在java中运行框架程序时出错

Question

I compiled the program it has no error but while running I get an error:

could not find or load frame.java

I saved program name as frame.java and run as java frame.java

import java.awt.*;
import java.awt.event.*;
public class frame extends Frame {

    Label l1, l2, l3, l4, l5, l6;

    frame() {
        super("my frame title");
        setLayout(new FlowLayout());
        l1 = new Label("name");
        l2 = new Label("fathers name");
        l3 = new Label("add");
        l4 = new Label("sex");
        l5 = new Label("course");
        l6 = new Label("hobbies");

        add(l1);
        add(l2);
        add(l3);
        add(l4);
        add(l5);
        add(l6);

        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                dispose();
            }
        }
        );
    }

    public static void main(String a[]) {
        frame o = new frame();
        o.setSize(500, 500);
        o.setVisible(true);
    }
}

Answer 1

A Java source file is compiled into a file of {name}.class.

But when running the class file, you don't need to supply the .class prefix, for example...

java frame

Another problem you might have is that there is an expectation that a class should belong to a package and you may have difficulty finding/running a class within the default package, for example...

package test;
import java.awt.*;
import java.awt.event.*;
public class frame extends Frame {

    Label l1, l2, l3, l4, l5, l6;

    frame() {
        super("my frame title");
        setLayout(new FlowLayout());
        l1 = new Label("name");
        l2 = new Label("fathers name");
        l3 = new Label("add");
        l4 = new Label("sex");
        l5 = new Label("course");
        l6 = new Label("hobbies");

        add(l1);
        add(l2);
        add(l3);
        add(l4);
        add(l5);
        add(l6);

        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                dispose();
            }
        }
        );
    }

    public static void main(String a[]) {
        frame o = new frame();
        o.setSize(500, 500);
        o.setVisible(true);
    }
}

The source file will now need to be saved in the test directory and compiled using something like...

javac test\frame.java

And run using something like

java test.frame

Assuming your are executing from the parent directory of the test directory

See Creating and Using Packages for more details.

I'd also recommend that:

• You use an IDE to start with, as it will make the process simpler
• You consider using Swing or JavaFX instead of AWT based class, as AWT doesn't have the same community support as Swing and JavaFX, which make it easier to solve problems you might have in the future
• You have a read through Code Conventions for the Java TM Programming Language , it will make it easier for people to read your code and for you to read others