Class Attribute


  • public class Attribute
    extends java.lang.Object
    A non standard class, field, method or code attribute.
    Author:
    Eric Bruneton, Eugene Kuleshov
    • Field Summary

      Fields 
      Modifier and Type Field Description
      java.lang.String type
      The type of this attribute.
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected Attribute​(java.lang.String type)
      Constructs a new empty attribute.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      protected Label[] getLabels()
      Returns the labels corresponding to this attribute.
      boolean isCodeAttribute()
      Returns true if this type of attribute is a code attribute.
      boolean isUnknown()
      Returns true if this type of attribute is unknown.
      protected Attribute read​(ClassReader cr, int off, int len, char[] buf, int codeOff, Label[] labels)
      Reads a type attribute.
      protected ByteVector write​(ClassWriter cw, byte[] code, int len, int maxStack, int maxLocals)
      Returns the byte array form of this attribute.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • type

        public final java.lang.String type
        The type of this attribute.
    • Constructor Detail

      • Attribute

        protected Attribute​(java.lang.String type)
        Constructs a new empty attribute.
        Parameters:
        type - the type of the attribute.
    • Method Detail

      • isUnknown

        public boolean isUnknown()
        Returns true if this type of attribute is unknown. The default implementation of this method always returns true.
        Returns:
        true if this type of attribute is unknown.
      • isCodeAttribute

        public boolean isCodeAttribute()
        Returns true if this type of attribute is a code attribute.
        Returns:
        true if this type of attribute is a code attribute.
      • getLabels

        protected Label[] getLabels()
        Returns the labels corresponding to this attribute.
        Returns:
        the labels corresponding to this attribute, or null if this attribute is not a code attribute that contains labels.
      • read

        protected Attribute read​(ClassReader cr,
                                 int off,
                                 int len,
                                 char[] buf,
                                 int codeOff,
                                 Label[] labels)
        Reads a type attribute. This method must return a new Attribute object, of type type, corresponding to the len bytes starting at the given offset, in the given class reader.
        Parameters:
        cr - the class that contains the attribute to be read.
        off - index of the first byte of the attribute's content in cr.b. The 6 attribute header bytes, containing the type and the length of the attribute, are not taken into account here.
        len - the length of the attribute's content.
        buf - buffer to be used to call readUTF8, readClass or readConst.
        codeOff - index of the first byte of code's attribute content in cr.b, or -1 if the attribute to be read is not a code attribute. The 6 attribute header bytes, containing the type and the length of the attribute, are not taken into account here.
        labels - the labels of the method's code, or null if the attribute to be read is not a code attribute.
        Returns:
        a new Attribute object corresponding to the given bytes.
      • write

        protected ByteVector write​(ClassWriter cw,
                                   byte[] code,
                                   int len,
                                   int maxStack,
                                   int maxLocals)
        Returns the byte array form of this attribute.
        Parameters:
        cw - the class to which this attribute must be added. This parameter can be used to add to the constant pool of this class the items that corresponds to this attribute.
        code - the bytecode of the method corresponding to this code attribute, or null if this attribute is not a code attributes.
        len - the length of the bytecode of the method corresponding to this code attribute, or null if this attribute is not a code attribute.
        maxStack - the maximum stack size of the method corresponding to this code attribute, or -1 if this attribute is not a code attribute.
        maxLocals - the maximum number of local variables of the method corresponding to this code attribute, or -1 if this attribute is not a code attribute.
        Returns:
        the byte array form of this attribute.