classUtils.javassist
Class CompileTimeClass

java.lang.Object
  classUtils.javassist.CompileTimeClass

Direct Known Subclasses:

CompileTimePrimitiveType

public abstract class CompileTimeClass
extends java.lang.Object

An instance of CtClass represents a class. It is obtained from ClassPool.

See Also:

ClassPool.get(String)

Field Summary

static CompileTimeClass	booleanType The CtClass object representing the boolean type.
static CompileTimeClass	byteType The CtClass object representing the byte type.
static CompileTimeClass	charType The CtClass object representing the char type.
static CompileTimeClass	doubleType The CtClass object representing the double type.
static CompileTimeClass	floatType The CtClass object representing the float type.
static CompileTimeClass	intType The CtClass object representing the int type.
static CompileTimeClass	longType The CtClass object representing the long type.
static CompileTimeClass	shortType The CtClass object representing the short type.
static java.lang.String	version The version number of this release.
static CompileTimeClass	voidType The CtClass object representing the void type.

Method Summary

void	addConstructor(CtConstructor c) Adds a constructor.
void	addField(CtField f) Adds a field.
void	addField(CtField f, CtField.Initializer init) Adds a field with an initial value.
void	addField(CtField f, java.lang.String init) Adds a field with an initial value.
void	addInterface(CompileTimeClass anInterface) Adds an interface.
void	addMethod(CtMethod m) Adds a method.
void	defrost() Defrosts the class so that the class can be modified again.
byte[]	getAttribute(java.lang.String name) Obtains an attribute with the given name.
JAClassFile	getClassFile() Returns a class file for this class.
JAClassFile	getClassFile2() Undocumented method.
CtConstructor	getClassInitializer() Gets the class initializer (static constructor) declared in the class.
ClassPool	getClassPool() Returns a ClassPool for this class.
CompileTimeClass	getComponentType() If this object represents an array, this method returns the component type of the array.
CtConstructor	getConstructor(java.lang.String desc) Returns the constructor with the given signature, which is represented by a character string called method descriptor.
CtConstructor[]	getConstructors() Returns an array containing CtConstructor objects representing all the public constructors of the class.
CtBehavior[]	getDeclaredBehaviors() Gets all the constructors and methods declared in the class.
CtConstructor	getDeclaredConstructor(CompileTimeClass[] params) Returns a constructor receiving the specified parameters.
CtConstructor[]	getDeclaredConstructors() Gets all the constructors declared in the class.
CtField	getDeclaredField(java.lang.String name) Retrieves the field with the specified name among the fields declared in the class.
CtField[]	getDeclaredFields() Gets all the fields declared in the class.
CtMethod	getDeclaredMethod(java.lang.String name) Retrieves the method with the specified name among the methods declared in the class.
CtMethod	getDeclaredMethod(java.lang.String name, CompileTimeClass[] params) Retrieves the method with the specified name and parameter types among the methods declared in the class.
CtMethod[]	getDeclaredMethods() Gets all methods declared in the class.
CtField	getField(java.lang.String name) Returns the field with the specified name.
CtField[]	getFields() Returns an array containing CtField objects representing all the public fields of the class.
CompileTimeClass[]	getInterfaces() Obtains the class objects representing the interfaces of the class.
CtMethod	getMethod(java.lang.String name, java.lang.String desc) Returns the method with the given name and signature.
CtMethod[]	getMethods() Returns an array containing CtMethod objects representing all the public methods of the class.
int	getModifiers() Returns the modifiers for this class, encoded in an integer.
java.lang.String	getName() Obtains the fully-qualified name of the class.
java.lang.String	getPackageName() Obtains the package name.
java.util.Collection	getRefClasses() Returns a collection of the names of all the classes referenced in this class.
java.lang.String	getSimpleName() Obtains the not-qualified class name.
CompileTimeClass	getSuperclass() Obtains the class object representing the superclass of the class.
void	instrument(CodeConverter converter) Applies the given converter to all methods and constructors declared in the class.
void	instrument(ExprEditor editor) Modifies the bodies of all methods and constructors declared in the class.
boolean	isArray() Returns true if this object represents an array type.
boolean	isFrozen() Returns true if the class has been loaded or written out and thus it cannot be modified any more.
boolean	isInterface() Determines whether this object represents a class or an interface.
boolean	isModified() Returns true if the definition of the class has been modified.
boolean	isPrimitive() Returns true if this object represents a primitive Java type: boolean, byte, char, short, int, long, float, double, or void.
CtConstructor	makeClassInitializer() Makes a class initializer (static constructor).
void	replaceClassName(ClassMap map) Changes class names appearing in the class file according to the given map.
void	replaceClassName(java.lang.String oldname, java.lang.String newname) Substitutes newName for all occurrences of a class name oldName in the class file.
void	setAttribute(java.lang.String name, byte[] data) Adds a named attribute.
void	setInterfaces(CompileTimeClass[] list) Sets interfaces.
void	setModifiers(int mod) Sets the modifiers.
void	setName(java.lang.String name) Sets the class name
void	setSuperclass(CompileTimeClass clazz) Changes a super class.
boolean	subclassOf(CompileTimeClass superclass) Determines whether the class directly or indirectly extends the given class.
boolean	subtypeOf(CompileTimeClass clazz) Returns true if this class extends or implements clazz.
byte[]	toBytecode() Converts this class to a class file.
java.lang.Class	toClass() Converts this class to a java.lang.Class object.
void	writeFile() Writes a class file represented by this CtClass object in the current directory.

Methods inherited from class java.lang.Object

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

Field Detail

version

public static final java.lang.String version

The version number of this release.

See Also:

Constant Field Values

booleanType

public static CompileTimeClass booleanType

The CtClass object representing the boolean type.

charType

public static CompileTimeClass charType

The CtClass object representing the char type.

byteType

public static CompileTimeClass byteType

The CtClass object representing the byte type.

shortType

public static CompileTimeClass shortType

The CtClass object representing the short type.

intType

public static CompileTimeClass intType

The CtClass object representing the int type.

longType

public static CompileTimeClass longType

The CtClass object representing the long type.

floatType

public static CompileTimeClass floatType

The CtClass object representing the float type.

doubleType

public static CompileTimeClass doubleType

The CtClass object representing the double type.

voidType

public static CompileTimeClass voidType

The CtClass object representing the void type.

Method Detail

getClassPool

public ClassPool getClassPool()

Returns a ClassPool for this class.

getClassFile

public JAClassFile getClassFile()

Returns a class file for this class.

This method is not available if isFrozen() is true.

getClassFile2

public JAClassFile getClassFile2()

Undocumented method. Do not use; internal-use only.

isModified

public boolean isModified()

Returns true if the definition of the class has been modified.

isFrozen

public boolean isFrozen()

Returns true if the class has been loaded or written out and thus it cannot be modified any more.

See Also:

defrost()

defrost

public void defrost()

Defrosts the class so that the class can be modified again. To avoid changes that will be never reflected, the class is frozen to be unmodifiable if it is loaded or written out. This method should be called only in a case that the class will be reloaded or written out later again.

See Also:

isFrozen()

isPrimitive

public boolean isPrimitive()

Returns true if this object represents a primitive Java type: boolean, byte, char, short, int, long, float, double, or void.

isArray

public boolean isArray()

Returns true if this object represents an array type.

getComponentType

public CompileTimeClass getComponentType()
                                  throws NotFoundException

If this object represents an array, this method returns the component type of the array. Otherwise, it returns null.

Throws:

NotFoundException

subtypeOf

public boolean subtypeOf(CompileTimeClass clazz)
                  throws NotFoundException

Returns true if this class extends or implements clazz. It also returns true if this class is the same as clazz.

Throws:

NotFoundException

getName

public java.lang.String getName()

Obtains the fully-qualified name of the class.

getSimpleName

public final java.lang.String getSimpleName()

Obtains the not-qualified class name.

getPackageName

public final java.lang.String getPackageName()

Obtains the package name. It may be null.

setName

public void setName(java.lang.String name)

Sets the class name

Parameters:

name - fully-qualified name

replaceClassName

public void replaceClassName(java.lang.String oldname,
                             java.lang.String newname)

Substitutes newName for all occurrences of a class name oldName in the class file.

Parameters:

oldname - replaced class name

newname - substituted class name

replaceClassName

public void replaceClassName(ClassMap map)

Changes class names appearing in the class file according to the given map.

All the class names appearing in the class file are tested with map to determine whether each class name is replaced or not. Thus this method can be used for collecting all the class names in the class file. To do that, first define a subclass of ClassMap so that get() records all the given parameters. Then, make an instance of that subclass as an empty hash-table. Finally, pass that instance to this method. After this method finishes, that instance would contain all the class names appearing in the class file.

Parameters:

map - the hashtable associating replaced class names with substituted names.

getRefClasses

public java.util.Collection getRefClasses()

Returns a collection of the names of all the classes referenced in this class. That collection includes the name of this class.

This method may return null.

isInterface

public boolean isInterface()

Determines whether this object represents a class or an interface. It returns true if this object represents an interface.

getModifiers

public int getModifiers()

Returns the modifiers for this class, encoded in an integer. For decoding, use javassist.Modifier.

See Also:

Modifier

setModifiers

public void setModifiers(int mod)

Sets the modifiers.

Parameters:

mod - modifiers encoded by javassist.Modifier

See Also:

Modifier

subclassOf

public boolean subclassOf(CompileTimeClass superclass)

Determines whether the class directly or indirectly extends the given class. If this class extends a class A and the class A extends a class B, then subclassof(B) returns true.

This method returns true if the given class is identical to the class represented by this object.

getSuperclass

public CompileTimeClass getSuperclass()
                               throws NotFoundException

Obtains the class object representing the superclass of the class. It returns null if this object represents the java.lang.Object class and thus it does not have the super class.

Throws:

NotFoundException

setSuperclass

public void setSuperclass(CompileTimeClass clazz)
                   throws CannotCompileException

Changes a super class. The new super class must be compatible with the old one.

Throws:

CannotCompileException

getInterfaces

public CompileTimeClass[] getInterfaces()
                                 throws NotFoundException

Obtains the class objects representing the interfaces of the class.

Throws:

NotFoundException

setInterfaces

public void setInterfaces(CompileTimeClass[] list)

Sets interfaces.

Parameters:

list - a list of the CtClass objects representing interfaces, or null if the class implements no interfaces.

addInterface

public void addInterface(CompileTimeClass anInterface)

Adds an interface.

Parameters:

anInterface - the added interface.

getFields

public CtField[] getFields()

Returns an array containing CtField objects representing all the public fields of the class. That array includes public fields inherited from the superclasses.

getField

public CtField getField(java.lang.String name)
                 throws NotFoundException

Returns the field with the specified name. The returned field may be a private field declared in a super class or interface.

Throws:

NotFoundException

getDeclaredFields

public CtField[] getDeclaredFields()

Gets all the fields declared in the class. The inherited fields are not included.

Note: the result does not include inherited fields.

getDeclaredField

public CtField getDeclaredField(java.lang.String name)
                         throws NotFoundException

Retrieves the field with the specified name among the fields declared in the class.

Note: this method does not search the superclasses.

Throws:

NotFoundException

getDeclaredBehaviors

public CtBehavior[] getDeclaredBehaviors()

Gets all the constructors and methods declared in the class.

getConstructors

public CtConstructor[] getConstructors()

Returns an array containing CtConstructor objects representing all the public constructors of the class.

getConstructor

public CtConstructor getConstructor(java.lang.String desc)
                             throws NotFoundException

Returns the constructor with the given signature, which is represented by a character string called method descriptor. For details of the method descriptor, see the JVM specification or javassist.bytecode.Descriptor.

Parameters:

desc - method descriptor

Throws:

NotFoundException

See Also:

Descriptor

getDeclaredConstructors

public CtConstructor[] getDeclaredConstructors()

Gets all the constructors declared in the class.

See Also:

CtConstructor

getDeclaredConstructor

public CtConstructor getDeclaredConstructor(CompileTimeClass[] params)
                                     throws NotFoundException

Returns a constructor receiving the specified parameters.

Parameters:

params - parameter types.

Throws:

NotFoundException

getClassInitializer

public CtConstructor getClassInitializer()

Gets the class initializer (static constructor) declared in the class. This method returns null if no class initializer is not declared.

See Also:

makeClassInitializer(), CtConstructor

getMethods

public CtMethod[] getMethods()

Returns an array containing CtMethod objects representing all the public methods of the class. That array includes public methods inherited from the superclasses.

getMethod

public CtMethod getMethod(java.lang.String name,
                          java.lang.String desc)
                   throws NotFoundException

Returns the method with the given name and signature. The returned method may be declared in a super class. The method signature is represented by a character string called method descriptor, which is defined in the JVM specification.

Parameters:

name - method name

desc - method descriptor

Throws:

NotFoundException

See Also:

Descriptor

getDeclaredMethods

public CtMethod[] getDeclaredMethods()

Gets all methods declared in the class. The inherited methods are not included.

See Also:

CtMethod

getDeclaredMethod

public CtMethod getDeclaredMethod(java.lang.String name,
                                  CompileTimeClass[] params)
                           throws NotFoundException

Retrieves the method with the specified name and parameter types among the methods declared in the class.

Note: this method does not search the superclasses.

Parameters:

name - method name

params - parameter types

Throws:

NotFoundException

See Also:

CtMethod

getDeclaredMethod

public CtMethod getDeclaredMethod(java.lang.String name)
                           throws NotFoundException

Retrieves the method with the specified name among the methods declared in the class. If there are multiple methods with the specified name, then this method returns one of them.

Note: this method does not search the superclasses.

Throws:

NotFoundException

See Also:

CtMethod

makeClassInitializer

public CtConstructor makeClassInitializer()
                                   throws CannotCompileException

Makes a class initializer (static constructor). If the class already includes a class initializer, this method returns it.

Throws:

CannotCompileException

See Also:

getClassInitializer()

addConstructor

public void addConstructor(CtConstructor c)
                    throws CannotCompileException

Adds a constructor.

Throws:

CannotCompileException

addMethod

public void addMethod(CtMethod m)
               throws CannotCompileException

Adds a method.

Throws:

CannotCompileException

addField

public void addField(CtField f)
              throws CannotCompileException

Adds a field.

The CtField belonging to another CtClass cannot be directly added to this class. Only a field created for this class can be added.

Throws:

CannotCompileException

See Also:

CtField.CtField(CtField,CompileTimeClass)

addField

public void addField(CtField f,
                     java.lang.String init)
              throws CannotCompileException

Adds a field with an initial value.

The CtField belonging to another CtClass cannot be directly added to this class. Only a field created for this class can be added.

The initial value is given as an expression written in Java. Any regular Java expression can be used for specifying the initial value. The followings are examples.

 cc.addField(f, "0")               // the initial value is 0.
 cc.addField(f, "i + 1")           // i + 1.
 cc.addField(f, "new Point()");    // a Point object.
 

Here, the type of variable cc is CtClass. The type of f is CtField.

Parameters:

init - an expression for the initial value.

Throws:

CannotCompileException

See Also:

CtField.Initializer.byExpr(String), CtField.CtField(CtField,CompileTimeClass)

addField

public void addField(CtField f,
                     CtField.Initializer init)
              throws CannotCompileException

Adds a field with an initial value.

The CtField belonging to another CtClass cannot be directly added to this class. Only a field created for this class can be added.

For example,

 CtClass cc = ...;
 addField(new CtField(CtClass.intType, "i", cc),
          CtField.Initializer.constant(1));
 

This code adds an int field named "i". The initial value of this field is 1.

Parameters:

init - specifies the initial value of the field.

Throws:

CannotCompileException

See Also:

CtField.CtField(CtField,CompileTimeClass)

getAttribute

public byte[] getAttribute(java.lang.String name)

Obtains an attribute with the given name. If that attribute is not found in the class file, this method returns null.

Parameters:

name - attribute name

setAttribute

public void setAttribute(java.lang.String name,
                         byte[] data)

Adds a named attribute. An arbitrary data (smaller than 64Kb) can be saved in the class file. Some attribute name are reserved by the JVM. The attributes with the non-reserved names are ignored when a class file is loaded into the JVM. If there is already an attribute with the same name, this method substitutes the new one for it.

Parameters:

name - attribute name

data - attribute value

instrument

public void instrument(CodeConverter converter)
                throws CannotCompileException

Applies the given converter to all methods and constructors declared in the class. This method calls instrument() on every CtMethod and CtConstructor object in the class.

Parameters:

converter - specifies how to modify.

Throws:

CannotCompileException

instrument

public void instrument(ExprEditor editor)
                throws CannotCompileException

Modifies the bodies of all methods and constructors declared in the class. This method calls instrument() on every CtMethod and CtConstructor object in the class.

Parameters:

editor - specifies how to modify.

Throws:

CannotCompileException

toClass

public java.lang.Class toClass()
                        throws NotFoundException,
                               java.io.IOException,
                               CannotCompileException

Converts this class to a java.lang.Class object. Once this method is called, further modifications are not possible any more.

This method is equivalent to:

this.getClassPool().writeAsClass(this.getName())

See the description of ClassPool.writeAsClass() before you use this method. This method is provided for convenience. If you need more complex functionality, you should write your own class loader.

Throws:

NotFoundException

java.io.IOException

CannotCompileException

See Also:

ClassPool.writeAsClass(String), ClassPool.forName(String)

toBytecode

public byte[] toBytecode()
                  throws NotFoundException,
                         java.io.IOException,
                         CannotCompileException

Converts this class to a class file. Once this method is called, further modifications are not possible any more.

This method is equivalent to:

this.getClassPool().write(this.getName())

Throws:

NotFoundException

java.io.IOException

CannotCompileException

See Also:

ClassPool.write(String)

writeFile

public void writeFile()
               throws NotFoundException,
                      java.io.IOException,
                      CannotCompileException

Writes a class file represented by this CtClass object in the current directory. Once this method is called, further modifications are not possible any more.

This method is equivalent to:

this.getClassPool().writeFile(this.getName())

Throws:

NotFoundException

java.io.IOException

CannotCompileException

See Also:

ClassPool.writeFile(String)