Package org.checkerframework.javacutil

Class SystemUtil

java.lang.Object

org.checkerframework.javacutil.SystemUtil

public class SystemUtil
extends Object

This file contains basic utility functions.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	jreVersion	The major version number of the Java runtime (JRE), such as 8, 11, or 17.

Method Summary

Modifier and Type	Method	Description
static @Nullable Integer	available(InputStream is)	Calls InputStream.available(), but returns null instead of throwing an IOException.
static int	getJreVersion()	Deprecated. use field jreVersion instead
static @Nullable String	getReleaseValue(ProcessingEnvironment env)	Returns the release value passed to the compiler or null if release was not passed.
static @Nullable String	getToolsJar()	Returns the pathname to the tools.jar file, or null if it does not exist.
static @Nullable Boolean	isWhitespaceOnly(InputStream is, int readLimit)	Returns true if the first readLimit bytes of the input stream consist only of whitespace.
static int	readCodePoint(InputStream is)	Reads a Unicode code point from an input stream.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

jreVersion

public static final int jreVersion

The major version number of the Java runtime (JRE), such as 8, 11, or 17.

Method Details

available

public static @Nullable Integer available(InputStream is)

Calls InputStream.available(), but returns null instead of throwing an IOException.

Parameters:

is - an input stream

Returns:

is.available(), or null if that throws an exception

isWhitespaceOnly

public static @Nullable Boolean isWhitespaceOnly(InputStream is,
 int readLimit)

Returns true if the first readLimit bytes of the input stream consist only of whitespace.

Parameters:

is - an input stream

readLimit - how many bytes to look ahead in the input stream

Returns:

null if !is.markSupported(); otherwise, true if the first readLimit characters of the input stream consist only of whitespace

readCodePoint

public static int readCodePoint(InputStream is)

Reads a Unicode code point from an input stream.

Parameters:

is - an input stream

Returns:

the Unicode code point for the next character in the input stream

getJreVersion

@Deprecated
public static int getJreVersion()

Deprecated.

use field jreVersion instead

Returns the major version number from the "java.version" system property, such as 8, 11, or 17.

This is different from the version passed to the compiler via --release; use getReleaseValue(ProcessingEnvironment) to get that version.

Two possible formats of the "java.version" system property are considered. Up to Java 8, from a version string like `1.8.whatever`, this method extracts 8. Since Java 9, from a version string like `11.0.1`, this method extracts 11.

Starting in Java 9, there is the int Runtime.version().feature(), but that does not exist on JDK 8.

Returns:

the major version of the Java runtime

getReleaseValue

public static @Nullable String getReleaseValue(ProcessingEnvironment env)

Returns the release value passed to the compiler or null if release was not passed.

Parameters:

env - the ProcessingEnvironment

Returns:

the release value or null if none was passed

getToolsJar

public static @Nullable String getToolsJar()

Returns the pathname to the tools.jar file, or null if it does not exist. Returns null on Java 9 and later.

Returns:

the pathname to the tools.jar file, or null