8274879: Replace uses of StringBuffer with StringBuilder within java.base classes

Reviewed-by: naoto

src/java.base/share/classes/java/io/FilePermission.java

@@ -179,7 +179,7 @@ public final class FilePermission extends Permission implements Serializable {
     private static final char WILD_CHAR = '*';
 
 //    public String toString() {
-//        StringBuffer sb = new StringBuffer();
+//        StringBuilder sb = new StringBuilder();
 //        sb.append("*** FilePermission on " + getName() + " ***");
 //        for (Field f : FilePermission.class.getDeclaredFields()) {
 //            if (!Modifier.isStatic(f.getModifiers())) {

src/java.base/share/classes/java/net/SocketPermission.java

@@ -1297,7 +1297,7 @@ public final class SocketPermission extends Permission
     /*
     public String toString()
     {
-        StringBuffer s = new StringBuffer(super.toString() + "\n" +
+        StringBuilder s = new StringBuilder(super.toString() + "\n" +
             "cname = " + cname + "\n" +
             "wildcard = " + wildcard + "\n" +
             "invalid = " + invalid + "\n" +

src/java.base/share/classes/java/net/URL.java

@@ -1762,7 +1762,7 @@ final class UrlDeserializedState {
 
     String reconstituteUrlString() {
 
-        // pre-compute length of StringBuffer
+        // pre-compute length of StringBuilder
         int len = protocol.length() + 1;
         if (authority != null && !authority.isEmpty())
             len += 2 + authority.length();

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

@@ -78,7 +78,7 @@ public class AttributedString {
         }
         else {
             // Build the String contents
-            StringBuffer buffer = new StringBuffer();
+            StringBuilder buffer = new StringBuilder();
             for (int counter = 0; counter < iterators.length; counter++) {
                 appendContents(buffer, iterators[counter]);
             }
@@ -668,9 +668,9 @@ public class AttributedString {
 
     /**
      * Appends the contents of the CharacterIterator iterator into the
-     * StringBuffer buf.
+     * StringBuilder buf.
      */
-    private final void appendContents(StringBuffer buf,
+    private final void appendContents(StringBuilder buf,
                                       CharacterIterator iterator) {
         int index = iterator.getBeginIndex();
         int end = iterator.getEndIndex();

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2021, 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
@@ -178,9 +178,9 @@ public class ChoiceFormat extends NumberFormat {
      *            is {@code null}
      */
     public void applyPattern(String newPattern) {
-        StringBuffer[] segments = new StringBuffer[2];
+        StringBuilder[] segments = new StringBuilder[2];
         for (int i = 0; i < segments.length; ++i) {
-            segments[i] = new StringBuffer();
+            segments[i] = new StringBuilder();
         }
         double[] newChoiceLimits = new double[30];
         String[] newChoiceFormats = new String[30];

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

@@ -1264,8 +1264,8 @@ public final class CompactNumberFormat extends NumberFormat {
         String zeros = "";
         for (int j = 1; j >= 0 && start < pattern.length(); --j) {
 
-            StringBuffer prefix = new StringBuffer();
+            StringBuilder prefix = new StringBuilder();
-            StringBuffer suffix = new StringBuffer();
+            StringBuilder suffix = new StringBuilder();
             boolean inQuote = false;
             // The phase ranges from 0 to 2.  Phase 0 is the prefix.  Phase 1 is
             // the section of the pattern with digits. Phase 2 is the suffix.
@@ -1275,7 +1275,7 @@ public final class CompactNumberFormat extends NumberFormat {
             int phase = 0;
 
             // The affix is either the prefix or the suffix.
-            StringBuffer affix = prefix;
+            StringBuilder affix = prefix;
 
             for (int pos = start; pos < pattern.length(); ++pos) {
                 char ch = pattern.charAt(pos);

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

@@ -2961,8 +2961,8 @@ public class DecimalFormat extends NumberFormat {
      * the expanded affix strings up to date.
      */
     private void expandAffixes() {
-        // Reuse one StringBuffer for better performance
+        // Reuse one StringBuilder for better performance
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
         if (posPrefixPattern != null) {
             positivePrefix = expandAffix(posPrefixPattern, buffer);
             positivePrefixFieldPositions = null;
@@ -2992,10 +2992,10 @@ public class DecimalFormat extends NumberFormat {
      * itself at the end of the pattern.
      *
      * @param pattern the non-null, possibly empty pattern
-     * @param buffer a scratch StringBuffer; its contents will be lost
+     * @param buffer a scratch StringBuilder; its contents will be lost
      * @return the expanded equivalent of pattern
      */
-    private String expandAffix(String pattern, StringBuffer buffer) {
+    private String expandAffix(String pattern, StringBuilder buffer) {
         buffer.setLength(0);
         for (int i=0; i<pattern.length(); ) {
             char c = pattern.charAt(i++);
@@ -3097,7 +3097,7 @@ public class DecimalFormat extends NumberFormat {
     }
 
     /**
-     * Appends an affix pattern to the given StringBuffer, quoting special
+     * Appends an affix pattern to the given StringBuilder, quoting special
      * characters as needed.  Uses the internal affix pattern, if that exists,
      * or the literal affix, if the internal affix pattern is null.  The
      * appended string will generate the same affix pattern (or literal affix)
@@ -3111,7 +3111,7 @@ public class DecimalFormat extends NumberFormat {
      * @param localized true if the appended pattern should contain localized
      * pattern characters; otherwise, non-localized pattern chars are appended
      */
-    private void appendAffix(StringBuffer buffer, String affixPattern,
+    private void appendAffix(StringBuilder buffer, String affixPattern,
                              String expAffix, boolean localized) {
         if (affixPattern == null) {
             appendAffix(buffer, expAffix, localized);
@@ -3156,11 +3156,11 @@ public class DecimalFormat extends NumberFormat {
     }
 
     /**
-     * Append an affix to the given StringBuffer, using quotes if
+     * Append an affix to the given StringBuilder, using quotes if
      * there are special characters.  Single quotes themselves must be
      * escaped in either case.
      */
-    private void appendAffix(StringBuffer buffer, String affix, boolean localized) {
+    private void appendAffix(StringBuilder buffer, String affix, boolean localized) {
         boolean needQuote;
         if (localized) {
             needQuote = affix.indexOf(symbols.getZeroDigit()) >= 0
@@ -3198,7 +3198,7 @@ public class DecimalFormat extends NumberFormat {
     /**
      * Does the real work of generating a pattern.  */
     private String toPattern(boolean localized) {
-        StringBuffer result = new StringBuffer();
+        StringBuilder result = new StringBuilder();
         for (int j = 1; j >= 0; --j) {
             if (j == 1)
                 appendAffix(result, posPrefixPattern, positivePrefix, localized);
@@ -3341,8 +3341,8 @@ public class DecimalFormat extends NumberFormat {
         int start = 0;
         for (int j = 1; j >= 0 && start < pattern.length(); --j) {
             boolean inQuote = false;
-            StringBuffer prefix = new StringBuffer();
+            StringBuilder prefix = new StringBuilder();
-            StringBuffer suffix = new StringBuffer();
+            StringBuilder suffix = new StringBuilder();
             int decimalPos = -1;
             int multiplier = 1;
             int digitLeftCount = 0, zeroDigitCount = 0, digitRightCount = 0;
@@ -3358,7 +3358,7 @@ public class DecimalFormat extends NumberFormat {
             int phase = 0;
 
             // The affix is either the prefix or the suffix.
-            StringBuffer affix = prefix;
+            StringBuilder affix = prefix;
 
             for (int pos = start; pos < pattern.length(); ++pos) {
                 char ch = pattern.charAt(pos);

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

@@ -401,7 +401,7 @@ final class RBTableBuilder {
         // can work right
         if (fwd && groupChars.length() > 1) {
             addContractFlags(groupChars);
-            addContractOrder(new StringBuffer(groupChars).reverse().toString(),
+            addContractOrder(new StringBuilder(groupChars).reverse().toString(),
                              anOrder, false);
         }
     }

src/java.base/share/classes/sun/security/util/Debug.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2021, 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
@@ -262,7 +262,7 @@ public class Debug {
     private static String marshal(String args) {
         if (args != null) {
             StringBuilder target = new StringBuilder();
-            StringBuffer source = new StringBuffer(args);
+            StringBuilder source = new StringBuilder(args);
 
             // obtain the "permission=<classname>" options
             // the syntax of classname: IDENTIFIER.IDENTIFIER
@@ -274,7 +274,7 @@ public class Debug {
                 "[a-zA-Z_$][a-zA-Z0-9_$]*([.][a-zA-Z_$][a-zA-Z0-9_$]*)*";
             Pattern pattern = Pattern.compile(reg);
             Matcher matcher = pattern.matcher(source);
-            StringBuffer left = new StringBuffer();
+            StringBuilder left = new StringBuilder();
             while (matcher.find()) {
                 String matched = matcher.group();
                 target.append(matched.replaceFirst(keyReg, keyStr));
@@ -298,7 +298,7 @@ public class Debug {
             reg = keyReg + "[^, ;]*";
             pattern = Pattern.compile(reg);
             matcher = pattern.matcher(source);
-            left = new StringBuffer();
+            left = new StringBuilder();
             while (matcher.find()) {
                 String matched = matcher.group();
                 target.append(matched.replaceFirst(keyReg, keyStr));

src/java.base/share/classes/sun/util/calendar/JulianCalendar.java

@@ -94,7 +94,7 @@ public class JulianCalendar extends BaseCalendar {
         public String toString() {
             String time = super.toString();
             time = time.substring(time.indexOf('T'));
-            StringBuffer sb = new StringBuffer();
+            StringBuilder sb = new StringBuilder();
             Era era = getEra();
             if (era != null) {
                 String n = era.getAbbreviation();

src/java.base/share/classes/sun/util/calendar/LocalGregorianCalendar.java

@@ -123,7 +123,7 @@ public class LocalGregorianCalendar extends BaseCalendar {
         public String toString() {
             String time = super.toString();
             time = time.substring(time.indexOf('T'));
-            StringBuffer sb = new StringBuffer();
+            StringBuilder sb = new StringBuilder();
             Era era = getEra();
             if (era != null) {
                 String abbr = era.getAbbreviation();