Summary: currently String.contentEquals( StringBuffer sb ) synchronizes
on sb, but String.contentEquals( CharSequence cs ) does not sync when cs
is a StringBuffer
Proposed change: remove contentEquals( StringBuffer ) and have
contentEquals( CharSequence ) do the checking and synchronize if the cs
is a StringBuffer.
Note: I expect this will require CCC approval because of the removal of
contentEquals( StringBuffer ).
Thanks,
Jim
Proposed patch:
diff --git a/src/share/classes/java/lang/String.java
b/src/share/classes/java/lang/String.java
--- a/src/share/classes/java/lang/String.java
+++ b/src/share/classes/java/lang/String.java
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1994, 2010, Oracle and/or its affiliates. All rights
reserved.
+ * Copyright (c) 1994, 2012, 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
@@ -984,30 +984,26 @@
return false;
}
- /**
- * Compares this string to the specified {@code StringBuffer}. The
result
- * is {@code true} if and only if this {@code String} represents
the same
- * sequence of characters as the specified {@code StringBuffer}.
- *
- * @param sb
- * The {@code StringBuffer} to compare this {@code String}
against
- *
- * @return {@code true} if this {@code String} represents the same
- * sequence of characters as the specified {@code
StringBuffer},
- * {@code false} otherwise
- *
- * @since 1.4
- */
- public boolean contentEquals(StringBuffer sb) {
- synchronized (sb) {
- return contentEquals((CharSequence) sb);
+ private boolean contentEquals(AbstractStringBuilder sb) {
+ char v1[] = value;
+ char v2[] = sb.getValue();
+ int i = 0;
+ int n = value.length;
+ while (n-- != 0) {
+ if (v1[i] != v2[i]) {
+ return false;
+ }
+ i++;
}
+ return true;
}
/**
- * Compares this string to the specified {@code CharSequence}. The
result
- * is {@code true} if and only if this {@code String} represents
the same
- * sequence of char values as the specified sequence.
+ * Compares this string to the specified {@code CharSequence}. The
+ * result is {@code true} if and only if this {@code String}
represents the
+ * same sequence of char values as the specified sequence. Note
that if the
+ * {@code CharSequence} is a {@code StringBuffer} then the method
+ * synchronizes on it.
*
* @param cs
* The sequence to compare this {@code String} against
@@ -1023,16 +1019,13 @@
return false;
// Argument is a StringBuffer, StringBuilder
if (cs instanceof AbstractStringBuilder) {
- char v1[] = value;
- char v2[] = ((AbstractStringBuilder) cs).getValue();
- int i = 0;
- int n = value.length;
- while (n-- != 0) {
- if (v1[i] != v2[i])
- return false;
- i++;
+ if (cs instanceof StringBuffer) {
+ synchronized(cs) {
+ return contentEquals((AbstractStringBuilder)cs);
+ }
+ } else {
+ return contentEquals((AbstractStringBuilder)cs);
}
- return true;
}
// Argument is a String
if (cs.equals(this))
--
Jim Gish | Consulting Member of Technical Staff | +1.781.442.0304
Oracle Java Platform Group | Core Libraries Team
35 Network Drive
Burlington, MA 01803
jim.g...@oracle.com
