Android外部文件不一致出现

Question

我正在使用IntentService将单个NMEA字符串附加到存储在Android设备上的外部公共存储中的日志文件中，但我的行为不一致。

当设备连接进行USB调试时，首先不会出现日志文件。我读到许多Android设备在通过USB连接时无法写入外部存储，但即使从USB断开连接，也可能需要多次打开和关闭它并在日志文件出现在文件系统之前重新运行应用程序。如果我不清除日志，我仍然需要重新启动手机才能再次开始追加该文件。

如何让文件每次都显示一致？

import android.app.IntentService;
import android.content.Intent;


public class LogFileService extends IntentService {

    DebugLog debug = new DebugLog("LogFileService");

    public static final String GPS_STR = "GPS_STR";
    public static final String FILE_PATH = "FILE_PATH";
    public static final String FILE_NAME = "gps_data.txt";




    public LogFileService() {
        super("LogFileService");
    }

    @Override
    protected void onHandleIntent(Intent intent) {


        debug.log("Handling intent");

        String data = intent.getStringExtra(GPS_STR);

        debug.log("Writing " + data);

        GpsLogFile logFile = new GpsLogFile(FILE_NAME);
        logFile.open();
        logFile.write(data);
        logFile.close();
    }

    @Override
    public void onCreate() {
        super.onCreate();

        debug.log("Created");
    }


}

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;

import android.content.Context;
import android.os.Environment;

public class GpsLogFile {

    DebugLog debug = new DebugLog("LogFile");


    private File filePath = Environment.getExternalStoragePublicDirectory(
            Environment.DIRECTORY_DOWNLOADS
    );

    private File logFile = null;
    private String fileName = null;


    private PrintWriter fileOut = null;

    public GpsLogFile(String name) {
        fileName = name;
    }

    public void open() {

        try {

            filePath.mkdirs();  

            if (!isExternalMediaAvailable()) {
                throw new IOException("External media not available.");
            }
            logFile = new File(filePath, fileName);
            //logFile.mkdirs();
            if (!logFile.exists()) {
                logFile.createNewFile();
            }
            fileOut = new PrintWriter(
                    new FileOutputStream(logFile.getAbsolutePath(), true)
            );

        } catch (IOException e) {
            debug.log("Unable to open file.");
            debug.log(e.getMessage());
        }

    }

    public void write(String data) {

        debug.log("Writing to " + logFile.getAbsolutePath() + " " + data);

        try {
            fileOut.write(data);
            //fileOut.newLine();
            checkPrintWriterError(fileOut);
            fileOut.flush();

        } catch (IOException e) {
            debug.log("Unable to write");
            debug.log(e.getMessage());
        }
    }

    public void close() {
        if (null != fileOut) {
            try {
                fileOut.close();
                checkPrintWriterError(fileOut);
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

    private void checkPrintWriterError(PrintWriter writer) throws IOException {
        if (true == writer.checkError()) {
            throw new IOException("Print writer error.");
        }
    }
}