java - android开发打开文件txt并返回内容

Question

在互联网上搜索，找不到有效的代码。如何获取 txt 文档的内容并将其返回。

假设我在（ src/my.proovi.namespace/data.txt ）中有一个 txt 文件，并且我创建了一个名为 refresh_all_data(); 的方法。我希望在哪里收集和返回数据。在主要活动方法中，我只需要将内容获取为（ String content = refresh_all_data(); ）就是这样。

应该很容易，但只是找不到有效的答案。非常感谢你。

Answer 1

将文件放在/assets项目的文件夹中，然后您可以InputStream通过以下方式打开它AssetManager：

InputStream in = getAssets().open("data.txt");

然后，您可以从文件中读取行并StringBuilder使用 a将它们添加到Reader：

//The buffered reader has a method readLine() that reads an entire line from the file, InputStreamReader is a reader that reads from a stream.
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
//This is the StringBuilder that we will add the lines to:
StringBuilder sb = new StringBuilder(512);
String line;
//While we can read a line, append it to the StringBuilder:
while((line = reader.readLine()) != null){
    sb.append(line);
}
//Close the stream:
reader.close();
//and return the result:
return sb.toString();

Answer 2

在一个函数中实现以下代码并在任何你想要的地方调用它。

try{
      // Open the file that is the first 
      // command line parameter
      FileInputStream fstream = new FileInputStream("textfile.txt");
      // Get the object of DataInputStream
      DataInputStream in = new DataInputStream(fstream);
      BufferedReader br = new BufferedReader(new InputStreamReader(in));
      String strLine;
      //Read File Line By Line
      while ((strLine = br.readLine()) != null)   {
      // Print the content on the console
      System.out.println (strLine);
      }
      //Close the input stream
      in.close();
        }catch (Exception e){//Catch exception if any
      System.err.println("Error: " + e.getMessage());
      }

Answer 3

好的，我得到了什么。

 public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    String test = null;
    try {
        test = refresh_all_data();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    TextView day1Label = new TextView(this);  
    day1Label.setText(test);
    setContentView(day1Label);

}

还有 refresh_all_data(); 方法。

private String refresh_all_data() throws IOException
{ 

    InputStream in = getAssets().open("data.txt");
    //The buffered reader has a method readLine() that reads an entire line from the file, InputStreamReader is a reader that reads from a stream.
    BufferedReader reader = new BufferedReader(new InputStreamReader(in));
    //This is the StringBuilder that we will add the lines to:
    StringBuilder sb = new StringBuilder(512);
    String line;
    //While we can read a line, append it to the StringBuilder:
    while((line = reader.readLine()) != null){
        sb.append(line);
    }
    //Close the stream:
    reader.close();
    //and return the result:
    return sb.toString();
}

感谢分配给 Jave。