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

After reading Java 7 Update 21 Security Improvements in Detail mention..

With the introduced changes it is most likely that no end-user is able to run your application when they are either self-signed or unsigned.

..I was wondering how this would go for loose class files - the 'simplest' applets of all.

Local file system

Dialog: Your security settings have blocked a local application from running
Your security settings have blocked a local application from running

That is the dialog seen for an applet consisting of loose class files being loaded off the local file system when the JRE is set to the default 'High' security setting.


Note that a slight quirk of the JRE only produced that on point 3 of.

  1. Load the applet page to see a broken applet symbol that leads to an empty console.
    Open the Java settings and set the level to Medium.
    Close browser & Java settings.
  2. Load the applet page to see the applet.
    Open the Java settings and set the level to High.
    Close browser & Java settings.
  3. Load the applet page to see a broken applet symbol & the above dialog.

Internet

If you load the simple applet (loose class file) seen at this resizable applet demo off the internet - which boasts an applet element of:

<applet
    code="PlafChanger.class"
    codebase="."
    alt="Pluggable Look'n'Feel Changer appears here if Java is enabled"
    width='100%'
    height='250'>
<p>Pluggable Look'n'Feel Changer appears here in a Java capable browser.</p>
</applet>

It also seems to load successfully. Implying that:-

Applets loaded from the local file system are now subject to a stricter security sandbox than those loaded from the internet or a local server.

Security settings descriptions

As of Java 7 update 51.

  • Very High: Most secure setting - Only Java applications identified by a non-expired certificate from a trusted authority will be allowed to run.
  • High (minimum recommended): Java applications identified by a certificate from a trusted authority will be allowed to run.
  • Medium - All Java applications will be allowed to run after presenting a security prompt.

Examples related to java

Under what circumstances can I call findViewById with an Options Menu / Action Bar item? How much should a function trust another function How to implement a simple scenario the OO way Two constructors How do I get some variable from another class in Java? this in equals method How to split a string in two and store it in a field How to do perspective fixing? String index out of range: 4 My eclipse won't open, i download the bundle pack it keeps saying error log

Examples related to security

Monitoring the Full Disclosure mailinglist Two Page Login with Spring Security 3.2.x How to prevent a browser from storing passwords JWT authentication for ASP.NET Web API How to use a client certificate to authenticate and authorize in a Web API Disable-web-security in Chrome 48+ When you use 'badidea' or 'thisisunsafe' to bypass a Chrome certificate/HSTS error, does it only apply for the current site? How does Content Security Policy (CSP) work? How to prevent Screen Capture in Android Default SecurityProtocol in .NET 4.5

Examples related to applet

Java unsupported major minor version 52.0 Unsupported major.minor version 52.0 "application blocked by security settings" prevent applets running using oracle SE 7 update 51 on firefox on Linux mint Can not run Java Applets in Internet Explorer 11 using JRE 7u51 Run local java applet in browser (chrome/firefox) "Your security settings have blocked a local application from running" Java Error: "Your security settings have blocked a local application from running" How to create a Rectangle object in Java using g.fillRect method socket programming multiple client to one server java.io.IOException: Invalid Keystore format How can I open Java .class files in a human-readable way?