FileStorage

package com.example.youngwind.helloworld.FileStorage;

import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

import com.example.youngwind.helloworld.R;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;

public class FileStorage extends AppCompatActivity {

    private EditText edit;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_file_storage);

        edit = (EditText) findViewById(R.id.edit);

        // 设置点击保存事件
        findViewById(R.id.save).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String inputText = edit.getText().toString();
                save(inputText);
                finish();
            }
        });

        String inputText = load();
        if (!TextUtils.isEmpty(inputText)) {
            edit.setText(inputText);
            edit.setSelection(inputText.length());
            Toast.makeText(this, "Resoring succedded", Toast.LENGTH_SHORT).show();
        }


    }

    // 保存数据到文件中
    public void save(String inputText) {
        FileOutputStream out = null;
        BufferedWriter writer = null;

        try {
            out = openFileOutput("data", Context.MODE_PRIVATE);
            writer = new BufferedWriter(new OutputStreamWriter(out));
            writer.write(inputText);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (writer != null) {
                    writer.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }


    // 从文件中读取数据
    public String load() {
        FileInputStream in = null;
        BufferedReader reader = null;
        StringBuilder content = new StringBuilder();
        try {
            in = openFileInput("data");
            reader = new BufferedReader(new InputStreamReader(in));
            String line = "";
            while ((line = reader.readLine()) != null) {
                content.append(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        return content.toString();

    }

    ;


}