package com.dianping.cat.log4j;
import java.io.PrintWriter;
import java.io.StringWriter;
import org.apache.log4j.AppenderSkeleton;
import org.apache.log4j.Level;
import org.apache.log4j.spi.LoggingEvent;
import org.apache.log4j.spi.ThrowableInformation;
import com.dianping.cat.Cat;
import com.dianping.cat.message.Message;
import com.dianping.cat.message.MessageProducer;
import com.dianping.cat.message.Trace;
import com.dianping.cat.message.Transaction;
import com.dianping.cat.message.spi.MessageTree;
public class CatAppender extends AppenderSkeleton {
@Override
protected void append(LoggingEvent event) {
boolean isTraceMode = Cat.getManager().isTraceMode();
Level level = event.getLevel();
if (level.isGreaterOrEqual(Level.ERROR)) {
logError(event);
} else if (isTraceMode) {
logTrace(event);
}
}
private String buildExceptionStack(Throwable exception) {
if (exception != null) {
StringWriter writer = new StringWriter(2048);
exception.printStackTrace(new PrintWriter(writer));
return writer.toString();
} else {
return "";
}
}
@Override
public void close() {
}
private void logError(LoggingEvent event) {
ThrowableInformation info = event.getThrowableInformation();
if (info != null) {
MessageProducer cat = Cat.getProducer();
Throwable exception = info.getThrowable();
Object message = event.getMessage();
MessageTree tree = Cat.getManager().getThreadLocalMessageTree();
if (tree == null) {
Transaction t = cat.newTransaction("System", "Log4jException");
if (message != null) {
cat.logError(String.valueOf(message), exception);
} else {
cat.logError(exception);
}
t.setStatus(Message.SUCCESS);
t.complete();
} else {
cat.logError(exception);
}
}
}
private void logTrace(LoggingEvent event) {
String type = "Log4j";
String name = event.getLevel().toString();
Object message = event.getMessage();
String data;
if (message instanceof Throwable) {
data = buildExceptionStack((Throwable) message);
} else {
data = event.getMessage().toString();
}
ThrowableInformation info = event.getThrowableInformation();
if (info != null) {
data = data + '\n' + buildExceptionStack(info.getThrowable());
}
Cat.logTrace(type, name, Trace.SUCCESS, data);
}
@Override
public boolean requiresLayout() {
return false;
}
}