java - Custom OutputStreamAppender not run: LOGBACK: No context given for <MYAPPENDER> -

i wish write custom appender on basis of outputstreamappender. wrote following class

package tests;  import java.io.ioexception; import java.io.outputstream;  import ch.qos.logback.core.outputstreamappender;  public class myappender<e> extends outputstreamappender<e> {     public myappender() {          system.out.println("myappender created");          setoutputstream(new outputstream() {              @override             public void write(int b) throws ioexception {                 throw new unsupportedoperationexception();             }         });     } } 

then wrote following runner:

package tests;  import org.slf4j.loggerfactory;  import ch.qos.logback.classic.logger;  public class runner {      private static final logger log = (logger) loggerfactory.getlogger(runner.class);       public static void main(string[] args) {          //log.addappender(new myappender<iloggingevent>());          log.info("hello world");     } } 

finally wrote following logback.xml:

<configuration>      <appender name="stdout" class="ch.qos.logback.core.consoleappender">         <encoder>             <pattern>%d{hh:mm:ss.sss} [%thread] %-5level %logger{0} - %msg%n</pattern>         </encoder>     </appender>      <appender name="myappender" class="tests.myappender">         <encoder>             <pattern>%d{hh:mm:ss.sss} [%thread] %-5level %logger{0} - %msg%n</pattern>         </encoder>     </appender>        <root level="debug">         <appender-ref ref="stdout" />     </root>  </configuration> 

and got following output:

myappender created logback: no context given tests.myappender[null] 20:45:29.957 [main] info  runner - hello world 

it indicates appender instantiated. absence of exceptions mean never called.

probably related error message don't understand: "logback: no context given tests.myappender[null]"

what mean , how fix?

how set filename want write there lots of other issues when extend outputstreamappender rather extend fileappender(which intern extension of outputsteamappender) , override write method perfrom custom task.

public class myappender<e> extends fileappender<e> {   @override   protected void writeout(e event) throws ioexception {     /**if (prudent) {       safewrite(event);     } else {       super.writeout(event);     } */     throw new unsupportedoperationexception();   }  }