Java Reader and Write Files

Read File

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;

File file = new File(FILE);
if (file.exists()) {
	//TODO
} else {
	//TODO
}

Read file

String FILE = "YOUR_LOG.log";
FileReader reader = new FileReader(FILE);
BufferedReader buffer = new BufferedReader(reader);
String line = null;
while ((line = buffer.readLine()) != null) {
	//TODO
	System.out.printf("%s\n", line);
}

buffer.close();

Write File

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

String FILE = "YOUR_LOG.log";
File file = new File(FILE);
if (file.exists()) {
	//TODO
} else {
	//TODO
}

Write File

String content = "Lorem ipsum dolor sit amet, consectetur adipiscing elit.";
String FILE = "YOUR_LOG.log";
FileWriter writer = new FileWriter(FILE);
BufferedWriter buffer = new BufferedWriter(writer);
buffer.write(content);
System.out.println("Success! You file is saved!");

buffer.close();

Exceptions

Some links for more in depth learning