从共享首选项类信息中检索变量以放入MySQL数据库(Android Studio使用Volley)

<uses-permission android:name="android.permission.INTERNET" />

public class PreferenceManager {
    private static final String PREF_NAME = "MyPrefs";
    private static final String KEY_USERNAME = "username";

    private static SharedPreferences getSharedPreferences(Context context) {
        return context.getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
    }

    public static void setUsername(Context context, String username) {
        SharedPreferences.Editor editor = getSharedPreferences(context).edit();
        editor.putString(KEY_USERNAME, username);
        editor.apply();
    }

    public static String getUsername(Context context) {
        return getSharedPreferences(context).getString(KEY_USERNAME, "");
    }
}

String username = PreferenceManager.getUsername(context);

dependencies {
    implementation 'com.android.volley:volley:1.2.0'
}

public class DatabaseManager {
    private static final String URL = "http://example.com/save_data.php";

    public static void saveData(Context context, String username) {
        StringRequest stringRequest = new StringRequest(Request.Method.POST, URL,
                response -> {
                    // 请求成功的回调处理
                },
                error -> {
                    // 请求失败的回调处理
                }) {
            @Override
            protected Map<String, String> getParams() {
                Map<String, String> params = new HashMap<>();
                params.put("username", username);
                return params;
            }
        };

        RequestQueue requestQueue = Volley.newRequestQueue(context);
        requestQueue.add(stringRequest);
    }
}