为了能够更好的在ELK平台分析日志，所以配置输出json格式的日志。

配置maven的依赖

      <dependency>
          <groupId>ch.qos.logback</groupId>
          <artifactId>logback-classic</artifactId>
          <version>1.0.13</version>
      </dependency>
      <dependency>
          <groupId>net.logstash.logback</groupId>
          <artifactId>logstash-logback-encoder</artifactId>
          <version>4.7</version>
      </dependency>

配置logback.xml

    <appender name="LOGSTASH" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <encoder class="net.logstash.logback.encoder.LogstashEncoder">
            <charset>utf8</charset>
        </encoder>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>D:\home\logs\ssm2logstash-%d{yyyy-MM-dd}.log</fileNamePattern>
        </rollingPolicy>
    </appender>