File Viewer
/******************************************************************************
* All Right Reserved.
* Copyright (c) 1998, 2004 Jackwind Li Guojie
*
* Created on 2004-5-13 10:10:07 by JACK
* $Id$
*
*****************************************************************************/
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.InvocationTargetException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.jface.action.Action;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.jface.action.StatusLineManager;
import org.eclipse.jface.action.ToolBarManager;
import org.eclipse.jface.operation.IRunnableWithProgress;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.window.ApplicationWindow;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.FileDialog;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
public class FileViewer extends ApplicationWindow {
// The text control used to display the file content.
Text text;
String content;
String lineDelimiter;
IRunnableWithProgress runnableWithProgress = new IRunnableWithProgress() {
public void run(IProgressMonitor monitor)
throws InvocationTargetException, InterruptedException {
System.out.println("Running from thread: " + Thread.currentThread().getName());
getShell().getDisplay().syncExec(new Runnable() {
public void run() {
content = text.getText();
lineDelimiter = text.getLineDelimiter();
}
});
monitor.beginTask("Counting total number of lines", content.length());
int lines = 1;
for(int i=0; i<content.length(); i++) {
if(monitor.isCanceled()) { // checks whether the operation has been cancelled.
monitor.done();
System.out.println("Action cancelled");
return;
}
// Checks the existance of the line delimiter.
if(i + lineDelimiter.length() < content.length()) {
if(lineDelimiter.equals(content.substring(i, i+lineDelimiter.length()))) {
lines ++;
}
}
monitor.worked(1);
Thread.sleep(1); // 1ms
}
monitor.done();
System.out.println("Total number of lines: " + lines);
}
};
Action actionCount = new Action("Count", ImageDescriptor.createFromFile(null, "icons/run.gif")) {
public void run() {
try {
FileViewer.this.run(true, true, runnableWithProgress);
} catch (InvocationTargetException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
};
/**
* @param parentShell
*/
public FileViewer(Shell parentShell) {
super(parentShell);
addMenuBar();
addStatusLine();
addToolBar(SWT.FLAT);
}
/* (non-Javadoc)
* @see org.eclipse.jface.window.Window#createContents(org.eclipse.swt.widgets.Composite)
*/
protected Control createContents(Composite parent) {
getShell().setText("FileViewer v2.0");
setStatus("Ready");
text = new Text(parent, SWT.MULTI | SWT.BORDER | SWT.H_SCROLL | SWT.V_SCROLL);
text.setSize(300, 200);
return text;
}
Action actionOpenFile = new Action("Open", ImageDescriptor.createFromFile(null, "icons/open.gif")) {
public void run() {
FileDialog dialog = new FileDialog(getShell(), SWT.OPEN);
final String file = dialog.open();
if(file != null) {
try {
String content = readFileAsAString(new File(file));
text.setText(content);
setStatus("File loaded successfully: " + file);
} catch (IOException e) {
e.printStackTrace();
setStatus("Failed to load file: " + file);
}
}
}
};
/* (non-Javadoc)
* @see org.eclipse.jface.window.ApplicationWindow#createMenuManager()
*/
protected MenuManager createMenuManager() {
MenuManager menuManager = new MenuManager("");
MenuManager fileMenuManager = new MenuManager("&File");
fileMenuManager.add(actionOpenFile);
menuManager.add(fileMenuManager);
MenuManager toolsMenuManager = new MenuManager("&Tools");
toolsMenuManager.add(actionCount);
menuManager.add(toolsMenuManager);
return menuManager;
}
/* (non-Javadoc)
* @see org.eclipse.jface.window.ApplicationWindow#createStatusLineManager()
*/
protected StatusLineManager createStatusLineManager() {
return super.createStatusLineManager();
}
/* (non-Javadoc)
* @see org.eclipse.jface.window.ApplicationWindow#createToolBarManager(int)
*/
protected ToolBarManager createToolBarManager(int style) {
ToolBarManager toolBarManager = new ToolBarManager(style);
toolBarManager.add(actionOpenFile);
toolBarManager.add(actionCount);
return toolBarManager;
}
public static void main(String[] args) {
ApplicationWindow viewer = new FileViewer(null);
viewer.setBlockOnOpen(true);
viewer.open();
}
/**
* Reads the content of a file into a String.
* @param file file to be read
* @return
* @throws IOException
*/
public static String readFileAsAString(File file) throws IOException {
return new String(getBytesFromFile(file));
}
/**
* Returns the contents of the file in a byte array.
* @param file
* @return
* @throws IOException
*/
public static byte[] getBytesFromFile(File file) throws IOException {
InputStream is = new FileInputStream(file);
// Get the size of the file
long length = file.length();
// You cannot create an array using a long type.
// It needs to be an int type.
// Before converting to an int type, check
// to ensure that file is not larger than Integer.MAX_VALUE.
if (length > Integer.MAX_VALUE) {
// File is too large
throw new IllegalArgumentException("File is too large! (larger or equal to 2G)");
}
// Create the byte array to hold the data
byte[] bytes = new byte[(int) length];
// Read in the bytes
int offset = 0;
int numRead = 0;
while (offset < bytes.length
&& (numRead = is.read(bytes, offset, bytes.length - offset)) >= 0) {
offset += numRead;
}
// Ensure all the bytes have been read in
if (offset < bytes.length) {
throw new IOException(
"Could not completely read file " + file.getName());
}
// Close the input stream and return bytes
is.close();
return bytes;
}
}
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