LogbackListAppender.java

package com.vip.saturn.job.utils;

/*******************************************************************************
 * Copyright (c) 2005, 2014 springside.github.io
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 *******************************************************************************/
import java.util.LinkedList;
import java.util.List;

import org.slf4j.LoggerFactory;

import ch.qos.logback.classic.Logger;
import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.core.UnsynchronizedAppenderBase;

/**
 * 在List中保存日志的Appender, 用于测试Logback的日志输出.
 *
 * 在测试开始前, 使用任意一种addToLogger()方法将此appender添加到需要侦听的logger中.
 *
 * @author calvin
 */
public class LogbackListAppender extends UnsynchronizedAppenderBase<ILoggingEvent> {

    private final List<ILoggingEvent> logs = new LinkedList<ILoggingEvent>();

    public LogbackListAppender() {
        start();
    }

    @Override
    protected void append(ILoggingEvent e) {
        logs.add(e);
    }

    /**
     * 返回之前append的第一个log.
     */
    public ILoggingEvent getFirstLog() {
        if (logs.isEmpty()) {
            return null;
        }
        return logs.get(0);
    }

    /**
     * 返回之前append的第一个log的内容.
     */
    public String getFirstMessage() {
        if (logs.isEmpty()) {
            return null;
        }
        return getFirstLog().getFormattedMessage();
    }

    /**
     * 返回之前append的最后一个log.
     */
    public ILoggingEvent getLastLog() {
        if (logs.isEmpty()) {
            return null;
        }
        return logs.get(logs.size() - 1);
    }

    /**
     * 返回之前append的最后一个log的内容.
     */
    public String getLastMessage() {
        if (logs.isEmpty()) {
            return null;
        }
        return getLastLog().getFormattedMessage();
    }

    /**
     * 返回之前append的所有log.
     */
    public List<ILoggingEvent> getAllLogs() {
        return logs;
    }

    /**
     * 返回Log的数量。
     */
    public int getLogsCount() {
        return logs.size();
    }

    /**
     * 判断是否有log.
     */
    public boolean isEmpty() {
        return logs.isEmpty();
    }

    /**
     * 清除之前append的所有log.
     */
    public void clearLogs() {
        logs.clear();
    }

    /**
     * 将此appender添加到logger中.
     */
    public void addToLogger(String loggerName) {
        Logger logger = (Logger) LoggerFactory.getLogger(loggerName);
        logger.addAppender(this);
    }

    /**
     * 将此appender添加到logger中.
     */
    public void addToLogger(Class<?> loggerClass) {
        Logger logger = (Logger) LoggerFactory.getLogger(loggerClass);
        logger.addAppender(this);
    }

    /**
     * 将此appender添加到root logger中.
     */
    public void addToRootLogger() {
        Logger logger = (Logger) LoggerFactory.getLogger(org.slf4j.Logger.ROOT_LOGGER_NAME);
        logger.addAppender(this);
    }

    /**
     * 将此appender从logger中移除.
     */
    public void removeFromLogger(String loggerName) {
        Logger logger = (Logger) LoggerFactory.getLogger(loggerName);
        logger.detachAppender(this);
    }

    /**
     * 将此appender从logger中移除.
     */
    public void removeFromLogger(Class<?> loggerClass) {
        Logger logger = (Logger) LoggerFactory.getLogger(loggerClass);
        logger.detachAppender(this);
    }

    /**
     * 将此appender从root logger中移除.
     */
    public void removeFromRootLogger() {
        Logger logger = (Logger) LoggerFactory.getLogger(org.slf4j.Logger.ROOT_LOGGER_NAME);
        logger.detachAppender(this);
    }

}