https://commons.apache.org/proper/commons-bcel: Apache Commons Bytecode Engineering Library (The Apache Software Foundation)
  • Enver Haase
  • David Dixon-Peugh
  • Patrick Beard
  • Conor MacNeill
  • Costin Manolache
  • Bill Pugh
  • First Hop Ltd / Torsten Rueger
  • Jérôme Leroux
  • Mark Roberts
  • Sam Yoon
  • Dave Brosius
  • Torsten Curdt (ASF)
  • Markus Dahm (it-frameworksolutions)
  • Jason van Zyl
  • Gary Gregory (Rocket Software) 
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */
package org.apache.bcel.util;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;

import org.apache.bcel.Const;
import org.apache.bcel.classfile.Attribute;
import org.apache.bcel.classfile.Code;
import org.apache.bcel.classfile.CodeException;
import org.apache.bcel.classfile.ConstantPool;
import org.apache.bcel.classfile.ConstantUtf8;
import org.apache.bcel.classfile.ConstantValue;
import org.apache.bcel.classfile.ExceptionTable;
import org.apache.bcel.classfile.InnerClass;
import org.apache.bcel.classfile.InnerClasses;
import org.apache.bcel.classfile.LineNumber;
import org.apache.bcel.classfile.LineNumberTable;
import org.apache.bcel.classfile.LocalVariable;
import org.apache.bcel.classfile.LocalVariableTable;
import org.apache.bcel.classfile.SourceFile;
import org.apache.bcel.classfile.Utility;


Convert found attributes into HTML file.

/**
 * Convert found attributes into HTML file.
 *
 *
 */
final class AttributeHTML {

    private final String class_name; // name of current class
    private final PrintWriter file; // file to write to
    private int attr_count = 0;
    private final ConstantHTML constant_html;
    private final ConstantPool constant_pool;


    AttributeHTML(final String dir, final String class_name, final ConstantPool constant_pool,
            final ConstantHTML constant_html) throws IOException {
        this.class_name = class_name;
        this.constant_pool = constant_pool;
        this.constant_html = constant_html;
        file = new PrintWriter(new FileOutputStream(dir + class_name + "_attributes.html"));
        file.println("<HTML><BODY BGCOLOR=\"#C0C0C0\"><TABLE BORDER=0>");
    }


    private String codeLink( final int link, final int method_number ) {
        return "<A HREF=\"" + class_name + "_code.html#code" + method_number + "@" + link
                + "\" TARGET=Code>" + link + "</A>";
    }


    void close() {
        file.println("</TABLE></BODY></HTML>");
        file.close();
    }


    void writeAttribute( final Attribute attribute, final String anchor ) {
        writeAttribute(attribute, anchor, 0);
    }


    void writeAttribute( final Attribute attribute, final String anchor, final int method_number ) {
        final byte tag = attribute.getTag();
        int index;
        if (tag == Const.ATTR_UNKNOWN) {
            return;
        }
        attr_count++; // Increment number of attributes found so far
        if (attr_count % 2 == 0) {
            file.print("<TR BGCOLOR=\"#C0C0C0\"><TD>");
        } else {
            file.print("<TR BGCOLOR=\"#A0A0A0\"><TD>");
        }
        file.println("<H4><A NAME=\"" + anchor + "\">" + attr_count + " " + Const.getAttributeName(tag)
                + "</A></H4>");
        /* Handle different attributes
         */
        switch (tag) {
            case Const.ATTR_CODE:
                final Code c = (Code) attribute;
                // Some directly printable values
                file.print("<UL><LI>Maximum stack size = " + c.getMaxStack()
                        + "</LI>\n<LI>Number of local variables = " + c.getMaxLocals()
                        + "</LI>\n<LI><A HREF=\"" + class_name + "_code.html#method"
                        + method_number + "\" TARGET=Code>Byte code</A></LI></UL>\n");
                // Get handled exceptions and list them
                final CodeException[] ce = c.getExceptionTable();
                final int len = ce.length;
                if (len > 0) {
                    file.print("<P><B>Exceptions handled</B><UL>");
                    for (final CodeException cex : ce) {
                        final int catch_type = cex.getCatchType(); // Index in constant pool
                        file.print("<LI>");
                        if (catch_type != 0) {
                            file.print(constant_html.referenceConstant(catch_type)); // Create Link to _cp.html
                        } else {
                            file.print("Any Exception");
                        }
                        file.print("<BR>(Ranging from lines "
                                + codeLink(cex.getStartPC(), method_number) + " to "
                                + codeLink(cex.getEndPC(), method_number) + ", handled at line "
                                + codeLink(cex.getHandlerPC(), method_number) + ")</LI>");
                    }
                    file.print("</UL>");
                }
                break;
            case Const.ATTR_CONSTANT_VALUE:
                index = ((ConstantValue) attribute).getConstantValueIndex();
                // Reference _cp.html
                file.print("<UL><LI><A HREF=\"" + class_name + "_cp.html#cp" + index
                        + "\" TARGET=\"ConstantPool\">Constant value index(" + index
                        + ")</A></UL>\n");
                break;
            case Const.ATTR_SOURCE_FILE:
                index = ((SourceFile) attribute).getSourceFileIndex();
                // Reference _cp.html
                file.print("<UL><LI><A HREF=\"" + class_name + "_cp.html#cp" + index
                        + "\" TARGET=\"ConstantPool\">Source file index(" + index + ")</A></UL>\n");
                break;
            case Const.ATTR_EXCEPTIONS:
                // List thrown exceptions
                final int[] indices = ((ExceptionTable) attribute).getExceptionIndexTable();
                file.print("<UL>");
                for (final int indice : indices) {
                    file.print("<LI><A HREF=\"" + class_name + "_cp.html#cp" + indice
                            + "\" TARGET=\"ConstantPool\">Exception class index(" + indice
                            + ")</A>\n");
                }
                file.print("</UL>\n");
                break;
            case Const.ATTR_LINE_NUMBER_TABLE:
                final LineNumber[] line_numbers = ((LineNumberTable) attribute).getLineNumberTable();
                // List line number pairs
                file.print("<P>");
                for (int i = 0; i < line_numbers.length; i++) {
                    file.print("(" + line_numbers[i].getStartPC() + ",&nbsp;"
                            + line_numbers[i].getLineNumber() + ")");
                    if (i < line_numbers.length - 1) {
                        file.print(", "); // breakable
                    }
                }
                break;
            case Const.ATTR_LOCAL_VARIABLE_TABLE:
                final LocalVariable[] vars = ((LocalVariableTable) attribute).getLocalVariableTable();
                // List name, range and type
                file.print("<UL>");
                for (final LocalVariable var : vars) {
                    index = var.getSignatureIndex();
                    String signature = ((ConstantUtf8) constant_pool.getConstant(index,
                            Const.CONSTANT_Utf8)).getBytes();
                    signature = Utility.signatureToString(signature, false);
                    final int start = var.getStartPC();
                    final int end = start + var.getLength();
                    file.println("<LI>" + Class2HTML.referenceType(signature) + "&nbsp;<B>"
                            + var.getName() + "</B> in slot %" + var.getIndex()
                            + "<BR>Valid from lines " + "<A HREF=\"" + class_name
                            + "_code.html#code" + method_number + "@" + start + "\" TARGET=Code>"
                            + start + "</A> to " + "<A HREF=\"" + class_name + "_code.html#code"
                            + method_number + "@" + end + "\" TARGET=Code>" + end + "</A></LI>");
                }
                file.print("</UL>\n");
                break;
            case Const.ATTR_INNER_CLASSES:
                final InnerClass[] classes = ((InnerClasses) attribute).getInnerClasses();
                // List inner classes
                file.print("<UL>");
                for (final InnerClass classe : classes) {
                    String name;
                    String access;
                    index = classe.getInnerNameIndex();
                    if (index > 0) {
                        name = ((ConstantUtf8) constant_pool.getConstant(index, Const.CONSTANT_Utf8))
                                .getBytes();
                    } else {
                        name = "&lt;anonymous&gt;";
                    }
                    access = Utility.accessToString(classe.getInnerAccessFlags());
                    file.print("<LI><FONT COLOR=\"#FF0000\">" + access + "</FONT> "
                            + constant_html.referenceConstant(classe.getInnerClassIndex())
                            + " in&nbsp;class "
                            + constant_html.referenceConstant(classe.getOuterClassIndex())
                            + " named " + name + "</LI>\n");
                }
                file.print("</UL>\n");
                break;
            default: // Such as Unknown attribute or Deprecated
                file.print("<P>" + attribute);
        }
        file.println("</TD></TR>");
        file.flush();
    }
}