Android数据存取之file (文件存取操作)

Android数据存取之file (文件存取操作)

总体按照MVC设计模式

1、javabean    （M）

package com.lybeen.Android;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class FileService {
    /**
     * 把数据写入文件中
     * @param outputStream
     * @param content
     * @throws IOException
     */
    public static void save(OutputStream outputStream , String content) throws IOException{
        outputStream.write(content.getBytes());
        outputStream.close();
    }
    /**
     * 从文件中读取数据
     * @param inputStream
     * @return
     * @throws IOException
     */
    public static String read(InputStream inputStream) throws IOException{
        int len=-1;
        byte[] b = new byte[1024];
        ByteArrayOutputStream arrayOutputStream = new ByteArrayOutputStream();
        while( ( len = inputStream.read(b) ) != -1){
            arrayOutputStream.write(b, 0, len);
        };
//        return arrayOutputStream.toByteArray().toString();
        return new String(arrayOutputStream.toByteArray());
    }
}

2.界面设计   （V）

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
      >
        <TextView 
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/filename"
            android:id="@+id/filenameLabel"
            android:textSize="20px"
            android:paddingTop="10px"
        />
        <EditText
            android:layout_width="200px"
            android:layout_height="wrap_content"
            android:layout_toRightOf="@id/filenameLabel"
            android:layout_alignTop="@id/filenameLabel"
            android:layout_marginLeft="10px"
            android:text="lybeen.txt"
            android:id="@+id/filename"
        />
    </RelativeLayout>
<TextView 
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/content"
    />
<EditText
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:lines="6"
    android:maxLines="10"
    android:id="@+id/content"
 />
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
            android:orientation="vertical"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
          >
            <Button
                android:layout_width="80px"
                android:layout_height="wrap_content"
                android:text="@string/save"
                android:id="@+id/save"
            />
            <Button
                android:layout_width="80px"
                android:layout_height="wrap_content"
                android:text="@string/read"
                android:layout_toRightOf="@id/save"
                android:id="@+id/read"
            />
    </RelativeLayout>
<TextView 
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:id="@+id/readContent"
   />
</LinearLayout>

3.Activity (C)

package com.lybeen.android;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

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

public class FileSaveReadActivity extends Activity {
    private EditText filenameText;
    private EditText contentText;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        filenameText = (EditText) this.findViewById(R.id.filename);
        contentText = (EditText) this.findViewById(R.id.content);
        Button saveButton = (Button) this.findViewById(R.id.save);
        Button readButton = (Button) this.findViewById(R.id.read);
       
        /*saveButton.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {
                String content = contentText.getText().toString();
                String filename = filenameText.getText().toString();
                String sendResult = "发送成功！";
                OutputStream outputStream;
                try {
                    outputStream = FileSaveReadActivity.this.openFileOutput(filename, MODE_APPEND);
                    FileService.save(outputStream, content);
                } catch (FileNotFoundException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                    sendResult = "发送失败";
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                    sendResult = "发送失败";
                }
                Toast.makeText(FileSaveReadActivity.this, sendResult, Toast.LENGTH_LONG).show();
            }
        });*/
       
        saveButton.setOnClickListener(onClickListener);
        readButton.setOnClickListener(onClickListener);
    }
    private View.OnClickListener onClickListener = new View.OnClickListener(){

        @Override
        public void onClick(View v) {
            Button button = (Button) v;
            String filename = filenameText.getText().toString();
            switch (button.getId()) {
            case R.id.save:
                String sendResult = "保存成功！";
                String content = contentText.getText().toString();
                OutputStream outputStream;
                try {
                    outputStream = FileSaveReadActivity.this.openFileOutput(filename, MODE_APPEND);
                    FileService.save(outputStream, content);
                } catch (FileNotFoundException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                    sendResult = "保存失败";
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                    sendResult = "保存失败";
                }
                Toast.makeText(FileSaveReadActivity.this, sendResult, Toast.LENGTH_LONG).show();
                break;

            case R.id.read:
                try {
                        InputStream inputStream = FileSaveReadActivity.this.openFileInput(filename);
                        String contentShow = FileService.read(inputStream);
                        TextView contentShowLabel = (TextView) FileSaveReadActivity.this.findViewById(R.id.readContent);
                        contentShowLabel.setText(contentShow);
                    } catch (FileNotFoundException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                        Toast.makeText(FileSaveReadActivity.this, "读取失败", Toast.LENGTH_LONG).show();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                        Toast.makeText(FileSaveReadActivity.this, "读取失败", Toast.LENGTH_LONG).show();
                    }
                break;
            }  
        }
    };
}