4 Data(1)

发表于 更新于 分类于 阅读次数：

4 Data(1)

文件存储读取

  • 存储

    • save()
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      private void save(String inputText) throws IOException {
            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();
                }
            }
        }
    • 在onDestroy()中保存
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      protected void onDestroy() { //将输入内容存入文件中
            super.onDestroy();
            String inputText = edit.getText().toString();
            try {
                save(inputText);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

  • 读取保存的文本

    • load()方法
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      private String load() throws FileNotFoundException {
            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){ //reader.readLine()
                    content.append(line);
                }
            }catch (IOException e){
                e.printStackTrace();
            }finally{
                if(reader != null){
                    try {
                        reader.close();
                    }catch (IOException e){
                        e.printStackTrace();
                    }
                }
                return content.toString();
            }
        }
    • onCreate中添加：
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      EditText edit = findViewById(R.id.edit);
            String inputText = null;
            try {
                inputText = load();
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
            if (!TextUtils.isEmpty(inputText)){
                edit.setText(inputText);
                edit.setSelection(inputText.length());
                Toast.makeText(this, "Restoring succeeded", Toast.LENGTH_SHORT).show();
            }
        }