package com.banksteel.log.demo.log4j; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.ObjectMapper; import org.apache.log4j.Layout; import org.apache.log4j.spi.LoggingEvent; import java.util.LinkedHashMap; import java.util.LinkedList; import java.util.List; import java.util.Map; /** * 扩展Log4j 1.x，使其支持 JsonLayout，与 log4j2.x 一样是基于Jackson进行解析，其格式也是完全参考 Log4J 2.x实现的。 * * @author 热血BUG男 * @version 1.0.0 * @since Created by gebug on 2016/5/8. */ public class JsonLayout extends Layout { private final ObjectMapper mapper = new ObjectMapper(); public String format(LoggingEvent loggingEvent) { String json; Map<String, Object> map = new LinkedHashMap<String, Object>(0); Map<String, Object> source = new LinkedHashMap<String, Object>(0); source.put("method", loggingEvent.getLocationInformation().getMethodName()); source.put("class", loggingEvent.getLocationInformation().getClassName()); source.put("file", loggingEvent.getLocationInformation().getFileName()); source.put("line", safeParse(loggingEvent.getLocationInformation().getLineNumber())); map.put("timeMillis", loggingEvent.getTimeStamp()); map.put("thread", loggingEvent.getThreadName()); map.put("level", loggingEvent.getLevel().toString()); map.put("loggerName", loggingEvent.getLocationInformation().getClassName()); map.put("source", source); map.put("endOfBatch", false); map.put("loggerFqcn", loggingEvent.getFQNOfLoggerClass()); map.put("message", safeToString(loggingEvent.getMessage())); map.put("thrown", formatThrowable(loggingEvent)); try { json = mapper.writeValueAsString(map); } catch (JsonProcessingException e) { return e.getMessage(); } return json; } private List<Map<String, Object>> formatThrowable(LoggingEvent le) { if (le.getThrowableInformation() == null || le.getThrowableInformation().getThrowable() == null) return null; List<Map<String, Object>> traces = new LinkedList<Map<String, Object>>(); Map<String, Object> throwableMap = new LinkedHashMap<String, Object>(0); StackTraceElement[] stackTraceElements = le.getThrowableInformation().getThrowable().getStackTrace(); for (StackTraceElement stackTraceElement : stackTraceElements) { throwableMap.put("class", stackTraceElement.getClassName()); throwableMap.put("file", stackTraceElement.getFileName()); throwableMap.put("line", stackTraceElement.getLineNumber()); throwableMap.put("method", stackTraceElement.getMethodName()); throwableMap.put("location", "?"); throwableMap.put("version", "?"); traces.add(throwableMap); } return traces; } private static String safeToString(Object obj) { if (obj == null) return null; try { return obj.toString(); } catch (Throwable t) { return "Error getting message: " + t.getMessage(); } } private static Integer safeParse(String obj) { try { return Integer.parseInt(obj.toString()); } catch (NumberFormatException t) { return null; } } public boolean ignoresThrowable() { return false; } public void activateOptions() { } }