android 資料儲存<一>----android簡訊傳送器之檔案的讀寫（手機+SD卡）
本文實踐知識點有有三：
1.佈局檔案，android佈局有相對佈局。線性佈局，絕對佈局。表格佈局。標籤佈局等，各個佈局能夠巢狀的。
本文的佈局檔案就是線性佈局的巢狀
l<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical"> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/Telhint" android:textSize="19sp" android:textColor="#FFFFFF" android:background="#000000" /> <EditText android:id="@+id/Tel" android:inputType="number" android:layout_width="fill_parent" android:layout_height="75sp" android:textSize="30sp" android:paddingLeft="10sp" android:paddingRight="10sp" android:background="@drawable/text1" /> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/Smshint" android:textSize="19sp" android:textColor="#FFFFFF" android:background="#000000" /> <EditText android:id="@+id/Sms" android:inputType="textMultiLine" android:layout_width="fill_parent" android:layout_height="180dip" android:textSize="19sp" android:minLines="10" android:gravity="left" android:background="@drawable/text2" android:paddingTop="19sp" android:paddingBottom="22sp" android:paddingLeft="22sp" android:paddingRight="15sp" /> <LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="horizontal"> <Button android:layout_marginTop="10sp" android:layout_marginLeft="3sp" android:id="@+id/button0" android:layout_width="wrap_content" android:layout_height="75sp" android:text="@string/send" android:textColor="#7cfc00" android:textSize="19sp" /> <Button android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="75sp" android:layout_marginTop="10sp" android:layout_marginLeft="3sp" android:text="@string/savephone" android:textColor="#800080" android:textSize="19sp" /> <Button android:id="@+id/button6" android:layout_marginTop="10sp" android:layout_width="wrap_content" android:layout_height="75sp" android:layout_marginLeft="3sp" android:text="@string/savecache" android:textColor="#800080" android:textSize="19sp" /> <Button android:id="@+id/button10" android:layout_width="wrap_content" android:layout_height="75sp" android:layout_marginTop="5sp" android:layout_marginLeft="1sp" android:layout_gravity="center" android:text="@string/deletecache" android:textColor="#800080" android:textSize="19sp" /> </LinearLayout> <LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="horizontal"> <Button android:layout_marginTop="10sp" android:layout_marginLeft="3sp" android:id="@+id/button2" android:layout_width="wrap_content" android:layout_height="75sp" android:text="@string/clear" android:textColor="#ff0000" android:textSize="19sp" /> <Button android:layout_marginTop="10sp" android:layout_marginLeft="3sp" android:id="@+id/button3" android:layout_width="wrap_content" android:layout_height="75sp" android:text="@string/savesdcard" android:textColor="#800080" android:textSize="19sp" /> <Button android:layout_marginTop="10sp" android:layout_marginLeft="3sp" android:id="@+id/button7" android:layout_width="wrap_content" android:layout_height="75sp" android:text="@string/Readcache" android:textColor="#800080" android:textSize="19sp" /> <Button android:id="@+id/button11" android:layout_width="wrap_content" android:layout_height="75sp" android:text="@string/future" android:layout_marginTop="2sp" android:layout_marginLeft="1sp" android:gravity="center" android:textColor="#800080" android:textSize="19sp" /> </LinearLayout> <LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="horizontal"> <Button android:id="@+id/button4" android:layout_width="90dp" android:layout_height="wrap_content" android:layout_marginTop="10sp" android:layout_marginLeft="1sp" android:text="@string/Readphone" android:textColor="#0000ff" android:textSize="19sp" /> <Button android:id="@+id/button5" android:layout_width="90dp" android:layout_height="wrap_content" android:layout_marginTop="10sp" android:layout_marginLeft="1sp" android:text="@string/Readsdcard" android:textColor="#0000ff" android:textSize="19sp" /> <Button android:id="@+id/button8" android:layout_width="90dp" android:layout_height="wrap_content" android:layout_marginTop="10sp" android:layout_marginLeft="1sp" android:text="@string/deletephone" android:textColor="#0000ff" android:textSize="19sp" /> <Button android:id="@+id/button9" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="10sp" android:layout_marginLeft="1sp" android:text="@string/deletesd" android:textColor="#0000ff" android:textSize="19sp" /> </LinearLayout> </LinearLayout>
2.佈局檔案裡使用字元以及Java原始碼中使用的字元最好在string.xml先定義，然後再引用
<?xml version="1.0" encoding="utf-8"?
> <resources> <string name="app_name">MySMS</string> <string name="Telhint">請輸入號碼：</string> <string name="Smshint">請輸入簡訊內容：</string> <string name="send">傳送</string> <string name="OK">傳送成功</string> <string name="savephone">to-手機</string> <string name="savesdcard">to-SD卡</string> <string name="ReadSD">讀SD卡資訊</string> <string name="clear">清除</string> <string name="action_settings">Settings</string> <string name="Readphone">讀手機簡訊</string> <string name="Readsdcard">讀sd卡簡訊</string> <string name="future"> --NULL-- </string> <string name="savecache">to-cache</string> <string name="Readcache">讀cache</string> <string name="deletephone">刪手機簡訊</string> <string name="deletesd">刪sd卡簡訊</string> <string name="deletecache">C-Cache</string> </resources>
3.涉及的安全方面的業務，必需在androidMainifest.xml註冊。如傳送簡訊。撥打電話，讀取SD卡資料等
<uses-permission android:name="android.permission.SEND_SMS"/>
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>"
當中當中豎屏翻轉，也須要在這裡註冊
android:screenOrientation="portrait"
<?xml version="1.0" encoding="utf-8"?
> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.mysms" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="19" /> <uses-permission android:name="android.permission.SEND_SMS"/> <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/> <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>" <application android:allowBackup="true" android:icon="@drawable/sms" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name="com.example.mysms.MainActivity" android:label="@string/app_name" android:screenOrientation="portrait" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>
4.操作檔案的功能實現最好新建一個業務類
package com.example.FileService;
import android.content.Context;
import android.os.Environment;
import android.util.Log;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
public class Fileservice {
private Context context;
public Fileservice(Context context) {
this.context = context;
}
private final String tag ="mytag";
public void SavefileToPhone(String filename,String content) throws Exception
{
Log.e(tag, "hello,start save file to phone internal");
FileOutputStream outStream = context.openFileOutput(filename, Context.MODE_PRIVATE);
Log.e(tag, "hello,open file is ok");
outStream.write(content.getBytes());
outStream.close();
}
public void SavefileToCache(String filename,String content) throws Exception
{
File cachedir = context.getCacheDir();
File file=new File(cachedir,filename);
OutputStream os = new FileOutputStream(file);
os.write(content.getBytes());
os.close();
}
public void SavefileToSD(String filename,String content) throws Exception
{
Log.e(tag,"SD card is begint!");
File path= Environment.getExternalStorageDirectory();
Log.e(tag,"SD card save is start!");
File file=new File(path,filename);
Log.e(tag,"SD card file is creat!");
OutputStream os = new FileOutputStream(file);
Log.e(tag,"SD card outputstream is get!");
os.write(content.getBytes());
Log.e(tag,"SD card is write!");
os.close();
}
public String ReadfileToSD(String filename) throws Exception
{
File path= Environment.getExternalStorageDirectory();
int len = 0;
byte[] buffer = new byte[1024];
Log.e(tag, "hello,Read cache file begin");
File file=new File(path,filename);
Log.e(tag, "hello,get a file string");
ByteArrayOutputStream outStream = new ByteArrayOutputStream();
Log.e(tag, "hello,get a outstream");
FileInputStream InputStream = new FileInputStream(file);
Log.e(tag, "hello,get a Inputstream");
while((len=InputStream.read(buffer))!=-1)
{
outStream.write(buffer, 0, len);
}
byte[] data=outStream.toByteArray();
InputStream.close();
return new String (data);
}
public String ReadfileFromcache(String filename) throws Exception
{
int len = 0;
byte[] buffer = new byte[1024];
File cachedir = context.getCacheDir();
Log.e(tag, "hello,Read cache file begin");
File file=new File(cachedir,filename);
Log.e(tag, "hello,get a file string");
ByteArrayOutputStream outStream = new ByteArrayOutputStream();
Log.e(tag, "hello,get a outstream");
FileInputStream InputStream = new FileInputStream(file);
Log.e(tag, "hello,get a Inputstream");
while((len=InputStream.read(buffer))!=-1)
{
outStream.write(buffer, 0, len);
}
byte[] data=outStream.toByteArray();
InputStream.close();
return new String (data);
}
public String ReadfileFromPhone(String file) throws Exception
{
int len = 0;
byte[] buffer = new byte[1024];
ByteArrayOutputStream outStream = new ByteArrayOutputStream();
FileInputStream InputStream= context.openFileInput(file);
while((len=InputStream.read(buffer))!=-1)
{
outStream.write(buffer, 0, len);
}
byte[] data=outStream.toByteArray();
return new String (data);
}
}
注意android操作檔案有兩種方式：
一。
使用context類，context提供了輸入輸出流介面。一般用於讀寫手機內部檔案
二。.使用file類，這個是更頂層的類，通過檔案路徑和檔名稱，能夠用於讀寫系統不論什麼地方的檔案。一般用於讀寫cache，SD卡。其它路徑檔案。
5.activity類，用於GUI操作
package com.example.mysms; import java.io.File; import java.util.ArrayList; import com.example.FileService.Fileservice; import android.support.v7.app.ActionBarActivity; import android.telephony.SmsManager; import android.util.Log; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; import android.view.View.OnClickListener; import android.os.Bundle; import android.os.Environment; public class MainActivity extends ActionBarActivity { EditText text1; EditText text2; Button bt,bt1,bt2,bt3,bt4,bt5,bt6,bt7,bt8,bt9,bt10; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); text1=(EditText)findViewById(R.id.Tel); text2=(EditText)findViewById(R.id.Sms); bt=(Button)findViewById(R.id.button0); bt1=(Button)findViewById(R.id.button1); bt2=(Button)findViewById(R.id.button2); bt3=(Button)findViewById(R.id.button3); bt4=(Button)findViewById(R.id.button4); bt5=(Button)findViewById(R.id.button5); bt6=(Button)findViewById(R.id.button6); bt7=(Button)findViewById(R.id.button7); bt8=(Button)findViewById(R.id.button8); bt9=(Button)findViewById(R.id.button9); bt10=(Button)findViewById(R.id.button10); bt.setOnClickListener(listener); bt1.setOnClickListener(listener); bt2.setOnClickListener(listener); bt3.setOnClickListener(listener); bt4.setOnClickListener(listener); bt5.setOnClickListener(listener); bt6.setOnClickListener(listener); bt7.setOnClickListener(listener); bt8.setOnClickListener(listener); bt9.setOnClickListener(listener); bt10.setOnClickListener(listener); } private OnClickListener listener =new OnClickListener() { String Tel; String Sms; String filename ; private final String Tag=new String("Activity_tag"); @Override public void onClick(View v) { Button btx=(Button)v; switch(btx.getId()) { case R.id.button0: Tel=text1.getText().toString(); Sms = text2.getText().toString(); if(Tel.equals("")==true) { Toast.makeText(MainActivity.this, "請輸入號碼！
", Toast.LENGTH_LONG).show(); return; } if(Sms.equals("")==true) { Toast.makeText(MainActivity.this, "請輸入資訊！", Toast.LENGTH_LONG).show(); return; } SmsManager smsm=SmsManager.getDefault(); ArrayList<String> texts=smsm.divideMessage(Sms); for(String text:texts) { smsm.sendTextMessage(Tel, null, text, null, null); } text1.setText(""); text2.setText(""); Toast.makeText(MainActivity.this, R.string.OK, Toast.LENGTH_LONG).show(); break; case R.id.button1: Tel=text1.getText().toString(); Sms = text2.getText().toString(); filename = Tel+".txt"; Fileservice savetophone = new Fileservice(getApplicationContext()); try { savetophone.SavefileToPhone(filename, Sms); Toast.makeText(getApplicationContext(), "儲存到手機成功", Toast.LENGTH_SHORT).show(); Toast.makeText(getApplicationContext(), "檔案路徑為"+getApplicationContext().getFilesDir().toString(), Toast.LENGTH_SHORT).show(); } catch(Exception e) { Toast.makeText(getApplicationContext(), "儲存到手機失敗", Toast.LENGTH_SHORT).show(); } break; case R.id.button2: text2.setText(""); Toast.makeText(getApplicationContext(), "清除成功", Toast.LENGTH_SHORT).show(); break; case R.id.button3: Tel=text1.getText().toString(); Sms = text2.getText().toString(); filename = Tel+".txt"; Fileservice service3 = new Fileservice(getApplicationContext()); try { if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) { service3.SavefileToSD(filename, Sms); File path= Environment.getExternalStorageDirectory(); String PATH = path.toString(); Toast.makeText(getApplicationContext(), "儲存SD卡中的簡訊成功", Toast.LENGTH_SHORT).show(); Toast.makeText(getApplicationContext(), "SD卡路徑為"+PATH, Toast.LENGTH_SHORT).show(); } else { Toast.makeText(getApplicationContext(), "SD卡無法識別", Toast.LENGTH_SHORT).show(); } } catch(Exception e) { Toast.makeText(getApplicationContext(), "儲存SD卡中的簡訊失敗", Toast.LENGTH_SHORT).show(); } break; case R.id.button4: Tel=text1.getText().toString(); filename = Tel+".txt"; Fileservice service = new Fileservice(getApplicationContext()); try { Sms=service.ReadfileFromPhone(filename); text2.setText(Sms); Toast.makeText(getApplicationContext(), "讀取手機中的簡訊成功", Toast.LENGTH_SHORT).show(); Toast.makeText(getApplicationContext(), "檔案路徑為"+getApplicationContext().getFilesDir().toString(), Toast.LENGTH_SHORT).show(); } catch(Exception e) { Toast.makeText(getApplicationContext(), "讀取手機中的簡訊失敗", Toast.LENGTH_SHORT).show(); } break; case R.id.button5: Tel=text1.getText().toString(); filename = Tel+".txt"; Fileservice service4 = new Fileservice(getApplicationContext()); try { if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) { text2.setText(service4.ReadfileToSD(filename)); Toast.makeText(getApplicationContext(), "讀取SD卡中的簡訊成功", Toast.LENGTH_SHORT).show(); } else { Toast.makeText(getApplicationContext(), "SD卡無法識別", Toast.LENGTH_SHORT).show(); } } catch(Exception e) { Toast.makeText(getApplicationContext(), "讀取SD卡中的簡訊失敗", Toast.LENGTH_SHORT).show(); } break; case R.id.button6: Tel=text1.getText().toString(); Sms = text2.getText().toString(); filename = Tel+".txt"; Fileservice savecache = new Fileservice(getApplicationContext()); try { savecache. SavefileToCache(filename, Sms); Toast.makeText(getApplicationContext(), "儲存到cache成功", Toast.LENGTH_SHORT).show(); Toast.makeText(getApplicationContext(), "檔案路徑為"+getApplicationContext().getCacheDir().toString(), Toast.LENGTH_SHORT).show(); } catch(Exception e) { Toast.makeText(getApplicationContext(), "儲存到手機失敗", Toast.LENGTH_SHORT).show(); } case R.id.button7: Tel=text1.getText().toString(); filename = Tel+".txt"; try{ Fileservice service1=new Fileservice(getApplicationContext()); text2.setText(service1.ReadfileFromcache(filename));; Toast.makeText(getApplicationContext(), "讀取cache中的資料成功", Toast.LENGTH_SHORT).show(); } catch(Exception e) { Toast.makeText(getApplicationContext(), "讀取cache中的資料失敗", Toast.LENGTH_SHORT).show(); } break; case R.id.button8: Tel=text1.getText().toString(); filename = Tel+".txt"; getApplicationContext().deleteFile(filename); Toast.makeText(getApplicationContext(), "刪除手機簡訊的簡訊成功", Toast.LENGTH_SHORT).show(); break; case R.id.button9: Tel=text1.getText().toString(); filename = Tel+".txt"; try { if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) { File file=new File(Environment.getExternalStorageDirectory(),filename); file.delete(); Toast.makeText(getApplicationContext(), "刪除SD卡中的簡訊成功", Toast.LENGTH_SHORT).show(); } else { Toast.makeText(getApplicationContext(), "SD卡無法識別", Toast.LENGTH_SHORT).show(); } } catch(Exception e) { Toast.makeText(getApplicationContext(), "刪除SD卡中的簡訊失敗", Toast.LENGTH_SHORT).show(); } break; case R.id.button10: Log.i(Tag,"Clear the cache\n"); File cachedir = getApplicationContext().getCacheDir(); Log.i(Tag,"Get the patch\n"); File file=new File(cachedir,filename); Log.i(Tag,"Get the file structor\n"); file.delete(); Log.i(Tag,"Clear the cache end\n"); Toast.makeText(getApplicationContext(), "刪除Cache中資料成功", Toast.LENGTH_SHORT).show(); break; } } }; }
在本實踐中還要學會除錯方式：
1.採用logcat檢視日誌除錯
2.通過File explorer 匯出檔案除錯
3.單元測試除錯
4. 怎樣通過google 官方手冊學習API的使用
重要類;context,上下文，一般一個類例項化後就有一個上下文。
測試結果：
