将json数据写入并读取到内部存储android

时间:2015-02-21 14:13:09

标签: java android arrays json file

我有一个从php

收到的json数组
[  
   {  
      "name":"Daniel Bryan",
      "img":"pictures\/smallest\/dierdrepic.jpg",
      "username":"@dbryan",
      "user_id":"4"
   },
   {  
      "name":"Devil Hacker",
      "img":"pictures\/smallest\/belitapic.jpg",
      "username":"@dvHack",
      "user_id":"1"
   }
]
  • 我想要的是在file_name.anyextension这些数据 我的应用数据文件夹或任何安全的地方。
  • 同时从file_name.anyextension读取此数据并将其转换为 可以进一步编辑的有效json array

有谁能告诉我一个方法我怎么可能这个东西?

2 个答案:

答案 0 :(得分:19)

private void writeToFile(String data) {
    try {
        OutputStreamWriter outputStreamWriter = new OutputStreamWriter(openFileOutput("config.txt", Context.MODE_PRIVATE));
        outputStreamWriter.write(data);
        outputStreamWriter.close();
    }
    catch (IOException e) {
        Log.e("Exception", "File write failed: " + e.toString());
    } 
}


private String readFromFile() {

    String ret = "";

    try {
        InputStream inputStream = context.openFileInput("config.txt");

        if ( inputStream != null ) {
            InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
            String receiveString = "";
            StringBuilder stringBuilder = new StringBuilder();

            while ( (receiveString = bufferedReader.readLine()) != null ) {
                stringBuilder.append(receiveString);
            }

            inputStream.close();
            ret = stringBuilder.toString();
        }
    }
    catch (FileNotFoundException e) {
        Log.e("login activity", "File not found: " + e.toString());
    } catch (IOException e) {
        Log.e("login activity", "Can not read file: " + e.toString());
    }

    return ret;
}

从文件读取字符串时,将其转换为JsonObject或JsonArray

JSONArray jarray = new JSONArray(str);

答案 1 :(得分:2)

修正了Morteza Soleimani的回答:

public static String readFromFile(String path) {
    String ret = "";
    try {
        InputStream inputStream = new FileInputStream(new File(path));

        if ( inputStream != null ) {
            InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
            String receiveString = "";
            StringBuilder stringBuilder = new StringBuilder();
            while ( (receiveString = bufferedReader.readLine()) != null ) {
                stringBuilder.append(receiveString);
            }
            inputStream.close();
            ret = stringBuilder.toString();
        }
    }
    catch (FileNotFoundException e) {
        Log.e("FileToJson", "File not found: " + e.toString());
    } catch (IOException e) {
        Log.e("FileToJson", "Can not read file: " + e.toString());
    }
    return ret;
}