Java 线程中记录日志

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;
public class ThreadLog
{
private final static String _detailLogFile = "log"+File.separator+"detail";
private static boolean _logFlag = true;
private static HashMap<String, String> _threadDetailFile = new HashMap<String, String>();
private static int _fileIndex = 1;
private static void generateLogFile(String fileName)
{
String absoluteFilePath = ProjectConfig.getNFSCAbsolutePath() +
File.separator + "log" + File.separator +fileName;

_threadDetailFile.put(String.valueOf(Thread.currentThread().getId()) + "_" + fileName,
absoluteFilePath);

File file = new File(absoluteFilePath);
//create a new file
if(!file.exists())
{
try
{
file.createNewFile();
}
catch(IOException ex)
{
ExceptionDefaultHandler.handle(ex, "threadlog.log");
}
}
}
private static void generateLogFile()
{
String fileName = _detailLogFile +
DateTimeUtil.getCurrentDateFormatString("yyyyMMddHHmmss") +"_"+
String.valueOf(_fileIndex++)+ ".log";

String absoluteFilePath = ProjectConfig.getNFSCAbsolutePath() +
File.separator + fileName;

_threadDetailFile.put(String.valueOf(Thread.currentThread().getId()), absoluteFilePath);

File file = new File(absoluteFilePath);
//if the file exist, we have to remove it.
if(file.exists())
{
try
{
file.delete();
}
catch(SecurityException ex)
{
ExceptionDefaultHandler.handle(ex, "threadlog.log");
}
}
//create a new file
try
{
file.createNewFile();
}
catch(IOException ex)
{
ExceptionDefaultHandler.handle(ex, "threadlog.log");
}
}
private static boolean hasThreadLogFile()
{
return _threadDetailFile.containsKey(String.valueOf(Thread.currentThread().getId()));
}
private static boolean hasThreadLogFi