Collected the code from one of the site, it does not invoke R Console from REngine. It breaks after creating REngine and does not go to try and catch.
problem:
Rengine re=new Rengine(args, true, new TextConsole2());
System.out.println("Rengine created, waiting for R");
Sample code (rtest2.java) - rJava/examples
import java.io.*;
import java.awt.*;
import javax.swing.*;
import org.rosuda.JRI.Rengine;
import org.rosuda.JRI.REXP;
import org.rosuda.JRI.RMainLoopCallbacks;
import org.rosuda.JRI.RConsoleOutputStream;
class TextConsole2 implements RMainLoopCallbacks
{
JFrame f;
public JTextArea textarea = new JTextArea();
public TextConsole2() {
f = new JFrame();
f.getContentPane().add(new JScrollPane(textarea));
f.setSize(new Dimension(800,600));
f.show();
}
public void rWriteConsole(Rengine re, String text, int oType) {
textarea.append(text);
}
public void rBusy(Rengine re, int which) {
System.out.println("rBusy("+which+")");
}
public String rReadConsole(Rengine re, String prompt, int addToHistory) {
System.out.print(prompt);
try {
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
String s=br.readLine();
return (s==null||s.length()==0)?s:s+"\n";
} catch (Exception e) {
System.out.println("jriReadConsole exception: "+e.getMessage());
}
return null;
}
public void rShowMessage(Rengine re, String message) {
System.out.println("rShowMessage \""+message+"\"");
}
public String rChooseFile(Rengine re, int newFile) {
FileDialog fd = new FileDialog(f, (newFile==0)?"Select a file":"Select a new file", (newFile==0)?FileDialog.LOAD:FileDialog.SAVE);
fd.show();
String res=null;
if (fd.getDirectory()!=null) res=fd.getDirectory();
if (fd.getFile()!=null) res=(res==null)?fd.getFile():(res+fd.getFile());
return res;
}
public void rFlushConsole (Rengine re) {
}
public void rLoadHistory (Rengine re, String filename) {
}
public void rSaveHistory (Rengine re, String filename) {
}
}
public class rtest2 {
public static void main(String[] args) {
System.out.println("Press <Enter> to continue (time to attach the debugger if necessary)");
try { System.in.read(); } catch(Exception e) {System.out.println("Exception"+e.toString());}
System.out.println("Creating Rengine (with arguments)");
Rengine re=new Rengine(args, true, new TextConsole2());
System.out.println("Rengine created, waiting for R");
if (!re.waitForR()) {
System.out.println("Cannot load R");
return;
}
System.out.println("re-routing stdout/err into R console");
System.setOut(new PrintStream(new RConsoleOutputStream(re, 0)));
System.setErr(new PrintStream(new RConsoleOutputStream(re, 1)));
System.out.println("Letting go; use main loop from now on");
}
}