我想以编程方式在java中使用log4j创建一个自定义appender，它将日志存储在内存中（将定义特定大小，例如DEFAULT_SIZE = 20）&一旦内存已满（内存中有20个日志）创建一个json数组这些日志并将其发送到服务器。除了日志消息，我还想要诸如（类、文件名、行号、方法名、级别等）之类的信息。
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更新 ：：
以下是我为相同开发的源代码。我面临的问题是我得到行号、方法名、文件名作为“？”。我不明白是什么原因。
package com.any.logger;
import java.util.ArrayList;
import org.apache.log4j.AppenderSkeleton;
import org.apache.log4j.spi.LoggingEvent;
public class Log4jAppender extends AppenderSkeleton {
private static final int DEFAULT_BUFFER_SIZE = 20;
private ArrayList<LoggingEvent> buffer;
private int bufferSize;
public Log4jAppender() {
this.bufferSize = Log4jAppender.DEFAULT_BUFFER_SIZE;
this.buffer = new ArrayList<LoggingEvent>();
}
public void close() {
}
public boolean requiresLayout() {
return false;
}
@Override
protected void append(LoggingEvent loggingEvent) {
synchronized (buffer) {
if (buffer.size() >= bufferSize) {
try {
System.out.println("Hello");
Log4jService service = new Log4jService(new ArrayList<LoggingEvent>
(buffer));
System.out.println("Buff >");
service.start();
} catch (Exception e) {
System.err.println("Failed to write logs");
e.printStackTrace();
} finally {
buffer.clear();
}
}
}
buffer.add(loggingEvent);
}
}
package com.any.logger;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Iterator;
import org.apache.log4j.Level;
import org.apache.log4j.spi.LoggingEvent;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
@SuppressWarnings("rawtypes")
public class Log4jService implements Runnable {
private ArrayList<LoggingEvent> buffer;
private Thread t;
private boolean flag;
public Log4jService(ArrayList<LoggingEvent> buffer) {
this.buffer = new ArrayList<LoggingEvent>(buffer);
this.flag = false;
}
public void start() {
if (!flag) {
this.flag = true;
this.t = new Thread(this);
this.t.start();
}
}
public void run() {
if (flag) {
String json = getLogJson(buffer);
}
}
/**
* Method to get the json log
*
* @param logEvents
* arrayList of log events
* @return an String which is json file
* @throws JSONException
*/
private String getLogJson(ArrayList<LoggingEvent> logEvents) {
System.out.println("In getLogJson");
JSONObject logger = new JSONObject();
try {
JSONArray logs = new JSONArray();
String message = "";
String time = "";
String level = "";
String tag = "";
String file = "";
String exceptionName = "";
String exceptionReason = "";
String line = "";
String clas = "";
String method = "";
int index = 0;
SimpleDateFormat formatter=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
for (Iterator i = logEvents.iterator(); i.hasNext();) {
LoggingEvent logEvent = (LoggingEvent) i.next();
boolean chk=logEvent.locationInformationExists();
System.out.println("Check :: "+chk);
clas=logEvent.getClass().toString();
JSONObject log = new JSONObject();
message = logEvent.getMessage().toString();
time = String.valueOf(formatter.format(logEvent.getTimeStamp()));
level = logEvent.getLevel().toString();
if (chk) {
System.out.println("hello");
file = logEvent.getLocationInformation().getFileName();
line = logEvent.getLocationInformation().getLineNumber();
method = logEvent.getLocationInformation().getMethodName();
}
if (logEvent.getLevel() == Level.ERROR || logEvent.getLevel() ==
Level.FATAL) {
exceptionReason = message;
}
log.put("message", message);
log.put("time", time);
log.put("level", level);
log.put("tag", tag);
log.put("file", file);
log.put("exceptionName", exceptionName);
log.put("exceptionReason", exceptionReason);
log.put("line", line);
log.put("class", clas);
log.put("method", method);
logs.put(index, log);
index++;
}
JSONObject logsObj = new JSONObject();
logsObj.put("logs", logs);
logger.put("log", logsObj);
System.out.println("Logs Array :: " + logsObj);
System.out.println("Logger Object :: " + logger);
} catch (Exception e) {
e.printStackTrace();
}
return logger.toString();
}
}