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Android 数据存取试验

 2010-02-27 09:45:00 来源:WEB开发网   
核心提示: Step2、Java代码package com.penguin7.filetest; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutput
  Step2、Java代码 package com.penguin7.filetest;

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

import org.apache.http.util.EncodingUtils;

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

public class FileTest extends Activity {
 private final String FILE_PATH = "/data/data/com.penguin7.filetest/";
 private final String FILE_NAME = "filetest.txt";

 // Definition file
 File file;
 FileOutputStream out;
 FileInputStream in;

 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);

  // execute store action
  Button btnStore = (Button) findViewById(R.id.btn_store);
  btnStore.setOnClickListener(new View.OnClickListener() {

   @Override
   public void onClick(View arg0) {
    try {
     // Create a file
     file = new File(FILE_PATH, FILE_NAME);
     file.createNewFile();

     // Open output stream for the file
     out = new FileOutputStream(file);

     // Get the content and store into the file
     EditText et = (EditText) findViewById(R.id.input);
     String info = et.getText().toString();
     // Transform the string to byte array then store into file
     out.write(info.getBytes());
     out.close();
    } catch (FileNotFoundException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    } catch (IOException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
   }
  });

  // Execute read action
  Button btnExtract = (Button) findViewById(R.id.btn_extract);
  btnExtract.setOnClickListener(new View.OnClickListener() {

   @Override
   public void onClick(View arg0) {
    try {
     // Create a file object to prepare read file's content
     file = new File(FILE_PATH, FILE_NAME);
     if (!file.exists()) {
      return;
     }
     // Open input stream for file
     in = new FileInputStream(file);
     // Get length of file and apply to a byte array to store file's information
     int length = (int) file.length();
     byte[] temp = new byte[length];
     in.read(temp, 0, length);
     TextView tv = (TextView) findViewById(R.id.display);
     // Before display the content we should transform to UTF-8 coding way
     tv.setText(EncodingUtils.getString(temp, "UTF-8"));
     in.close();
    } catch (FileNotFoundException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    } catch (IOException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }

   }
  });
 }
}

Tags:Android 数据 存取

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