sourcelineannotation.java

一个查找java程序里bug的程序的源代码,该程序本身也是java写的,对提高java编程水平很有用

/*
 * FindBugs - Find bugs in Java programs
 * Copyright (C) 2003,2004 University of Maryland
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package edu.umd.cs.findbugs;

import edu.umd.cs.findbugs.visitclass.DismantleBytecode;
import edu.umd.cs.findbugs.visitclass.PreorderVisitor;

import edu.umd.cs.findbugs.xml.XMLAttributeList;
import edu.umd.cs.findbugs.xml.XMLOutput;

import java.io.IOException;

import org.apache.bcel.classfile.Code;
import org.apache.bcel.classfile.LineNumber;
import org.apache.bcel.classfile.LineNumberTable;
import org.apache.bcel.generic.InstructionHandle;
import org.apache.bcel.generic.MethodGen;

/**
 * A BugAnnotation that records a range of source lines
 * in a class.
 *
 * @author David Hovemeyer
 * @see BugAnnotation
 */
public class SourceLineAnnotation implements BugAnnotation {
	private static final String DEFAULT_ROLE = "SOURCE_LINE_DEFAULT";

	/**
	 * String returned if the source file is unknown.
	 * This must match what BCEL uses when the source file is unknown.
	 */
	public static final String UNKNOWN_SOURCE_FILE = "<Unknown>";

	private String description;
	private String className;
	private String sourceFile;
	private int startLine;
	private int endLine;
	private int startBytecode;
	private int endBytecode;

	/**
	 * Constructor.
	 *
	 * @param className     the class to which the line number(s) refer
	 * @param sourceFile    the name of the source file
	 * @param startLine     the first line (inclusive)
	 * @param endLine       the ending line (inclusive)
	 * @param startBytecode the first bytecode offset (inclusive)
	 * @param endBytecode   the end bytecode offset (inclusive)
	 */
	public SourceLineAnnotation(String className, String sourceFile, int startLine, int endLine,
	                            int startBytecode, int endBytecode) {
		if (className == null) throw new IllegalArgumentException("class name is null");
		if (sourceFile == null) throw new IllegalArgumentException("source file is null");
		this.description = DEFAULT_ROLE;
		this.className = className;
		this.sourceFile = sourceFile;
		this.startLine = startLine;
		this.endLine = endLine;
		this.startBytecode = startBytecode;
		this.endBytecode = endBytecode;
	}

	/**
	 * Factory method to create an unknown source line annotation.
	 *
	 * @param className the class name
	 * @return the SourceLineAnnotation
	 */
	public static SourceLineAnnotation createUnknown(String className, String sourceFile) {
		return createUnknown(className, sourceFile, -1, -1);
	}

	public static SourceLineAnnotation createUnknown(String className, String sourceFile, int startBytecode, int endBytecode) {
		SourceLineAnnotation result = new SourceLineAnnotation(className, sourceFile, -1, -1, startBytecode, endBytecode);
		result.setDescription("SOURCE_LINE_UNKNOWN");
		return result;
	}

	/**
	 * Factory method for creating a source line annotation describing
	 * an entire method.
	 *
	 * @param visitor a BetterVisitor which is visiting the method
	 * @return the SourceLineAnnotation
	 */
	public static SourceLineAnnotation fromVisitedMethod(PreorderVisitor visitor) {
		LineNumberTable lineNumberTable = getLineNumberTable(visitor);
		String className = visitor.getDottedClassName();
		String sourceFile = visitor.getSourceFile();
		Code code = visitor.getMethod().getCode();
		int codeSize = (code != null) ? code.getCode().length : 0;
		if (lineNumberTable == null)
			return createUnknown(className, sourceFile, 0, codeSize - 1);
		return forEntireMethod(className, sourceFile, lineNumberTable, codeSize);
	}

	/**
	 * Factory method for creating a source line annotation describing
	 * an entire method.
	 *
	 * @param methodGen the method being visited
	 * @return the SourceLineAnnotation, or null if we do not have line number information
	 *         for the method
	 */
	public static SourceLineAnnotation fromVisitedMethod(MethodGen methodGen, String sourceFile) {
		LineNumberTable lineNumberTable = methodGen.getLineNumberTable(methodGen.getConstantPool());
		String className = methodGen.getClassName();
		int codeSize = methodGen.getInstructionList().getLength();
		if (lineNumberTable == null)
			return createUnknown(className, sourceFile, 0, codeSize - 1);
		return forEntireMethod(className, sourceFile, lineNumberTable, codeSize);
	}

	private static SourceLineAnnotation forEntireMethod(String className, String sourceFile,
	                                                    LineNumberTable lineNumberTable, int codeSize) {
		LineNumber[] table = lineNumberTable.getLineNumberTable();
		if (table != null && table.length > 0) {
			LineNumber first = table[0];
			LineNumber last = table[table.length - 1];
			return new SourceLineAnnotation(className, sourceFile, first.getLineNumber(), last.getLineNumber(),
			        0, codeSize - 1);
		} else {
			return createUnknown(className, sourceFile, 0, codeSize - 1);
		}
	}

	/**
	 * Factory method for creating a source line annotation describing the
	 * source line number for the instruction being visited by given visitor.
	 *
	 * @param visitor a BetterVisitor which is visiting the method
	 * @param pc      the bytecode offset of the instruction in the method
	 * @return the SourceLineAnnotation, or null if we do not have line number information
	 *         for the instruction
	 */
	public static SourceLineAnnotation fromVisitedInstruction(PreorderVisitor visitor, int pc) {
		return fromVisitedInstructionRange(visitor, pc, pc);
	}

	/**
	 * Factory method for creating a source line annotation describing the
	 * source line numbers for a range of instructions in the method being
	 * visited by the given visitor.
	 *
	 * @param visitor a BetterVisitor which is visiting the method
	 * @param startPC the bytecode offset of the start instruction in the range
	 * @param endPC   the bytecode offset of the end instruction in the range
	 * @return the SourceLineAnnotation, or null if we do not have line number information
	 *         for the instruction
	 */
	public static SourceLineAnnotation fromVisitedInstructionRange(PreorderVisitor visitor, int startPC, int endPC) {
		LineNumberTable lineNumberTable = getLineNumberTable(visitor);
		String className = visitor.getDottedClassName();
		String sourceFile = visitor.getSourceFile();

		if (lineNumberTable == null)
			return createUnknown(className, sourceFile, startPC, endPC);

		int startLine = lineNumberTable.getSourceLine(startPC);
		int endLine = lineNumberTable.getSourceLine(endPC);
		return new SourceLineAnnotation(className, sourceFile, startLine, endLine, startPC, endPC);
	}

	/**
	 * Factory method for creating a source line annotation describing the
	 * source line number for the instruction being visited by given visitor.
	 *
	 * @param visitor a DismantleBytecode visitor which is visiting the method
	 * @return the SourceLineAnnotation, or null if we do not have line number information
	 *         for the instruction
	 */
	public static SourceLineAnnotation fromVisitedInstruction(DismantleBytecode visitor) {
		return fromVisitedInstruction(visitor, visitor.getPC());
	}

	/**
	 * Factory method for creating a source line annotation describing the
	 * source line number for a visited instruction.
	 *
	 * @param methodGen the MethodGen object representing the method
	 * @param handle    the InstructionHandle containing the visited instruction
	 * @return the SourceLineAnnotation, or null if we do not have line number information
	 *         for the instruction
	 */
	public static SourceLineAnnotation fromVisitedInstruction(MethodGen methodGen, String sourceFile, InstructionHandle handle) {
		LineNumberTable table = methodGen.getLineNumberTable(methodGen.getConstantPool());
		String className = methodGen.getClassName();

		int bytecodeOffset = handle.getPosition();

		if (table == null)
			return createUnknown(className, sourceFile, bytecodeOffset, bytecodeOffset);

		int lineNumber = table.getSourceLine(handle.getPosition());
		return new SourceLineAnnotation(className, sourceFile, lineNumber, lineNumber, bytecodeOffset, bytecodeOffset);
	}

	/**
	 * Factory method for creating a source line annotation describing
	 * the source line numbers for a range of instruction in a method.
	 *
	 * @param methodGen the method
	 * @param start     the start instruction
	 * @param end       the end instruction (inclusive)
	 */
	public static SourceLineAnnotation fromVisitedInstructionRange(MethodGen methodGen, String sourceFile, InstructionHandle start, InstructionHandle end) {
		LineNumberTable lineNumberTable = methodGen.getLineNumberTable(methodGen.getConstantPool());
		String className = methodGen.getClassName();

		if (lineNumberTable == null)
			return createUnknown(className, sourceFile, start.getPosition(), end.getPosition());

		int startLine = lineNumberTable.getSourceLine(start.getPosition());
		int endLine = lineNumberTable.getSourceLine(end.getPosition());
		return new SourceLineAnnotation(className, sourceFile, startLine, endLine, start.getPosition(), end.getPosition());
	}

	private static LineNumberTable getLineNumberTable(PreorderVisitor visitor) {
		Code code = visitor.getMethod().getCode();
		if (code == null)
			return null;
		return code.getLineNumberTable();
	}

	/**
	 * Get the class name.
	 */
	public String getClassName() {
		return className;
	}

	/**
	 * Get the source file name.
	 */
	public String getSourceFile() {
		return sourceFile;
	}

	/**
	 * Is the source file known?
	 */
	public boolean isSourceFileKnown() {
		return !sourceFile.equals(UNKNOWN_SOURCE_FILE);
	}

	/**
	 * Set the source file name.
	 *
	 * @param sourceFile the source file name
	 */
	public void setSourceFile(String sourceFile) {
		this.sourceFile = sourceFile;
	}

	/**
	 * Get the package name.
	 */
	public String getPackageName() {
		int lastDot = className.lastIndexOf('.');
		if (lastDot < 0)
			return "";
		else
			return className.substring(0, lastDot);
	}

	/**
	 * Get the start line (inclusive).
	 */
	public int getStartLine() {
		return startLine;
	}

	/**
	 * Get the ending line (inclusive).
	 */
	public int getEndLine() {
		return endLine;
	}

	/**
	 * Get start bytecode (inclusive).
	 */
	public int getStartBytecode() {
		return startBytecode;
	}

	/**
	 * Get end bytecode (inclusive).
	 */
	public int getEndBytecode() {
		return endBytecode;
	}

	/**
	 * Is this an unknown source line annotation?
	 */
	public boolean isUnknown() {
		return startLine < 0 || endLine < 0;
	}

	public void accept(BugAnnotationVisitor visitor) {
		visitor.visitSourceLineAnnotation(this);
	}

	public String format(String key) {
		if (key.equals("")) {
			StringBuffer buf = new StringBuffer();
			buf.append(sourceFile);
			appendLines(buf);
			return buf.toString();
		} else if (key.equals("full")) {
			StringBuffer buf = new StringBuffer();
			String pkgName = getPackageName();
			if (!pkgName.equals("")) {
				buf.append(pkgName.replace('.', '/'));
				buf.append('/');
			}
			buf.append(sourceFile);
			appendLines(buf);
			return buf.toString();
		} else
			throw new IllegalStateException("Unknown format key " + key);
	}

	private void appendLines(StringBuffer buf) {
		buf.append(":[");
		if (startLine == endLine) {
			buf.append("line ");
			buf.append(startLine);
		} else {
			buf.append("lines ");
			buf.append(startLine);
			buf.append('-');
			buf.append(endLine);
		}
		buf.append(']');
	}

	public String getDescription() {
		return description;
	}

	public void setDescription(String description) {
		this.description = description;
	}

	public String toString() {
		String pattern = I18N.instance().getAnnotationDescription(description);
		FindBugsMessageFormat format = new FindBugsMessageFormat(pattern);
		return format.format(new BugAnnotation[]{this});
	}

	public int compareTo(BugAnnotation o) {
		if (!(o instanceof SourceLineAnnotation)) // All BugAnnotations must be comparable
			return this.getClass().getName().compareTo(o.getClass().getName());

		SourceLineAnnotation other = (SourceLineAnnotation) o;

		int cmp = className.compareTo(other.className);
		if (cmp != 0)
			return cmp;
		cmp = startLine - other.startLine;
		if (cmp != 0)
			return cmp;
		return endLine - other.endLine;
	}

	public int hashCode() {
		return className.hashCode() + startLine + endLine;
	}

	public boolean equals(Object o) {
		if (!(o instanceof SourceLineAnnotation))
			return false;
		SourceLineAnnotation other = (SourceLineAnnotation) o;
		return className.equals(other.className)
		        && startLine == other.startLine
		        && endLine == other.endLine;
	}

	/* ----------------------------------------------------------------------
	 * XML Conversion support
	 * ---------------------------------------------------------------------- */

	private static final String ELEMENT_NAME = "SourceLine";

	public void writeXML(XMLOutput xmlOutput) throws IOException {
		XMLAttributeList attributeList = new XMLAttributeList()
			.addAttribute("classname", getClassName())
			.addAttribute("start", String.valueOf(getStartLine()))
			.addAttribute("end", String.valueOf(getEndLine()))
			.addAttribute("startBytecode", String.valueOf(getStartBytecode()))
			.addAttribute("endBytecode", String.valueOf(getEndBytecode()));

		if (isSourceFileKnown())
			attributeList.addAttribute("sourcefile", sourceFile);

		String role = getDescription();
		if (!role.equals(DEFAULT_ROLE))
			attributeList.addAttribute("role", getDescription());

		xmlOutput.openCloseTag(ELEMENT_NAME, attributeList);
	}
}

// vim:ts=4