Android App中各种数据保存方式的使用实例总结

<?xml version='1.0' encoding='utf-8' standalone='yes' ?><map><int name="count" value="3" /><string name="time">写入日期:2013年10月07日,时间:11:28:09</string></map>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:tools="http://schemas.android.com/tools"  android:layout_width="match_parent"  android:layout_height="match_parent"   android:orientation="vertical"  tools:context=".MainActivity" >   <Button   android:id="@+id/write"   android:layout_width="wrap_content"   android:layout_height="wrap_content"    android:layout_gravity="center_horizontal"   android:text="写入数据" />   <Button   android:id="@+id/read"   android:layout_width="wrap_content"   android:layout_height="wrap_content"    android:layout_gravity="center_horizontal"   android:text="读入数据" />  <TextView   android:id="@+id/txtCount"   android:layout_width="match_parent"   android:layout_height="wrap_content"/>   <TextView   android:id="@+id/txt1"   android:layout_width="match_parent"   android:layout_height="wrap_content" />  </LinearLayout> 

package com.android.xiong.sharepreferencestest;  import java.text.SimpleDateFormat; import java.util.Date;  import android.app.Activity; import android.content.Context; import android.content.SharedPreferences; import android.content.SharedPreferences.Editor; import android.os.Bundle; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.TextView;  public class MainActivity extends Activity {   private Button write;  private Button read;   private TextView txt1;  private TextView countTxt;    SharedPreferences share ;    Editor editor;   int countO=0;  @Override  protected void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   setContentView(R.layout.activity_main);   //获取SharedPreferences对象   share = this.getSharedPreferences("share",     Context.MODE_PRIVATE);   //获取Editor对象   editor = share.edit();   write = (Button) findViewById(R.id.write);   read = (Button) findViewById(R.id.read);   txt1 = (TextView) findViewById(R.id.txt1);   countTxt=(TextView)findViewById(R.id.txtCount);   //获取share中key为count的值   countO=share.getInt("count", 0);   countO++;   //修改share中key为count的值   editor.putInt("count", countO);   //提交修改   editor.commit();   System.out.println("该应用程序使用了:"+countO+"次");   countTxt.setText("该应用程序使用了:"+countO+"次");      OnClickListener writeListener = new OnClickListener() {     @Override    public void onClick(View v) {     // TODO Auto-generated method stub      SimpleDateFormat data = new SimpleDateFormat(       "写入日期:yyyy年MM月dd日,时间:hh:mm:ss");     editor.putString("time",       data.format(new Date()));     editor.commit();     }   };   OnClickListener readListener=new OnClickListener() {        @Override    public void onClick(View v) {     // TODO Auto-generated method stub     if(!share.contains("share")){      txt1.setText(share.getString("time", null));     }         }   };   write.setOnClickListener(writeListener);   read.setOnClickListener(readListener);   }   @Override  public boolean onCreateOptionsMenu(Menu menu) {   // Inflate the menu; this adds items to the action bar if it is present.   getMenuInflater().inflate(R.menu.main, menu);   return true;  }  } 

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:tools="http://schemas.android.com/tools"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:layout_gravity="center_horizontal"  android:orientation="vertical"  tools:context=".MainActivity" >  <EditText   android:layout_width="match_parent"   android:layout_height="wrap_content"   android:id="@+id/ed1"   android:inputType="textMultiLine"/>  <Button   android:id="@+id/write"   android:text="写入"   android:layout_width="match_parent"   android:layout_height="wrap_content"/>  <Button   android:id="@+id/read"   android:layout_width="match_parent"   android:layout_height="wrap_content"   android:text="读入"/>  <EditText   android:id="@+id/ed2"   android:layout_width="match_parent"   android:layout_height="wrap_content"   android:inputType="textMultiLine"/>  <Button   android:id="@+id/delete"   android:layout_width="match_parent"   android:layout_height="wrap_content"   android:text="删除指定的文件"   />  <EditText   android:id="@+id/ed3"   android:layout_width="match_parent"   android:layout_height="wrap_content"   />  </LinearLayout> 

package com.android.xiong.fileiotest;  import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.InputStreamReader; import java.lang.reflect.Array; import java.util.ArrayList; import java.util.Arrays; import java.util.List;  import android.app.Activity; import android.os.Bundle; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText;  public class MainActivity extends Activity {   private Button read;  private Button write;  private EditText ed1;  private EditText ed2;  private EditText ed3;  private Button delete;   @Override  protected void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   setContentView(R.layout.activity_main);   read = (Button) findViewById(R.id.read);   write = (Button) findViewById(R.id.write);   delete = (Button) findViewById(R.id.delete);   ed3 = (EditText) findViewById(R.id.ed3);   ed2 = (EditText) findViewById(R.id.ed2);   ed1 = (EditText) findViewById(R.id.ed1);   write.setOnClickListener(new OnClickListener() {    @Override    public void onClick(View v) {     String str = ed1.getText().toString();     if (!str.equals("")) {      write(str);     }     }   });   read.setOnClickListener(new OnClickListener() {     @Override    public void onClick(View v) {     read();     }   });   delete.setOnClickListener(new OnClickListener() {    @Override    public void onClick(View v) {     String str = ed3.getText().toString();     if (!str.equals("")) {      deleteFiles(str);     } else {      ed3.setText(str + ":该文件输入错误或不存在!");     }     }   });   }   private void write(String content) {   try {    // 以追加的方式打开文件输出流    FileOutputStream fileOut = this.openFileOutput("test.txt",      this.MODE_APPEND);    // 写入数据    fileOut.write(content.getBytes());    // 关闭文件输出流    fileOut.close();    } catch (Exception e) {    e.printStackTrace();   }  }   private void read() {   try {    ed2.setText("");    // 打开文件输入流    FileInputStream fileInput = this.openFileInput("test.txt");    BufferedReader br = new BufferedReader(new InputStreamReader(      fileInput));    String str = null;    StringBuilder stb = new StringBuilder();    while ((str = br.readLine()) !=null ) {     stb.append(str);    }    ed2.setText(stb);   } catch (Exception e) {    e.printStackTrace();   }   }    //删除指定的文件  private void deleteFiles(String fileName) {   try {    // 获取data文件中的所有文件列表    List<String> name = Arrays.asList(this.fileList());    if (name.contains(fileName)) {     this.deleteFile(fileName);     ed3.setText(fileName + ":该文件成功删除！");    } else     ed3.setText(fileName + ":该文件输入错误或不存在!");    } catch (Exception e) {    e.printStackTrace();   }  }   @Override  public boolean onCreateOptionsMenu(Menu menu) {   getMenuInflater().inflate(R.menu.main, menu);   return true;  }  } 

<!-- 在SD卡上创建与删除权限 --><uses-permission Android:name="android.permission.MOUNT_FORMAT_FILESYSTEMS" /><!-- 向SD卡上写入权限 --><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:tools="http://schemas.android.com/tools"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:gravity="center_horizontal"  android:orientation="vertical"  tools:context=".MainActivity" >  <EditText   android:id="@+id/ed1"   android:layout_width="match_parent"   android:layout_height="wrap_content"   android:inputType="textMultiLine"/>  <Button   android:id="@+id/write"   android:layout_width="match_parent"   android:layout_height="wrap_content"   android:text="写入SD卡中"/>  <Button   android:id="@+id/read"   android:layout_width="match_parent"   android:layout_height="wrap_content"   android:text="读取SD文件"/>  <TextView   android:id="@+id/txt1"   android:layout_width="match_parent"   android:layout_height="wrap_content"/> </LinearLayout> 

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"  package="com.android.xiong.sdcardtest"  android:versionCode="1"  android:versionName="1.0" >   <uses-sdk   android:minSdkVersion="14"   android:targetSdkVersion="17" />  <!-- 在SD卡上创建与删除权限 -->  <uses-permission android:name="android.permission.MOUNT_FORMAT_FILESYSTEMS" />  <!-- 向SD卡上写入权限 -->  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />   <application   android:allowBackup="true"   android:icon="@drawable/ic_launcher"   android:label="@string/app_name"   android:theme="@style/AppTheme" >   <activity    android:name="com.android.xiong.sdcardtest.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>  </application>  </manifest> 

package com.android.xiong.sdcardtest;  import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.InputStreamReader;  import android.app.Activity; import android.os.Bundle; import android.os.Environment; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.TextView;  public class MainActivity extends Activity {   private Button write;  private Button read;   private EditText ed1;  private TextView txt1;   @Override  protected void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   setContentView(R.layout.activity_main);   write = (Button) findViewById(R.id.write);   read = (Button) findViewById(R.id.read);   ed1 = (EditText) findViewById(R.id.ed1);   txt1 = (TextView) findViewById(R.id.txt1);   write.setOnClickListener(new OnClickListener() {     @Override    public void onClick(View v) {     // TODO Auto-generated method stub     writeSDcard(ed1.getText().toString());     }   });   read.setOnClickListener(new OnClickListener() {     @Override    public void onClick(View v) {     // TODO Auto-generated method stub      txt1.setText(readSDcard());    }   });  }   // 把数据写入SD卡   private void writeSDcard(String str) {    try {    // 判断是否存在SD卡    if (Environment.getExternalStorageState().equals(      Environment.MEDIA_MOUNTED)) {     // 获取SD卡的目录     File file = Environment.getExternalStorageDirectory();     FileOutputStream fileW = new FileOutputStream(file.getCanonicalPath() + "/test.txt");     fileW.write(str.getBytes());     fileW.close();    }   } catch (Exception e) {    e.printStackTrace();   }   }   // 从SD卡中读取数据  private String readSDcard() {   StringBuffer str = new StringBuffer();   try {    // 判断是否存在SD    if (Environment.getExternalStorageState().equals(      Environment.MEDIA_MOUNTED)) {     File file = new File(Environment.getExternalStorageDirectory()       .getCanonicalPath() + "/test.txt");                     // 判断是否存在该文件     if (file.exists()) {      // 打开文件输入流      FileInputStream fileR = new FileInputStream(file);      BufferedReader reads = new BufferedReader(        new InputStreamReader(fileR));      String st = null;      while ((st =reads.readLine())!=null ) {       str.append(st);      }      fileR.close();     } else {      txt1.setText("该目录下文件不存在");     }    }    } catch (Exception e) {    e.printStackTrace();   }   return str.toString();  }   @Override  public boolean onCreateOptionsMenu(Menu menu) {   // Inflate the menu; this adds items to the action bar if it is present.   getMenuInflater().inflate(R.menu.main, menu);   return true;  }  } 

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"   package="com.android.xiong.sqlitelogin"   android:versionCode="1"   android:versionName="1.0" >    <uses-sdk     android:minSdkVersion="8"     android:targetSdkVersion="14" />    <application     android:allowBackup="true"     android:icon="@drawable/ic_launcher"     android:label="@string/app_name"     android:theme="@style/AppTheme" >     <activity       android:name="com.android.xiong.sqlitelogin.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>     <activity       android:name="com.android.xiong.sqlitelogin.RegistersActivity"       android:label="@string/app_name" >     </activity>   </application>  </manifest> 

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"   xmlns:tools="http://schemas.android.com/tools"   android:layout_width="match_parent"   android:layout_height="match_parent"   tools:context=".MainActivity" >    <TextView     android:id="@+id/login"     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:layout_margin="30dp"     android:gravity="center_horizontal"     android:textColor="#8a2be2"     android:textSize="35dp"     android:text="登录界面" />   <TextView      android:id="@+id/txtname"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_below="@id/login"     android:layout_marginRight="5dp"     android:layout_marginBottom="30dp"     android:textSize="28dp"     android:text="用户帐号:"/>   <EditText      android:id="@+id/edname"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_marginBottom="30dp"     android:layout_below="@id/login"     android:layout_toRightOf="@id/txtname"     android:layout_alignParentRight="true"      android:hint="请输入用户帐号"/>     <TextView      android:id="@+id/txtpassword"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_below="@id/txtname"     android:layout_marginRight="5dp"     android:textSize="28dp"     android:text="用户密码:"/>   <EditText      android:id="@+id/edpassword"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_below="@id/edname"     android:layout_toRightOf="@id/txtpassword"     android:layout_alignParentRight="true"     android:inputType="textPassword"     android:hint="请输入用户密码"/>   <LinearLayout      android:layout_below="@id/edpassword"     android:orientation="horizontal"     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:layout_marginTop="30dp"     android:gravity="center_horizontal" >   <Button      android:id="@+id/btregister"     android:layout_height="wrap_content"     android:layout_width="wrap_content"     android:layout_marginRight="20dp"     android:text="用户注册"/>    <Button      android:id="@+id/btlogin"     android:layout_height="wrap_content"     android:layout_width="wrap_content"     android:text="用户登录"/>    </LinearLayout>  </RelativeLayout> 

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"   android:layout_width="match_parent"   android:layout_height="match_parent" >       <TextView     android:id="@+id/txt1"     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:layout_margin="30dp"     android:gravity="center_horizontal"     android:text="注册界面"     android:textColor="#8a2be2"     android:textSize="35dp" />    <TextView     android:id="@+id/txtname1"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_below="@id/txt1"     android:layout_marginBottom="30dp"     android:layout_marginRight="5dp"     android:text="帐号:"     android:textSize="28dp" />    <EditText     android:id="@+id/edname1"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_alignParentRight="true"     android:layout_below="@id/txt1"      android:layout_toRightOf="@id/txtname1"     android:layout_marginBottom="30dp" />    <TextView     android:id="@+id/txtpassword1"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_below="@id/txtname1"     android:layout_marginRight="5dp"     android:text="密码:"     android:textSize="28dp" />    <EditText     android:id="@+id/edpassword1"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_alignParentRight="true"     android:layout_below="@id/edname1"     android:layout_toRightOf="@id/txtpassword1" />    <LinearLayout     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:layout_below="@id/edpassword1"     android:layout_marginTop="30dp"     android:gravity="center_horizontal"     android:orientation="horizontal" >      <Button       android:id="@+id/btregister1"       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:layout_marginRight="20dp"       android:text="提交数据" />   </LinearLayout> </RelativeLayout> 

package com.android.xiong.sqlitelogin;  import android.app.Activity; import android.app.AlertDialog; import android.content.Intent; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteException; import android.os.Bundle; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText;  public class MainActivity extends Activity {    // 帐号和密码   private EditText edname;   private EditText edpassword;    private Button btregister;   private Button btlogin;   // 创建SQLite数据库   public static SQLiteDatabase db;    @Override   protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);     edname = (EditText) findViewById(R.id.edname);     edpassword = (EditText) findViewById(R.id.edpassword);     btregister = (Button) findViewById(R.id.btregister);     btlogin = (Button) findViewById(R.id.btlogin);     db = SQLiteDatabase.openOrCreateDatabase(MainActivity.this.getFilesDir().toString()         + "/test.dbs", null);     // 跳转到注册界面     btregister.setOnClickListener(new OnClickListener() {        @Override       public void onClick(View v) {         // TODO Auto-generated method stub         Intent intent = new Intent();         intent.setClass(MainActivity.this, RegistersActivity.class);         startActivity(intent);       }     });     btlogin.setOnClickListener(new LoginListener());   }    @Override   protected void onDestroy() {     // TODO Auto-generated method stub     super.onDestroy();     db.close();   }     class LoginListener implements OnClickListener {      @Override     public void onClick(View v) {       // TODO Auto-generated method stub       String name = edname.getText().toString();       String password = edpassword.getText().toString();       if (name.equals("") || password.equals("")) {         // 弹出消息框         new AlertDialog.Builder(MainActivity.this).setTitle("错误")             .setMessage("帐号或密码不能空").setPositiveButton("确定", null)             .show();       } else {         isUserinfo(name, password);       }     }      // 判断输入的用户是否正确     public Boolean isUserinfo(String name, String pwd) {       try{         String str="select * from tb_user where name=? and password=?";         Cursor cursor = db.rawQuery(str, new String []{name,pwd});         if(cursor.getCount()<=0){           new AlertDialog.Builder(MainActivity.this).setTitle("错误")           .setMessage("帐号或密码错误！").setPositiveButton("确定", null)           .show();           return false;         }else{           new AlertDialog.Builder(MainActivity.this).setTitle("正确")           .setMessage("成功登录").setPositiveButton("确定", null)           .show();           return true;         }                }catch(SQLiteException e){         createDb();       }       return false;     }      }   // 创建数据库和用户表   public void createDb() {     db.execSQL("create table tb_user( name varchar(30) primary key,password varchar(30))");   }   @Override   public boolean onCreateOptionsMenu(Menu menu) {     // Inflate the menu; this adds items to the action bar if it is present.     getMenuInflater().inflate(R.menu.main, menu);     return true;   }  } 

package com.android.xiong.sqlitelogin;  import android.app.Activity; import android.app.AlertDialog; import android.content.DialogInterface; import android.content.Intent; import android.database.sqlite.SQLiteDatabase; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText;  public class RegistersActivity extends Activity {    private EditText edname1;   private EditText edpassword1;   private Button btregister1;   SQLiteDatabase db;    @Override   protected void onDestroy() {     // TODO Auto-generated method stub     super.onDestroy();     db.close();   }    @Override   protected void onCreate(Bundle savedInstanceState) {     // TODO Auto-generated method stub     super.onCreate(savedInstanceState);     setContentView(R.layout.register);     edname1 = (EditText) findViewById(R.id.edname1);     edpassword1 = (EditText) findViewById(R.id.edpassword1);     btregister1 = (Button) findViewById(R.id.btregister1);     btregister1.setOnClickListener(new OnClickListener() {        @Override       public void onClick(View v) {         // TODO Auto-generated method stub         String name = edname1.getText().toString();         String password = edpassword1.getText().toString();         if (!(name.equals("") && password.equals(""))) {           if (addUser(name, password)) {             DialogInterface.OnClickListener ss = new DialogInterface.OnClickListener() {               @Override               public void onClick(DialogInterface dialog,                   int which) {                 // TODO Auto-generated method stub                 // 跳转到登录界面                 Intent in = new Intent();                 in.setClass(RegistersActivity.this,                     MainActivity.class);                 startActivity(in);                 // 销毁当前activity                 RegistersActivity.this.onDestroy();               }             };             new AlertDialog.Builder(RegistersActivity.this)                 .setTitle("注册成功").setMessage("注册成功")                 .setPositiveButton("确定", ss).show();            } else {             new AlertDialog.Builder(RegistersActivity.this)                 .setTitle("注册失败").setMessage("注册失败")                 .setPositiveButton("确定", null);           }         } else {           new AlertDialog.Builder(RegistersActivity.this)               .setTitle("帐号密码不能为空").setMessage("帐号密码不能为空")               .setPositiveButton("确定", null);         }        }     });    }    // 添加用户   public Boolean addUser(String name, String password) {     String str = "insert into tb_user values(?,?) ";     MainActivity main = new MainActivity();     db = SQLiteDatabase.openOrCreateDatabase(this.getFilesDir().toString()         + "/test.dbs", null);     main.db = db;     try {       db.execSQL(str, new String[] { name, password });       return true;     } catch (Exception e) {       main.createDb();     }     return false;   }  }