JSONObject.toBean轉換出錯

Exception in thread "main" net.sf.json.JSONException: java.lang.NoSuchMethodException: com.lsxy.framework.mq.events.ussd.DelaySendEvent.<init>()
    at net.sf.json.JSONObject.toBean(JSONObject.java:288)
    at net.sf.json.JSONObject.toBean(JSONObject.java:233)
    at com.lsxy.framework.mq.ons.OnsMessageParser.parse(OnsMessageParser.java:37)
    at com.lsxy.framework.mq.ons.OnsMessageParser.main(OnsMessageParser.java:55)
Caused by: java.lang.NoSuchMethodException: com.lsxy.framework.mq.events.ussd.DelaySendEvent.<init>()
    at java.lang.Class.getConstructor0(Class.java:3082)
    at java.lang.Class.getDeclaredConstructor(Class.java:2178)
    at net.sf.json.util.NewBeanInstanceStrategy$DefaultNewBeanInstanceStrategy.newInstance(NewBeanInstanceStrategy.java:55)
    at net.sf.json.JSONObject.toBean(JSONObject.java:282)
    ... 3 more

要將json字符創轉換成類。需要類提供空構造函數。如果

net.sf.json.JSONException: java.lang.NoSuchMethodException:

這個錯的話，大家就檢查一下是否是少了構造函數。