net.openhft.compiler

Enum CompilerUtils

java.lang.Object

java.lang.Enum<CompilerUtils>

net.openhft.compiler.CompilerUtils

All Implemented Interfaces:

Serializable, Comparable<CompilerUtils>

public enum CompilerUtils
extends Enum<CompilerUtils>

Provides static utility methods for runtime Java compilation, dynamic class loading, and class-path manipulation. Acts as the primary entry point for simple compilation tasks.

Field Summary

Fields

Modifier and Type	Field and Description
static CachedCompiler	CACHED_COMPILER In-memory singleton compiler reused across calls.
static boolean	DEBUGGING Indicates whether the JVM started with debugging enabled.

Method Summary

Modifier and Type	Method and Description
static boolean	addClassPath(@NotNull String dir) Adds a directory to the compilation class-path.
static Class<?>	defineClass(@Nullable ClassLoader classLoader, @NotNull String className, @NotNull byte[] bytes) Defines a class from the supplied bytecode.
static void	defineClass(@NotNull String className, @NotNull byte[] bytes) Define a class for byte code.
static Class<?>	loadFromResource(@NotNull String className, @NotNull String resourceName) Loads a class from a source file found on the class-path or local file system.
static CompilerUtils	valueOf(String name) Returns the enum constant of this type with the specified name.
static CompilerUtils[]	values() Returns an array containing the constants of this enum type, in the order they are declared.
static boolean	writeBytes(@NotNull File file, @NotNull byte[] bytes) Writes the given bytes to the specified file.
static boolean	writeText(@NotNull File file, @NotNull String text) Writes the provided text to the target file using UTF-8.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Field Detail

DEBUGGING

public static final boolean DEBUGGING

Indicates whether the JVM started with debugging enabled.

CACHED_COMPILER

public static final CachedCompiler CACHED_COMPILER

In-memory singleton compiler reused across calls.

Method Detail

values

public static CompilerUtils[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (CompilerUtils c : CompilerUtils.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static CompilerUtils valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

loadFromResource

public static Class<?> loadFromResource(@NotNull
                                        @NotNull String className,
                                        @NotNull
                                        @NotNull String resourceName)
                                 throws IOException,
                                        ClassNotFoundException

Loads a class from a source file found on the class-path or local file system. Thread-safe as it delegates to the cached compiler.

Parameters:

className - expected class name of the outer class.

resourceName - full file name with extension.

Returns:

the loaded outer class.

Throws:

IOException - if the resource cannot be read.

ClassNotFoundException - if the compiled class name differs or fails to initialise.

addClassPath

public static boolean addClassPath(@NotNull
                                   @NotNull String dir)

Adds a directory to the compilation class-path. This method is not thread-safe and should be called in a single-threaded context.

Parameters:

dir - directory to add.

Returns:

true if the directory exists and was appended.

Throws:

AssertionError - if the compiler cannot be reinitialised.

defineClass

public static void defineClass(@NotNull
                               @NotNull String className,
                               @NotNull
                               @NotNull byte[] bytes)

Define a class for byte code.

Parameters:

className - expected to load.

bytes - of the byte code.

defineClass

public static Class<?> defineClass(@Nullable
                                   @Nullable ClassLoader classLoader,
                                   @NotNull
                                   @NotNull String className,
                                   @NotNull
                                   @NotNull byte[] bytes)

Defines a class from the supplied bytecode. Thread-safe and uses Unsafe to bypass access checks.

Parameters:

classLoader - class loader to define the class within.

className - expected binary name.

bytes - compiled bytecode for the class.

Returns:

the defined class instance.

Throws:

AssertionError - if defineClass cannot be invoked.

writeText

public static boolean writeText(@NotNull
                                @NotNull File file,
                                @NotNull
                                @NotNull String text)

Writes the provided text to the target file using UTF-8. Not thread-safe and may create or overwrite the file.

Parameters:

file - destination file.

text - text to write.

Returns:

true if the contents changed.

Throws:

IllegalStateException - if the file cannot be written.

writeBytes

public static boolean writeBytes(@NotNull
                                 @NotNull File file,
                                 @NotNull
                                 @NotNull byte[] bytes)

Writes the given bytes to the specified file. Not thread-safe.

Parameters:

file - destination file.

bytes - bytes to write.

Returns:

true if the file contents were updated.

Throws:

IllegalStateException - if the write fails.