Log4j2：如何扩展AbstractAppender

Question

因此，正如大多数人尝试做的那样，我尝试扩展Log4j2中的“ AbstractExtender”。但是，当我加载程序时，出现以下错误：“ FooAppender包含无效的元素或属性“ fileName” ”。现在，我对任何编程都不陌生，我知道我需要以某种方式实现filename属性。但是我对如何实际做到这一点感到困惑。这是我的代码和配置-我被困在如何将filename属性传递到正确的位置。提前很多帮助为您服务！ ：）

package my.appenders;

import java.io.Serializable;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

import org.apache.logging.log4j.core.Filter;
import org.apache.logging.log4j.core.Layout;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.appender.AbstractAppender;
import org.apache.logging.log4j.core.appender.AppenderLoggingException;
import org.apache.logging.log4j.core.appender.FileAppender;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
import org.apache.logging.log4j.core.config.plugins.PluginElement;
import org.apache.logging.log4j.core.config.plugins.PluginFactory;
import org.apache.logging.log4j.core.layout.PatternLayout;

// note: class name need not match the @Plugin name.
@Plugin(name = "FooAppender", category = "Core", elementType = "appender", printObject = true)
public final class FooAppender extends AbstractAppender
{

    private final ReadWriteLock rwLock = new ReentrantReadWriteLock();
    private final Lock readLock = rwLock.readLock();

    protected FooAppender(String name, String fileName, Filter filter, Layout<? extends Serializable> layout,
            final boolean ignoreExceptions)
    {
        super(name, filter, layout, ignoreExceptions);

    }

    // The append method is where the appender does the work.
    // Given a log event, you are free to do with it what you want.
    // This example demonstrates:
    // 1. Concurrency: this method may be called by multiple threads concurrently
    // 2. How to use layouts
    // 3. Error handling
    @Override
    public void append(LogEvent event)
    {
        readLock.lock();
        try
        {
            final byte[] bytes = getLayout().toByteArray(event);
            System.out.write(bytes);
        } catch (Exception ex)
        {
            if (!ignoreExceptions())
            {
                throw new AppenderLoggingException(ex);
            }
        } finally
        {
            readLock.unlock();
        }
    }

    // Your custom appender needs to declare a factory method
    // annotated with `@PluginFactory`. Log4j will parse the configuration
    // and call this factory method to construct an appender instance with
    // the configured attributes.
    @PluginFactory
    public static FooAppender createAppender(
            @PluginAttribute("name") String name,
            @PluginAttribute("fileName") String fileName,
            @PluginElement("Layout") Layout<? extends Serializable> layout,
            @PluginElement("Filter") final Filter filter, @PluginAttribute("otherAttribute") String otherAttribute)
    {
        if (name == null)
        {
            LOGGER.error("No name provided for FooAppender");
            return null;
        }
        if (layout == null)
        {
            layout = PatternLayout.createDefaultLayout();
        }
        return new FooAppender(name, fileName, filter, layout, true);
    }
}

和配置：

<?xml version="1.0" encoding="utf-8"?>
<Configuration debug="true" status="trace" packages="my.appenders">
    <Properties>
        <Property name="logPath">E:\Code\Workspace_Java\Log4jTest\bin</Property>
    </Properties>
    <Appenders>
        <Console name="Console" target="SYSTEM_OUT">
            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" />
        </Console>
        <File name="default.log"
            fileName="${logPath}/SignatureVerifier_${date:yyyy-MM-dd-HH-mm-ss}.log">
            <PatternLayout>
                <pattern>%d{yyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n</pattern>
            </PatternLayout>
        </File >

        <FooAppender name="debug.log"
            fileName="${logPath}/Debug_${date:yyyy-MM-dd-HH-mm-ss}.log">
            <PatternLayout>
                <pattern>%d{yyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n</pattern>
            </PatternLayout>
        </FooAppender >
    </Appenders>

    <Loggers>
        <Root level="TRACE">
            <AppenderRef ref="Console" Level="INFO" />
            <AppenderRef ref="default.log" Level="INFO"/>
            <Appender-ref ref="debug.log" Level="ALL"/>
        </Root>
    </Loggers>

</Configuration>