ClientLogger.java

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;
import java.time.LocalDateTime;

public class ClientLogger {
    private final Path logPath;

    public ClientLogger(Path logPath) {
        this.logPath = logPath;
    }

    public void write(String message) throws IOException {
        String full = LocalDateTime.now().toString().concat(" ").concat(message).concat("\n");
        if (!Files.exists(logPath)) {
           Files.createFile(logPath);
        }

        Files.write(logPath, full.getBytes(), StandardOpenOption.APPEND);
    }

    public void writeError(String message) {
        try {
            String full = LocalDateTime.now().toString().concat(": ERROR - ").concat(message).concat("\n");
            Files.write(logPath, full.getBytes(), StandardOpenOption.APPEND);
        } catch (IOException ioe) {
            ioe.printStackTrace();
            throw new RuntimeException("Failure when writing to logs.");
        }
    }
}