Android Open Source - DataPersistence Main Activity

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License

The source code is released under:

Apache License

Java Source Code

package com.example.datapersistencedemo;
/*from w  ww.ja  va 2 s . co  m*/
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;

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

//???openFileOutput????????????????????openFileinput??????????????????
public class MainActivity extends Activity {

  private EditText inputText;
  private TextView outpuTextView;
  private Button saveButton,loadButton;
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.file_io);
    init();
    
    saveButton.setOnClickListener(new View.OnClickListener() {
      
      @Override
      public void onClick(View arg0) {
        if (!TextUtils.isEmpty(inputText.getText())) {
          onSave(inputText.getText().toString());
        }
      }
    });
    
  
    loadButton.setOnClickListener(new View.OnClickListener() {
      
      @Override
      public void onClick(View arg0) {
        outpuTextView.setText(onLoad());
      }
    });
  }

  private String onLoad() {
    InputStream in = null;
    BufferedReader br = null;
    StringBuilder content = new StringBuilder();
    try {
      in = openFileInput("EditTextdata");
      br = new BufferedReader(new InputStreamReader(in));
      String line = "";
      while((line = br.readLine()) != null){
        content.append(line);
      }
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }finally{
      if (br != null) {
        try {
          br.close();
          Toast.makeText(MainActivity.this, "onLoad method is valid!", Toast.LENGTH_SHORT).show();
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
    }
    
    return content.toString();
  }

  private void onSave(String inputText) {
    //??EditText-et_input??????????java??????EditTextdata?????
    OutputStream os = null;
    BufferedWriter bw = null;
    
    try {
      os = openFileOutput("EditTextdata", MODE_PRIVATE);
      bw = new BufferedWriter(new OutputStreamWriter(os));
      bw.write(inputText);      
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }finally{
      try {
        if (bw != null) {
          Toast.makeText(MainActivity.this, "onSave method is valid.", Toast.LENGTH_SHORT).show();
          bw.close();
        }
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  }

  private void init() {
    inputText = (EditText) findViewById(R.id.et_input);
    outpuTextView = (TextView) findViewById(R.id.tv_output);
    saveButton = (Button) findViewById(R.id.btn_save);
    loadButton = (Button) findViewById(R.id.btn_load);
  }
}

Java Source Code List

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