Class related object

Question

How can I create a class related object??
In my code the class doens't find the log object(FileWriter)
example:
public class LogFile
public LogFile()
try
File outputFile = new File("/Java/Iss/log/BatchQuery.log");
FileWriter log = new FileWriter(outputFile);
catch (IOException exp)
System.out.println("Fatal error, can't write to log - "+exp.getMessage());
private static LogFile instance = new LogFile();
public static LogFile getInstance()
if(instance==null)
return instance = new LogFile();
else
return instance;
public static synchronized void write(String toLog)
log.write(toLog);
log.write("\n");
public static synchronized void close()
log.close();
}

Answer 1

Hi, shouldn t your code be like this ? :
public class LogFile
private static LogFile instance = new LogFile();
private FileWritter log = null;
public LogFile()
try
File outputFile = new File("/Java/Iss/log/BatchQuery.log");
log = new FileWriter(outputFile);
catch (IOException exp)
System.out.println("Fatal error, can't write to log - "+exp.getMessage());
public static LogFile getInstance()
if(instance==null)
return instance = new LogFile();
else
return instance;
public synchronized void write(String toLog)
log.write(toLog);
log.write("\n");
public synchronized void close()
log.close();
instance = null;
So now you have a static getInstance() method to recover the unique instance.
All others methods shouldn t be static so that they shall be called only if an instance has been generated.