在 log4j/log4net 中捕获标准输出

import org.apache.log4j.AppenderSkeleton;
import org.apache.log4j.spi.LoggingEvent;

public class StdoutAppender extends AppenderSkeleton {
    @Override
    protected void append(LoggingEvent event) {
        System.out.println(event.getMessage());
    }

    @Override
    public boolean requiresLayout() {
        return false;
    }

    @Override
    public void close() {
    }
}

using System;
using log4net.Appender;
using log4net.Core;

public class StdoutAppender : AppenderSkeleton
{
    protected override void Append(LoggingEvent loggingEvent)
    {
        Console.WriteLine(loggingEvent.RenderedMessage);
    }

    protected override bool RequiresLayout
    {
        get { return false; }
    }

    protected override void CloseAppender()
    {
    }
}

import java.io.ByteArrayOutputStream;
import java.io.PrintStream;

public class Main {
    public static void main(String[] args) {
        ByteArrayOutputStream outContent = new ByteArrayOutputStream();
        System.setOut(new PrintStream(outContent));

        System.out.println("Hello, World!");

        String capturedOutput = outContent.toString();
        System.out.println("Captured output: " + capturedOutput);
    }
}

using System;
using System.IO;

class Program
{
    static void Main()
    {
        using (var writer = new StringWriter())
        {
            Console.SetOut(writer);
            Console.WriteLine("Hello, World!");
            string capturedOutput = writer.ToString();
            Console.WriteLine("Captured output: " + capturedOutput);
        }
    }
}