Android 文件存储详解（SD卡或手机内存存储）

来源：互联网发布：知乎一小时第三季mobi 编辑：程序博客网时间：2024/06/07 14:14

package gongzibai.co.cc;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.PrintStream;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;

public class Ex6Activity extends Activity {
/** Called when the activity is first created. */
final String FILE = "jason.bin";

@Override
public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  Button read = (Button) findViewById(R.id.read);
  Button write = (Button) findViewById(R.id.write);

  final EditText edit1 = (EditText) findViewById(R.id.edit1);
  final EditText edit2 = (EditText) findViewById(R.id.edit2);
  write.setOnClickListener(new OnClickListener() {

   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    write(edit1.getText().toString());
    edit1.setText("");

}

   private void write(String string) {
    // TODO Auto-generated method stub
    try {
     FileOutputStream fos = openFileOutput(FILE, MODE_APPEND);
     PrintStream ps = new PrintStream(fos);
     ps.println(string);
     ps.close();

    } catch (Exception e) {
     // TODO: handle exception
     e.printStackTrace();
    }

}
});

read.setOnClickListener(new OnClickListener() {

   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    edit2.setText(read());

}

   private CharSequence read() {
    // TODO Auto-generated method stub
    try {
     FileInputStream fis = openFileInput(FILE);
     byte[] buffer = new byte[1024];
     int hasRead = 0;
     StringBuilder sb = new StringBuilder("");
     while ((hasRead = fis.read(buffer)) > 0) {
      sb.append(new String(buffer, 0, hasRead));

}
return sb.toString();

    } catch (Exception e) {
     // TODO: handle exception
     e.printStackTrace();

    }
    return null;
   }
  });

}
}

----------------创建文件到SD卡中

File file = new File("/sdcard/json.txt");
  if (!file.exists()) {
   try {
    file.createNewFile();
   } catch (IOException e) {
    e.printStackTrace();
   }
  }

-------------------存储在SD卡中数据

package gongzibai.co.cc;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;

public class Ex6Activity extends Activity {
/** Called when the activity is first created. */
final String FILE = "/sdcard/gogo.txt";

@Override
public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  File path = new File(FILE);
  if (!path.exists())
  {
   try {
    path.createNewFile();
   } catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
  }
  Button read = (Button) findViewById(R.id.read);
  Button write = (Button) findViewById(R.id.write);

  final EditText edit1 = (EditText) findViewById(R.id.edit1);
  final EditText edit2 = (EditText) findViewById(R.id.edit2);
  write.setOnClickListener(new OnClickListener() {

   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    write(edit1.getText().toString());
    edit1.setText("");

}

   private void write(String string) {
    // TODO Auto-generated method stub
    try {
      OutputStream os = new FileOutputStream(FILE,true);
     os.write(string.getBytes());
     os.close();

    } catch (Exception e) {
     // TODO: handle exception
     e.printStackTrace();
    }

}
});

read.setOnClickListener(new OnClickListener() {

   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    edit2.setText(read());

}

   private CharSequence read() {
    // TODO Auto-generated method stub
    try {
     FileInputStream fis = new FileInputStream(FILE);
     byte[] buffer = new byte[1024];
     int hasRead = 0;
     StringBuilder sb = new StringBuilder("");
     while ((hasRead = fis.read(buffer)) > 0) {
      sb.append(new String(buffer, 0, hasRead));

}
return sb.toString();

    } catch (Exception e) {
     // TODO: handle exception
     e.printStackTrace();
    }
    return null;
   }
  });

}
}