Module org.cojen.maker

Package org.cojen.maker

Interface ClassMaker

All Superinterfaces:

Maker

public interface ClassMaker
extends Maker

Allows new classes and interfaces to be defined dynamically.

See Also:

• begin()

Method Summary

Modifier and Type	Method	Description
ClassMaker	abstract_()	Switch this class to be abstract.
MethodMaker	addClinit()	Add code to the static initializer of this class.
default MethodMaker	addConstructor(MethodType type)	Add a constructor to this class.
MethodMaker	addConstructor(Object... paramTypes)	Add a constructor to this class.
FieldMaker	addField(Object type, String name)	Add a field to the class.
ClassMaker	addInnerClass(String className)	Add an inner class to this class.
MethodMaker	addMethod(Object retType, String name, Object... paramTypes)	Add a method to this class.
default MethodMaker	addMethod(String name, MethodType type)	Add a method to this class.
ClassMaker	annotation()	Indicate that this class is defining an annotation interface.
ClassMaker	another(String className)	Begin defining another class with the same loader and lookup as this one.
Object	arrayType(int dimensions)	Returns an opaque type object which represents the class being made as an array.
MethodMaker	asRecord()	Convert this class to a record, and return a newly added constructor for it.
static ClassMaker	begin()	Begin defining a class with an automatically assigned name.
static ClassMaker	begin(String className)	Begin defining a class with the given name, but the actual name will have a suffix applied to ensure uniqueness.
static ClassMaker	begin(String className, ClassLoader parentLoader)	Begin defining a class with the given name, but the actual name will have a suffix applied to ensure uniqueness.
static ClassMaker	begin(String className, ClassLoader parentLoader, Object key)	Begin defining a class with the given name, but the actual name will have a suffix applied to ensure uniqueness.
static ClassMaker	begin(String className, MethodHandles.Lookup lookup)	Begin defining a class with the given name, but the actual name will have a suffix applied to ensure uniqueness.
static ClassMaker	beginExplicit(String className, ClassLoader parentLoader, Object key)	Begin defining a class with an explicitly specified name.
static ClassMaker	beginExternal(String className)	Begin defining a class intended to be loaded from a file.
ClassLoader	classLoader()	Returns the class loader that the finished class will be loaded into.
ClassMaker	enum_()	Indicate that this class is defining an enum.
ClassMaker	extend(Object superClass)	Set a class that this class extends.
ClassMaker	final_()	Switch this class to be final.
Class<?>	finish()	Finishes the definition of the new class.
byte[]	finishBytes()	Finishes the definition of the new class into a byte array.
MethodHandles.Lookup	finishHidden()	Finishes the definition of a new hidden class, returning a lookup which has full privilege access to the class.
MethodHandles.Lookup	finishLookup()	Finishes the definition of the new class, returning a lookup which has full privilege access to the class.
void	finishTo(OutputStream out)	Finishes the definition of the new class and writes it to a stream.
ClassMaker	implement(Object iface)	Add an interface that this class or interface implements.
boolean	installClass(Class<?> clazz)	Directly install a dependent class into the class loader used by the finished class.
ClassMaker	interface_()	Switch this class to be an interface.
String	name()	Returns the tentative name of the class being made.
ClassMaker	permitSubclass(Object subclass)	Convert this class into a sealed class by permitting a subclass.
ClassMaker	private_()	Switch this class to be private.
ClassMaker	protected_()	Switch this class to be protected.
ClassMaker	public_()	Switch this class to be public.
ClassMaker	signature(Object... components)	Define a signature for this member, which is a string for supporting generic types.
ClassMaker	sourceFile(String fileName)	Set the source file of this class file by adding a source file attribute.
ClassMaker	static_()	Switch this class to be static.
ClassMaker	synthetic()	Indicate that this class is synthetic.
Set<String>	unimplementedMethods()	Returns the set of methods which would need to be implemented by this class in order for it to be non-abstract.

Methods inherited from interface org.cojen.maker.Maker

addAnnotation, addAttribute, classMaker

Method Details

begin

static ClassMaker begin()

Begin defining a class with an automatically assigned name.

begin

static ClassMaker begin(String className)

Begin defining a class with the given name, but the actual name will have a suffix applied to ensure uniqueness.

Parameters:

className - fully qualified class name; pass null to automatically assign a name

begin

static ClassMaker begin(String className,
 ClassLoader parentLoader)

Begin defining a class with the given name, but the actual name will have a suffix applied to ensure uniqueness.

Parameters:

className - fully qualified class name; pass null to automatically assign a name

parentLoader - parent class loader; pass null to use default

begin

static ClassMaker begin(String className,
 ClassLoader parentLoader,
 Object key)

Begin defining a class with the given name, but the actual name will have a suffix applied to ensure uniqueness.

Parameters:

className - fully qualified class name; pass null to automatically assign a name

parentLoader - parent class loader; pass null to use default

key - an opaque key used for creating distinct class loaders; can be null

begin

static ClassMaker begin(String className,
 MethodHandles.Lookup lookup)

Begin defining a class with the given name, but the actual name will have a suffix applied to ensure uniqueness.

Parameters:

className - fully qualified class name; pass null to automatically assign a name

lookup - finish loading the class using this lookup object

beginExplicit

static ClassMaker beginExplicit(String className,
 ClassLoader parentLoader,
 Object key)

Begin defining a class with an explicitly specified name.

Parameters:

className - fully qualified class name

parentLoader - parent class loader; pass null to use default

key - an opaque key used for creating distinct class loaders; can be null

beginExternal

static ClassMaker beginExternal(String className)

Begin defining a class intended to be loaded from a file. The class name exactly matches the one given, and setExact is unsupported. All classes defined from this maker will also be external.

Parameters:

className - fully qualified class name

See Also:

• finishBytes()
• finishTo(java.io.OutputStream)

another

ClassMaker another(String className)

Begin defining another class with the same loader and lookup as this one. The actual class name will have a suffix applied to ensure uniqueness, unless this maker creates explicit or external classes.

The returned ClassMaker instance isn't attached to this maker, and so it can be acted upon by a different thread.

Parameters:

className - fully qualified class name; pass null to automatically assign a name (unless explicit or external)

See Also:

• addInnerClass(java.lang.String)

name

String name()

Returns the tentative name of the class being made. If finishHidden is called, then the actual class name will differ.

Specified by:

name in interface Maker

public_

ClassMaker public_()

Switch this class to be public. Classes are package-private by default.

Specified by:

public_ in interface Maker

Returns:

this

private_

ClassMaker private_()

Switch this class to be private. Classes are package-private by default.

Specified by:

private_ in interface Maker

Returns:

this

protected_

ClassMaker protected_()

Switch this class to be protected. Classes are package-private by default.

Specified by:

protected_ in interface Maker

Returns:

this

static_

ClassMaker static_()

Switch this class to be static. Classes are non-static by default.

Specified by:

static_ in interface Maker

Returns:

this

final_

ClassMaker final_()

Switch this class to be final. Classes are non-final by default.

Specified by:

final_ in interface Maker

Returns:

this

interface_

ClassMaker interface_()

Switch this class to be an interface. Classes are classes by default.

Returns:

this

abstract_

ClassMaker abstract_()

Switch this class to be abstract. Classes are non-abstract by default.

Returns:

this

synthetic

ClassMaker synthetic()

Indicate that this class is synthetic. Classes are non-synthetic by default.

Specified by:

synthetic in interface Maker

Returns:

this

enum_

ClassMaker enum_()

Indicate that this class is defining an enum. No checks or modifications are performed to ensure that the enum class is defined correctly.

Returns:

this

annotation

ClassMaker annotation()

Indicate that this class is defining an annotation interface.

Returns:

this

extend

ClassMaker extend(Object superClass)

Set a class that this class extends.

Parameters:

superClass - non-null type, specified by a Class or a String, etc.

Returns:

this

Throws:

IllegalArgumentException - if the type is unsupported

IllegalStateException - if already assigned

implement

ClassMaker implement(Object iface)

Add an interface that this class or interface implements. Call this method multiple times to implement more interfaces.

Parameters:

iface - non-null type, specified by a Class or a String, etc.

Returns:

this

Throws:

IllegalArgumentException - if the type is unsupported

signature

ClassMaker signature(Object... components)

Define a signature for this member, which is a string for supporting generic types. The components can be strings or types (class, ClassMaker, etc.), which are concatenated into a single string. Consult the JVM specification for the signature syntax.

Specified by:

signature in interface Maker

Returns:

this

permitSubclass

ClassMaker permitSubclass(Object subclass)

Convert this class into a sealed class by permitting a subclass. Call this method multiple times to permit more subclasses.

Parameters:

subclass - non-null type, specified by a Class or a String, etc.

Returns:

this

Throws:

IllegalArgumentException - if the type is unsupported

addField

FieldMaker addField(Object type,
 String name)

Add a field to the class.

Parameters:

type - a class or name

Throws:

IllegalArgumentException - if the type is unsupported

IllegalStateException - if field is already defined

addMethod

MethodMaker addMethod(Object retType,
 String name,
 Object... paramTypes)

Add a method to this class.

Parameters:

retType - a class or name; can be null if method returns void

paramTypes - classes or names; can be null if method accepts no parameters

Throws:

IllegalArgumentException - if a type is unsupported

addMethod

default MethodMaker addMethod(String name,
 MethodType type)

Add a method to this class.

Parameters:

type - defines the return type and parameter types

addConstructor

MethodMaker addConstructor(Object... paramTypes)

Add a constructor to this class.

Parameters:

paramTypes - classes or names; can be null if constructor accepts no parameters

Throws:

IllegalArgumentException - if a type is unsupported

addConstructor

default MethodMaker addConstructor(MethodType type)

Add a constructor to this class.

Parameters:

type - defines the parameter types

Throws:

IllegalArgumentException - if the return type isn't void

addClinit

MethodMaker addClinit()

Add code to the static initializer of this class. Multiple initializers can be added, and they're all stitched together when the class definition is finished. Returning from one initializer only breaks out of the local scope.

asRecord

MethodMaker asRecord()

Convert this class to a record, and return a newly added constructor for it. Each field which is currently defined in this class is treated as a record component, and each is also represented by a constructor parameter. The constructor shouldn't set the fields directly, since this is performed automatically at the end.

Unless already defined, the equals, hashCode, and toString methods are automatically added. The same rule applies for the component accessor methods.

addInnerClass

ClassMaker addInnerClass(String className)

Add an inner class to this class. The actual class name will have a suitable suffix applied to ensure uniqueness.

The returned ClassMaker instance isn't attached to this maker, and so it can be acted upon by a different thread.

Parameters:

className - simple class name; pass null to use default

Throws:

IllegalArgumentException - if not given a simple class name

See Also:

• another(java.lang.String)

sourceFile

ClassMaker sourceFile(String fileName)

Set the source file of this class file by adding a source file attribute.

Returns:

this

arrayType

Object arrayType(int dimensions)

Returns an opaque type object which represents the class being made as an array.

Parameters:

dimensions - must be at least 1

Throws:

IllegalArgumentException - if the given dimensions is less than 1 or greater than 255

classLoader

ClassLoader classLoader()

Returns the class loader that the finished class will be loaded into.

installClass

boolean installClass(Class<?> clazz)

Directly install a dependent class into the class loader used by the finished class. This is necessary when the given class cannot be found by the normal hierarchical class loading technique.

Note: When installed, the given class is held by a weak reference, to facilitate unloading. If the installed class can be unloaded before finishing the new class, a reachability fence might be required.

Returns:

true if installed, or else false if the class was already installed

Throws:

IllegalStateException - if this maker was begun with a lookup object, or if the class loader already refers to a different class with the same name

unimplementedMethods

Set<String> unimplementedMethods()

Returns the set of methods which would need to be implemented by this class in order for it to be non-abstract. Each method in the set is represented by a simple signature.

Returns:

a non-null set, possibly empty

finish

Class<?> finish()

Finishes the definition of the new class.

Throws:

IllegalStateException - if already finished or if the definition is broken

finishLookup

MethodHandles.Lookup finishLookup()

Finishes the definition of the new class, returning a lookup which has full privilege access to the class. Calling this method has the side effect of forcing the new class to be initialized.

Returns:

the lookup for the class; call lookupClass to obtain the actual class

Throws:

IllegalStateException - if already finished or if the definition is broken

finishHidden

MethodHandles.Lookup finishHidden()

Finishes the definition of a new hidden class, returning a lookup which has full privilege access to the class. Hidden classes are automatically unloaded when no longer referenced, even if the class loader still is. If a lookup object was passed to the begin method, the hidden class is defined in the same nest as the lookup class.

Returns:

the lookup for the class; call lookupClass to obtain the actual class

Throws:

IllegalStateException - if already finished or if the definition is broken

finishBytes

byte[] finishBytes()

Finishes the definition of the new class into a byte array.

Throws:

IllegalStateException - if already finished or if the definition is broken

finishTo

void finishTo(OutputStream out)
       throws IOException

Finishes the definition of the new class and writes it to a stream.

Throws:

IllegalStateException - if already finished or if the definition is broken

IOException