我有一个名为“and.doc”的文件,它有大量的记录,每个记录都有这种形状
表达: defenition ;
所以我正在尝试
;
作为分隔符我正在使用此代码
try {
mf =new File("/home/agh/AndroidStudioProjects/Dicod/app/src/main/res/raw/and.doc");
inputFile = new Scanner(mf);
inputFile.useDelimiter(";");
while (inputFile.hasNext())
{
String x = inputFile.next();
Toast.makeText(getApplicationContext(),x,Toast.LENGTH_LONG).show();
//Splitting and adding to the databse
}
}
catch(FileNotFoundException e) {
e.printStackTrace();
}`
但我一直收到这个错误
06-23 04:38:28.771 23620-23620/? W/System.err: java.io.FileNotFoundException: /home/agh/AndroidStudioProjects/Dicod/app/src/main/res/raw/and.txt: open failed: ENOENT (No such file or directory)
06-23 04:38:28.771 23620-23620/? W/System.err: at libcore.io.IoBridge.open(IoBridge.java:465)
06-23 04:38:28.771 23620-23620/? W/System.err: at java.io.FileInputStream.<init>(FileInputStream.java:76)
06-23 04:38:28.771 23620-23620/? W/System.err: at java.util.Scanner.<init>(Scanner.java:158)
06-23 04:38:28.772 23620-23620/? W/System.err: at java.util.Scanner.<init>(Scanner.java:138)
06-23 04:38:28.772 23620-23620/? W/System.err: at com.example.agh.dicod.MainActivity.onCreate(MainActivity.java:28)
06-23 04:38:28.772 23620-23620/? W/System.err: at android.app.Activity.performCreate(Activity.java:5990)
06-23 04:38:28.772 23620-23620/? W/System.err: at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
06-23 04:38:28.772 23620-23620/? W/System.err: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2332)
06-23 04:38:28.772 23620-23620/? W/System.err: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2442)
06-23 04:38:28.772 23620-23620/? W/System.err: at android.app.ActivityThread.access$800(ActivityThread.java:156)
06-23 04:38:28.772 23620-23620/? W/System.err: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1351)
06-23 04:38:28.772 23620-23620/? W/System.err: at android.os.Handler.dispatchMessage(Handler.java:102)
06-23 04:38:28.772 23620-23620/? W/System.err: at android.os.Looper.loop(Looper.java:211)
06-23 04:38:28.772 23620-23620/? W/System.err: at android.app.ActivityThread.main(ActivityThread.java:5389)
06-23 04:38:28.772 23620-23620/? W/System.err: at java.lang.reflect.Method.invoke(Native Method)
06-23 04:38:28.772 23620-23620/? W/System.err: at java.lang.reflect.Method.invoke(Method.java:372)
06-23 04:38:28.772 23620-23620/? W/System.err: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1020)
06-23 04:38:28.772 23620-23620/? W/System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:815)
06-23 04:38:28.772 23620-23620/? W/System.err: Caused by: android.system.ErrnoException: open failed: ENOENT (No such file or directory)
06-23 04:38:28.773 23620-23620/? W/System.err: at libcore.io.Posix.open(Native Method)
06-23 04:38:28.773 23620-23620/? W/System.err: at libcore.io.BlockGuardOs.open(BlockGuardOs.java:186)
06-23 04:38:28.773 23620-23620/? W/System.err: at libcore.io.IoBridge.open(IoBridge.java:451)
06-23 04:38:28.773 23620-23620/? W/System.err: ... 17 more
答案 0 :(得分:1)
可能该文件不存在于所选目录中,或者未授予READ_EXTERNAL_STORAGE权限。
请注意,如果您的目标是API 23,则必须在运行时请求权限,而不仅仅是在Manifest中。
http://developer.android.com/training/permissions/requesting.html
答案 1 :(得分:0)
文件不存在。使用File()
类创建文件并将流写入其中。然后从中读取数据。尝试将权限添加到Manifest.xml并尝试一下。
<manifest ...>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"
/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"
/>
...
</manifest>
答案 2 :(得分:0)
@Abdul2511 i'm not sure i understand the write stream part
我想他的意思是这个虽然下面的代码将读取目录中存在的文本文件内容
作为参数传递的文件 myfile 应该是解压目录
// getdata() is the method which reads the data
// the data that is saved in byte format in the file
private String getdata(File myfile) {
FileInputStream fileInputStream = null;
try {
Log.i("file_read_send_to_getData_function",myfile.toString());
fileInputStream = new FileInputStream(myfile);
int i = -1;
StringBuffer buffer = new StringBuffer();
while ((i = fileInputStream.read()) != -1) {
buffer.append((char) i);
}
return buffer.toString();
} catch (Exception e) {
e.printStackTrace();
} finally {
if (fileInputStream != null) {
try {
fileInputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return null;
}
答案 3 :(得分:0)
我认为你正在传递的目录
"/home/agh/AndroidStudioProjects/Dicod/app/src/main/res/raw/and.doc"
存在于您的计算机上,但文件需要来自您的 android 设备或 android 模拟器的目录,这就是它抛出异常的原因
如果您的“and.doc”存在于您的 android 设备“/storage/emulated/0/Documents/”的共享外部存储中,那么我认为 File 将能够访问它,前提是您正确提取了目录>
以获取 sd 卡中文档文件夹的目录为例
File externalStorageDirectory = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS); //getting external storage directory
//it's another method to get the directory of a file inside the external storage of a device
File folder = new File(externalStorageDirectory + "/Password");
用您的文件夹名称代替“/Password”
答案 4 :(得分:0)
@Abdul2511 and somehow add them to my Sqlite Database
这是一个示例代码,您可以将其用作有关如何在 android 设备中从 sqlLITE 数据库保存和检索数据的参考
我们的 SQLite 数据库的根类是 SQLiteOpenHelper
extends SQLiteOpenHelper 会将 SQLite 数据库的根类导入到我们的数据库类中
//root class of our SQLite database is SQLiteOpenHelper
//extends SQLiteOpenHelper will import that root class of SQLite databse into our NoteDatabase class
public class NoteDatabase extends SQLiteOpenHelper {
private static final int DATABASEVERSION= 2;
private static final String DATABASE_NAME = "your database name";
private static final String DATABASE_TABLE = "your table name";
//column names for database
private static final String KEY_ID="id";
private static final String KEY_TITLE="expression";
private static final String KEY_CONTENT="defenition";
private static final String KEY_DATE="date";
private static final String KEY_TIME="time";
public static List<Note> allNotes;
//creating a constructor for our noteDatabase
NoteDatabase(Context context){
super(context,DATABASE_NAME,null,DATABASEVERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
//onCreate is called everytime the noteDatabase instance is created inside any class of this application
//creating the database table
String query = "CREATE TABLE " + DATABASE_TABLE +" ("+ KEY_ID +" INTEGER PRIMARY KEY AUTOINCREMENT , "+
KEY_TITLE+" TEXT, "+
KEY_CONTENT+" TEXT, "+
KEY_DATE+" TEXT, "+
KEY_TIME+" TEXT "+")";
db.execSQL(query);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
//checking for updates for our database
if(oldVersion>=newVersion){
return;
}
else{
//update the table if new version is available
db.execSQL("DROP TABLE IF EXISTS "+DATABASE_TABLE);
onCreate(db);
}
}
//it will take Note as a parameter this note will contain all the information like title, content , date and time
//and it will send that note from addnote activity to this node database
//Note note is the class that we just created
public long addnote(Note note){
//here we will insert the data
SQLiteDatabase db = this.getWritableDatabase();
//this contentValues will create a dictionary like structure
ContentValues contentValues = new ContentValues();
//now we can save our value to the keys that we have created in this class
// contentValues.put(KEY_ID,note.getID()); ***Do not insert Id inside SQLite instead auto increament the id to be unique
contentValues.put(KEY_TITLE,note.getTitle());
contentValues.put(KEY_CONTENT,note.getContent());
contentValues.put(KEY_TIME,note.getTime());
contentValues.put(KEY_DATE,note.getDate());
//now we will insert the data
//if the data is inserted successfully it will return the long value of the primary key
long ID = db.insert(DATABASE_TABLE,null,contentValues);
db.close();
Log.i("ID", Long.toString(ID));
return ID;
}
//this will get all the notes present in the database
//so that we can desplay it in our ListView
public List<Note> getNotes(){
//we will pull the data from the database using element's unique id
//select * from databse where id = whatever the id we have passed on here
//* means acessing all the data in that particular id elements
//creating an instance of our database
SQLiteDatabase db = this.getReadableDatabase();
//creating a list of generic type called Note
allNotes = new ArrayList<>();
String query = "SELECT * FROM "+DATABASE_TABLE;
Cursor cursor = db.rawQuery(query,null);
if(cursor.moveToFirst()){
//i am going to pull all the data from the database and pass that data onto our listView
do{
//now creating a new note and save the data from the database by using cursor
Note note = new Note();
note.setID(cursor.getLong(0));
note.setTitle(cursor.getString(1));
note.setContent(cursor.getString(2));
note.setDate(cursor.getString(3));
note.setTime(cursor.getString(4));
//adding this to lisView
allNotes.add(note);
}while(cursor.moveToNext());
}
return allNotes;
}
//updating the database
//replacing the old data with the updated data set inside the database
public int editNote(Note note){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(KEY_TITLE,note.getTitle());
contentValues.put(KEY_CONTENT,note.getContent());
contentValues.put(KEY_DATE,note.getDate());
contentValues.put(KEY_TIME,note.getTime());
return db.update(DATABASE_TABLE, contentValues,KEY_ID+"=?",new String[]{String.valueOf(note.getID())});
}
//the method will handel the deletion of the notes
//this method will be called from the noteDetails.class
void deleteNote(long id){
SQLiteDatabase db = this.getWritableDatabase();
db.delete(DATABASE_TABLE,KEY_ID+"=?",new String[]{String.valueOf(id)});
db.close();
}
}
注意:-