JSONException异常

下面是net.sf.json.JSONException: java.lang.reflect.InvocationTargetException异常：

net.sf.json.JSONException: java.lang.reflect.InvocationTargetException

    at net.sf.json.JSONObject.defaultBeanProcessing(JSONObject.java:818)

    at net.sf.json.JSONObject._fromBean(JSONObject.java:699)

    at net.sf.json.JSONObject.fromObject(JSONObject.java:172)

    at net.sf.json.AbstractJSON._processValue(AbstractJSON.java:274)

    at net.sf.json.JSONObject._processValue(JSONObject.java:2655)

    at net.sf.json.JSONObject.processValue(JSONObject.java:2721)

    at net.sf.json.JSONObject.setInternal(JSONObject.java:2736)

    at net.sf.json.JSONObject.setValue(JSONObject.java:1424)

    at net.sf.json.JSONObject.defaultBeanProcessing(JSONObject.java:765)

    at net.sf.json.JSONObject._fromBean(JSONObject.java:699)

    at net.sf.json.JSONObject.fromObject(JSONObject.java:172)

    at net.sf.json.AbstractJSON._processValue(AbstractJSON.java:274)

    at net.sf.json.JSONArray._processValue(JSONArray.java:2513)

    at net.sf.json.JSONArray.processValue(JSONArray.java:2538)

    at net.sf.json.JSONArray.addValue(JSONArray.java:2525)

    at net.sf.json.JSONArray._fromCollection(JSONArray.java:1056)

    at net.sf.json.JSONArray.fromObject(JSONArray.java:123)

    at net.sf.json.AbstractJSON._processValue(AbstractJSON.java:240)

    at net.sf.json.JSONObject._processValue(JSONObject.java:2655)

    at net.sf.json.JSONObject.processValue(JSONObject.java:2721)

    at net.sf.json.JSONObject.setInternal(JSONObject.java:2736)

    at net.sf.json.JSONObject.setValue(JSONObject.java:1424)

    at net.sf.json.JSONObject.defaultBeanProcessing(JSONObject.java:765)

    at net.sf.json.JSONObject._fromBean(JSONObject.java:699)

    at net.sf.json.JSONObject.fromObject(JSONObject.java:172)

    at net.sf.json.JSONObject.fromObject(JSONObject.java:134)

    at com.web.util.DBUtil.jsonObjectReturn(DBUtil.java:108)

    at com.web.servlet.RepertoryCheckServlet.bsgBills(RepertoryCheckServlet.java:316)

    at com.web.servlet.RepertoryCheckServlet.doPost(RepertoryCheckServlet.java:77)

    at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)

    at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)

    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)

    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

    at com.web.filter.FilterEconding.doFilter(FilterEconding.java:26)

    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)

    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)

    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)

    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)

    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)

    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)

    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)

    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)

    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)

    at java.lang.Thread.run(Thread.java:745)

net.sf.json.JSONException异常通常是因为成员变量数据类型不一致，转换为JSON数据时就会报异常，这次抛异常是因为从数据库查询出的时间数据类型Date没有从java.sql.Date转换为java.util.Date所导致，代码如下：

        List billsInfos = new ArrayList();

        try {

            StringBuffer buffer = new StringBuffer(selectBills);

            con = DBUtil.getConnection();

            ps = con.prepareStatement(buffer.toString());

            rs = ps.executeQuery();

            while (rs.next()) {

                BillsInfo info = new BillsInfo();

                info.setBillsID(rs.getInt("BillsID"));

                info.setStaffMC(rs.getString("StaffMC"));

                info.setEnteringTime(rs.getDate("EnteringTime"));

                info.setRemarkBills(rs.getString("RemarkBills"));

                billsInfos.add(info);

            }          

        } catch (SQLException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        } finally {

            DBUtil.close(con, ps, rs);

    }

上面中BillsInfo类里面的enteringTime变量是java.util.Date类型，而通过jdbc从数据库查询出来的数据类型是java.sql.Date类型，虽然用set方法赋值是不会出现问题，但当用JSONObject转为JSON数据的时候就会报net.sf.json.JSONException异常，此时应该怎么改呢，只需要把rs.getDate("EnteringTime")改一下格式就不会再报这个异常了，如下：

Date date = new Date(rs.getDate("EnteringTime").getTime());

info.setEnteringTime(date);