I am moving from SSIS to Pentaho, also new in java. What I would like to do is to show a simple message box in Pentaho using the Defined Java Class step (or another one).
First I tried with this code:
import javax.swing.JOptionPane;
public class MyClass
{
public static void main(String args[]){
JOptionPane.showMessageDialog(null,"Hello, this message is in a message type box." );
System.exit(0);
}
}
But I got this error:
Non-abstract class "Processor" must implement method "boolean org.pentaho.di.trans.steps.userdefinedjavaclass.TransformClassBase.processRow
I modified the code:
import javax.swing.JOptionPane;
public boolean processRow(StepMetaInterface smi, StepDataInterface sdi) throws KettleException
{
JOptionPane.showMessageDialog(null,"Hello world!");
System.exit(0);
return true;
}
I tested the class, I did not receive any error message, but I could not see the message box that I was expecting.
So, my question is, what else do I need to import, specify or modify in order to achieve what I want to do.
Regards.
In pdi transformations most steps require some input. Your processRow() method is called for each row, received by your User Defined Java Class step. So, if you don't have input row - the method is not called.
You may want to place some step, producing one row before and pass the output to the java step. You may use "Detect empty stream" step - it will output exactly one row without any columns. However, your java code would still require some adjustments (not sure what exactly you need to do it in java, but it seems, like you need to create some ).
So, the easiest option for you would be to use "Modified Java Script Value" (it uses Rhino javascript, not java) step and call Alert("Hello world!") function inside. But nevertheless you would still need an input row.
If you still want to do it java way, you may try following code (but I am not a java developer, so I am not sure how good that code is):
import javax.swing.*;
public boolean processRow(StepMetaInterface smi, StepDataInterface sdi) throws KettleException
{
Object[] r = getRow();
if (r == null) {
setOutputDone();
return false;
}
if (first)
{
first = false;
myFrame = new MyFrame();
// myFrame.setVisible(true);
JOptionPane.showMessageDialog(myFrame, "Hello world");
myFrame.dispose();
}
return true;
}
private MyFrame myFrame;
private class MyFrame extends JFrame {
public MyFrame() {
super();
// this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
Also, please keep in mind, that kettle jobs/transformations usually are not supposed to be interactive. They may be executed on linux systems, which may have no windowing system.
So displaying such messages is usually used only for debugging and is disabled in production versions.
Related
I'm currently making a reading app in Java, and this is my main menu.
What I want is that when I press the bottom button after selecting a book another window with the book opens. What I did now is a function that will open the other window while closing the one I'm currently in to free a little bit of memory.
I first close the current window after retrieving the necessary information from it (the index of the book) like this:
btnOuvrirLeLivre.addSelectionListener(new SelectionAdapter() {
#Override
public void widgetSelected(SelectionEvent e) {
int index = list.getSelectionIndex();
LiseuseController controller = new LiseuseController(null, null);
parent.dispose();
controller.viewBookController(index);
}
});
(I'm using the MVC method for my project), parent is just the composite used to open the frame.
public void viewBookController(int index) {
Display displayBook = new Display();
Shell shellBook = new Shell(displayBook);
shellBook.setLayout(new GridLayout(1, false));
index += 250;
LiseuseView lecture = new LiseuseView(shellBook, SWT.NONE, index);
shellBook.pack();
shellBook.open();
while(!shellBook.isDisposed()) {
if(!displayBook.readAndDispatch())
displayBook.sleep();
}
displayBook.dispose();
}
The index is just the book's number in my database, everything should be fine but I get this error when I do this after pressing the button to open the book:
Exception in thread "main" org.eclipse.swt.SWTException: Invalid thread access
at org.eclipse.swt.SWT.error(SWT.java:4875)
at org.eclipse.swt.SWT.error(SWT.java:4790)
at org.eclipse.swt.SWT.error(SWT.java:4761)
at org.eclipse.swt.widgets.Display.checkDisplay(Display.java:824)
at org.eclipse.swt.widgets.Display.create(Display.java:887)
at org.eclipse.swt.graphics.Device.<init>(Device.java:126)
at org.eclipse.swt.widgets.Display.<init>(Display.java:563)
at org.eclipse.swt.widgets.Display.<init>(Display.java:554)
at Controller.LiseuseController.viewBookController(LiseuseController.java:133)
at View.LiseuseHome$4.widgetSelected(LiseuseHome.java:81)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:252)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:89)
at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4209)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1037)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4026)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3626)
at Controller.LiseuseController.viewController(LiseuseController.java:126)
at Main.Main.main(Main.java:59)
(LiseuseController.java:133) contains "Display displayBook = new Display();"
And (LiseuseController.java:126) contains
if(!display.readAndDispatch())
display.sleep();
This is from the other function used to open the first window.
I don't really understand what is causing this error and I can't just put one in "visible" and the other one "invisible" like if I'm using Jframe because the 2 windows are on 2 different .java files.
Do you have any idea on how to fix this?
From the API documentation of org.eclipse.swt.widgets.Display
Applications which are built with SWT will almost always require only
a single display. In particular, some platforms which SWT supports
will not allow more than one active display. In other words, some
platforms do not support creating a new display if one already exists
that has not been sent the dispose() message.
You should therefore adapt your application to use only one instance of Display. Since the class LiceuseController already manages opening the initial window and the supplementary window(s), it seems fitting for it to manage an instance of Display for both uses.
This instance should be created at the application's start, maintained by the LiceuseController class and finally disposed when the application shuts down.
Another problem is that none of the methods in LiceuseController actually returns. As you can see from the stack trace, Display.readAndDispatch from LiseuseController.viewController is still active when you are creating the new window. I guess you also want to reopen the original window when the supplementary window is closed. Opening and closing windows in this manner will, however, endlessly increase your call stack until you end up with a StackOverflowException.
Instead, the LiceuseController should be able to create windows without outside interference. Therefore, instead of actively calling a method in the controller class to open another window, the listener should only tell the controller what window it should open next when the current window was closed.
An example could look like
public enum WindowType {
MAIN, BOOK, NONE
}
public class LiceuseController {
Display display;
WindowType nextToOpen = WindowType.MAIN;
public LiceuseController() {
display = new Display();
}
public void setNextToOpen(WindowType value) {
nextToOpen = value;
}
public void run() {
for (boolean run = true; run;) {
switch(nextToOpen) {
case MAIN:
viewController();
break;
case BOOK:
viewBookController();
break;
case NONE:
run = false;
break;
default:
throw new RuntimeException("unexpected enum constant");
}
}
/*
* Depending on how you want to manage the instance of this class,
* you could also extract this into a separate method.
*/
display.dispose();
}
private void viewController() {
// open main window using 'display'
}
private void viewBookController() {
// open book window using 'display'
}
}
so that a listener only needs to call LiceuseController.setNextToOpen and then close the current window. This will cause either viewController or viewBookController to return after which the loop will reenter and open the requested window. To shut down the application, call setNextToOpen with WindowType.NONE.
I am using java and trying to write a simple sudo mouse recorder that will store the mouse position when the space key is pressed. The only key I need to detect is the space key (Although if another key is easier, that will work).
I need the whole mouse recorder to be written in java, but it is OK if the function for the keypress is in another language. And I will be runing this in Windows 7.
What is the simplest way to do what has been described? All of the methods I have found require at minimum 20 lines of code. This is OK, except I don't understand how to implement them. I have an example source below:
import java.awt.MouseInfo;
import javax.swing.JOptionPane;
public class MouseRecorder {
public static void main (String[] args)
{
int slot = 0;
int xLoc[10];
int yLoc[10];
while (slot <= 10)
{
if (keyPressed(KEY_SPACE)) //<<<<This obviously won't work, but I'm looking for the simplest way to code this
{
xLoc[slot] = MouseInfo.getPointerInfo().getLocation().x;
yLoc[slot] = MouseInfo.getPointerInfo().getLocation().y;
slot++;
}
}
//The mouse information can now be utilized
}
}
Again your question is not clear since you have not addressed my comment:
It smells like to me that you might want a system-wide key logger that only responds to one key press, and that doesn't need a GUI. If this is so, then your best solution is to not use Java to create your application but to use a tool that can get closer to the OS. AutoIt comes to mind if this is for a Windows project. Please define your needs better.
and this forces us to guess at the problem and its solution.
If you are interested in creating a Swing GUI, having it take focus, and have it listen to key events, then the solution is to do this:
Create your Swing GUI and display it, leaving it as the active windowed application while your application is running.
Using Key Bindings have it listen for space bar presses
And then log the mouse location when the space bar is pressed.
As noted, this will not be achievable in 5 lines of code, so put that idea to the side.
If on the other hand your desire is to not have a GUI but rather listen for hot-key presses while any and all applications are running, then
The possible platforms used will be critical since your solution will require OS-specific code since creating a hot-key means having to create a keyboard handler routine, often in C, and doing this for each platform, and then linking it in to Java using JNI or JNA.
Or as noted another way is to link your Java program with an OS specific utility program or script such as AutoIt.
If you need more specific help, then please clarify your question.
Edit
You state:
Thank you for the answer, but as I have described above: "Changing languages is out of the question although it seems like that might be easier." and "I dont want a gui, if I can avoid it"
Then my second answer is what you're looking for. How adept are you at C/C++, JNI or JNA, and how good is your knowledge of operating system libraries? If you want a Java only solution, I would consider your requirements far above beginner or intermediate Java and into the realm of advanced -- or at least beyond my abilities at the moment, although I am sure that I could come up with some solutions after several days to a week or two of study.
... or consider getting rid of your "changing languages" requirement and instead allow at least meshing Java together with a scripting utility, like AutoIt. That could allow creation of solutions in a shorter period of time, at least for me. A limitation though is that these would be platform specific solutions. What is your purpose behind all of this? Could this be an XY problem in disguise?
Edit 2
I decided to try to solve this with a small AutoIt utility that I meshed with Java, and this is what I came up with.
My AutoIt program is called CaptureHotKey.au3, and it is compiled to an exe before use:
$key = $CmdLine[1]
HotKeySet($key, "hotKeyFunction")
While 1
Sleep(100)
WEnd
Func hotKeyFunction()
ConsoleWrite(#CRLF)
EndFunc
There's not much to it. All it does is set a hot-key from the first command line parameter, provides an endless while loop so that it will continue to run, and a hotkey function that is quite simple and only sends a carriage-return/line-feed to the console (which will be the standard output).
Then a Java class to help interact with this. It uses SwingPropertyLanguageSupport to allow addition of PropertyChangeListeners that respond on the Swing thread (in case I want to use this with a GUI).
import java.beans.PropertyChangeListener;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import javax.swing.event.SwingPropertyChangeSupport;
public class CaptureHotKey implements Runnable {
public static final String HOT_KEY = "hot key";
private String hotKey;
private SwingPropertyChangeSupport pcSupport = new SwingPropertyChangeSupport(
this);
private Scanner scanner;
private CaptureHotKeyFromAutoIt capture;
public CaptureHotKey(final String hotKey) throws IOException {
this.hotKey = hotKey;
capture = new CaptureHotKeyFromAutoIt(hotKey);
scanner = new Scanner(capture.getReadable());
}
public void startCapturing() {
new Thread(this).start();
}
public void exit() {
if (capture != null) {
capture.exit();
}
if (scanner != null) {
scanner.close();
}
}
public void addPropertyChangeListener(PropertyChangeListener listener) {
pcSupport.addPropertyChangeListener(listener);
}
public void removePropertyChangeListener(PropertyChangeListener listener) {
pcSupport.removePropertyChangeListener(listener);
}
public String getHotKey() {
return hotKey;
}
#Override
public void run() {
while (scanner != null && scanner.hasNextLine()) {
scanner.nextLine();
pcSupport.firePropertyChange(HOT_KEY, true, false);
}
}
private static class CaptureHotKeyFromAutoIt {
public static final String AUTO_IT_APP_PATH = "CaptureHotKey.exe";
private Process process = null;
private ProcessBuilder pb;
public CaptureHotKeyFromAutoIt(String hotKey) throws IOException {
List<String> cmdList = new ArrayList<>();
cmdList.add(AUTO_IT_APP_PATH);
cmdList.add(hotKey);
pb = new ProcessBuilder(cmdList);
pb.redirectErrorStream(true);
process = pb.start();
}
public void exit() {
if (process != null) {
process.destroy();
}
}
public Readable getReadable() {
if (process != null) {
return new InputStreamReader(process.getInputStream());
}
return null;
}
}
}
Finally a Java class to test this set up:;
This adds a PropertyChangeListener to the class above to allow it to be notified if the hot-key is pressed:
import java.awt.MouseInfo;
import java.awt.PointerInfo;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.io.IOException;
import java.util.Scanner;
public class CaptureHotKeyTest {
public static final String CTRL_R = "^r"; // "{SPACE}" works for spacebar
private static final String EXIT = "exit";
private CaptureHotKey capture;
public CaptureHotKeyTest() {
try {
capture = new CaptureHotKey(CTRL_R);
capture.addPropertyChangeListener(new HotKeyPropertyChngListener());
capture.startCapturing();
Scanner scan = new Scanner(System.in);
System.out.println("Press control-r to get mouse position.");
System.out.println("Type \"exit\" to exit program");
while (scan.hasNextLine()) {
String line = scan.nextLine();
if (line.equalsIgnoreCase(EXIT)) {
scan.close();
capture.exit();
break;
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
private class HotKeyPropertyChngListener implements PropertyChangeListener {
#Override
public void propertyChange(PropertyChangeEvent evt) {
if (evt.getPropertyName().equals(CaptureHotKey.HOT_KEY)) {
System.out.println("hot key pressed");
PointerInfo pointerInfo = MouseInfo.getPointerInfo();
System.out.println("Mouse: " + pointerInfo.getLocation());
}
}
}
public static void main(String[] args) {
new CaptureHotKeyTest();
}
}
You should use KeyListener: http://docs.oracle.com/javase/tutorial/uiswing/events/keylistener.html
It works fine with Swing
I've programmed a DLL in C. The first function sends a pointer of the callback function that is called when new data is available.
So I use JNA to wrap this function.
In order to avoid the end of the app, I use an InputStreamReader that wait data from the standard input. And when new data are available the callback is called and data are printed in the console.
But, if I use a JFrame to avoid the end of the program before closing the window, it doesn’t work properly. In fact, if I don’t resize the JFrame window, the callback is called about 30 times and after that nothing (even if new data are available). If I resize the window, the callback if never called (even if new data are available).
Please could you help me?
Thanks
Edit : This is my main method.
package jsigmausblib;
import com.sun.jna.Native;
import com.sun.jna.Pointer;
import javax.swing.JFrame;
public class JSigmaUSBLib {
public static void main(String[] args) {
NativeSigmaUSBLibInterface nsuli = (NativeSigmaUSBLibInterface) Native.loadLibrary("SigmaUSBLib1.0", NativeSigmaUSBLibInterface.class);
ReadCallback rc = new ReadCallback() {
#Override
public void callbackFunction(Pointer readData, byte len) {
System.out.println("ok"+readData.getByte(0));
}
};
SigmaUSBLibConfigStruct.ByValue config = new SigmaUSBLibConfigStruct.ByValue();
nsuli.SigmaUSBLibInit(rc , config);
JFrame frame = new JFrame("Debug");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(80, 60);
frame.setVisible(true);
}
}
This is for a kiosk application where this message is not desired. It's odd because Mac doesn't display this message in either browser -- seems to only happen on Ubuntu.
Using this example applet on Ubuntu 10, Firefox 12, I was able to reproduce the message "Applet initialized," illustrated below. It doesn't appear to be from an overridden init(), and the super implementation is empty; I presume it's a feature of either the plug-in or the browser itself. Oddly, the message actually moves from one lower corner of the browser window to the other, as the mouse cursor approaches it.
For embedded use, consider starting the applet (or hybrid application) via java-web-start as shown in the example.
Addendum: Andrew's example produces the message "Applet started."
Seems like futzing to me, but if by 'status bar' you mean the little bar at the bottom of older browsers, try using Applet.showStatus("") at the end of init() or start().
Edit: Using the following command produces the expected result in appletviwer.
$ appletviewer NoMessageApplet.java
Code:
// intended only to show attributes - view in browser
// <applet code='NoMessageApplet' width=400 height=400></applet>
import java.awt.BorderLayout;
import javax.swing.*;
public class NoMessageApplet extends JApplet {
String noMessage = " Nobody Here But Us Chickens..";
JTextArea output;
#Override
public void init() {
try {
SwingUtilities.invokeAndWait( new Runnable() {
public void run() {
initGui();
}
});
} catch(Exception e) {
e.printStackTrace();
}
}
public void initGui() {
JPanel gui = new JPanel(new BorderLayout(5,5));
output = new JTextArea(5,20);
gui.add(new JScrollPane(output));
setContentPane(gui);
setMessage("initGui()" + noMessage);
}
#Override
public void start() {
setMessage("start()" + noMessage);
}
/** Both sets the message as the 'status' message &
appends it to the output control */
public void setMessage(final String message) {
SwingUtilities.invokeLater( new Runnable() {
public void run() {
output.append(message + "\n");
}
});
showStatus(message);
}
}
This is not a direct answer to your question but definitely a possible solution to your problem (Was a comment. Added as an answer as suggested by #Andrew Thompson):
If it is a kiosk application then why is there a status bar at all?
If you have control over the system where the application is used from (or where the browser is installed), you can either deactivate the status bar in the browser or make the browser to be displayed always in full screen mode.
Most kiosk applications operate this way.
FF13 fixed it (so does the most recent version of Chrome). Both now currently do not enable status bar's by default (they did when I made this initial post). Not quite an answer, but an answer that worked for me.
I'm looking for a simple solution for a yes/no dialog to use in a Java ME midlet. I'd like to use it like this but other ways are okey.
if (YesNoDialog.ask("Are you sure?") == true) {
// yes was chosen
} else {
// no was chosen
}
You need an Alert:
An alert is a screen that shows data to the user and waits for a certain period of time before proceeding to the next Displayable. An alert can contain a text string and an image. The intended use of Alert is to inform the user about errors and other exceptional conditions.
With 2 commands ("Yes"/"No" in your case):
If there are two or more Commands present on the Alert, it is automatically turned into a modal Alert, and the timeout value is always FOREVER. The Alert remains on the display until a Command is invoked.
These are built-in classes supported in MIDP 1.0 and higher. Also your code snippet will never work. Such an API would need to block the calling thread awaiting for the user to select and answer. This goes exactly in the opposite direction of the UI interaction model of MIDP, which is based in callbacks and delegation. You need to provide your own class, implementing CommandListener, and prepare your code for asynchronous execution.
Here is an (untested!) example class based on Alert:
public class MyPrompter implements CommandListener {
private Alert yesNoAlert;
private Command softKey1;
private Command softKey2;
private boolean status;
public MyPrompter() {
yesNoAlert = new Alert("Attention");
yesNoAlert.setString("Are you sure?");
softKey1 = new Command("No", Command.BACK, 1);
softKey2 = new Command("Yes", Command.OK, 1);
yesNoAlert.addCommand(softKey1);
yesNoAlert.addCommand(softKey2);
yesNoAlert.setCommandListener(this);
status = false;
}
public Displayable getDisplayable() {
return yesNoAlert;
}
public boolean getStatus() {
return status;
}
public void commandAction(Command c, Displayable d) {
status = c.getCommandType() == Command.OK;
// maybe do other stuff here. remember this is asynchronous
}
};
To use it (again, untested and on top of my head):
MyPrompter prompt = new MyPrompter();
Display.getDisplay(YOUR_MIDLET_INSTANCE).setCurrent(prompt.getDisplayable());
This code will make the prompt the current displayed form in your app, but it won't block your thread like in the example you posted. You need to continue running and wait for a commandAction invocation.
I dont have programed in Java ME, but i found in it's reference for optional packages the
Advanced Graphics and User Interface API, and it's used like the Java SE API to create these dialogs with the JOptionPane Class
int JOptionPane.showConfirmDialog(java.awt.Component parentComponent, java.lang.Object >message, java.lang.String title, int optionType)
Return could be
JOptionPane.YES_OPTION, JOptionPane.NO_OPTION, JOptionPane.CANCEL_OPTION...