package com.example.day11_datastoreage01;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.os.Environment;
import android.os.StatFs;
import android.util.Log;
import android.view.View;
import android.widget.Toast;
public class MainActivity extends Activity {
private Context mcontext =this ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void cunchu(View v){
//1 判断存储的目录的状态
String state =
Environment.getExternalStorageState();
if(Environment.MEDIA_UNMOUNTED.equals(state) || Environment.isExternalStorageRemovable()){
Toast.makeText(mcontext, "sdcard 不可用", 0).show();
return ;
}
//2获得存储的目录
//2.1 获得应用程序共有目录(大家都可以访问的目录)
File sdcard = //mnt/sdcard
Environment.getExternalStorageDirectory();
Log.i("TAG", sdcard.getPath());
File sdcardMusic = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MOVIES);
Log.i("TAG", sdcardMusic.getPath());
//2 2 获得应用程序私有存储目录（私有目录，应用程序卸载时候此目录中的数据会被删除）
File privateCache = getExternalCacheDir(); //需要添加权限
Log.i("TAG", privateCache.getPath());
File privateMusic = getExternalFilesDir(Environment.DIRECTORY_MOVIES);
Log.i("TAG", privateMusic.getPath());
//3 获得目录空间大小（statFs）
StatFs sf = new StatFs(sdcard.getPath());
//3.1 获得总的块数
int blockCount = sf.getBlockCount();
//3.2获得可用块数
int aCount = sf.getAvailableBlocks();
//3.3获得空闲块数(>=可用块数)
int fCount = sf.getFreeBlocks();
//3.4获得每块字节数
int size=sf.getBlockSize();
//3.5获得磁盘目录总大小(M)
double tSize=blockCount*size*1.0/1024/1024;
//3.6获得可用大小
double aSize=aCount*size*1.0/1024/1024;
Log.i("TAG", "总大小:"+tSize);
Log.i("TAG", "可用大小:"+aSize);
//4.向磁盘写入数据
String data="helloworld";
if(data.getBytes().length>aCount*size){
Toast.makeText(this, "磁盘空间不足", 0).show();
return;
}
FileOutputStream out=null;
try{
out=new FileOutputStream(new File(sdcard,"s1.txt"));
out.write(data.getBytes());
Log.i("TAG", "write ok");
Toast.makeText(this, "write ok", 0).show();
}catch(Exception e){
e.printStackTrace();
}finally{
if(out!=null)try{out.close();}catch(Exception e){}
}
}
public void ReadSdcard(View v){
File sdCardPath = Environment.getExternalStorageDirectory();
File f = new File(sdCardPath, "s1.txt");
InputStream in = null ;
try {
in = new FileInputStream(f);
byte buffer[] =new byte[in.available()];
int readlen = in.read(buffer);
String s = new String(buffer, 0, readlen);
Toast.makeText(mcontext, s, 0).show();
} catch (Exception e) {
e.printStackTrace();
}finally {
if(in != null){
try {
in.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
}
