Log4j2 custom layout

Question

I am using Log4j2 with a PatternLayout. Is it possible to write my own Layout that extends AbstractStringLayout, so that I can customize my output message?

I have read the docs but I only see variations of layouts - no custom one.

https://logging.apache.org/log4j/2.x/manual/layouts.html

user_5097663 · Answer

package com.mytest;
@Plugin(name = "MyHtmlLayout", category = Node.CATEGORY, elementType = Layout.ELEMENT_TYPE, printObject = true)

public class MyHtmlLayout  extends AbstractStringLayout{
    protected MyHtmlLayout( Charset charset ){
        super( charset );
    }

    @Override
    public String toSerializable( LogEvent event ) {
        StringBuilder throwable = new StringBuilder();
        if (event.getThrown() != null) {
            StringWriter sw = new StringWriter();
            PrintWriter pw = new PrintWriter(sw);
            pw.println();
            event.getThrown().printStackTrace(pw);
            pw.close();
            throwable.append(sw.toString());
        }
        StringBuilder retValue=new StringBuilder();
        retValue.append("").append(new SimpleDateFormat("dd-MM-yyyy HH:mm:ss:S").format(event.getTimeMillis())).append(" ")
        .append(event.getLevel().toString()).append(" ").append(event.getLoggerName()).append(" ").append(event.getMessage().getFormattedMessage()).append(" ").append(throwable).append("
");

        return retValue.toString();
    }

    @PluginFactory
    public static MyHtmlLayout createLayout(@PluginAttribute(value = "charset", defaultString = "UTF-8") Charset charset) {
        return new MyHtmlLayout(charset);
    }
    @Override
    public byte[] getHeader() {
        return ("
  
" + "
").getBytes();
    }
    @Override
    public byte[] getFooter() {
        return ("

").getBytes();
    }
}

Configuration file:

Log4j2 custom layout

2 Answers