سؤال
I am writing a java program and it is properly running on Eclipse, there are no errors and the program gives accurate output. However when I compile it using command prompt it gives me 39 errors.
https://stackoverflow.com/questions/23640196
italiano
english
français
española
中国
日本の
العربية
Deutsch
한국어
Português
Russianimport java.util.*;
import javax.swing.*;
import java.awt.Color;
import java.awt.event.*;
import java.io.*;
import java.nio.channels.ReadableByteChannel;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.*;
public class Main extends JFrame{
public static void main (String args [])
{
JFrame frame = new JFrame (); // making a frame in which we will add all the
// components
FrameWork work = new FrameWork ();
frame.setLayout(null);
frame.setBounds (10,10,700,500);
frame.setResizable(false); // making the frame non resizeable so that components are not misplaced
frame.add (work);
frame.setDefaultCloseOperation (EXIT_ON_CLOSE);
frame.setVisible (true);
} // main ends here
} // main class ends here
class FrameWork extends JPanel
{
// panel in which all the components are added
JPanel panel = new JPanel ();
JTextArea jarea = new JTextArea();
JTextField jfield = new JTextField();
// Buttons that can be used to switch between standard IO NIO and NIO2
JButton IO = new JButton ("Standard IO");
JButton NIO = new JButton ("New IO");
JButton NIO2 = new JButton ("New IO2");
JScrollPane scroll = new JScrollPane();
FrameWork ()
{
// setting the lay out null so that componenets can be places at respective postions
add(panel);
setLayout (null);
setBounds (0,0,700,500);
setBackground(Color.white);
add(jarea);
jarea.setBounds(5,85,670,360);
//setting border arround the JText area
jarea.setBorder(BorderFactory.createLineBorder(Color.black));
jarea.add(scroll);
add(jfield);
jfield.setBounds(10,10,650,25);
// adding Standard IO button and Implemnting action listener
add(IO);
IO.setBounds (50,40,150,40);
IO.addMouseListener(new MouseListener(){
@Override
public void mouseClicked(MouseEvent ae)
{
try {
FileReader reader = new FileReader("test.txt");
BufferedReader buff = new BufferedReader(reader);
jarea.read(buff,null);
buff.close();
}
catch (IOException e) {
}
}
@Override
public void mouseEntered(MouseEvent ae) {
}
@Override
public void mouseExited(MouseEvent ae) {
}
@Override
public void mousePressed(MouseEvent ae) {
}
@Override
public void mouseReleased(MouseEvent ae) {
}});
// adding Standard NIO button and Implementing action listener
add(NIO);
NIO.setBounds (250,40,150,40);
NIO.addMouseListener(new MouseListener(){
@Override
public void mouseClicked(MouseEvent ae) {
// some part of this code from java docs
Path file = Paths.get("test.txt");
try (InputStream in = Files.newInputStream(file);
BufferedReader reader =new BufferedReader(new InputStreamReader(in)))
{
String line = null;
while ((line = reader.readLine()) != null) {
jarea.read(reader,null);
}
} catch (IOException x) {
System.err.println(x);
}
}
@Override
public void mouseEntered(MouseEvent ae) {
}
@Override
public void mouseExited(MouseEvent ae) {
}
@Override
public void mousePressed(MouseEvent ae) {
}
@Override
public void mouseReleased(MouseEvent ae) {
}});
// adding Standard NIO2 button and Implemnting action listener
add(NIO2);
NIO2.setBounds (450,40,150,40);
NIO2.addMouseListener(new MouseListener(){
@Override
public void mouseClicked(MouseEvent ae) {
try
{
ByteBuffer buffer = ByteBuffer.allocate(1024*1024);
Path file = Paths.get("test.txt");
ReadableByteChannel rbc = Files.newByteChannel(file);
int counter =0;
int flag = 0;
int enter = 0;
while(counter != -1)
{
buffer.rewind ();
counter = rbc.read(buffer);
buffer.rewind();
flag++;
for(enter =0 ; enter <= counter-1 ; enter++)
{
byte by = buffer.get();
jarea.append(""+(char)by);
}
}
}
catch(Exception e){}
}
@Override
public void mouseEntered(MouseEvent ae) {
}
@Override
public void mouseExited(MouseEvent ae) {
}
@Override
public void mousePressed(MouseEvent ae) {
}
@Override
public void mouseReleased(MouseEvent ae) {
}});
} // constructor ends
} //FrameWork Class ends
Errors:
المحلول
Edit: based on the images of errors that you uploaded later, it looks like you are using a Java 1.6 or earlier compiler. Do java -version to see what version you are using.
Update your windows path to use the java 1.7 version that you have elsewhere on your machine.
نصائح أخرى
In Command Line - Remove the imported packages on top , when it is a single file and standalone application.
Check List:-
Make user the libraries are available to the existing location.
Set the class path perfectly.
Execute the below commands to ensure they environmental variables are set properly for jdk and jre
c:\javac
c:\java
I ran into a similar issue today. My program was working fine in the Eclipse debugger but misbehaving from the OS command line. It finally turned out to be a CLASSPATH issue. My code was incompatible with a JAR that I had included in my CLASSPATH environment variable for the OS shell. This JAR was not even required for my program. For Eclipse I had only linked the requisite JARs, so this problem did not manifest in the Eclipse debugger. After excluding the offending JAR from my CLASSPATH, the problem disappeared.
