Question

我的json文件如下：

[
    {
        "title": "hardik2",
        "note": "new note created",
        "date": "current date"
    },
    {
        "title": "hardik2",
        "note": "2 new note",
        "date": "2 current date"
    },
        ......I want to add same object here like previous one
]

我想在同一数组中添加更多对象而不丢失前一个对象怎么做？

我目前正在做的是

FileOutputStream outputStream=openFileOutput("note.json",MODE_APPEND);

JSONArray jsonArray=new JSONArray();
JSONObject jsonObject=new JSONObject();
jsonObject.put("title",title.getText().toString());
jsonObject.put("date","current date");
jsonObject.put("note",note.getText().toString());

jsonArray.put(jsonObject);
outputStream.write(jsonObject.toString().getBytes());

Answer 1

这是使用Gson的简单方法。

GSON

Gson解决方案

第一个make类，具有三个变量title，note和date。

    class DataOfJson {

    private String title;
    private String note;
    private String date;


    public DataOfJson(String title, String note, String date){
    this.title=title;
    this.note=note;
    this.date=date;
    }
}

在列表中添加项目

FileOutputStream outputStream=openFileOutput("note.json",MODE_APPEND);
String data= getStringFromFile("path/note.json");

Type listType = new TypeToken<List<DataOfJson>>() {}.getType();

List<DataOfJson> yourList = new Gson().fromJson(data,listType);
yourList.add( new DataOfJson(title.getText().toStri g(),note.getText().toString(),"current date");

outputStream.write(new Gson().toJson(yourList));




 public static String convertStreamToString(InputStream is) throws Exception {
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        StringBuilder sb = new StringBuilder();
        String line = null;
        while ((line = reader.readLine()) != null) {
          sb.append(line).append("\n");
        }
        reader.close();
        return sb.toString();
    }

    public static String getStringFromFile (String filePath) throws Exception {
        File fl = new File(filePath);
        FileInputStream fin = new FileInputStream(fl);
        String ret = convertStreamToString(fin);
        //Make sure you close all streams.
        fin.close();      


    return ret;
}

使用JSONObject Android将数据写入内部存储器中的Json File

1 个答案: