CODEWITHSUNDEEP
javahtmlsecurityappletsettings
Owen_AR
Owen_AR

Reputation: 3027

*What* Java "security settings have blocked a local application from running"?

I have a simple test applet that's supposed to draw a little triangle (and works fine using appletviewer Triangle.class from the command line), but when I try to view Triangle.htm in my browser, I get this message (from Java itself, as far as I can tell, not my Firefox or Chrome):

"Your security settings have blocked a local application from running."

However, I can't figure out what settings to change. I tried just putting the general settings at their lowest (called "medium" ha ha what is this like cup sizes in a coffee shop-- Oh. Right.) but that didn't work, and if the solution is buried somewhere in the more advanced options, it's painfully non-obvious to me... :/

This question sounded like my problem:

Java Error: "Your security settings have blocked a local application from running"

But the original poster said, "Resolved: the problem was that the compiler used JDK6 instead of JDK7."

And I checked I had the latest version before re-compiling the class file:

> java -version
java version "1.7.0_25"
Java(TM) SE Runtime Environment (build 1.7.0_25-b17)
Java HotSpot(TM) Client VM (build 23.25-b01, mixed mode, sharing)

> javac Triangle.java

Anyway, can anyone see if they get the same problem and tell me how you fix it?

For easy replication, this is the source of the class file:

Triangle.java:

import java.awt.*;
import java.applet.Applet;
public class Triangle extends Applet {
    public void paint (Graphics g){
        int bottomX=80;
        int bottomY=200;
        int base=100;
        int height=100;
        g.drawLine(bottomX,bottomY,bottomX+base,bottomY);
        g.drawLine(bottomX+base,bottomY,bottomX+base/2,bottomY-height);
        g.drawLine(bottomX+base/2,bottomY-height, bottomX,bottomY);
    }
}

And this is the htm that's in the folder with the class file:

Triangle.htm:

<applet code="Triangle.class" width=400 height=400></applet>

Upvotes: 3

Views: 20358

Answers (2)

Andrew Thompson
Andrew Thompson

Reputation: 168845

I just tried your code using Java version 1.7.0_25-b17. It works just fine in the browser on the two lower settings seen here.

Java Control Panel - Security Tab

To get it to work for the highest security level, it needs to be put in a Jar and signed using a valid certificate.

Upvotes: 4

3yakuya
3yakuya

Reputation: 2672

It was officially stated (Oracle's response to my school-team's email) that some older remains of virtual machines may actually cause security alerts with applets even if you set security settings to absolute minimum (had it many times with my applet). I guess it is a school/study work (as it is an applet), so it is probably worth trying to run it directly by appletviewer.

Upvotes: 0

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