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, that is, 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:

  • Field Details

  • 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()
      Gets the comparison strategy object.
      Returns:
      Comparison strategy object.

    • setComparator

      public static void setComparator(BCELComparator<JavaClass> comparator)
      Sets the comparison strategy object.
      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. That is, the hierarchy of methods, fields, attributes, and other elements forms 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()
      Creates a deep copy of this class.
      Returns:
      deep copy of this class.

    • dump

      public void dump(DataOutputStream file) throws IOException
      Dumps Java class to output stream in binary format.

      For versions 45.0 through 45.2, all method Code attributes use compact four-byte headers if any method's Code attribute returns true from Code.isCompactCodeHeader(). Otherwise, all method Code attributes use standard eight-byte headers. Versions 45.3 and later always use standard headers, including after a version change. The header size refers only to max_stack, max_locals, and code_length. These encoding adjustments do not modify the methods or their attributes.

      Parameters:
      file - Output stream.
      Throws:
      IOException - Thrown if an I/O error occurs.
      ClassFormatException - Thrown if a method's values do not fit the selected Code header layout.

    • dump

      public void dump(File file) throws IOException
      Dumps class to a file.
      Parameters:
      file - Output file.
      Throws:
      IOException - Thrown if an I/O error occurs.

    • dump

      public void dump(OutputStream file) throws IOException
      Dumps Java class to output stream in binary format.
      Parameters:
      file - Output stream.
      Throws:
      IOException - Thrown if an I/O error occurs.

    • dump

      public void dump(String fileName) throws IOException
      Dumps class to a file named fileName.
      Parameters:
      fileName - Output file name.
      Throws:
      IOException - Thrown 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:

    • findField

      public Field findField(String fieldName, Type fieldType) throws ClassNotFoundException
      Finds a visible field by name and type in this class and its superclasses.
      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 - Thrown if the class cannot be found.
      Since:
      6.8.0

    • getAllInterfaces

      public JavaClass[] getAllInterfaces() throws ClassNotFoundException
      Gets all interfaces implemented by this JavaClass (transitively).
      Returns:
      all interfaces.
      Throws:
      ClassNotFoundException - Thrown if any of the class's superclasses or interfaces can't be found.

    • getAnnotationEntries

      public AnnotationEntry[] getAnnotationEntries()
      Gets annotations on the class.
      Returns:
      Annotations on the class.
      Since:
      6.0

    • getAttribute

      public final <T extends Attribute> T getAttribute(byte tag)
      Gets attribute for given tag.
      Type Parameters:
      T - The attribute type.
      Parameters:
      tag - The attribute 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()
      Gets attributes of the class.
      Returns:
      Attributes of the class.

    • getBytes

      public byte[] getBytes()
      Gets class in binary format.
      Returns:
      class in binary format.

    • getClassName

      public String getClassName()
      Gets the class name.
      Returns:
      Class name.

    • getClassNameIndex

      public int getClassNameIndex()
      Gets the class name index.
      Returns:
      Class name index.

    • getConstantPool

      public ConstantPool getConstantPool()
      Gets the constant pool.
      Returns:
      Constant pool.

    • getFields

      public Field[] getFields()
      Gets the fields.
      Returns:
      Fields, that is, 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()
      Gets the file name of class.
      Returns:
      File name of class, aka SourceFile attribute value.

    • getInterfaceIndices

      public int[] getInterfaceIndices()
      Gets indices in constant pool of implemented interfaces.
      Returns:
      Indices in constant pool of implemented interfaces.

    • getInterfaceNames

      public String[] getInterfaceNames()
      Gets names of implemented interfaces.
      Returns:
      Names of implemented interfaces.

    • getInterfaces

      public JavaClass[] getInterfaces() throws ClassNotFoundException
      Gets interfaces directly implemented by this JavaClass.
      Returns:
      The interfaces.
      Throws:
      ClassNotFoundException - Thrown if any of the class's interfaces can't be found.

    • getMajor

      public int getMajor()
      Gets the major number of class file version.
      Returns:
      Major number of class file version.

    • getMethod

      public Method getMethod(Method m)
      Gets a Method corresponding to java.lang.reflect.Method if any.
      Parameters:
      m - The method to find.
      Returns:
      A Method corresponding to java.lang.reflect.Method if any.

    • getMethods

      public Method[] getMethods()
      Gets the methods of the class.
      Returns:
      Methods of the class.

    • getMinor

      public int getMinor()
      Gets the minor number of class file version.
      Returns:
      Minor number of class file version.

    • getPackageName

      public String getPackageName()
      Gets the package name.
      Returns:
      Package name.

    • getRepository

      public Repository getRepository()
      Gets the ClassRepository which holds its definition. By default this is the same as SyntheticRepository.getInstance().
      Returns:
      The repository.

    • getSource

      public final byte getSource()
      Gets the source.
      Returns:
      either HEAP (generated), FILE, or ZIP.

    • getSourceFileName

      public String getSourceFileName()
      Gets the file name where this class was read from.
      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
      Gets the superclass for this JavaClass object, or null if this is Object.
      Returns:
      The superclass for this JavaClass object, or null if this is Object.
      Throws:
      ClassNotFoundException - Thrown if the superclass can't be found.

    • getSuperClasses

      public JavaClass[] getSuperClasses() throws ClassNotFoundException
      Gets the list of superclasses of this class in ascending order.
      Returns:
      list of superclasses of this class in ascending order, that is, Object is always the last element.
      Throws:
      ClassNotFoundException - Thrown if any of the superclasses can't be found.

    • getSuperclassName

      public String getSuperclassName()
      Gets the superclass 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()
      Gets the class name index.
      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:

    • implementationOf

      public boolean implementationOf(JavaClass inter) throws ClassNotFoundException
      Checks if this class is an implementation of interface inter.
      Parameters:
      inter - The interface to check.
      Returns:
      true, if this class is an implementation of interface inter.
      Throws:
      ClassNotFoundException - Thrown 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.
      Parameters:
      superclass - The superclass to check.
      Returns:
      true if this JavaClass is derived from the superclass.
      Throws:
      ClassNotFoundException - Thrown if superclasses or superinterfaces of this object can't be found.

    • isAnonymous

      public final boolean isAnonymous()
      Tests whether this class is anonymous.
      Returns:
      true if anonymous.
      Since:
      6.0

    • isClass

      public final boolean isClass()
      Tests whether this is a class.
      Returns:
      true if this is a class.

    • isNested

      public final boolean isNested()
      Tests whether this class is nested.
      Returns:
      true if nested.
      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()
      Tests whether the ACC_SUPER flag is set.
      Returns:
      true if the ACC_SUPER flag is set.

    • setAttributes

      public void setAttributes(Attribute[] attributes)
      Sets the attributes.
      Parameters:
      attributes - The attributes.

    • setClassName

      public void setClassName(String className)
      Sets the class name.
      Parameters:
      className - The class name.

    • setClassNameIndex

      public void setClassNameIndex(int classNameIndex)
      Sets the class name index.
      Parameters:
      classNameIndex - The class name index.

    • setConstantPool

      public void setConstantPool(ConstantPool constantPool)
      Sets the constant pool.
      Parameters:
      constantPool - The constant pool.

    • setFields

      public void setFields(Field[] fields)
      Sets the fields.
      Parameters:
      fields - The fields.

    • setFileName

      public void setFileName(String fileName)
      Sets the source file name of the class, that is, the SourceFile attribute value.
      Parameters:
      fileName - The file name.

    • setInterfaceNames

      public void setInterfaceNames(String[] interfaceNames)
      Sets the interface names.
      Parameters:
      interfaceNames - The interface names.

    • setInterfaces

      public void setInterfaces(int[] interfaces)
      Sets the interfaces.
      Parameters:
      interfaces - The interfaces.

    • setMajor

      public void setMajor(int major)
      Sets the major version.
      Parameters:
      major - The major version.

    • setMethods

      public void setMethods(Method[] methods)
      Sets the methods.
      Parameters:
      methods - The methods.

    • setMinor

      public void setMinor(int minor)
      Sets the minor version.
      Parameters:
      minor - The minor version.

    • setRepository

      public void setRepository(Repository repository)
      Sets the ClassRepository which loaded the JavaClass. Should be called immediately after parsing is done.
      Parameters:
      repository - The repository.

    • setSourceFileName

      public void setSourceFileName(String sourceFileName)
      Sets absolute path to file this class was read from.
      Parameters:
      sourceFileName - The source file name.

    • setSuperclassName

      public void setSuperclassName(String superclassName)
      Sets the superclass name.
      Parameters:
      superclassName - The superclass name.

    • setSuperclassNameIndex

      public void setSuperclassNameIndex(int superclassNameIndex)
      Sets the superclass name index.
      Parameters:
      superclassNameIndex - The superclass name index.

    • toString

      public String toString()
      Overrides:
      toString in class Object
      Returns:
      String representing class contents.