如何从原始文件夹中获取 json 文件？

Question

我想使用原始文件夹中的 user.json 来获取新文件:

// read from file, convert it to user class
User user = mapper.readValue(new File(**R.raw.user**), User.class);

我发现 InputStream 可以做到：

InputStream ins = res.openRawResource(
                        getResources().getIdentifier("raw/user",
                                "raw", getPackageName()));

有没有更好的方法，直接使用我的 json 文件 ID？

Answer 1

InputStream is = getResources().openRawResource(R.raw.json_file);
Writer writer = new StringWriter();
char[] buffer = new char[1024];
try {
    Reader reader = new BufferedReader(new InputStreamReader(is, "UTF-8"));
    int n;
    while ((n = reader.read(buffer)) != -1) {
        writer.write(buffer, 0, n);
    }
} finally {
    is.close();
}

String jsonString = writer.toString();

Answer 2

ObjectMapper.readValue 也以 InputStream 为来源。使用 json 文件中的 openRawResource 方法获取 InputStream 并将其传递给 readValue :

InputStream in = getResources().openRawResource(R.raw.user);
User user = mapper.readValue(in, User.class);

Answer 3

Kotlin 方式：

val raw = resources.openRawResource(R.raw.posts)
        val writer: Writer = StringWriter()
        val buffer = CharArray(1024)
        raw.use { rawData ->
            val reader: Reader = BufferedReader(InputStreamReader(rawData, "UTF-8"))
            var n: Int
            while (reader.read(buffer).also { n = it } != -1) {
                writer.write(buffer, 0, n)
            }
        }

        val jsonString = writer.toString()

如何从原始文件夹中获取 json 文件？

How to get a json file from raw folder?

android

json

jackson

inputstream