将Assets文件读为字符串

Question

我想将资产中的文件内容作为字符串读取.例如,位于的文本文档src/main/assets/

原始问题
我发现这个问题主要用作阅读资产文件的"FAQ",因此我总结了上述问题.以下是我最初的天真问题

我正在尝试将资源文件作为字符串读取,我在这里尝试了20个答案,但它们对我不起作用.

我的资产文件夹中有一个文件:data.opml,我必须将内容放在一个字符串中.我发送它像:

 OPML.importFromFile(string, MainTabActivity.this);

收到它像:

 importFromFile(String filename, Context context); 

有效的东西(但它不是资产文件):

 OPML.importFromFile(new StringBuilder(Environment.getExternalStorageDirectory().toString()).append(File.separator).append(fileNames[which]).toString(),MainTabActivity.this);

我试过了:

 AssetFileDescriptor descriptor = getAssets().openFd("data.opml");
 FileReader reader = new FileReader(descriptor.getFileDescriptor());
 And also:
 InputStream input = getAssets().open("data.opml");
 Reader reader = new InputStreamReader(input, "UTF-8");

Maby我做错了什么,但它只是不起作用,因为它项目给出错误(分别:OPML不能用于参数文件阅读器和阅读器),如果有人知道如何做到这一点,我将非常感激!

Answer 1

getAssets().open()会回来的InputStream.使用标准Java I/O读取:

Java:

StringBuilder sb = new StringBuilder();
InputStream is = getAssets().open("book/contents.json");
BufferedReader br = new BufferedReader(new InputStreamReader(is, StandardCharsets.UTF_8 ));
String str;
while ((str = br.readLine()) != null) {
    sb.append(str);
}
br.close();

科特林:

val str = assets.open("book/contents.json").bufferedReader().use { it.readText() }

Answer 2

有一个小错误CommonsWare的代码 - 换行字符被丢弃而不添加到字符串中.这是一些准备复制+粘贴的固定代码:

private String loadAssetTextAsString(Context context, String name) {
        BufferedReader in = null;
        try {
            StringBuilder buf = new StringBuilder();
            InputStream is = context.getAssets().open(name);
            in = new BufferedReader(new InputStreamReader(is));

            String str;
            boolean isFirst = true;
            while ( (str = in.readLine()) != null ) {
                if (isFirst)
                    isFirst = false;
                else
                    buf.append('\n');
                buf.append(str);
            }
            return buf.toString();
        } catch (IOException e) {
            Log.e(TAG, "Error opening asset " + name);
        } finally {
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    Log.e(TAG, "Error closing asset " + name);
                }
            }
        }

        return null;
    }

Answer 3

您也可以这样做，而无需使用循环。这很简单

AssetManager assetManager = getAssets();
InputStream input;
String text = "";

    try {
        input = assetManager.open("test.txt");

        int size = input.available();
        byte[] buffer = new byte[size];
        input.read(buffer);
        input.close();

        // byte buffer into a string
        text = new String(buffer);

    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    Log.v("TAG", "Text File: " + text);

Answer 4

嗨，我认为这是最干净的方法：

  public static String loadTextFromAssets(Context context, String assetsPath, Charset charset) throws IOException {
        InputStream is = context.getResources().getAssets().open(assetsPath);
        byte[] buffer = new byte[1024];
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        for (int length = is.read(buffer); length != -1; length = is.read(buffer)) {
            baos.write(buffer, 0, length);
        }
        is.close();
        baos.close();
        return charset == null ? new String(baos.toByteArray()) : new String(baos.toByteArray(), charset);
    }

因为读者可能会遇到换行问题。