  * questions.
  */
 
-/*
-    (this test doesn't have an at-test tag because it's run by Bug4170614TestRun.java
-     instead of directly by the test harness)
-*/
-
 /*
  * This file is available under and governed by the GNU General Public
  * License version 2 only, as published by the Free Software Foundation.
@@ -61,13 +56,22 @@
  * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
  *
  */
+
+/* @test
+ * @bug 4170614
+ * @summary Test internal hashCode() and equals() functions
+ * @library ../../../../patch-src
+ * @build java.base/java.text.Bug4170614Test
+ * @run main java.base/java.text.Bug4170614Test
+ */
+
 package java.text;
 import sun.text.IntHashtable;
 
 
 /**
  * This class tests some internal hashCode() functions.
- * Bug #4170614 complained that we had two iternal classes that
+ * Bug #4170614 complained that we had two internal classes that
  * break the invariant that if a.equals(b) than a.hashCode() ==
  * b.hashCode().  This is because these classes overrode equals()
  * but not hashCode().  These are both purely internal classes, and
@@ -142,15 +146,15 @@ public static void testIntHashtable() throws Exception {
 
     public static void testPatternEntry() throws Exception {
         PatternEntry fred = new PatternEntry(1,
-                                             new StringBuffer("hello"),
-                                             new StringBuffer("up"));
+                                             new StringBuilder("hello"),
+                                             new StringBuilder("up"));
         PatternEntry barney = new PatternEntry(1,
-                                               new StringBuffer("hello"),
-                                               new StringBuffer("down"));
+                                               new StringBuilder("hello"),
+                                               new StringBuilder("down"));
         // (equals() only considers the "chars" field, so fred and barney are equal)
         PatternEntry homer = new PatternEntry(1,
-                                              new StringBuffer("goodbye"),
-                                              new StringBuffer("up"));
+                                              new StringBuilder("goodbye"),
+                                              new StringBuilder("up"));
 
         if (fred.equals(barney)) {
             System.out.println("fred.equals(barney)");