net.bytebuddy.dynamic.loading

Enum ClassLoadingStrategy.Default

java.lang.Object

java.lang.Enum<ClassLoadingStrategy.Default>

net.bytebuddy.dynamic.loading.ClassLoadingStrategy.Default

All Implemented Interfaces:

Serializable, Comparable<ClassLoadingStrategy.Default>, ClassLoadingStrategy<ClassLoader>, ClassLoadingStrategy.Configurable<ClassLoader>

Enclosing interface:

ClassLoadingStrategy<T extends ClassLoader>

public static enum ClassLoadingStrategy.Default
extends Enum<ClassLoadingStrategy.Default>
implements ClassLoadingStrategy.Configurable<ClassLoader>

This class contains implementations of default class loading strategies.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	ClassLoadingStrategy.Default.InjectionDispatcher A class loading strategy which applies a class loader injection while applying a given ProtectionDomain on class injection.
protected static class	ClassLoadingStrategy.Default.WrappingDispatcher A class loading strategy which creates a wrapping class loader while applying a given ProtectionDomain on class loading.

Nested classes/interfaces inherited from interface net.bytebuddy.dynamic.loading.ClassLoadingStrategy

ClassLoadingStrategy.Configurable<S extends ClassLoader>, ClassLoadingStrategy.Default, ClassLoadingStrategy.ForBootstrapInjection, ClassLoadingStrategy.ForJnaInjection, ClassLoadingStrategy.ForPreloadedTypes, ClassLoadingStrategy.ForUnsafeInjection, ClassLoadingStrategy.UsingLookup

Enum Constant Summary

Enum Constants

Enum Constant and Description
CHILD_FIRST The child-first class loading strategy is a modified version of the WRAPPER where the dynamic types are given priority over any types of a parent class loader with the same name.
CHILD_FIRST_PERSISTENT The strategy is identical to CHILD_FIRST but exposes the byte arrays that represent a class by ClassLoader.getResourceAsStream(String).
INJECTION This strategy does not create a new class loader but injects all classes into the given ClassLoader by reflective access.
WRAPPER This strategy creates a new ByteArrayClassLoader with the given class loader as its parent.
WRAPPER_PERSISTENT The strategy is identical to WRAPPER but exposes the byte arrays that represent a class by ClassLoader.getResourceAsStream(String).

Field Summary

Fields inherited from interface net.bytebuddy.dynamic.loading.ClassLoadingStrategy

BOOTSTRAP_LOADER, NO_PROTECTION_DOMAIN

Method Summary

Modifier and Type	Method and Description
ClassLoadingStrategy.Configurable<ClassLoader>	allowExistingTypes() Determines if this class loading strategy should not throw an exception when attempting to load a class that was already loaded.
Map<TypeDescription,Class<?>>	load(ClassLoader classLoader, Map<TypeDescription,byte[]> types) Loads a given collection of classes given their binary representation.
ClassLoadingStrategy.Configurable<ClassLoader>	opened() With an opened class loading strategy, it is assured that types can be added to the class loader, either by indirect injection using this strategy or by creating a class loader that explicitly supports injection.
static ClassLoadingStrategy.Default	valueOf(String name) Returns the enum constant of this type with the specified name.
static ClassLoadingStrategy.Default[]	values() Returns an array containing the constants of this enum type, in the order they are declared.
ClassLoadingStrategy.Configurable<ClassLoader>	with(PackageDefinitionStrategy packageDefinitionStrategy) Defines the supplied package definition strategy to be used for defining packages.
ClassLoadingStrategy.Configurable<ClassLoader>	with(ProtectionDomain protectionDomain) Overrides the implicitly set default ProtectionDomain with an explicit one.

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

Enum Constant Detail

WRAPPER

public static final ClassLoadingStrategy.Default WRAPPER

This strategy creates a new ByteArrayClassLoader with the given class loader as its parent. The byte array class loader is aware of a any dynamically created type and can natively load the given classes. This allows to load classes with cyclic load-time dependencies since the byte array class loader is queried on each encountered unknown class. Due to the encapsulation of the classes that were loaded by a byte array class loader, this strategy will lead to the unloading of these classes once this class loader, its classes or any instances of these classes become unreachable.

WRAPPER_PERSISTENT

public static final ClassLoadingStrategy.Default WRAPPER_PERSISTENT

The strategy is identical to WRAPPER but exposes the byte arrays that represent a class by ClassLoader.getResourceAsStream(String). For this purpose, all class files are persisted as byte arrays withing the wrapping class loader.

CHILD_FIRST

public static final ClassLoadingStrategy.Default CHILD_FIRST

The child-first class loading strategy is a modified version of the WRAPPER where the dynamic types are given priority over any types of a parent class loader with the same name.

Important: This does not replace a type of the same name, but it makes the type invisible by the reach of this class loader.

CHILD_FIRST_PERSISTENT

public static final ClassLoadingStrategy.Default CHILD_FIRST_PERSISTENT

The strategy is identical to CHILD_FIRST but exposes the byte arrays that represent a class by ClassLoader.getResourceAsStream(String). For this purpose, all class files are persisted as byte arrays withing the wrapping class loader.

INJECTION

public static final ClassLoadingStrategy.Default INJECTION

This strategy does not create a new class loader but injects all classes into the given ClassLoader by reflective access. This prevents the loading of classes with cyclic load-time dependencies but avoids the creation of an additional class loader. The advantage of this strategy is that the loaded classes will have package-private access to other classes within their package of the class loader into which they are injected what is not permitted when the wrapper class loader is used. This strategy is implemented using a ClassInjector.UsingReflection. Note that this strategy usually yields a better runtime performance.

Important: Class injection requires access to JVM internal methods that are sealed by security managers and the Java Platform module system. Since Java 11, access to these methods is no longer feasible unless those packages are explicitly opened.

Note: This class loader does not define packages for injected classes by default. Therefore, calls to Class.getPackage() might return null. Packages are only defined manually by a class loader prior to Java 9.

Method Detail

values

public static ClassLoadingStrategy.Default[] 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 (ClassLoadingStrategy.Default c : ClassLoadingStrategy.Default.values())
    System.out.println(c);

Returns:

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

valueOf

public static ClassLoadingStrategy.Default 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

load

public Map<TypeDescription,Class<?>> load(ClassLoader classLoader,
                                          Map<TypeDescription,byte[]> types)

Loads a given collection of classes given their binary representation.

Specified by:

load in interface ClassLoadingStrategy<ClassLoader>

Parameters:

classLoader - The class loader to used for loading the classes.

types - Byte array representations of the types to be loaded mapped by their descriptions, where an iteration order defines an order in which they are supposed to be loaded, if relevant.

Returns:

A collection of the loaded classes which will be initialized in the iteration order of the returned collection.

with

public ClassLoadingStrategy.Configurable<ClassLoader> with(ProtectionDomain protectionDomain)

Overrides the implicitly set default ProtectionDomain with an explicit one.

Specified by:

with in interface ClassLoadingStrategy.Configurable<ClassLoader>

Parameters:

protectionDomain - The protection domain to apply or null if no protection domain is set.

Returns:

This class loading strategy with an explicitly set ProtectionDomain.

with

public ClassLoadingStrategy.Configurable<ClassLoader> with(PackageDefinitionStrategy packageDefinitionStrategy)

Defines the supplied package definition strategy to be used for defining packages.

Specified by:

with in interface ClassLoadingStrategy.Configurable<ClassLoader>

Parameters:

packageDefinitionStrategy - The package definer to be used.

Returns:

A version of this class loading strategy that applies the supplied package definition strategy.

allowExistingTypes

public ClassLoadingStrategy.Configurable<ClassLoader> allowExistingTypes()

Determines if this class loading strategy should not throw an exception when attempting to load a class that was already loaded. In this case, the already loaded class is used instead of the generated class.

Specified by:

allowExistingTypes in interface ClassLoadingStrategy.Configurable<ClassLoader>

Returns:

A version of this class loading strategy that does not throw an exception when a class is already loaded.

opened

public ClassLoadingStrategy.Configurable<ClassLoader> opened()

With an opened class loading strategy, it is assured that types can be added to the class loader, either by indirect injection using this strategy or by creating a class loader that explicitly supports injection.

Specified by:

opened in interface ClassLoadingStrategy.Configurable<ClassLoader>

Returns:

A version of this class loading strategy that opens for future injections into a class loader.