android访问自定义文件出现的问题

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原创最新推荐文章于 2026-08-01 10:38:30 发布 1.2k 阅读 AI 写同款· GEO 优化 ›

ContentProvider package com.example.tigongzhe; import android.R.integer; import android.content.ContentProvider; import android.content.ContentUris; import android.content.ContentValues; import android.content.Context; import android.content.UriMatcher; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteDatabase.CursorFactory; import android.database.sqlite.SQLiteOpenHelper; import android.net.Uri; import android.provider.SyncStateContract.Helpers; import android.text.Selection; import android.util.Log; public class provider extends ContentProvider { private MyOpenHelper myOpenHelper; private SQLiteDatabase sqLiteDatabase; private static final UriMatcher URI_MATCHER=new UriMatcher(UriMatcher.NO_MATCH); private final String TAG="provider"; private static final String authority="com.example.tigongzhe.provider"; static { URI_MATCHER.addURI(authority, "contacter", 1); URI_MATCHER.addURI(authority, "contacter/#", 2); } private static final String _id="id"; private static final String name="name"; private static final String num="num"; @Override public boolean onCreate() { // TODO Auto-generated method stub myOpenHelper=new MyOpenHelper(getContext(), DB_Name, null, version_1); return true; } @Override public String getType(Uri uri) { // TODO Auto-generated method stub int flag=URI_MATCHER.match(uri); switch (flag) { case 2: return "vnd.android.cursor.item/contacter"; case 1: return "vnd.android.dir.item/contacter"; default: throw new IllegalArgumentException("异常参数"); } } @Override public Uri insert(Uri uri, ContentValues values) { // TODO Auto-generated method stub sqLiteDatabase=myOpenHelper.getWritableDatabase(); int flag=URI_MATCHER.match(uri); switch (flag) { case 1: sqLiteDatabase.insert(Table_Name, name, values); break; case 2: long id=sqLiteDatabase.insert(Table_Name, name, values); ContentUris.withAppendedId(uri, id); default: break; } return uri; } @Override public Cursor query(Uri uri, String[] arg1, String arg2, String[] arg3, String arg4) { // TODO Auto-generated method stub Cursor cursor; sqLiteDatabase=myOpenHelper.getReadableDatabase(); int flag=URI_MATCHER.match(uri); switch (flag) { case 1: cursor=sqLiteDatabase.query(Table_Name, arg1, arg2, arg3, null, null,arg4); break; case 2: long id=ContentUris.parseId(uri); arg2=(arg2==null||"".equals(arg2.trim()))? _id+"="+id:arg2+"and"+_id+"="+id; cursor=sqLiteDatabase.query(Table_Name, arg1, arg2, arg3, null, null,arg4); default: throw new IllegalArgumentException("参数错误"); } return cursor; } @Override public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { // TODO Auto-generated method stub int num=0; sqLiteDatabase=myOpenHelper.getWritableDatabase(); int flag=URI_MATCHER.match(uri); switch (flag) { case 1: num=sqLiteDatabase.update(Table_Name, values,selection, selectionArgs); break; case 2: long id=ContentUris.parseId(uri); selection=(selection==null||"".equals(selection.trim()))? _id+"="+id:selection+"and"+_id+"="+id; num=sqLiteDatabase.update(Table_Name, values,selection, selectionArgs); default: break; } return num; } @Override public int delete(Uri uri, String selection, String[] selectionArgs) { // TODO Auto-generated method stub int num=0; sqLiteDatabase=myOpenHelper.getWritableDatabase(); int flag=URI_MATCHER.match(uri); switch (flag) { case 1: num=sqLiteDatabase.delete(Table_Name, selection, selectionArgs); break; case 2: long id=ContentUris.parseId(uri); selection=(selection==null||"".equals(selection.trim()))?_id+"="+id:selection+"and"+_id+"="+id; num=sqLiteDatabase.delete(Table_Name, selection, selectionArgs); default: throw new IllegalArgumentException("异常参数"); } return num; } private final String DB_Name = "mydb.db"; private final String Table_Name="contacter"; private final int version_1=1; private class MyOpenHelper extends SQLiteOpenHelper { public MyOpenHelper(Context context, String name, CursorFactory factory, int version) { super(context, name, factory, version); } /** * @description 当数据表无连接时创建新的表 */ @Override public void onCreate(SQLiteDatabase db) { String sql = " create table if not exists " + Table_Name + "(id INTEGER PRIMARY KEY AUTOINCREMENT," + "name varchar(64),num varchar(64))"; db.execSQL(sql); } /** * @description 当版本更新时触发的方法 */ @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { String sql = " drop table if exists " + Table_Name; db.execSQL(sql); onCreate(db); } } } +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.tigongzhe" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="18" /> <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name="com.example.tigongzhe.MainActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <provider android:name=".provider" android:authorities="com.example.tigongzhe.provider" android:multiprocess="true" android:exported="true" android:permission="com.example.tigongzhe.permission" ></provider> </application> <permission android:name="com.example.tigongzhe.permission" android:protectionLevel="normal"></permission> </manifest> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++package com.example.tigongzhe; import android.R.integer; import android.content.ContentProvider; import android.content.ContentUris; import android.content.ContentValues; import android.content.Context; import android.content.UriMatcher; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteDatabase.CursorFactory; import android.database.sqlite.SQLiteOpenHelper; import android.net.Uri; import android.provider.SyncStateContract.Helpers; import android.text.Selection; import android.util.Log; public class provider extends ContentProvider { private MyOpenHelper myOpenHelper; private SQLiteDatabase sqLiteDatabase; private static final UriMatcher URI_MATCHER=new UriMatcher(UriMatcher.NO_MATCH); private final String TAG="provider"; private static final String authority="com.example.tigongzhe.provider"; static { URI_MATCHER.addURI(authority, "contacter", 1); URI_MATCHER.addURI(authority, "contacter/#", 2); } private static final String _id="id"; private static final String name="name"; private static final String num="num"; @Override public boolean onCreate() { // TODO Auto-generated method stub myOpenHelper=new MyOpenHelper(getContext(), DB_Name, null, version_1); return true; } @Override public String getType(Uri uri) { // TODO Auto-generated method stub int flag=URI_MATCHER.match(uri); switch (flag) { case 2: return "vnd.android.cursor.item/contacter"; case 1: return "vnd.android.dir.item/contacter"; default: throw new IllegalArgumentException("异常参数"); } } @Override public Uri insert(Uri uri, ContentValues values) { // TODO Auto-generated method stub sqLiteDatabase=myOpenHelper.getWritableDatabase(); int flag=URI_MATCHER.match(uri); switch (flag) { case 1: sqLiteDatabase.insert(Table_Name, name, values); break; case 2: long id=sqLiteDatabase.insert(Table_Name, name, values); ContentUris.withAppendedId(uri, id); default: break; } return uri; } @Override public Cursor query(Uri uri, String[] arg1, String arg2, String[] arg3, String arg4) { // TODO Auto-generated method stub Cursor cursor; sqLiteDatabase=myOpenHelper.getReadableDatabase(); int flag=URI_MATCHER.match(uri); switch (flag) { case 1: cursor=sqLiteDatabase.query(Table_Name, arg1, arg2, arg3, null, null,arg4); break; case 2: long id=ContentUris.parseId(uri); arg2=(arg2==null||"".equals(arg2.trim()))? _id+"="+id:arg2+"and"+_id+"="+id; cursor=sqLiteDatabase.query(Table_Name, arg1, arg2, arg3, null, null,arg4); default: throw new IllegalArgumentException("参数错误"); } return cursor; } @Override public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { // TODO Auto-generated method stub int num=0; sqLiteDatabase=myOpenHelper.getWritableDatabase(); int flag=URI_MATCHER.match(uri); switch (flag) { case 1: num=sqLiteDatabase.update(Table_Name, values,selection, selectionArgs); break; case 2: long id=ContentUris.parseId(uri); selection=(selection==null||"".equals(selection.trim()))? _id+"="+id:selection+"and"+_id+"="+id; num=sqLiteDatabase.update(Table_Name, values,selection, selectionArgs); default: break; } return num; } @Override public int delete(Uri uri, String selection, String[] selectionArgs) { // TODO Auto-generated method stub int num=0; sqLiteDatabase=myOpenHelper.getWritableDatabase(); int flag=URI_MATCHER.match(uri); switch (flag) { case 1: num=sqLiteDatabase.delete(Table_Name, selection, selectionArgs); break; case 2: long id=ContentUris.parseId(uri); selection=(selection==null||"".equals(selection.trim()))?_id+"="+id:selection+"and"+_id+"="+id; num=sqLiteDatabase.delete(Table_Name, selection, selectionArgs); default: throw new IllegalArgumentException("异常参数"); } return num; } private final String DB_Name = "mydb.db"; private final String Table_Name="contacter"; private final int version_1=1; private class MyOpenHelper extends SQLiteOpenHelper { public MyOpenHelper(Context context, String name, CursorFactory factory, int version) { super(context, name, factory, version); } /** * @description 当数据表无连接时创建新的表 */ @Override public void onCreate(SQLiteDatabase db) { String sql = " create table if not exists " + Table_Name + "(id INTEGER PRIMARY KEY AUTOINCREMENT," + "name varchar(64),num varchar(64))"; db.execSQL(sql); } /** * @description 当版本更新时触发的方法 */ @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { String sql = " drop table if exists " + Table_Name; db.execSQL(sql); onCreate(db); } } } 立即下载

android访问自定义文件出现的问题

在android项目中自定义一个配置文件，并访问时出现找不到路径或文件不存在的问题并报如下异常：

/data/data/huazi.helloworld/files/user.properties (No such file or directory)

分析：形同sharpreference的文件一般都是保存在“/data/data/huazi.helloworld/files/”这个路径下，虚拟机在查找相关文件时也是在路径下查找。自己在项目中新建的文件，都是保存在项目文件夹下，所以找不到相关文件。

解决办法：将相关的配置文件导入到虚拟机上去。

在DDMS的File Explorer中将相关的文件导入到/data/data/huazi.helloworld/files 文件夹中去。找到项目的文件夹后

点击手机图标导入相关文件即可。（注意android中的文件的访问权限的问题）

收录于

android

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#android #虚拟机 #file #手机

版权声明：本文为博主原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接和本声明。

Android7.0 自定义文件管理器获取文件夹路径 自定义文件管理器模仿真实文件管理器，里面的逻辑皆可以自己手动修改，应为需所以去写了个获取文件夹路径demo,本人手机Android7.0亲测。立即下载

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