Question

我正在尝试在外部目录上创建文件，如此

File sd = Environment.getExternalStorageDirectory();
if (sd == null) {
    Toast.makeText(mContext,
            "External Storage does not exist..No Export",
            Toast.LENGTH_LONG).show();
    return false;
}

File dataDir = new File(sd.getAbsolutePath()+ "/"+ DBHandler.folderName);
if(!dataDir.exists()){
    dataDir.mkdir();
}

File wbfile = new File(dataDir.getAbsolutePath()+ "/"+filename+".xls");

但我在少数设备上获得以下内容

java.io.FileNotFoundException: /storage/emulated/0/AplicationXX Data/report.xls: open failed: ENOENT (No such file or directory)
    at libcore.io.IoBridge.open(IoBridge.java:409)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:88)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:73)
    FileOutputStream out  = new FileOutputStream(wbFile);

任何想法可能是什么原因？

Answer 1

您必须检查设备存储（内部或外部），如下所示

boolean mExternalStorageAvailable ;
boolean mExternalStorageWriteable ;
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
    mExternalStorageAvailable = mExternalStorageWriteable = true;
} else if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {
    mExternalStorageAvailable = true;
    mExternalStorageWriteable = false;
} else {
    mExternalStorageAvailable = mExternalStorageWriteable = false;
    //internalstorage stuff
}

并在android清单文件中添加权限，

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

仅在某些设备上出现FileNotFoundException

1 个答案: