Help java file manipulation.....

[jeffbroodwar]

Hi everyone,

Please help me accomplish the following :

1. how can i copy a file in java then paste it in a desired location

2. how can i run a .jar file run by just double clicking on it....

I need to know the answer asap... please reply asap... thanks.


Regards,
Jeff

[jeffbroodwar]

hey i found how to run the .jar by double clicking on it.... i noticed that there are 2 files that are recommended to open it.... Java(TM)2 SE Binary and Java(TM) SE Binary. i chose the Java(TM) SE Binary and it worked.... guess i need to clean my machine and try to make a clean install of Java. 1 down....how to copy and paste a file is left.... please help...

[r035198x]

Hi everyone,

Please help me accomplish the following :

1. how can i copy a file in java then paste it in a desired location

2. how can i run a .jar file run by just double clicking on it....

I need to know the answer asap... please reply asap... thanks.


Regards,
Jeff

To copy files, you must read the source file and write it to the destination file. You can use a BufferedInputStream and BufferedOutputStream for that. N.B To move files, you can simply use the renameTo method in java.io.File class.

For number 2, read the jar file tutorial from sun.

[jeffbroodwar]

will this work if for example i want to put sample.war in c:\Jeffbroodwar folder from C:\ .I know this is gonna be spoon feeding... but can you help me with this, i mean can you give me a working code? cause i really need to finish this before i lose my job..... ^^; besides, i'm not that type....... i.e. if you dont mind r035198x Thanks,


Best Regards,
Jeff

[r035198x]

will this work if for example i want to put sample.war in c:\Jeffbroodwar folder from C:\ .I know this is gonna be spoon feeding... but can you help me with this, i mean can you give me a working code? cause i really need to finish this before i lose my job..... ^^; besides, i'm not that type....... i.e. if you dont mind r035198x Thanks,


Best Regards,
Jeff

If you don't want to lose your job you might as well start to write that program now. The code will just be about 15 or so lines anyway. Read the file from its current location and write it to the new location. It really is just as easy as that.

[jeffbroodwar]

ooow... a bit rude... thanks anyway. gudluck to me. ^^;

[JosAH]

Also note that if the file contains binary data (non-characters) it's better to use
streams instead of Readers and Writers; the latter apply character encoding and
deconding while streams read and write byte values as they are.

kind regards,

Jos

[r035198x]

ooow... a bit rude... thanks anyway. gudluck to me. ^^;

Remember that we are waiting here to see what you come up with. Don't make us wait too long. If you open the specs for those streams, this shouldn't take you 10 minutes.

[jeffbroodwar]

i was able to read the file and print its contents :

 //READ A FILE
                try
                {
                    FileInputStream fin = new FileInputStream("SampleWebService.war");
                    BufferedInputStream bin = new BufferedInputStream(fin);
                    int ch=0;
                    while((ch=bin.read())> -1)
                    {
                            StringBuffer buf = new StringBuffer();
                            buf.append((char)ch);
                            System.out.print(buf.toString());
                            saveVariable = String.valueOf(buf);
                    }
 
                }
                catch(IOException ex)
                {
                    System.out.println(ex.getMessage());
                }

the only problem is how can i write it....to a new file....example putting it inside
the folder DestinationFolder...

hope you guys can help me...

Regards,
Jeff

[r035198x]

1.)Put the logic in a static method with the following signature

public static void boolean(String fromPath, String toPath) {

2.) Use while

while(ch != -1) {

what if the value read is 0?
3.)Close those streams after using them.

[jeffbroodwar]

how can i write it? i mean after placing it inside... where's my buffer output stream? i tried this code :

//WRITE FILE
try
{

FileOutputStream fos = new FileOutputStream("Sample.war");

BufferedOutputStream bos = new BufferedOutputStream(fos);

bos.write(Byte.parseByte(saveVariable));


}
catch (Exception e)
{
System.out.println("Exception: " + e);
}


errrr..... but it gave me 0 bytes when i tried to look at it in the directory. the original file is 6 bytes.....

[jeffbroodwar]

Please help me with this one... i can make a code that will put the files in its desired location later. what i need now is how to write a new file after reading the original one... and placing it in other directory / even just renaming the new file and placing it in the same directory

[JosAH]

Please help me with this one... i can make a code that will put the files in its desired location later. what i need now is how to write a new file after reading the original one... and placing it in other directory / even just renaming the new file and placing it in the same directory

properly close() your BufferedOutputStream (it will close the FileOutputStream
for you too), when you're done with it.

kind regards,

Jos

[r035198x]

You can simply use

int val = bis.read();
while(val != -1) {
       bos.write(val);
       val = bis.read();
}

For the reading and writing.

[jeffbroodwar]

Still.... it creates 0kb file..... ^^; eheheh i know it's easy for you guys.... sorry. i'm still new in java i guess....

[r035198x]

Still.... it creates 0kb file..... ^^; eheheh i know it's easy for you guys.... sorry. i'm still new in java i guess....

Can you post the full class that you're using?

[jeffbroodwar]

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import javax.swing.JOptionPane;
 
 
// This code goes inside the button's action performed //
 
 
// Paste a file in a folder Button
String saveVariable = null;
                //READ A FILE
                try
                {
                    FileInputStream fin = new FileInputStream("SampleWebService.war");
                    BufferedInputStream bin = new BufferedInputStream(fin);
                    int ch=0;
 
                    while((ch=bin.read())> -1)
                    {
                            StringBuffer buf = new StringBuffer();
                            buf.append((char)ch);
                            System.out.print(buf.toString());
                            saveVariable = String.valueOf(buf);
                    }
 
                            //WRITE A FILE
                            try 
                            {
 
                              FileOutputStream fos = new FileOutputStream("Sample.war");
 
                              BufferedOutputStream bos = new BufferedOutputStream(fos);
 
                                while(ch != -1)
                                {
                                       bos.write(ch);
                                       ch = bin.read();
 
                                }
                                bos.close();
 
                            } 
                            catch (Exception e) 
                            {
                              System.out.println("Exception: " + e);
                            }
 
                }
                catch(IOException ex)
                {
                    System.out.println(ex.getMessage());
                }
// END OF CODE //

Hope we can figure it out.... thanks.

Best Regards,
Jeff

[jeffbroodwar]

incase i can't give a reply, i'll try to be online again tomorrow, but if i'll have a solution fast enough i might be able to make this thing work now. thanks in advance for all your help guys. specially r035198x. I ran out of money... i'm in a net cafe. thanks, hope i can make it work...... i'll still wait for your suggestions and hoping to make this thing work before they cut my connection. err...... thanks

[r035198x]

1.) Please use code tags each time when posting code.
2.) Do you want to copy a file from one location to another or do you want to rename a file because you are using the same directory (current) in your code?
3.) Here's the code that can copy a file for you

public static void copy(String fromPath, String toPath) {
        try {
            FileInputStream fis = new FileInputStream(fromPath);
            BufferedInputStream bis = new BufferedInputStream(fis);
            FileOutputStream fos = new FileOutputStream(toPath);
            BufferedOutputStream bos = new BufferedOutputStream(fos);
            int val = bis.read();
            while(val != -1) {
                bos.write(val);
                val = bis.read();
            }
 
        }
        catch(Exception e) {
            e.printStackTrace();
        }
        finally {
            bis.close();
            bos.close();
        }
    }

Putting it in a method like this allows me to call it from anywhere with any arguments I want.

[jeffbroodwar]

Thanks man, it worked not yet late !!! Ehehehehe..... though the finally didn't work it says : cannot find symbol... i'm using netbeans 5.5. i don't know why it can't detect the initialization above... anyway. i'll try to figure it out myself. it's now working thanks again r035198x and jos. about the code format, sorry i didn't have the time to make it neat, i'm really in a hurry. thanks again !!


Best Regards,
Jeff

[r035198x]

Thanks man, it worked not yet late !!! Ehehehehe..... though the finally didn't work it says : cannot find symbol... i'm using netbeans 5.5. i don't know why it can't detect the initialization above... anyway. i'll try to figure it out myself. it's now working thanks again r035198x and jos. about the code format, sorry i didn't have the time to make it neat, i'm really in a hurry. thanks again !!


Best Regards,
Jeff

That's not your netbeans' problem. That's my mistake in the code (so much for posting before testing and so much for trying to give someone all the code)

You can change your method contents to

try {
            FileInputStream fis = new FileInputStream(fromPath);
            BufferedInputStream bis = new BufferedInputStream(fis);
            FileOutputStream fos = new FileOutputStream(toPath);
            BufferedOutputStream bos = new BufferedOutputStream(fos);
            int val = bis.read();
            while(val != -1) {
                bos.write(val);
                val = bis.read();
            }
            bis.close();
            bos.close();
 
        }
        catch(Exception e) {
            e.printStackTrace();
        }

P.S:I hope you realized why the code didn't work like that.

[jeffbroodwar]

yup got it. I just thought that what you gave me doesn't have any errors.. I'm too confident that you've tested it before giving it to me. reason why i blamed myself for the error.......That's a mistake on my part. Thanks again. ^^

[blazedaces]

That's not your netbeans' problem. That's my mistake in the code (so much for posting before testing and so much for trying to give someone all the code)

You can change your method contents to

try {
            FileInputStream fis = new FileInputStream(fromPath);
            BufferedInputStream bis = new BufferedInputStream(fis);
            FileOutputStream fos = new FileOutputStream(toPath);
            BufferedOutputStream bos = new BufferedOutputStream(fos);
            int val = bis.read();
            while(val != -1) {
                bos.write(val);
                val = bis.read();
            }
            bis.close();
            bos.close();
 
        }
        catch(Exception e) {
            e.printStackTrace();
        }

P.S:I hope you realized why the code didn't work like that.

Just a tip since I was doing something like this earlier, add a finally parameter at the end for closing the streams like this:

try {
            FileInputStream fis = new FileInputStream(fromPath);
            BufferedInputStream bis = new BufferedInputStream(fis);
            FileOutputStream fos = new FileOutputStream(toPath);
            BufferedOutputStream bos = new BufferedOutputStream(fos);
            int val = bis.read();
            while(val != -1) {
                bos.write(val);
                val = bis.read();
            }
 
        }
        catch(Exception e) {
            e.printStackTrace();
        }
        finally {
            bis.close();
            bos.close();
        }
 
 

This way if you either interrupt the program or something goes wrong these don't stay open. If they do, you'll have to stop java.exe from running or it will keep going in the background at times...

Finally makes sure those are closed no matter what, either by interruption or exception. Finally is what will always happen following a try clause, no matter what.

Good luck,

-blazed

[JosAH]

Just a tip since I was doing something like this earlier, add a finally parameter at the end for closing the streams like this:

try {
            FileInputStream fis = new FileInputStream(fromPath);
            BufferedInputStream bis = new BufferedInputStream(fis);
            FileOutputStream fos = new FileOutputStream(toPath);
            BufferedOutputStream bos = new BufferedOutputStream(fos);
            int val = bis.read();
            while(val != -1) {
                bos.write(val);
                val = bis.read();
            }
 
        }
        catch(Exception e) {
            e.printStackTrace();
        }
        finally {
            bis.close();
            bos.close();
        }
 
 

This way if you either interrupt the program or something goes wrong these don't stay open. If they do, you'll have to stop java.exe from running or it will keep going in the background at times...

Finally makes sure those are closed no matter what, either by interruption or exception. Finally is what will always happen following a try clause, no matter what.

Good luck,

-blazed

While we're at it: a close() call can throw an IOException too so you'd better
change that finally clause to:

try {
   ...
}
catch ( ... ) { ... }
finallly {
   try { bis.close(); } catch (IOException ioe) { /* muffle */ }
   try { bos.close(); } catch (IOException ioe) { /* muffle */ }
}
 

kind regards,

Jos

[r035198x]

While we're at it: a close() call can throw an IOException too so you'd better
change that finally clause to:

try {
   ...
}
catch ( ... ) { ... }
finallly {
   try { bis.close(); } catch (IOException ioe) { /* muffle */ }
   try { bos.close(); } catch (IOException ioe) { /* muffle */ }
}
 

kind regards,

Jos

Indeed .