Package org.apache.bcel.classfile

Class JavaClass

java.lang.Object

org.apache.bcel.classfile.AccessFlags

org.apache.bcel.classfile.JavaClass

All Implemented Interfaces:

Cloneable, Comparable<JavaClass>, Node

public class JavaClass
extends AccessFlags
implements Cloneable, Node, Comparable<JavaClass>

Represents a Java class, i.e., the data structures, constant pool, fields, methods and commands contained in a Java .class file. See JVM specification for details. The intent of this class is to represent a parsed or otherwise existing class file. Those interested in programmatically generating classes should see the ClassGen class.

See Also:

• ClassGen

Field Summary

Fields

Modifier and Type	Field	Description
static final JavaClass[]	EMPTY_ARRAY	Empty array.
static final String	EXTENSION	The standard class file extension.
static final byte	FILE
static final byte	HEAP
static final byte	ZIP

Fields inherited from class org.apache.bcel.classfile.AccessFlags

access_flags

Constructor Summary

Constructors

Constructor	Description
JavaClass(int classNameIndex, int superclassNameIndex, String fileName, int major, int minor, int accessFlags, ConstantPool constantPool, int[] interfaces, Field[] fields, Method[] methods, Attribute[] attributes)	Constructor gets all contents as arguments.
JavaClass(int classNameIndex, int superclassNameIndex, String fileName, int major, int minor, int accessFlags, ConstantPool constantPool, int[] interfaces, Field[] fields, Method[] methods, Attribute[] attributes, byte source)	Constructor gets all contents as arguments.

Method Summary

Modifier and Type	Method	Description
void	accept(Visitor v)	Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
int	compareTo(JavaClass obj)	Return the natural ordering of two JavaClasses.
JavaClass	copy()
void	dump(DataOutputStream file)	Dump Java class to output stream in binary format.
void	dump(File file)	Dump class to a file.
void	dump(OutputStream file)	Dump Java class to output stream in binary format.
void	dump(String fileName)	Dump class to a file named fileName.
boolean	equals(Object obj)	Return value as defined by given BCELComparator strategy.
Field	findField(String fieldName, Type fieldType)	Finds a visible field by name and type in this class and its super classes.
JavaClass[]	getAllInterfaces()	Gets all interfaces implemented by this JavaClass (transitively).
AnnotationEntry[]	getAnnotationEntries()
final <T extends Attribute> T	getAttribute(byte tag)	Gets attribute for given tag.
Attribute[]	getAttributes()
byte[]	getBytes()
String	getClassName()
int	getClassNameIndex()
static BCELComparator<JavaClass>	getComparator()
ConstantPool	getConstantPool()
Field[]	getFields()
String	getFileName()
int[]	getInterfaceIndices()
String[]	getInterfaceNames()
JavaClass[]	getInterfaces()	Gets interfaces directly implemented by this JavaClass.
int	getMajor()
Method	getMethod(Method m)
Method[]	getMethods()
int	getMinor()
String	getPackageName()
Repository	getRepository()	Gets the ClassRepository which holds its definition.
final byte	getSource()
String	getSourceFileName()
String	getSourceFilePath()	Gets the source file path including the package path.
JavaClass	getSuperClass()
JavaClass[]	getSuperClasses()
String	getSuperclassName()	returns the super class name of this class.
int	getSuperclassNameIndex()
int	hashCode()	Return value as defined by given BCELComparator strategy.
boolean	implementationOf(JavaClass inter)
final boolean	instanceOf(JavaClass superclass)	Equivalent to runtime "instanceof" operator.
final boolean	isAnonymous()
final boolean	isClass()
final boolean	isNested()
boolean	isRecord()	Tests whether this class was declared as a record
final boolean	isSuper()
void	setAttributes(Attribute[] attributes)
void	setClassName(String className)
void	setClassNameIndex(int classNameIndex)
static void	setComparator(BCELComparator<JavaClass> comparator)
void	setConstantPool(ConstantPool constantPool)
void	setFields(Field[] fields)
void	setFileName(String fileName)	Sets File name of class, aka SourceFile attribute value
void	setInterfaceNames(String[] interfaceNames)
void	setInterfaces(int[] interfaces)
void	setMajor(int major)
void	setMethods(Method[] methods)
void	setMinor(int minor)
void	setRepository(Repository repository)	Sets the ClassRepository which loaded the JavaClass.
void	setSourceFileName(String sourceFileName)	Sets absolute path to file this class was read from.
void	setSuperclassName(String superclassName)
void	setSuperclassNameIndex(int superclassNameIndex)
String	toString()

Methods inherited from class org.apache.bcel.classfile.AccessFlags

getAccessFlags, getModifiers, isAbstract, isAbstract, isAnnotation, isAnnotation, isEnum, isEnum, isFinal, isFinal, isInterface, isInterface, isNative, isNative, isPrivate, isPrivate, isProtected, isProtected, isPublic, isPublic, isStatic, isStatic, isStrictfp, isStrictfp, isSynchronized, isSynchronized, isSynthetic, isSynthetic, isTransient, isTransient, isVarArgs, isVarArgs, isVolatile, isVolatile, setAccessFlags, setModifiers

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

EXTENSION

public static final String EXTENSION

The standard class file extension.

Since:

6.7.0

See Also:

• Constant Field Values

EMPTY_ARRAY

public static final JavaClass[] EMPTY_ARRAY

Empty array.

Since:

6.6.0

HEAP

public static final byte HEAP

See Also:

• Constant Field Values

FILE

public static final byte FILE

See Also:

• Constant Field Values

ZIP

public static final byte ZIP

See Also:

• Constant Field Values

Constructor Details

JavaClass

public JavaClass(int classNameIndex,
 int superclassNameIndex,
 String fileName,
 int major,
 int minor,
 int accessFlags,
 ConstantPool constantPool,
 int[] interfaces,
 Field[] fields,
 Method[] methods,
 Attribute[] attributes)

Constructor gets all contents as arguments.

Parameters:

classNameIndex - Class name

superclassNameIndex - Superclass name

fileName - File name

major - Major compiler version

minor - Minor compiler version

accessFlags - Access rights defined by bit flags

constantPool - Array of constants

interfaces - Implemented interfaces

fields - Class fields

methods - Class methods

attributes - Class attributes

JavaClass

public JavaClass(int classNameIndex,
 int superclassNameIndex,
 String fileName,
 int major,
 int minor,
 int accessFlags,
 ConstantPool constantPool,
 int[] interfaces,
 Field[] fields,
 Method[] methods,
 Attribute[] attributes,
 byte source)

Constructor gets all contents as arguments.

Parameters:

classNameIndex - Index into constant pool referencing a ConstantClass that represents this class.

superclassNameIndex - Index into constant pool referencing a ConstantClass that represents this class's superclass.

fileName - File name

major - Major compiler version

minor - Minor compiler version

accessFlags - Access rights defined by bit flags

constantPool - Array of constants

interfaces - Implemented interfaces

fields - Class fields

methods - Class methods

attributes - Class attributes

source - Read from file or generated in memory?

Method Details

getComparator

public static BCELComparator<JavaClass> getComparator()

Returns:

Comparison strategy object.

setComparator

public static void setComparator(BCELComparator<JavaClass> comparator)

Parameters:

comparator - Comparison strategy object.

accept

public void accept(Visitor v)

Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.

Specified by:

accept in interface Node

Parameters:

v - Visitor object

compareTo

public int compareTo(JavaClass obj)

Return the natural ordering of two JavaClasses. This ordering is based on the class name

Specified by:

compareTo in interface Comparable<JavaClass>

Since:

6.0

copy

public JavaClass copy()

Returns:

deep copy of this class

dump

public void dump(DataOutputStream file)
          throws IOException

Dump Java class to output stream in binary format.

Parameters:

file - Output stream

Throws:

IOException - if an I/O error occurs.

dump

public void dump(File file)
          throws IOException

Dump class to a file.

Parameters:

file - Output file

Throws:

IOException - if an I/O error occurs.

dump

public void dump(OutputStream file)
          throws IOException

Dump Java class to output stream in binary format.

Parameters:

file - Output stream

Throws:

IOException - if an I/O error occurs.

dump

public void dump(String fileName)
          throws IOException

Dump class to a file named fileName.

Parameters:

fileName - Output file name

Throws:

IOException - if an I/O error occurs.

equals

public boolean equals(Object obj)

Return value as defined by given BCELComparator strategy. By default two JavaClass objects are said to be equal when their class names are equal.

Overrides:

equals in class Object

See Also:

• Object.equals(Object)

findField

public Field findField(String fieldName,
 Type fieldType)
                throws ClassNotFoundException

Finds a visible field by name and type in this class and its super classes.

Parameters:

fieldName - the field name to find

fieldType - the field type to find

Returns:

field matching given name and type, null if field is not found or not accessible from this class.

Throws:

ClassNotFoundException

Since:

6.8.0

getAllInterfaces

public JavaClass[] getAllInterfaces()
                             throws ClassNotFoundException

Gets all interfaces implemented by this JavaClass (transitively).

Throws:

ClassNotFoundException - if any of the class's superclasses or interfaces can't be found.

getAnnotationEntries

public AnnotationEntry[] getAnnotationEntries()

Returns:

Annotations on the class

Since:

6.0

getAttribute

public final <T extends Attribute> T getAttribute(byte tag)

Gets attribute for given tag.

Returns:

Attribute for given tag, null if not found. Refer to Const.ATTR_UNKNOWN constants named ATTR_* for possible values.

Since:

6.10.0

getAttributes

public Attribute[] getAttributes()

Returns:

Attributes of the class.

getBytes

public byte[] getBytes()

Returns:

class in binary format

getClassName

public String getClassName()

Returns:

Class name.

getClassNameIndex

public int getClassNameIndex()

Returns:

Class name index.

getConstantPool

public ConstantPool getConstantPool()

Returns:

Constant pool.

getFields

public Field[] getFields()

Returns:

Fields, i.e., variables of the class. Like the JVM spec mandates for the classfile format, these fields are those specific to this class, and not those of the superclass or superinterfaces.

getFileName

public String getFileName()

Returns:

File name of class, aka SourceFile attribute value

getInterfaceIndices

public int[] getInterfaceIndices()

Returns:

Indices in constant pool of implemented interfaces.

getInterfaceNames

public String[] getInterfaceNames()

Returns:

Names of implemented interfaces.

getInterfaces

public JavaClass[] getInterfaces()
                          throws ClassNotFoundException

Gets interfaces directly implemented by this JavaClass.

Throws:

ClassNotFoundException - if any of the class's interfaces can't be found.

getMajor

public int getMajor()

Returns:

Major number of class file version.

getMethod

public Method getMethod(Method m)

Returns:

A Method corresponding to java.lang.reflect.Method if any

getMethods

public Method[] getMethods()

Returns:

Methods of the class.

getMinor

public int getMinor()

Returns:

Minor number of class file version.

getPackageName

public String getPackageName()

Returns:

Package name.

getRepository

public Repository getRepository()

Gets the ClassRepository which holds its definition. By default this is the same as SyntheticRepository.getInstance();

getSource

public final byte getSource()

Returns:

returns either HEAP (generated), FILE, or ZIP

getSourceFileName

public String getSourceFileName()

Returns:

file name where this class was read from

getSourceFilePath

public String getSourceFilePath()

Gets the source file path including the package path.

Returns:

path to original source file of parsed class, relative to original source directory.

Since:

6.7.0

getSuperClass

public JavaClass getSuperClass()
                        throws ClassNotFoundException

Returns:

the superclass for this JavaClass object, or null if this is Object

Throws:

ClassNotFoundException - if the superclass can't be found

getSuperClasses

public JavaClass[] getSuperClasses()
                            throws ClassNotFoundException

Returns:

list of super classes of this class in ascending order, i.e., java.lang.Object is always the last element

Throws:

ClassNotFoundException - if any of the superclasses can't be found

getSuperclassName

public String getSuperclassName()

returns the super class name of this class. In the case that this class is Object, it will return itself (Object). This is probably incorrect but isn't fixed at this time to not break existing clients.

Returns:

Superclass name.

getSuperclassNameIndex

public int getSuperclassNameIndex()

Returns:

Class name index.

hashCode

public int hashCode()

Return value as defined by given BCELComparator strategy. By default return the hash code of the class name.

Overrides:

hashCode in class Object

See Also:

• Object.hashCode()

implementationOf

public boolean implementationOf(JavaClass inter)
                         throws ClassNotFoundException

Returns:

true, if this class is an implementation of interface inter

Throws:

ClassNotFoundException - if superclasses or superinterfaces of this class can't be found

instanceOf

public final boolean instanceOf(JavaClass superclass)
                         throws ClassNotFoundException

Equivalent to runtime "instanceof" operator.

Returns:

true if this JavaClass is derived from the super class

Throws:

ClassNotFoundException - if superclasses or superinterfaces of this object can't be found

isAnonymous

public final boolean isAnonymous()

Since:

6.0

isClass

public final boolean isClass()

isNested

public final boolean isNested()

Since:

6.0

isRecord

public boolean isRecord()

Tests whether this class was declared as a record

Returns:

true if a record attribute is present, false otherwise.

Since:

6.9.0

isSuper

public final boolean isSuper()

setAttributes

public void setAttributes(Attribute[] attributes)

Parameters:

attributes - .

setClassName

public void setClassName(String className)

Parameters:

className - .

setClassNameIndex

public void setClassNameIndex(int classNameIndex)

Parameters:

classNameIndex - .

setConstantPool

public void setConstantPool(ConstantPool constantPool)

Parameters:

constantPool - .

setFields

public void setFields(Field[] fields)

Parameters:

fields - .

setFileName

public void setFileName(String fileName)

Sets File name of class, aka SourceFile attribute value

setInterfaceNames

public void setInterfaceNames(String[] interfaceNames)

Parameters:

interfaceNames - .

setInterfaces

public void setInterfaces(int[] interfaces)

Parameters:

interfaces - .

setMajor

public void setMajor(int major)

Parameters:

major - .

setMethods

public void setMethods(Method[] methods)

Parameters:

methods - .

setMinor

public void setMinor(int minor)

Parameters:

minor - .

setRepository

public void setRepository(Repository repository)

Sets the ClassRepository which loaded the JavaClass. Should be called immediately after parsing is done.

setSourceFileName

public void setSourceFileName(String sourceFileName)

Sets absolute path to file this class was read from.

setSuperclassName

public void setSuperclassName(String superclassName)

Parameters:

superclassName - .

setSuperclassNameIndex

public void setSuperclassNameIndex(int superclassNameIndex)

Parameters:

superclassNameIndex - .

toString

public String toString()

Overrides:

toString in class Object

Returns:

String representing class contents.