ICU-21219 Fix for Java version number overflow problem
Internal API VersionInfo.javaVersion() maps Java version number to 4 integer fields. Each field must be up to 255. However, recent OpenJDK 8 update exceed this range.
Luckily, we have only one reference in our code base for checking Java version. CharsetUTF16 uses maxBytePerChar = 4 for Java 5 and older, maxBytePerChar = 2 for newer Java version. Because we no longer support Java 5 runtime, we don't need this conditional check.
We don't have any other uses of VersionInfo.javaVersion(). Java's version range is not what we can control, so I decided to delete the internal use only API completely.
diff --git a/icu4j/main/classes/charset/src/com/ibm/icu/charset/CharsetUTF16.java b/icu4j/main/classes/charset/src/com/ibm/icu/charset/CharsetUTF16.java
index a401441..13f703a 100644
--- a/icu4j/main/classes/charset/src/com/ibm/icu/charset/CharsetUTF16.java
+++ b/icu4j/main/classes/charset/src/com/ibm/icu/charset/CharsetUTF16.java
@@ -17,7 +17,6 @@
import com.ibm.icu.text.UTF16;
import com.ibm.icu.text.UnicodeSet;
-import com.ibm.icu.util.VersionInfo;
/**
* @author Niti Hantaweepant
@@ -65,13 +64,10 @@
this.endianXOR = ENDIAN_XOR_LE;
}
- /* UnicodeBig and UnicodeLittle requires maxBytesPerChar set to 4 in Java 5 or less */
- if ((VersionInfo.javaVersion().getMajor() == 1 && VersionInfo.javaVersion().getMinor() <= 5)
- && (isEndianSpecified && version == 1)) {
- maxBytesPerChar = 4;
- } else {
- maxBytesPerChar = 2;
- }
+ // UnicodeBig and UnicodeLittle used to require maxBytesPerChar set to 4 in Java 5 or less,
+ // but it's no longer necessary for newer Java versions. Java 5 or older runtime is no
+ // longer supported.
+ maxBytesPerChar = 2;
minBytesPerChar = 2;
maxCharsPerByte = 1;
diff --git a/icu4j/main/classes/core/src/com/ibm/icu/util/VersionInfo.java b/icu4j/main/classes/core/src/com/ibm/icu/util/VersionInfo.java
index 8a418ae..48a2b4f 100644
--- a/icu4j/main/classes/core/src/com/ibm/icu/util/VersionInfo.java
+++ b/icu4j/main/classes/core/src/com/ibm/icu/util/VersionInfo.java
@@ -372,56 +372,6 @@
return getInstance(major, 0, 0, 0);
}
- private static volatile VersionInfo javaVersion;
-
- /**
- * @internal
- * @deprecated This API is ICU internal only.
- */
- @Deprecated
- public static VersionInfo javaVersion() {
- if (javaVersion == null) {
- synchronized(VersionInfo.class) {
- if (javaVersion == null) {
- String s = System.getProperty("java.version");
- // clean string
- // preserve only digits, separated by single '.'
- // ignore over 4 digit sequences
- // does not test < 255, very odd...
-
- char[] chars = s.toCharArray();
- int r = 0, w = 0, count = 0;
- boolean numeric = false; // ignore leading non-numerics
- while (r < chars.length) {
- char c = chars[r++];
- if (c < '0' || c > '9') {
- if (numeric) {
- if (count == 3) {
- // only four digit strings allowed
- break;
- }
- numeric = false;
- chars[w++] = '.';
- ++count;
- }
- } else {
- numeric = true;
- chars[w++] = c;
- }
- }
- while (w > 0 && chars[w-1] == '.') {
- --w;
- }
-
- String vs = new String(chars, 0, w);
-
- javaVersion = VersionInfo.getInstance(vs);
- }
- }
- }
- return javaVersion;
- }
-
/**
* Returns the String representative of VersionInfo in the format of
* "major.minor.milli.micro"
