Question

我想从字符串变量中转换json数据，如下例所示：

String in = "{'employees': [{'firstName':'John' , 'lastName':'Doe' },"
                + "{  'firstName' : 'Anna'  ,  'lastName' :'Smith' },"
                + "{  'firstName' : 'Peter'  ,  'lastName' : 'Jones'  }]}";
        try {
            String country = "";
            JSONArray Array = new JSONArray(in);
            for (int i = 0; i < Array.length(); i++) {
                JSONObject sys = Array.getJSONObject(i);
                country += "  " + sys.getString("firstName");
            }

            Toast.makeText(this, country, Toast.LENGTH_LONG).show();

        } catch (JSONException e) {
            // TODO Auto-generated catch block
            Toast.makeText(this,    e.toString(), Toast.LENGTH_LONG).show();

        };

当我尝试此代码时，我收到此错误：

Error parsing data org.json.JSONException: Value 0 of type java.lang.Integer cannot be   
converted to JSONObject

Answer 1

尝试替换此行：

JSONArray Array = new JSONArray(in);

有了这个：

JSONObject json = new JSONObject(in);
JSONArray Array = new JSONArray(json.getJSONArray("employees"));

Answer 2

尝试以下代码： -

JSONObejct j = new JSONObejct(in);
JSONArray Array = j.getJSONArray("employees");

请注意： -

{}表示JSONObject。（{employe}）
[]表示JSONArray。（employee[]）

Answer 3

您的字符串in是一个键为employees且值为JSONArray的对象。

因此，您需要将in解析为JSONObject并从该对象获取JSONArray employees。

Answer 4

试试这个

String in = "{'employees': [{'firstName':'John' , 'lastName':'Doe' },"
            + "{  'firstName' : 'Anna'  ,  'lastName' :'Smith' },"
            + "{  'firstName' : 'Peter'  ,  'lastName' : 'Jones'  }]}";
    try {
        String country = "";
        JSONObject jObj = new JSONObject(in);

            JSONArray jArray = jObj.getJSONArray("employees");
            for(int j=0; j <jArray.length(); j++){
                JSONObject sys = jArray.getJSONObject(j);
                 country += "  " + sys.getString("firstName");
            }



        Toast.makeText(this, country, Toast.LENGTH_LONG).show();

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

    };

Answer 5

实际上你的JSON格式错误。

使用以下字符串

String in = "{\"employees\": [{\"firstName\": \"John\",\"lastName\": \"Doe\"},{\"firstName\": \"Anna\",\"lastName\": \"Smith\"},{\"firstName\": \"Peter\",\"lastName\": \"Jones\"}]}";

try {
    String country = "";
    JSONObject jObj = new JSONObject(in);

        JSONArray jArray = jObj.getJSONArray("employees");
        for(int j=0; j <jArray.length(); j++){
            JSONObject sys = jArray.getJSONObject(j);
             country += "  " + sys.getString("firstName");
        }



    Toast.makeText(this, country, Toast.LENGTH_LONG).show();

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

};

如何将json数据从字符串变量转换为要显示的数据

5 个答案: