Problem in AST parser

Question

Hi,

I downloaded AST explorer code from a website.

But i get the error as the following org.eclipse packages doesn't exists, I use eclipse IDE and the code is below, please help me

package astexplorer;

/**
 * Parses a source file and displays its nodes in a SWT Tree widget
 * You should run the main method inside the Eclipse IDE. 
 * Do not forget to add the jvm option java.library.path specifing
 * the SWT native library. On a Windows system it may look like this:
 * -Djava.library.path=C:\eclipse\plugins\org.eclipse.swt.win32_3.0.2\os\win32\x86  
 * @author Manoel Marques
 */
import java.io.*;

import org.eclipse.core.runtime.*;
import org.eclipse.jdt.core.compiler.IProblem;
import org.eclipse.jdt.core.dom.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;
import org.eclipse.swt.*;
import org.eclipse.swt.custom.*;
import org.eclipse.swt.events.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.jface.dialogs.*;
import org.eclipse.jface.operation.*;
import java.lang.reflect.*;

public class ASTExplorer extends Composite {

    private Text addressControl;
    private Tree treeControl;
    private StyledText textControl;
    private StyledText errorsTextControl;
    private IProblem[] problems;
    private Color blue;
    private Color red;

    public ASTExplorer(Composite parent,int style) {
        super(parent,style);
        this.problems = new IProblem[0];
        this.blue = getDisplay().getSystemColor(SWT.COLOR_BLUE);
        this.red = getDisplay().getSystemColor(SWT.COLOR_RED);

        GridLayout gridLayout = new GridLayout();
        super.setLayout(gridLayout);

        Composite composite = new Composite(this,SWT.NONE);
        gridLayout = new GridLayout();
        gridLayout.numColumns = 3;
        composite.setLayout(gridLayout);
        composite.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));

        Button button = new Button(composite,SWT.PUSH);
        button.setText("File...");
        button.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_END));

        button.addSelectionListener(new SelectionAdapter() {
            public void widgetSelected(SelectionEvent event) {
                Shell shell = ((Button)event.widget).getShell();  
                FileDialog dialog = new FileDialog(shell,SWT.PRIMARY_MODAL | SWT.OPEN);
                dialog.setText("Java Source File");
                dialog.setFilterExtensions(new String[] {"*.java"});
                String file = dialog.open(); 
                if (file == null) return; 
                addressControl.setText(file);
                go();
            }
        });

        this.addressControl = new Text(composite,SWT.BORDER); 
        this.addressControl.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));

        button = new Button(composite,SWT.PUSH);
        button.setText("Go");
        button.getShell().setDefaultButton(button); 
        button.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_END));
        button.addSelectionListener(new SelectionAdapter() {
            public void widgetSelected(SelectionEvent event) {
                go();
            }
        });

        SashForm sashFormVertical = new SashForm(this,SWT.VERTICAL);
        sashFormVertical.setLayoutData(new GridData(GridData.GRAB_HORIZONTAL | GridData.GRAB_VERTICAL | 
                GridData.HORIZONTAL_ALIGN_FILL | GridData.VERTICAL_ALIGN_FILL));

        SashForm sashFormHorizontal = new SashForm(sashFormVertical,SWT.HORIZONTAL);
        sashFormHorizontal.setLayoutData(new GridData(GridData.GRAB_HORIZONTAL | GridData.GRAB_VERTICAL | 
                GridData.HORIZONTAL_ALIGN_FILL | GridData.VERTICAL_ALIGN_FILL));

        this.treeControl = new Tree(sashFormHorizontal,SWT.BORDER | SWT.SINGLE);
        this.treeControl.setLayoutData(new GridData(GridData.GRAB_VERTICAL | GridData.VERTICAL_ALIGN_FILL));
        this.treeControl.addSelectionListener(new SelectionAdapter() {
            public void widgetSelected(SelectionEvent e) {
                // first reset any previous selections 
                StyleRange styleRange = new StyleRange();
                styleRange.start = 0;
                styleRange.length = textControl.getCharCount();
                textControl.setStyleRange(styleRange);

                // select text
                int startSelection = -1;
                Tree tree = (Tree) e.widget;
                Display display = tree.getDisplay(); 
                TreeItem[] items = tree.getSelection();
                for (int i=0; i < items.length; ++i) {
                    ASTNode node = (ASTNode) items[i].getData(ASTExplorerVisitor.NODE);
                    if (node != null) {
                        styleRange = createRange(node.getStartPosition(),node.getLength(),blue);
                        textControl.setStyleRange(styleRange);
                        if (startSelection < 0 || styleRange.start < startSelection)
                            startSelection = styleRange.start;
                    }
                }
                if (startSelection >= 0)
                    textControl.setSelection(startSelection);

                // select errors
                for (int i=0; i < problems.length; ++i) {
                    IProblem problem = problems[i];
                    String msg = problem.getMessage();
                    styleRange = createRange(problem.getSourceStart(),
                                problem.getSourceEnd() - problem.getSourceStart() + 1,red);
                    textControl.setStyleRange(styleRange);
                }
            }
        });

        this.textControl = new StyledText(sashFormHorizontal, SWT.BORDER | SWT.READ_ONLY | SWT.H_SCROLL | SWT.V_SCROLL);
        this.textControl.setLayoutData(new GridData(GridData.GRAB_HORIZONTAL
                | GridData.GRAB_VERTICAL | GridData.HORIZONTAL_ALIGN_FILL
                | GridData.VERTICAL_ALIGN_FILL));

        this.errorsTextControl = new StyledText(sashFormVertical, SWT.BORDER | SWT.READ_ONLY | SWT.H_SCROLL | SWT.V_SCROLL);
        this.errorsTextControl.setLayoutData(new GridData(GridData.GRAB_HORIZONTAL | GridData.HORIZONTAL_ALIGN_FILL));

        sashFormVertical.setWeights(new int[]{80, 20});
    }

    static private StyleRange createRange(int start,int length,Color color) {
        StyleRange styleRange = new StyleRange();
        styleRange.start = start;
        styleRange.length = length; 
        styleRange.fontStyle = SWT.BOLD;
        styleRange.foreground = color;
        return styleRange;
    }

    private void go() {
        try {           
            SetFile(addressControl.getText());
        }
        catch (InterruptedException e) {    
            reset();
        }
        catch (InvocationTargetException e) {
            reset();
            showError(e.getTargetException());
        }
        catch (Exception e) {
            reset();
            showError(e);
        }
    }

    private void reset() {
        this.treeControl.removeAll();
        this.textControl.setText("");
        this.errorsTextControl.setText("");
        this.problems = new IProblem[0];
    }

    private void SetFile(final String path) throws InterruptedException, InvocationTargetException {
        reset();
        ProgressMonitorDialog dialog = new ProgressMonitorDialog(getShell());
        dialog.run(true, true, new IRunnableWithProgress() {
            public void run(final IProgressMonitor monitor) throws InvocationTargetException {
                try {   
                    File file = new File(path);
                    BufferedReader in = new BufferedReader(new FileReader(file));
                    StringBuffer buffer = new StringBuffer(); 
                    String line = null;
                    while (null != (line = in.readLine())) {
                        buffer.append("\t" + line);
                        buffer.append("\n");
                        if (monitor.isCanceled()) return;
                    }   

                    ASTParser parser = ASTParser.newParser(AST.JLS2);
                    if (monitor.isCanceled()) return;
                    parser.setKind(ASTParser.K_COMPILATION_UNIT);
                    if (monitor.isCanceled()) return;
                    final String text = buffer.toString();
                    parser.setSource(text.toCharArray());
                    if (monitor.isCanceled()) return;
                    final CompilationUnit node = (CompilationUnit) parser.createAST(monitor);
                    if (monitor.isCanceled()) return;
                    getDisplay().syncExec(new Runnable() {
                        public void run() {
                            ASTVisitor visitor = new ASTExplorerVisitor(treeControl,monitor);
                            node.accept(visitor);
                            if (!monitor.isCanceled()) {
                                textControl.setText(text);  
                                IProblem[] errors = node.getProblems();
                                if (errors != null && errors.length > 0) {
                                    problems = errors;
                                    int startSelection = -1;
                                    StringBuffer msg = new StringBuffer(); 
                                    for (int i=0; i < problems.length; ++i) {
                                        IProblem problem = problems[i];
                                        StyleRange errorRange = createRange(problem.getSourceStart(),
                                                    problem.getSourceEnd() - problem.getSourceStart() + 1,red);
                                        textControl.setStyleRange(errorRange);
                                        if (startSelection < 0 || errorRange.start < startSelection)
                                            startSelection = errorRange.start;

                                        String message = problem.getMessage() + " line: " + 
                                                problem.getSourceLineNumber();  
                                        msg.append(message);
                                        msg.append("\n");
                                    }
                                    if (startSelection >= 0)
                                        textControl.setSelection(startSelection);

                                    if (msg.length() > 0)
                                        errorsTextControl.setText(msg.toString());
                                }
                            }   
                        }
                    });                     
                }
                catch (IOException e) {
                    throw new InvocationTargetException(e);
                }
            }
        }); 
    }

    // do not allow layout modifications
    public void setLayout(Layout layout) {
    }

    private void showError(Throwable e) {
        MessageBox msgBox = new MessageBox(addressControl.getShell(),
                SWT.APPLICATION_MODAL | SWT.OK | SWT.ICON_ERROR); 
        msgBox.setText("AST Explorer Error");
        String msg = e.getMessage();
        if (null == msg) 
            msg = e.toString();

        msgBox.setMessage(msg);
        msgBox.open(); 
    }

    public static void main(String[] args) {
        Display display = new Display();
        Shell shell = new Shell(display);
        shell.setText("AST Explorer");
        shell.setLayout(new FillLayout());

        ASTExplorer astExplorer = new ASTExplorer(shell,SWT.NONE);
        final Point minimum = shell.computeSize(SWT.DEFAULT,SWT.DEFAULT,true);
        shell.addControlListener(new ControlAdapter() {
            public void controlResized(ControlEvent e) {
                Shell shell = (Shell)e.widget;
                Point size = shell.getSize();
                boolean change = false; 
                if (size.x < minimum.x) {
                    size.x = minimum.x;
                    change = true; 
                }   
                if (size.y < minimum.y) {
                    size.y = minimum.y;
                    change = true; 
                }               
                if (change) 
                    shell.setSize(size);
            }
        });
        shell.open();

        while (!shell.isDisposed()) {
            if (!display.readAndDispatch())
                display.sleep();
        }
        display.dispose();
    }
}

Answer 1

 * Do not forget to add the jvm option java.library.path specifying
 * the SWT native library. On a Windows system it may look like this:
 * -Djava.library.path=C:\eclipse\plugins\org.eclipse.swt.win32_3.0.2\os\win32\x86  

Please read the javadocs for the class. Did you set this library path when you ran? Are the Eclipse JARs in the CLASSPATH of your project to compile and run? If not, that would explain your problem.

Answer 2

It seems that this comes from an Eclipse plugin -- at least that should be a way to make it compile and run within Eclipse: turn the project into a Plugin project, and add the required dependencies to the manifest (e.g. using Eclipse's suggested help when selecting one of the troublesome imports).

It seems the following required bundles should do:

Require-Bundle: org.eclipse.core.runtime, org.eclipse.swt, org.eclipse.jdt.core, org.eclipse.jface

Update: These bundles or part of the Eclipse IDE, so if you have Eclipse (with the Java Development Tools), you just need to list them in the plugin's manifest.