Package org.springframework.asm

Class ClassVisitor

java.lang.Object
org.springframework.asm.ClassVisitor
Direct Known Subclasses:
ClassTransformer, ClassVisitorTee, ClassWriter, DebuggingClassWriter
public abstract class ClassVisitor extends Object
A visitor to visit a Java class. The methods of this class must be called in the following order: visit [ visitSource ] [ visitModule ][ visitNestHost ][ visitOuterClass ] ( visitAnnotation | visitTypeAnnotation | visitAttribute )* ( visitNestMember | [ * visitPermittedSubclass ] | visitInnerClass | visitRecordComponent | visitField | visitMethod )* visitEnd.
Author:
Eric Bruneton

  • Field Details

    • api

      protected final int api
      The ASM API version implemented by this visitor. The value of this field must be one of the ASMx values in Opcodes.

    • cv

      protected ClassVisitor cv
      The class visitor to which this visitor must delegate method calls. May be null.

  • Constructor Details

    • ClassVisitor

      protected ClassVisitor(int api)
      Constructs a new ClassVisitor.
      Parameters:
      api - the ASM API version implemented by this visitor. Must be one of the ASMx values in Opcodes.

    • ClassVisitor

      protected ClassVisitor(int api, ClassVisitor classVisitor)
      Constructs a new ClassVisitor.
      Parameters:
      api - the ASM API version implemented by this visitor. Must be one of the ASMx values in Opcodes.
      classVisitor - the class visitor to which this visitor must delegate method calls. May be null.

  • Method Details

    • getDelegate

      public ClassVisitor getDelegate()
      The class visitor to which this visitor must delegate method calls. May be null.
      Returns:
      the class visitor to which this visitor must delegate method calls, or null.

    • visit

      public void visit(int version, int access, String name, String signature, String superName, String[] interfaces)
      Visits the header of the class.
      Parameters:
      version - the class version. The minor version is stored in the 16 most significant bits, and the major version in the 16 least significant bits.
      access - the class's access flags (see Opcodes). This parameter also indicates if the class is deprecated Opcodes.ACC_DEPRECATED or a record Opcodes.ACC_RECORD.
      name - the internal name of the class (see Type.getInternalName()).
      signature - the signature of this class. May be null if the class is not a generic one, and does not extend or implement generic classes or interfaces.
      superName - the internal of name of the super class (see Type.getInternalName()). For interfaces, the super class is Object. May be null, but only for the Object class.
      interfaces - the internal names of the class's interfaces (see Type.getInternalName()). May be null.

    • visitSource

      public void visitSource(String source, String debug)
      Visits the source of the class.
      Parameters:
      source - the name of the source file from which the class was compiled. May be null.
      debug - additional debug information to compute the correspondence between source and compiled elements of the class. May be null.

    • visitModule

      public ModuleVisitor visitModule(String name, int access, String version)
      Visit the module corresponding to the class.
      Parameters:
      name - the fully qualified name (using dots) of the module.
      access - the module access flags, among ACC_OPEN, ACC_SYNTHETIC and ACC_MANDATED.
      version - the module version, or null.
      Returns:
      a visitor to visit the module values, or null if this visitor is not interested in visiting this module.

    • visitNestHost

      public void visitNestHost(String nestHost)
      Visits the nest host class of the class. A nest is a set of classes of the same package that share access to their private members. One of these classes, called the host, lists the other members of the nest, which in turn should link to the host of their nest. This method must be called only once and only if the visited class is a non-host member of a nest. A class is implicitly its own nest, so it's invalid to call this method with the visited class name as argument.
      Parameters:
      nestHost - the internal name of the host class of the nest (see Type.getInternalName()).

    • visitOuterClass

      public void visitOuterClass(String owner, String name, String descriptor)
      Visits the enclosing class of the class. This method must be called only if this class is a local or anonymous class. See the JVMS 4.7.7 section for more details.
      Parameters:
      owner - internal name of the enclosing class of the class (see Type.getInternalName()).
      name - the name of the method that contains the class, or null if the class is not enclosed in a method or constructor of its enclosing class (for example, if it is enclosed in an instance initializer, static initializer, instance variable initializer, or class variable initializer).
      descriptor - the descriptor of the method that contains the class, or null if the class is not enclosed in a method or constructor of its enclosing class (for example, if it is enclosed in an instance initializer, static initializer, instance variable initializer, or class variable initializer).

    • visitAnnotation

      public AnnotationVisitor visitAnnotation(String descriptor, boolean visible)
      Visits an annotation of the class.
      Parameters:
      descriptor - the class descriptor of the annotation class.
      visible - true if the annotation is visible at runtime.
      Returns:
      a visitor to visit the annotation values, or null if this visitor is not interested in visiting this annotation.

    • visitTypeAnnotation

      public AnnotationVisitor visitTypeAnnotation(int typeRef, TypePath typePath, String descriptor, boolean visible)
      Visits an annotation on a type in the class signature.
      Parameters:
      typeRef - a reference to the annotated type. The sort of this type reference must be TypeReference.CLASS_TYPE_PARAMETER, TypeReference.CLASS_TYPE_PARAMETER_BOUND or TypeReference.CLASS_EXTENDS. See TypeReference.
      typePath - the path to the annotated type argument, wildcard bound, array element type, or static inner type within 'typeRef'. May be null if the annotation targets 'typeRef' as a whole.
      descriptor - the class descriptor of the annotation class.
      visible - true if the annotation is visible at runtime.
      Returns:
      a visitor to visit the annotation values, or null if this visitor is not interested in visiting this annotation.

    • visitAttribute

      public void visitAttribute(Attribute attribute)
      Visits a non standard attribute of the class.
      Parameters:
      attribute - an attribute.

    • visitNestMember

      public void visitNestMember(String nestMember)
      Visits a member of the nest. A nest is a set of classes of the same package that share access to their private members. One of these classes, called the host, lists the other members of the nest, which in turn should link to the host of their nest. This method must be called only if the visited class is the host of a nest. A nest host is implicitly a member of its own nest, so it's invalid to call this method with the visited class name as argument.
      Parameters:
      nestMember - the internal name of a nest member (see Type.getInternalName()).

    • visitPermittedSubclass

      public void visitPermittedSubclass(String permittedSubclass)
      Visits a permitted subclasses. A permitted subclass is one of the allowed subclasses of the current class.
      Parameters:
      permittedSubclass - the internal name of a permitted subclass (see Type.getInternalName()).

    • visitInnerClass

      public void visitInnerClass(String name, String outerName, String innerName, int access)
      Visits information about an inner class. This inner class is not necessarily a member of the class being visited. More precisely, every class or interface C which is referenced by this class and which is not a package member must be visited with this method. This class must reference its nested class or interface members, and its enclosing class, if any. See the JVMS 4.7.6 section for more details.
      Parameters:
      name - the internal name of C (see Type.getInternalName()).
      outerName - the internal name of the class or interface C is a member of (see Type.getInternalName()). Must be null if C is not the member of a class or interface (for example, for local or anonymous classes).
      innerName - the (simple) name of C. Must be null for anonymous inner classes.
      access - the access flags of C originally declared in the source code from which this class was compiled.

    • visitRecordComponent

      public RecordComponentVisitor visitRecordComponent(String name, String descriptor, String signature)
      Visits a record component of the class.
      Parameters:
      name - the record component name.
      descriptor - the record component descriptor (see Type).
      signature - the record component signature. May be null if the record component type does not use generic types.
      Returns:
      a visitor to visit this record component annotations and attributes, or null if this class visitor is not interested in visiting these annotations and attributes.

    • visitField

      public FieldVisitor visitField(int access, String name, String descriptor, String signature, Object value)
      Visits a field of the class.
      Parameters:
      access - the field's access flags (see Opcodes). This parameter also indicates if the field is synthetic and/or deprecated.
      name - the field's name.
      descriptor - the field's descriptor (see Type).
      signature - the field's signature. May be null if the field's type does not use generic types.
      value - the field's initial value. This parameter, which may be null if the field does not have an initial value, must be an Integer, a Float, a Long, a Double or a String (for int, float, long or String fields respectively). This parameter is only used for static fields. Its value is ignored for non static fields, which must be initialized through bytecode instructions in constructors or methods.
      Returns:
      a visitor to visit field annotations and attributes, or null if this class visitor is not interested in visiting these annotations and attributes.

    • visitMethod

      public MethodVisitor visitMethod(int access, String name, String descriptor, String signature, String[] exceptions)
      Visits a method of the class. This method must return a new MethodVisitor instance (or null) each time it is called, i.e., it should not return a previously returned visitor.
      Parameters:
      access - the method's access flags (see Opcodes). This parameter also indicates if the method is synthetic and/or deprecated.
      name - the method's name.
      descriptor - the method's descriptor (see Type).
      signature - the method's signature. May be null if the method parameters, return type and exceptions do not use generic types.
      exceptions - the internal names of the method's exception classes (see Type.getInternalName()). May be null.
      Returns:
      an object to visit the byte code of the method, or null if this class visitor is not interested in visiting the code of this method.

    • visitEnd

      public void visitEnd()
      Visits the end of the class. This method, which is the last one to be called, is used to inform the visitor that all the fields and methods of the class have been visited.