Frequently Asked Questions

Applet

1. My application in applet throws the java.security.AccessControlException: access denied (java.util.PropertyPermission ... read)

1. Error preverifying class org.any.IOUtils VERIFIER ERROR org/any/IOUtils.load()V: Cannot find class java/io/FilterInputStream
2. How do I use avetanaBluetooth or BlueCove with MicroEmulator
3. When I run MIDlet compiled with avetana I get error java.lang.NoClassDefFoundError: de/avetana/bluetooth/connection/Connector.

1. How can I ask MicroEmulator to use proxy server.

Applet

My application in applet throws the java.security.AccessControlException: access denied (java.util.PropertyPermission ... read)

Applet security restriction do not allow calls to System.getProperty(). You should use "Save for Web..." menu in main MicroEmulator application.

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Compilation

Error preverifying class org.any.IOUtils VERIFIER ERROR org/any/IOUtils.load()V: Cannot find class java/io/FilterInputStream

This is beacuse you are compiling your code with J2SE java.io. And DataInputStream and DataOutputStream are inherited from FilterInputStream in J2SE The problem in close() function. Solution is to use InputStream.close(). Consider this example: Instead of:

   DataInputStream din = new DataInputStream(..);
   din.close();
                   

Use:

   DataInputStream din = new DataInputStream(..);
   ((InputStream)din).close();

    // or even better...

   silentClose(din);

   private void silentClose(InputStream is) {
        if (is == null) {
            return;
        }
        try {
            is.close();
        } catch (IOException ignore) {
        }
    }
               

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How do I use avetanaBluetooth or BlueCove with MicroEmulator

All you need to do is to add avetanaBluetooth.jar to classpath after microemulator.jar. Remember that these JSR-82 implementations will not run in applet.

java -cp microemulator.jar;avetanaBluetooth.jar;YourApp.jar org.microemu.app.Main com.yourcompany.YourMidlet
or
java -cp microemulator.jar;bluecove-1.2.3.jar;YourApp.jar org.microemu.app.Main com.yourcompany.YourMidlet

If you add microemulator.jar after JSR-82 implementations then Generic Connection Framework provided by MicroEmulator will not work. This includes http and Socket Connections.

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When I run MIDlet compiled with avetana I get error java.lang.NoClassDefFoundError: de/avetana/bluetooth/connection/Connector.

This is because avetanaBluetooth.jar contains empty class javax.microedition.io.Connector that inherits from de.avetana.bluetooth.connection.Connector. This problem should be fixed in next avetana version 1.3.12.

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Network configuration

How can I ask MicroEmulator to use proxy server.

Edit the configuration file $home/.microemulator/config2.xml.

<config>
    ...
    <system-properties>
	    <system-property name="http.proxyHost" value="webcache.mydomain.com"></system-property>
	    <system-property name="http.proxyPort" value="8080"></system-property>
	    <system-property name="http.nonProxyHosts" value="localhost"></system-property>
   </system-properties>
    ...
</config>

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