Log4j2打印一行日志时返回本行日志的字符串

import org.apache.logging.log4j.Level;
import org.apache.logging.log4j.core.impl.Log4jLogEvent;
import org.apache.logging.log4j.core.layout.PatternLayout;
import org.apache.logging.log4j.message.SimpleMessage;

/**
 * Created by lanhuajian on 2017/3/29.
 */
public class StringLogger {
    private String loggerName;
    private static String FQCN = StringLogger.class.getName();
    private static final PatternLayout PATTERN_LAYOUT = PatternLayout.newBuilder()
        .withPattern("%d %t %-5p [%c]%L %m%n")
        .build();

    private StringLogger(String loggerName) {
        this.loggerName = loggerName;
    }

    public static StringLogger getLogger(Class loggerClass) {
        return new StringLogger(loggerClass.getName());
    }

    public static StringLogger getLogger(String loggerName) {
        return new StringLogger(loggerName);
    }

    public String info(String msg) {
        return PATTERN_LAYOUT.toSerializable(buildEvent(msg, Level.INFO));
    }

    public String warn(String msg) {
        return PATTERN_LAYOUT.toSerializable(buildEvent(msg, Level.WARN));
    }

    public String debug(String msg) {
        return PATTERN_LAYOUT.toSerializable(buildEvent(msg, Level.DEBUG));
    }

    public String error(String msg) {
        return PATTERN_LAYOUT.toSerializable(buildEvent(msg, Level.ERROR));
    }

    private Log4jLogEvent buildEvent(String msg, Level level) {
        return Log4jLogEvent.newBuilder()
            .setIncludeLocation(true)
            .setLoggerName(loggerName)
            .setLoggerFqcn(FQCN)
            .setLevel(level)
            .setMessage(new SimpleMessage(msg))
            .build();
    }
}