对于想了解PHP文件夹读取的读者，本文将是一篇不可错过的文章，我们将详细介绍php读取文件夹文件名，并且为您提供关于AndroidSQLite从外部存储文件夹读取数据库、Android使用C(ndk)
对于想了解PHP 文件夹读取的读者，本文将是一篇不可错过的文章，我们将详细介绍php读取文件夹文件名，并且为您提供关于Android SQLite从外部存储文件夹读取数据库、Android使用C(ndk)从资产文件夹读取文本文件、Java从resources文件夹读取配置文件、maven下resource文件夹读取文件的方法的有价值信息。
本文目录一览：- PHP 文件夹读取（php读取文件夹文件名）
- Android SQLite从外部存储文件夹读取数据库
- Android使用C(ndk)从资产文件夹读取文本文件
- Java从resources文件夹读取配置文件
- maven下resource文件夹读取文件的方法
PHP 文件夹读取（php读取文件夹文件名）
方法一
读取某个文件夹下的内容， opendir readdir结合while循环过滤，得到当前文件夹和父文件夹来操作
function readFolderFiles($path)
{
$list = [];
$resource = opendir($path);
while ($file = readdir($resource))
{
//排除根目录
if ($file != ".." && $file != ".")
{
//根目录下的文件
$list[] = $file;
}
}
closedir($resource);
return $list ? $list : [];
}
方法二
scandir函数 可以扫描文件夹下内容 代替while循环读取（scandir，默认升序。设置降序scandir(path,1)）
function scandirFolderfiles($path)
{
$list = scandir($path);
return $list;
}
Android SQLite从外部存储文件夹读取数据库
目前,我正在开发一个Android应用程序,我的要求是从外部位置的固定位置读取sqlite数据库.但我无法打开数据库.我正在尝试的代码如下：
DatabaseHelper：
import android.content.Context;
import android.database.sqlException;
import android.database.sqlite.sqliteDatabase;
import android.database.sqlite.sqliteOpenHelper;
import android.os.Environment;
import android.util.Log;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
public class DataBaseHelper extends sqliteOpenHelper
{
private static final int DB_VERSION = 1;
//private static final String DB_NAME = "MedRec.db";
private static final String DB_NAME = "MedRec";
public DataBaseHelper(Context context)
{
//super(context,DB_NAME,null,DB_VERSION);
super(context, Environment.getExternalStorageDirectory() + "/EMIS/MedRec", null, 1);
//super(context, context.getExternalFilesDir(null).getAbsolutePath() + "/EMIS/" + DB_NAME, null, 1);
Log.d("DB_PATH:", context.getExternalFilesDir(null).getAbsolutePath() + "/EMIS/" + DB_NAME);
}
@Override
public void onCreate(sqliteDatabase database)
{
Log.d("CREATING TABLE :", "SUCCESS");
}
@Override
public void onUpgrade(sqliteDatabase database,int oldVersion,int newVersion)
{
Log.d("UPGRADING TABLE :", "SUCCESS");
onCreate(database);
}
}
PatientDataSource：
package com.medrecordapp.main.database;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlException;
import android.database.sqlite.sqliteDatabase;
import android.util.Log;
import com.medrecordapp.main.model.Patient;
import java.util.ArrayList;
public class PatientDataSource
{
private sqliteDatabase database;
private DataBaseHelper dbHelper;
public static final String TABLE_PATIENT = "Patient";
public final static String ID = "_id";
public final static String PATIENT_ID = "PatientID";
public final static String NHS_NUMBER = "NHSNumber";
public final static String FirsT_NAME = "FirstName";
public final static String LAST_NAME = "LastName";
public final static String CATEGORY = "category";
public final static String PHONE_1 = "phone1";
public final static String PHONE_2 = "phone2";
public final static String PHOTO_FILE = "photofile";
public final static String PROFESSION = "profession";
public final static String STREET = "Street";
public final static String VILLAGE = "Village";
public final static String TOWN = "Town";
public final static String COUNTRY = "County";
public final static String POST_CODE = "PostCode";
public final static String COMMENT = "comment";
public final static String E1 = "E1";
public final static String E2 = "E2";
public final static String E3 = "E3";
public final static String E4 = "E4";
public final static String E5 = "E5";
public final static String UPD_DATE = "upddate";
public PatientDataSource(Context context)
{
dbHelper = new DataBaseHelper(context);
}
public void open() throws sqlException
{
///dbHelper.openDataBase();
//dbHelper.getReadableDatabase();
//database = dbHelper.getReadableDatabase();
database = dbHelper.getWritableDatabase();
}
public void close()
{
dbHelper.close();
}
public long addPatient(Patient patient)
{
open();
ContentValues patientValue = new ContentValues();
patientValue.put(PATIENT_ID, patient.getPatientId());
patientValue.put(NHS_NUMBER, patient.getNhsNumber());
patientValue.put(FirsT_NAME, patient.getFirstName());
patientValue.put(LAST_NAME, patient.getFirstName());
patientValue.put(CATEGORY, patient.getFirstName());
patientValue.put(PHONE_1, patient.getFirstName());
patientValue.put(PHONE_2, patient.getFirstName());
patientValue.put(PHOTO_FILE, patient.getFirstName());
patientValue.put(PROFESSION, patient.getFirstName());
patientValue.put(STREET, patient.getFirstName());
patientValue.put(VILLAGE, patient.getFirstName());
patientValue.put(TOWN, patient.getFirstName());
patientValue.put(COUNTRY, patient.getFirstName());
patientValue.put(POST_CODE, patient.getFirstName());
patientValue.put(COMMENT, patient.getFirstName());
patientValue.put(E1, patient.getFirstName());
patientValue.put(E2, patient.getFirstName());
patientValue.put(E3, patient.getFirstName());
patientValue.put(E4, patient.getFirstName());
patientValue.put(E5, patient.getFirstName());
patientValue.put(UPD_DATE, patient.getFirstName());
long insertId = database.insert(TABLE_PATIENT,null,patientValue);
Log.d("RESULT :", insertId + "");
close();
return insertId;
}
public ArrayList<Patient> loadPatient()
{
open();
ArrayList<Patient> patientList = new ArrayList<Patient>();
Cursor cursor = database.rawQuery(" SELECT * FROM Patient " , null );
cursor.movetoFirst();
while (!cursor.isAfterLast())
{
Patient patient = new Patient(
cursor.getInt(cursor.getColumnIndex("_id")) , cursor.getString(cursor.getColumnIndex("PatientID")), cursor.getString(2), cursor.getString(3),
cursor.getString(4), cursor.getString(5), cursor.getString(6), cursor.getString(6),
cursor.getString(7), cursor.getString(8), cursor.getString(9), cursor.getString(10),
cursor.getString(11), cursor.getString(12), cursor.getString(13), cursor.getString(14),
cursor.getString(15), cursor.getString(16), cursor.getString(17), cursor.getString(18),
cursor.getString(19), cursor.getString(20), cursor.getString(21)
);
patientList.add(patient);
cursor.movetoNext();
}
cursor.close();
close();
return patientList;
}
public ArrayList<Patient> loadPatient(String patientId)
{
open();
ArrayList<Patient> patientList = new ArrayList<Patient>();
Cursor cursor = database.rawQuery(" SELECT * FROM Patient WHERE _id = ?" , new String[]{ patientId } );
cursor.movetoFirst();
while (!cursor.isAfterLast())
{
Patient patient = new Patient(
cursor.getInt(0) , cursor.getString(1), cursor.getString(2), cursor.getString(3),
cursor.getString(4), cursor.getString(5), cursor.getString(6), cursor.getString(6),
cursor.getString(7), cursor.getString(8), cursor.getString(9), cursor.getString(10),
cursor.getString(11), cursor.getString(12), cursor.getString(13), cursor.getString(14),
cursor.getString(15), cursor.getString(16), cursor.getString(17), cursor.getString(18),
cursor.getString(19), cursor.getString(20), cursor.getString(21)
);
patientList.add(patient);
cursor.movetoNext();
}
cursor.close();
close();
return patientList;
}
/*public void updateFavorites(Favorites favoritesInfo,String id)
{
open();
ContentValues favoritesInfovalues = new ContentValues();
String strFilter = "id = " + id;
favoritesInfovalues.put(ID, favoritesInfo.getFavoritesId());
favoritesInfovalues.put(JOKES_ID, favoritesInfo.getJokesId());
//Update using the sqlite update function.
database.update(TABLE_FAVORITES, favoritesInfovalues, strFilter, null);
//Close the opened database connection
close();
}*/
public boolean deletePatient(String id)
{
open();
String strFilter = "_id =" + id;
boolean res = database.delete(TABLE_PATIENT, strFilter , null) > 0;
close();
return res;
}
}
清单Permissions：
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
但我得到的是以下例外情况：
10-25 12:49:25.838 30502-30502/com.medrecodapp.main.database E/sqliteLog﹕ (14) cannot open file at line 31278 of [2ef4f3a5b1]
10-25 12:49:25.838 30502-30502/com.medrecodapp.main.database E/sqliteLog﹕ (14) os_unix.c:31278: (2) open(/storage/emulated/0/EMIS/MedRec) -
10-25 12:49:25.838 30502-30502/com.medrecodapp.main.database E/sqliteConnection﹕ DB info: sqlite3_open_v2, path: /storage/emulated/0/EMIS/MedRec, flag: 6, ret: 14
10-25 12:49:25.838 30502-30502/com.medrecodapp.main.database E/sqliteConnection﹕ DB info: errno = 2, errno message = No such file or directory
10-25 12:49:25.839 30502-30502/com.medrecodapp.main.database E/sqliteDatabase﹕ Failed to open database '/storage/emulated/0/EMIS/MedRec'.
android.database.sqlite.sqliteCantOpenDatabaseException: unkNown error (code 14): Could not open database
at android.database.sqlite.sqliteConnection.nativeOpen(Native Method)
at android.database.sqlite.sqliteConnection.open(sqliteConnection.java:237)
at android.database.sqlite.sqliteConnection.open(sqliteConnection.java:221)
at android.database.sqlite.sqliteConnectionPool.openConnectionLocked(sqliteConnectionPool.java:468)
at android.database.sqlite.sqliteConnectionPool.open(sqliteConnectionPool.java:190)
at android.database.sqlite.sqliteConnectionPool.open(sqliteConnectionPool.java:182)
at android.database.sqlite.sqliteDatabase.openInner(sqliteDatabase.java:876)
at android.database.sqlite.sqliteDatabase.open(sqliteDatabase.java:856)
at android.database.sqlite.sqliteDatabase.openDatabase(sqliteDatabase.java:754)
at android.app.ContextImpl.openorCreateDatabase(ContextImpl.java:579)
at android.content.Contextwrapper.openorCreateDatabase(Contextwrapper.java:269)
at android.database.sqlite.sqliteOpenHelper.getDatabaseLocked(sqliteOpenHelper.java:223)
at android.database.sqlite.sqliteOpenHelper.getWritableDatabase(sqliteOpenHelper.java:163)
at com.medrecordapp.main.database.PatientDataSource.open(PatientDataSource.java:53)
at com.medrecordapp.main.database.PatientDataSource.loadPatient(PatientDataSource.java:100)
at com.medrecordapp.main.activity.PatientListActivity.onCreate(PatientListActivity.java:90)
at android.app.Activity.performCreate(Activity.java:6262)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1125)
at android.app.ActivityThread.performlaunchActivity(ActivityThread.java:2462)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2569)
at android.app.ActivityThread.access$900(ActivityThread.java:150)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1399)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:168)
at android.app.ActivityThread.main(ActivityThread.java:5885)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:819)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:709)
10-25 12:49:25.840 30502-30502/com.medrecodapp.main.database E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.medrecodapp.main.database, PID: 30502
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.medrecodapp.main.database/com.medrecordapp.main.activity.PatientListActivity}: android.database.sqlite.sqliteCantOpenDatabaseException: unkNown error (code 14): Could not open database
at android.app.ActivityThread.performlaunchActivity(ActivityThread.java:2509)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2569)
at android.app.ActivityThread.access$900(ActivityThread.java:150)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1399)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:168)
at android.app.ActivityThread.main(ActivityThread.java:5885)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:819)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:709)
Caused by: android.database.sqlite.sqliteCantOpenDatabaseException: unkNown error (code 14): Could not open database
at android.database.sqlite.sqliteConnection.nativeOpen(Native Method)
at android.database.sqlite.sqliteConnection.open(sqliteConnection.java:237)
at android.database.sqlite.sqliteConnection.open(sqliteConnection.java:221)
at android.database.sqlite.sqliteConnectionPool.openConnectionLocked(sqliteConnectionPool.java:468)
at android.database.sqlite.sqliteConnectionPool.open(sqliteConnectionPool.java:190)
at android.database.sqlite.sqliteConnectionPool.open(sqliteConnectionPool.java:182)
at android.database.sqlite.sqliteDatabase.openInner(sqliteDatabase.java:876)
at android.database.sqlite.sqliteDatabase.open(sqliteDatabase.java:856)
at android.database.sqlite.sqliteDatabase.openDatabase(sqliteDatabase.java:754)
at android.app.ContextImpl.openorCreateDatabase(ContextImpl.java:579)
at android.content.Contextwrapper.openorCreateDatabase(Contextwrapper.java:269)
at android.database.sqlite.sqliteOpenHelper.getDatabaseLocked(sqliteOpenHelper.java:223)
at android.database.sqlite.sqliteOpenHelper.getWritableDatabase(sqliteOpenHelper.java:163)
at com.medrecordapp.main.database.PatientDataSource.open(PatientDataSource.java:53)
at com.medrecordapp.main.database.PatientDataSource.loadPatient(PatientDataSource.java:100)
at com.medrecordapp.main.activity.PatientListActivity.onCreate(PatientListActivity.java:90)
at android.app.Activity.performCreate(Activity.java:6262)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1125)
at android.app.ActivityThread.performlaunchActivity(ActivityThread.java:2462)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2569)
at android.app.ActivityThread.access$900(ActivityThread.java:150)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1399)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:168)
at android.app.ActivityThread.main(ActivityThread.java:5885)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:819)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:709)
该文件已放入以下文件夹中：
我要提到的最后一件事是我在HTC 10上测试它,它没有任何外部存储,而是模拟存储.任何帮助将受到高度赞赏.
谢谢
解决方法:
取自@k3b answers：
如果提供自定义ContextClass并且您具有对目标目录的写访问权,则可以将sqliteOpenHelper与自定义路径一起使用.
public class DatabaseHelper extends sqliteOpenHelper {
private static final int DATABASE_VERSION = 3;
.....
DatabaseHelper(final Context context, String databaseName) {
super(new DatabaseContext(context), databaseName, null, DATABASE_VERSION);
}
}
这是自定义DatabaseContext类,可以完成所有的魔术：
class DatabaseContext extends Contextwrapper {
private static final String DEBUG_CONTEXT = "DatabaseContext";
public DatabaseContext(Context base) {
super(base);
}
@Override
public File getDatabasePath(String name) {
File sdcard = Environment.getExternalStorageDirectory();
String dbfile = sdcard.getAbsolutePath() + File.separator+ "databases" + File.separator + name;
if (!dbfile.endsWith(".db")) {
dbfile += ".db" ;
}
File result = new File(dbfile);
if (!result.getParentFile().exists()) {
result.getParentFile().mkdirs();
}
if (Log.isLoggable(DEBUG_CONTEXT, Log.WARN)) {
Log.w(DEBUG_CONTEXT, "getDatabasePath(" + name + ") = " + result.getAbsolutePath());
}
return result;
}
/* this version is called for android devices >= api-11. thank to @damccull for fixing this. */
@Override
public sqliteDatabase openorCreateDatabase(String name, int mode, sqliteDatabase.CursorFactory factory, DatabaseErrorHandler errorHandler) {
return openorCreateDatabase(name,mode, factory);
}
/* this version is called for android devices < api-11 */
@Override
public sqliteDatabase openorCreateDatabase(String name, int mode, sqliteDatabase.CursorFactory factory) {
sqliteDatabase result = sqliteDatabase.openorCreateDatabase(getDatabasePath(name), null);
// sqliteDatabase result = super.openorCreateDatabase(name, mode, factory);
if (Log.isLoggable(DEBUG_CONTEXT, Log.WARN)) {
Log.w(DEBUG_CONTEXT, "openorCreateDatabase(" + name + ",,) = " + result.getPath());
}
return result;
}
}
这是如何运作的：
普通的Android应用程序拥有相对于app文件夹的本地数据库文件.通过使用覆盖了getDatabasePath()的客户上下文,数据库现在相对于SD卡上的不同目录.
Android使用C(ndk)从资产文件夹读取文本文件
我需要从
android中的资产文件夹中读取文本文件,通过互联网进行搜索,我发现有来自android 2.3以上的asset_manager api.由于我只针对平板电脑设备,这是非常有用的.但是,由于我不是C语言的专家,我无法找到任何关于如何使用文件描述符读/写文件的例子.我发现许多使用FILE *的例子(文件指针)
My goal is to decrypt a js file from asset folder which is encrypted
using C (for securing the code),as js code is visible if end user
decompiled my apk. Because asset folder is inside zip file is it possible to do?
解决方法
这是使用asset_manager ndk lib从android资产文件夹中读取文件的代码
AAssetManager* mgr = AAssetManager_fromJava(env,assetManager);
AAsset* asset = AAssetManager_open(mgr,(const char *) js,AASSET_MODE_UNKNowN);
if (NULL == asset) {
__android_log_print(ANDROID_LOG_ERROR,NF_LOG_TAG,"_ASSET_NOT_FOUND_");
return JNI_FALSE;
}
long size = AAsset_getLength(asset);
char* buffer = (char*) malloc (sizeof(char)*size);
AAsset_read (asset,buffer,size);
__android_log_print(ANDROID_LOG_ERROR,buffer);
AAsset_close(asset);
添加以下行到我的Android.mk
# for native asset manager LOCAL_LDLIBS += -landroid
并且不要忘记源文件中的include
#include <android/asset_manager.h>
Java从resources文件夹读取配置文件
列举了2种方式，第一种是绝对路径，就是写死路径，不推荐
第二种是相对路径，使用到了ClassLoader
package com.StadyJava.day22;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.Properties;
public class LoadResourceDemo {
public static void main(String[] args) throws Exception{
test2();
}
//方式1，写死路径。这种方式可以读取文件的内容。但是不要使用这种方法，没有路径是写死的
public static void test1() throws Exception{
Properties p=new Properties();
InputStream inStream=new FileInputStream("F:\\Study Java\\ch1helloworld\\src\\main\\resources\\properties");
p.load(inStream);
System.out.println(p);
}
//方式2，采用相对路径。相对于Classpath的根路径。ClassLoader就是src文件夹下，resources文件夹一般放资源文件，比如配置文件
public static void test2() throws Exception{
Properties p=new Properties();
//ClassLoader loader=LoadResourceDemo.class.getClassLoader();这种方式也可以获取ClassLoader，但是写出了类名，不推荐
ClassLoader loader=Thread.currentThread().getContextClassLoader();
InputStream inStream=loader.getResourceAsStream("properties");
p.load(inStream);
System.out.println(p);
}
}
maven下resource文件夹读取文件的方法
在maven工程中，我们会将配置文件放到，src/main/resources 下面，例如
我们需要确认resource 下的文件 编译之后存放的位置
它编译的路径直接位于classes下面，这个路径其实就是classPath的路径，所以，在resources 根目录下的配置文件其实就是 classPath的路径:
- public static void main(String[] args) throws ParserConfigurationException, Exception{
- ClassLoader classLoader = TestDom.class.getClassLoader();
- URL resource = classLoader.getResource("test.xml");
- String path = resource.getPath();
- System.out.println(path);
- InputStream resourceAsStream = classLoader.getResourceAsStream("test.xml");
在一个maven工程下，通常有resource文件夹，其中再存放相关的资源文件,
比如resource下有个files文件夹，其中有个文件叫test.txt，则读取方法之一为：
Java代码 收藏代码
private String getFile(String fileName) {
StringBuilder result = new StringBuilder("");
/
ClassLoader classLoader = getClass().getClassLoader();
File file = new File(classLoader.getResource(fileName).getFile());
try (Scanner scanner = new Scanner(file)) {
while (scanner.hasNextLine()) {
String line = scanner.nextLine();
result.append(line).append("\n");
}
scanner.close();
} catch (IOException e) {
e.printStackTrace();
}
return result.toString();
}
调用方法为:obj.getFile("file/test.txt")
2 使用apache commons的io包：
Java代码 收藏代码
String result = "";
ClassLoader classLoader = getClass().getClassLoader();
try {
result = IOUtils.toString(classLoader.getResourceAsStream(fileName));
} catch (IOException e) {
e.printStackTrace();
}
return result;
}
可以看到apache commons io包真方便
今天关于PHP 文件夹读取和php读取文件夹文件名的介绍到此结束，谢谢您的阅读，有关Android SQLite从外部存储文件夹读取数据库、Android使用C(ndk)从资产文件夹读取文本文件、Java从resources文件夹读取配置文件、maven下resource文件夹读取文件的方法等更多相关知识的信息可以在本站进行查询。
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