问题
My JApplet is producing a error when DrawOvalInputs.html runs and calls the class file of DrawOvalInputs. So far, I have only been able to get it work as an actual application (Which is why the main is in a block quote).
My goal for this program is to be able to run a .html file to start up the JApplet with a medium security setting on the java console, yet no matter what I've done it simply won't function.
I have looked around on quite a few pages and searches before coming here. Regrettably, I just can't figure this JApplet out, so if someone could guide me in the right direction I'd be most thankful!
My Code below:
DrawOvalInputs.java
package drawovalapplet;
import java.awt.BorderLayout;
import java.awt.Frame;
import java.awt.Graphics;
import javax.swing.JApplet;
import javax.swing.JOptionPane;
/**
* This applet inputs a number of values, and then computes the size of
* an oval with those given values.
*
* @author [Redacted]
* @version 2014-05-02, [Redacted]
*/
public class DrawOvalInputs extends JApplet
{
private static int x; //left edge of the oval
private static int y; //top edge of the oval
private static int width; //width of oval
private static int height; //height of oval
private static int windowWidth; //Holds necessary width of window.
private static int windowHeight; //Holds necessary height of window.
private static int windowBox; //Holds box form of window.
@Override
public void init()
{
try
{
/** Collect the input values. */
Input.inputAll();
/** creates dimensions for box */
windowWidth = width + x + 50;
windowHeight = height + y + 50;
/**
* If... else... function to gather data to create
* a fitting box for the oval
*/
if(windowWidth > windowHeight)
windowBox = windowWidth;
else
windowBox = windowHeight;
} catch (Input.CanceledException ex) {
System.exit(1);
}
}
@Override
public void paint(Graphics g)
{
super.paint(g);
g.drawOval(x, y, width, height);
} // end method pain
/**
* Main entry point.
* <p> Execute:
* <pre>java drawovalapplet.DrawOvalInputs</pre>
*
* @param args not used.
*/
/*public static void main(String args[])
{
Frame frame = new Frame("DrawOvalInputs");
DrawOvalInputs drawOval = new DrawOvalInputs();
drawOval.init();
drawOval.start();
frame.add(drawOval);
frame.setSize(drawOval.windowBox, drawOval.windowBox);
frame.setVisible(true);
}*/
//------------------------------- Nested Classes --------------------------------
/**
* Enumeration of the name and value of the input values.
*/
private enum Input
{
/**
* Message for the entering the x coordinate.
*/
XVALUE("Enter the argument for the x coordinate of the upper left corner of the oval to be drawn:"),
/**
* Message for the entering the y coordinate.
*/
YVALUE("Enter the argument for the y coordinate of the upper left corner of the oval to be drawn:"),
/**
* Message for entering the width.
*/
WIDTHVALUE("Enter the desired width of the oval to be drawn:"),
/**
* Message for entering the height.
*/
HEIGHTVALUE("Enter the desired height of the oval:");
/**
* String to use in messages (from the constructor).
*/
protected String invitation;
/**
* String to use for error messages.
*/
protected String error = "Not an integer value--please re-enter:";
/**
* Value of this {@literal <variable>}.
*/
protected int value;
/**
* @param label string to use in messages
*/
Input(String invitation)
{
this.invitation = invitation;
}
public static void inputAll() throws CanceledException
{
/* Decide which input value is currently being used. */
int count = 0;
/* Collect the input numbers. */
for(Input input : Input.values())
{
/* Set up the invitation to enter each number. */
String message = input.invitation;
/* Loop until the user inputs an acceptably formatted number. */
while(true) // repetition environment
{
String response;
/* Null return from the JOptionPane indicates CANCEL was pressed. */
if( (response = JOptionPane.showInputDialog(message)) == null)
throw new CanceledException();
message = input.error; // just in case
try
{
input.value = Integer.parseInt(response);
break; // success in acquiring value
}
catch(NumberFormatException nfe) {}// ignore all, and try again
}
count++;
if(count == 1)
x = input.value;
else if(count == 2)
y = input.value;
else if (count == 3)
width = input.value;
else if (count == 4)
height = input.value;
else
System.out.println("Error. Revise.");
}
}
@SuppressWarnings("serial")
public static class CanceledException extends Exception {}
}
}
DrawOvalInputs.html I've run this with DrawOvalInputs.java and the one below, as well as with .class instead.
<html>
<body>
<applet code=drawovalapplet.DrawOvalInputs.java width=400 height=400>
</applet>
</body>
</html>
Thanks!
回答1:
you must call it with the right path
if your path is like
DrawOvalApplet\build\classes\drawovalapplet\DrawOvalInputs.class
and your .html is in
DrawOvalApplet\build\DrawOvalInputs.html
call it
...
<applet code=classes.drawovalapplet.DrawOvalInputs.class width=400 height=400>
</applet>
...
much better your .html is in
DrawOvalApplet\build\classes\DrawOvalInputs.html
call it
...
<applet code=drawovalapplet.DrawOvalInputs.class width=400 height=400>
</applet>
...
result :
applet running
You can call htmlconverter and let do it for you
java -jar htmlconverter.jar -gui
Result DrawOvalInputs.html
<html>
<body>
<!--"CONVERTED_APPLET"-->
<!-- HTML CONVERTER -->
<object
classid = "clsid:CAFEEFAC-0017-0000-0051-ABCDEFFEDCBA"
codebase = "http://java.sun.com/update/1.7.0/jinstall-7u51-windows-i586.cab#Version=7,0,510,13"
WIDTH = 400 HEIGHT = 400 >
<PARAM NAME = CODE VALUE = drawovalapplet.DrawOvalInputs.class >
<param name = "type" value = "application/x-java-applet;jpi-version=1.7.0_51">
<param name = "scriptable" value = "false">
<comment>
<embed
type = "application/x-java-applet;jpi-version=1.7.0_51" \
CODE = drawovalapplet.DrawOvalInputs.class \
WIDTH = 400 \
HEIGHT = 400
scriptable = false
pluginspage = "http://java.sun.com/products/plugin/index.html#download">
<noembed>
</noembed>
</embed>
</comment>
</object>
<!--
<APPLET CODE = drawovalapplet.DrawOvalInputs.class WIDTH = 400 HEIGHT = 400>
</APPLET>
-->
<!--"END_CONVERTED_APPLET"-->
</body>
</html>
回答2:
Use the class file and the actual file path and name. For example:
<applet code=DrawOvalInputs.class width=400 height=400>
</applet>
if the class file is located in the same folder as your HTML file.
来源：https://stackoverflow.com/questions/23448848/japplet-not-running-no-main-classes-found