log4j+slf4j 升级为 logback混合异步日志

log4j在高并发的情况下，同步打日志会出现blocked进程。对log4j进行升级

1. 删除log4j的pom依赖

　删除slf4j-log4j12 和 log4j

2.添加logback的pom依赖

<properties>
    <slf4j-api.version>1.7.25</slf4j-api.version>
    <logback.version>1.2.3</logback.version
</properties>



<!-- log -->
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>${slf4j-api.version}</version>
</dependency>
<!-- 把common-logging.jar桥接到slf4j -->
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>jcl-over-slf4j</artifactId>
    <version>${slf4j-api.version}</version>
</dependency>
<!-- 把log4j1.x.jar桥接到slf4j -->
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>log4j-over-slf4j</artifactId>
    <version>${slf4j-api.version}</version>
</dependency>
<dependency>
    <groupId>ch.qos.logback</groupId>
    <artifactId>logback-classic</artifactId>
    <version>${logback.version}</version>
</dependency>
<dependency>
    <groupId>ch.qos.logback</groupId>
    <artifactId>logback-access</artifactId>
    <version>${logback.version}</version>
</dependency>

3. 部分pom引用可能依赖的log4j比较深，如果使用idea则可以使用Maven conflict插件去exclude冲突

4. 配置logback.xml文件，路径 src/main/resources

<?xml version="1.0" encoding="UTF-8"?>
<configuration debug="false">
    <!-- 控制台输出 -->
    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</pattern>
            <charset>UTF-8</charset>
        </encoder>
    </appender>

    <!-- 按照每天生成日志文件 -->
    <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <!--日志文件输出的文件名-->
            <FileNamePattern>/data/logs/temp.%d{yyyy-MM-dd}.log</FileNamePattern>
            <!--日志文件保留天数-->
            <MaxHistory>15</MaxHistory>
        </rollingPolicy>

        <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</pattern>
            <charset>UTF-8</charset>
        </encoder>
    </appender>

    <!-- 异步appender -->
    <appender name="ACCESS_FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <!--日志文件输出的文件名-->
            <FileNamePattern>/data/logs/access.%d{yyyy-MM-dd}.log</FileNamePattern>
            <!--日志文件保留天数-->
            <MaxHistory>7</MaxHistory>
        </rollingPolicy>

        <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</pattern>
            <charset>UTF-8</charset>
        </encoder>
    </appender>

    <!-- 异步输出 -->
    <appender name="ASYNC" class="ch.qos.logback.classic.AsyncAppender">
        <!-- 不丢失日志.默认的,如果队列的80%已满,则会丢弃TRACT、DEBUG、INFO级别的日志 -->
        <discardingThreshold>0</discardingThreshold>
        <!-- 更改默认的队列的深度,该值会影响性能.默认值为256 -->
        <queueSize>256</queueSize>
        <!-- 添加附加的appender,最多只能添加一个 -->
        <appender-ref ref="ACCESS_FILE"/>
    </appender>

    <logger name="ASYNC_ACCESS_LOG" level="info" additivity="false">
        <appender-ref ref="ASYNC" />
    </logger>
    <!-- 日志输出级别 -->
    <root level="INFO">
        <appender-ref ref="FILE" />
        <appender-ref ref="STDOUT" />
    </root>
</configuration>

在一些请求访问的日志，采用的异步处理方式，只需要在要打印日志的地方声明ASYNC_ACCESS_LOG即可。

private static Logger accesslogger = LoggerFactory.getLogger("ASYNC_ACCESS_LOG");
private static Logger logger = LoggerFactory.getLogger("当前类名");

accesslogger.info("异步打印");
logger.info("同步打印")