classreader.java

jboss规则引擎

                final byte[] c = new byte[b.length + 1000];
                System.arraycopy( b,
                                  0,
                                  c,
                                  0,
                                  len );
                b = c;
            }
        }
    }

    // ------------------------------------------------------------------------
    // Public methods
    // ------------------------------------------------------------------------

    /**
     * Makes the given visitor visit the Java class of this {@link ClassReader}.
     * This class is the one specified in the constructor (see
     * {@link #ClassReader(byte[]) ClassReader}).
     * 
     * @param classVisitor the visitor that must visit this class.
     * @param skipDebug <tt>true</tt> if the debug information of the class
     *        must not be visited. In this case the
     *        {@link MethodVisitor#visitLocalVariable visitLocalVariable} and
     *        {@link MethodVisitor#visitLineNumber visitLineNumber} methods will
     *        not be called.
     */
    public void accept(final ClassVisitor classVisitor,
                       final boolean skipDebug) {
        accept( classVisitor,
                new Attribute[0],
                skipDebug );
    }

    /**
     * Makes the given visitor visit the Java class of this {@link ClassReader}.
     * This class is the one specified in the constructor (see
     * {@link #ClassReader(byte[]) ClassReader}).
     * 
     * @param classVisitor the visitor that must visit this class.
     * @param attrs prototypes of the attributes that must be parsed during the
     *        visit of the class. Any attribute whose type is not equal to the
     *        type of one the prototypes will be ignored.
     * @param skipDebug <tt>true</tt> if the debug information of the class
     *        must not be visited. In this case the
     *        {@link MethodVisitor#visitLocalVariable visitLocalVariable} and
     *        {@link MethodVisitor#visitLineNumber visitLineNumber} methods will
     *        not be called.
     */
    public void accept(final ClassVisitor classVisitor,
                       final Attribute[] attrs,
                       final boolean skipDebug) {
        final byte[] b = this.b; // the bytecode array
        final char[] c = new char[this.maxStringLength]; // buffer used to read strings
        int i, j, k; // loop variables
        int u, v, w; // indexes in b
        Attribute attr;

        int access;
        String name;
        String desc;
        String attrName;
        String signature;
        int anns = 0;
        int ianns = 0;
        Attribute cattrs = null;

        // visits the header
        u = this.header;
        access = readUnsignedShort( u );
        name = readClass( u + 2,
                          c );
        v = this.items[readUnsignedShort( u + 4 )];
        final String superClassName = v == 0 ? null : readUTF8( v,
                                                                c );
        final String[] implementedItfs = new String[readUnsignedShort( u + 6 )];
        w = 0;
        u += 8;
        for ( i = 0; i < implementedItfs.length; ++i ) {
            implementedItfs[i] = readClass( u,
                                            c );
            u += 2;
        }

        // skips fields and methods
        v = u;
        i = readUnsignedShort( v );
        v += 2;
        for ( ; i > 0; --i ) {
            j = readUnsignedShort( v + 6 );
            v += 8;
            for ( ; j > 0; --j ) {
                v += 6 + readInt( v + 2 );
            }
        }
        i = readUnsignedShort( v );
        v += 2;
        for ( ; i > 0; --i ) {
            j = readUnsignedShort( v + 6 );
            v += 8;
            for ( ; j > 0; --j ) {
                v += 6 + readInt( v + 2 );
            }
        }
        // reads the class's attributes
        signature = null;
        String sourceFile = null;
        String sourceDebug = null;
        String enclosingOwner = null;
        String enclosingName = null;
        String enclosingDesc = null;

        i = readUnsignedShort( v );
        v += 2;
        for ( ; i > 0; --i ) {
            attrName = readUTF8( v,
                                 c );
            if ( attrName.equals( "SourceFile" ) ) {
                sourceFile = readUTF8( v + 6,
                                       c );
            } else if ( attrName.equals( "Deprecated" ) ) {
                access |= Opcodes.ACC_DEPRECATED;
            } else if ( attrName.equals( "Synthetic" ) ) {
                access |= Opcodes.ACC_SYNTHETIC;
            } else if ( attrName.equals( "Annotation" ) ) {
                access |= Opcodes.ACC_ANNOTATION;
            } else if ( attrName.equals( "Enum" ) ) {
                access |= Opcodes.ACC_ENUM;
            } else if ( attrName.equals( "InnerClasses" ) ) {
                w = v + 6;
            } else if ( attrName.equals( "Signature" ) ) {
                signature = readUTF8( v + 6,
                                      c );
            } else if ( attrName.equals( "SourceDebugExtension" ) ) {
                final int len = readInt( v + 2 );
                sourceDebug = readUTF( v + 6,
                                       len,
                                       new char[len] );
            } else if ( attrName.equals( "EnclosingMethod" ) ) {
                enclosingOwner = readClass( v + 6,
                                            c );
                final int item = readUnsignedShort( v + 8 );
                if ( item != 0 ) {
                    enclosingName = readUTF8( this.items[item],
                                              c );
                    enclosingDesc = readUTF8( this.items[item] + 2,
                                              c );
                }
            } else if ( attrName.equals( "RuntimeVisibleAnnotations" ) ) {
                anns = v + 6;
            } else if ( attrName.equals( "RuntimeInvisibleAnnotations" ) ) {
                ianns = v + 6;
            } else {
                attr = readAttribute( attrs,
                                      attrName,
                                      v + 6,
                                      readInt( v + 2 ),
                                      c,
                                      -1,
                                      null );
                if ( attr != null ) {
                    attr.next = cattrs;
                    cattrs = attr;
                }
            }
            v += 6 + readInt( v + 2 );
        }
        // calls the visit method
        classVisitor.visit( readInt( 4 ),
                            access,
                            name,
                            signature,
                            superClassName,
                            implementedItfs );

        // calls the visitSource method
        if ( sourceFile != null || sourceDebug != null ) {
            classVisitor.visitSource( sourceFile,
                                      sourceDebug );
        }

        // calls the visitOuterClass method
        if ( enclosingOwner != null ) {
            classVisitor.visitOuterClass( enclosingOwner,
                                          enclosingName,
                                          enclosingDesc );
        }

        // visits the class annotations
        for ( i = 1; i >= 0; --i ) {
            v = i == 0 ? ianns : anns;
            if ( v != 0 ) {
                j = readUnsignedShort( v );
                v += 2;
                for ( ; j > 0; --j ) {
                    desc = readUTF8( v,
                                     c );
                    v += 2;
                    v = readAnnotationValues( v,
                                              c,
                                              classVisitor.visitAnnotation( desc,
                                                                            i != 0 ) );
                }
            }
        }

        // visits the class attributes
        while ( cattrs != null ) {
            attr = cattrs.next;
            cattrs.next = null;
            classVisitor.visitAttribute( cattrs );
            cattrs = attr;
        }

        // class the visitInnerClass method
        if ( w != 0 ) {
            i = readUnsignedShort( w );
            w += 2;
            for ( ; i > 0; --i ) {
                classVisitor.visitInnerClass( readUnsignedShort( w ) == 0 ? null : readClass( w,
                                                                                              c ),
                                              readUnsignedShort( w + 2 ) == 0 ? null : readClass( w + 2,
                                                                                                  c ),
                                              readUnsignedShort( w + 4 ) == 0 ? null : readUTF8( w + 4,
                                                                                                 c ),
                                              readUnsignedShort( w + 6 ) );
                w += 8;
            }
        }

        // visits the fields
        i = readUnsignedShort( u );
        u += 2;
        for ( ; i > 0; --i ) {
            access = readUnsignedShort( u );
            name = readUTF8( u + 2,
                             c );
            desc = readUTF8( u + 4,
                             c );
            // visits the field's attributes and looks for a ConstantValue
            // attribute
            int fieldValueItem = 0;
            signature = null;
            anns = 0;
            ianns = 0;
            cattrs = null;

            j = readUnsignedShort( u + 6 );
            u += 8;
            for ( ; j > 0; --j ) {
                attrName = readUTF8( u,
                                     c );
                if ( attrName.equals( "ConstantValue" ) ) {
                    fieldValueItem = readUnsignedShort( u + 6 );
                } else if ( attrName.equals( "Synthetic" ) ) {
                    access |= Opcodes.ACC_SYNTHETIC;
                } else if ( attrName.equals( "Deprecated" ) ) {
                    access |= Opcodes.ACC_DEPRECATED;
                } else if ( attrName.equals( "Enum" ) ) {
                    access |= Opcodes.ACC_ENUM;
                } else if ( attrName.equals( "Signature" ) ) {
                    signature = readUTF8( u + 6,
                                          c );
                } else if ( attrName.equals( "RuntimeVisibleAnnotations" ) ) {
                    anns = u + 6;
                } else if ( attrName.equals( "RuntimeInvisibleAnnotations" ) ) {
                    ianns = u + 6;
                } else {
                    attr = readAttribute( attrs,
                                          attrName,
                                          u + 6,
                                          readInt( u + 2 ),
                                          c,
                                          -1,
                                          null );
                    if ( attr != null ) {
                        attr.next = cattrs;
                        cattrs = attr;
                    }
                }
                u += 6 + readInt( u + 2 );
            }
            // reads the field's value, if any
            final Object value = (fieldValueItem == 0 ? null : readConst( fieldValueItem,
                                                                          c ));
            // visits the field
            final FieldVisitor fv = classVisitor.visitField( access,
                                                             name,
                                                             desc,
                                                             signature,
                                                             value );
            // visits the field annotations and attributes
            if ( fv != null ) {
                for ( j = 1; j >= 0; --j ) {
                    v = j == 0 ? ianns : anns;
                    if ( v != 0 ) {
                        k = readUnsignedShort( v );
                        v += 2;