How to read text file in memory card from MIDlet?

[Bharathi Dhas Krishnasamy]

How to read text file in memory card from MIDlet?

[Gopinath Karyadath]

// get memcard path path

  private String checkMCRoot() {
        String rootMC = System.getProperty("fileconn.dir.memorycard");
        String fpath = null;

        if (rootMC != null) {
            fpath = rootMC;
        } else {

            return fpath;
        }
        return fpath;
    }


[color=red]// Call Readfile 

//String[]    arrayitems = Readfile(checkMCRoot()+"/yourfilename.txt"
[/color]

[b]
  private String[] readfile(String file) throws IOException {

        String des = "";
        Vector v = new Vector();
        int ch = 0;
        String[] listItems = new String[0];
        FileConnection f = (FileConnection) Connector.open(file);

        if (!f.exists()) {
            return null;
        }
        DataInputStream fis = f.openDataInputStream(); // f.openInputStream();

        int i = 0;
        try {
            while ((ch = fis.read()) != -1) {
                des += ((char) ch);
                if (ch == 13) {
                    des = des.trim().toUpperCase();
                    v.addElement( des) );
                    des = "";
                    System.gc();
                }
            }
        } catch (IOException ex) {
            System.out.println(ex.toString() );
        } finally {
            try {
                fis.close();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
        System.gc();

        if (!v.isEmpty()) {
            if (v.size() > 0) {
                listItems = new String[v.size()];
                v.copyInto(listItems);
                v.removeAllElements();

            }
        }
        v = null;
        des = null;
        System.gc();

        return listItems ;


    }


[/b]

[Bharathi Dhas Krishnasamy]

Thank you Mr.Gobinath

[Gopinath Karyadath]

You are Welcome .. Happy Coding

[Bharathi Dhas Krishnasamy]

Hi Gobinath actually I have to retrieve data from file in memory card and show in display.
I’m still struggle with that.
I got a error in “ FileConnection fileConnection = (FileConnection) Connector.open(file);” line.
But I could get memory card path.

[Swastik Dey]

What is the error message? And what value are you getting in file variable?

[Bharathi Dhas Krishnasamy]

Swastik Dey wrote:What is the error message? And what value are you getting in file variable?

MCTest.java

package hello;

import java.io.DataInputStream;
import java.io.IOException;
import java.util.Vector;
import javax.microedition.io.Connector;
import javax.microedition.io.file.FileConnection;

public class MCTest{

    public String rootMC ;
    public String[] fileData;
    public String myTrack = "1 ";

    public MCTest() throws IOException{
        rootMC = checkMCRoot()+"download/MyFile.txt";
        fileData = readfile(rootMC);
    }

//    get memcard path path
    private String checkMCRoot() {
        String rootMC = null;
        rootMC = System.getProperty("fileconn.dir.memorycard");
        return rootMC;
    }
    
    private String[] readfile(String file) throws IOException {

        String des = "";
        myTrack = myTrack + "2 ";
        Vector v = new Vector();
        int ch = 0;
        String[] listItems = new String[0];
        FileConnection fileConnection = (FileConnection) Connector.open(file);
           myTrack = myTrack + "3 ";
        if (!fileConnection.exists()) {
            myTrack = myTrack + "4 ";
            return null;
        }
        DataInputStream fis = fileConnection.openDataInputStream();
//        DataInputStream fis = (DataInputStream) fileConnection.openInputStream();
        myTrack = myTrack + "5 ";
        int i = 0;
        try {
            myTrack = myTrack + "6 ";
            while ((ch = fis.read()) != -1) {
                myTrack = myTrack + "7 ";
                des += ((char) ch);
                if (ch == 13) {
                    myTrack = myTrack + "8 ";
                    des = des.trim().toUpperCase();
                    v.addElement(des);
                    des = "";
                    System.gc();
                }
            }
        } catch (IOException ex) {
            System.out.println(ex.toString() );
        } finally {
            try {
                myTrack = myTrack + "9 ";
                fis.close();
            } catch (IOException ex) {
                myTrack = myTrack + "10 ";
                ex.printStackTrace();
            }
        }
        System.gc();
        myTrack = myTrack + "11 ";
        if (!v.isEmpty()) {
            myTrack = myTrack + "12 ";
            if (v.size() > 0) {
                myTrack = myTrack + "13 ";
                listItems = new String[v.size()];
                v.copyInto(listItems);
                v.removeAllElements();
            }
        }
        v = null;
        des = null;
        System.gc();
        myTrack = myTrack + "14 ";
        return listItems ;
    }


}

MCReadDemo.java

package hello;

import java.io.IOException;
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class MCReadDemo extends MIDlet implements CommandListener{

    private Form form;
    private Command myExit,myBack;
    private StringItem message1, message2,message3;
    private int index1;
    private Display display;

    public MCReadDemo() throws IOException{
        MCTest mcTest = new MCTest();
        String rootMC = mcTest.rootMC;
        String myTrack = mcTest.myTrack;
        
        String[] fileData = mcTest.fileData;
        String showData = "Your Data : ";

        if(fileData != null)
        for(int count=0; count<fileData.length; count++){
            showData = showData + fileData[count];
        }


        display = Display.getDisplay(this);
        form = new Form("My Form");
        myExit = new Command("My Exit","Exit Command",Command.EXIT,1);
        myBack = new Command("My Back","Back Command",Command.BACK,2);

        message2 = new StringItem("Your file location: ", rootMC);
        message1 = new StringItem("Your file Data: ", showData);
        message3 = new StringItem("My Track: ", myTrack);
        index1 = form.append(message1);
        form.append(message3);
        form.insert(index1,message2);
        
        form.addCommand(myExit);
//        form.addCommand(myBack);
        form.setCommandListener(this);
        
    }
    public void startApp(){
        display.setCurrent(form);
    }
    public void pauseApp(){
    }
    public void destroyApp(boolean unconditional) {

    }
    public void commandAction(Command command,Displayable displayable){
        if(command == myExit){
            destroyApp(true);
            notifyDestroyed();
        }else if(command == myBack){
            display.setCurrent(form);
        }
    }
}

I got this output in my Mobile

Your file location:
file:///E:/download/MyFile.txt

Your file Data:
Your Data:

My Track:
1 2 3 5 6 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 9 11 14

[Swastik Dey]

You track counter never gets a value of 8, it means it is failing to satisfy

if (ch == 13) {

and the data is not getting appended to the vector.

So in addition to new line character, there might be carriage return character as well.

Instead of checking for one character, how about using readUTF()?

[Bharathi Dhas Krishnasamy]

MCReadDemoMidlet

package hello;

import java.io.IOException;
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class MCReadDemoMidlet extends MIDlet implements CommandListener{

    private Form form;
    private Command myExit,myBack;
    private StringItem message1, message2,message3;
    private int index1;
    private Display display;

    public MCReadDemoMidlet() throws IOException{
        MCTest mcTest = new MCTest();
        String rootMC = mcTest.rootMC;
        String myTrack = mcTest.myTrack;

        String fileData = mcTest.fileData;
        
        display = Display.getDisplay(this);
        form = new Form("My Form");
        myExit = new Command("My Exit","Exit Command",Command.EXIT,1);
        myBack = new Command("My Back","Back Command",Command.BACK,2);

        message2 = new StringItem("Your file location: ", rootMC);
        message1 = new StringItem("Your file Data: ", fileData);
        message3 = new StringItem("My Track: ", myTrack);
        index1 = form.append(message1);
        form.append(message3);
        form.insert(index1,message2);

        form.addCommand(myExit);
//        form.addCommand(myBack);
        form.setCommandListener(this);

    }
    public void startApp(){
        display.setCurrent(form);
    }
    public void pauseApp(){
    }
    public void destroyApp(boolean unconditional) {

    }
    public void commandAction(Command command,Displayable displayable){
        if(command == myExit){
            destroyApp(true);
            notifyDestroyed();
        }else if(command == myBack){
            display.setCurrent(form);
        }
    }
}

MCTest

package hello;

import java.io.DataInputStream;
import java.io.IOException;
import java.util.Vector;
import javax.microedition.io.Connector;
import javax.microedition.io.file.FileConnection;

public class MCTest{

    public String rootMC ;
    public String fileData;
    public String myTrack = "1 ";

    public MCTest() throws IOException{
        rootMC = checkMCRoot()+"/download//GFox.txt";
        fileData = readfile(rootMC);
    }

//    get memcard path path
    private String checkMCRoot() {
        String rootMC = null;
        rootMC = System.getProperty("fileconn.dir.memorycard");
        return rootMC;
    }

    private String readfile(String file) throws IOException {
        myTrack = myTrack + "2 ";
        int chars = 0;
        FileConnection fileConnection = (FileConnection) Connector.open(file);
        StringBuffer stringBuffer = new StringBuffer();
        myTrack = myTrack + "3 ";
        if (!fileConnection.exists()) {
            myTrack = myTrack + "FileConection is NULL ";
            return null;
        }
        myTrack = myTrack + "4 ";
        DataInputStream dataInputStream = fileConnection.openDataInputStream(); // f.openInputStream();

        try {
            myTrack = myTrack + "5 ";
            while ((chars = dataInputStream.read()) != -1) {
               myTrack = myTrack + "6 ";
               stringBuffer.append((char) chars);
            }
        } catch (IOException ex) {
            System.out.println(ex.toString() );
        } finally {
            try {
                dataInputStream.close();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }

        System.gc();
        myTrack = myTrack + "7 ";
        return stringBuffer.toString() ;
        
    }


}

I got this Exception


Starting emulator in execution mode
Installing suite from: http://127.0.0.1:1993/MCReadDemo-2.jad
java.lang.IllegalArgumentException
at javax.microedition.io.Connector.openPrim(), bci=51
at javax.microedition.io.Connector.open(), bci=3
at javax.microedition.io.Connector.open(), bci=3
at javax.microedition.io.Connector.open(), bci=2
at hello.MCTest.readfile(MCTest.java:31)
at hello.MCTest.<init>(MCTest.java:18)
at hello.MCReadDemoMidlet.<init>(MCReadDemoMidlet.java:17)
at java.lang.Class.newInstance(), bci=0
at com.sun.midp.main.CldcMIDletLoader.newInstance(), bci=46
at com.sun.midp.midlet.MIDletStateHandler.createMIDlet(), bci=66
at com.sun.midp.midlet.MIDletStateHandler.createAndRegisterMIDlet(), bci=17
at com.sun.midp.midlet.MIDletStateHandler.startSuite(), bci=27
at com.sun.midp.main.AbstractMIDletSuiteLoader.startSuite(), bci=52
at com.sun.midp.main.CldcMIDletSuiteLoader.startSuite(), bci=8
at com.sun.midp.main.AbstractMIDletSuiteLoader.runMIDletSuite(), bci=161
at com.sun.midp.main.AppIsolateMIDletSuiteLoader.main(), bci=26

Anyone can help?

[yuvaraj KumarAmudhan]

visit these sites. You may get answers here.

http://discussion.forum.nokia.com/forum/showthread.php?57674-is-there-a-File-class-equivalent-in-J2ME

http://www.forum.nokia.com/info/sw.nokia.com/id/82644083-2f4b-4775-a292-c02d6bf5be57/Introduction_To_The_FileConnection_API_v1_1.zip.html

http://www.velocityreviews.com/forums/t236775-using-files-in-j2me.

[Bharathi Dhas Krishnasamy]

Still I didn't get solution....!

Ranch help me soon...!