性能测试之一----I/O读写速度（1）

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.os.SystemClock;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends ActionBarActivity {

    private TextView mWriteTime;
    private Button mBtnTest;
    private static final String    TAG  = "Ilejia::TestSDCard";
    private TestAsyncTask mTestTask = null;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mWriteTime = (TextView)findViewById(R.id.write_time);

        mBtnTest = (Button) findViewById(R.id.btn_test);
        mBtnTest.setOnClickListener(new View.OnClickListener() {
            
            @Override
            public void onClick(View v) {
                if (mTestTask != null && mTestTask.getStatus() != AsyncTask.Status.FINISHED) {
                    return;
                }
                
                mTestTask = new TestAsyncTask();
                mTestTask.execute((Void[])null);
            }
        });
    }
    
    private class TestAsyncTask extends AsyncTask<Void, Void, Long> {
        @Override
        protected void onPreExecute() {
            mBtnTest.setEnabled(false);
            mWriteTime.setText("Testing...");
        }

        @Override
        protected Long doInBackground(Void... params) {
            return runTest();
        }
        
        protected void onPostExecute(Long result) {
            mBtnTest.setEnabled(true);
            if (result > 0) {
                mWriteTime.setText("写100M数据耗时" + result + "ms");
            }
        };
    }
 long runTest() {
        File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM), "Ilejia");
        File mediaFile = new File(mediaStorageDir.getPath() + File.separator + "test.dat");
        if (!mediaStorageDir.exists()) {
            if (!mediaStorageDir.mkdirs()) {
                Log.e(TAG , "failed to create directory");
                return -1;
            }
        }
//        if (mediaFile.exists()) {
//            mediaFile.delete();
//        }
        Log.i(TAG , "preparing data");
        
        StringBuilder s =  new StringBuilder();
        s.append("this is a test string writing to file.");
        for(int i = 0; i < 1000; i++){
            s.append("0123456789");
        }
        Log.i(TAG , "write data");
        long startTime = SystemClock.uptimeMillis();

        FileOutputStream stream = null;
        try {
            stream = new FileOutputStream(mediaFile);
            byte[] buf = s.toString().getBytes();
            for(int i = 0; i < 10000; ++i){  
                stream.write(buf);            
            }
            stream.close();  
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            if (stream != null) {
                try {
                    stream.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
        Log.i(TAG , "write data successful");
        return SystemClock.uptimeMillis() - startTime;
    }

    @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;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}