java - JSP Page error While inserting data -

-

enter image description here

im noob programming please following code.while running code gave me nullpointer exception

you never call establishconnection in dao class. result of con null.

add method establishconnection in constructor of persondao:

public persondao(){     establishconnection(); }

and try again.

furthermore read java code conventions. class name should start uppercase: persondao correct , follows camelcase code conventions.


Comments

Post a Comment

Popular posts from this blog

javascript - IndexedDB error: Uncaught DataCloneError: Failed to execute 'put' on 'IDBObjectStore': An object could not be cloned -

-
i using google maps api along html 5 geolocation api display position marker on map. once marker displayed have simple on marker double click function saves new marker current position using indexeddb. goes until object stored, recieve message " uncaught datacloneerror: failed execute 'put' on 'idbobjectstore': object not cloned. " in console. code follows: function initialize() { var mapproperties = { // set maps properties center:new google.maps.latlng(55.8580,-4.2590), zoom:8, maptypeid:google.maps.maptypeid.roadmap }; var map=new google.maps.map(document.getelementbyid("map-overview"),mapproperties); //display map in map-overview div function nogeolocation(e) { //a function handle users not have geolocation if (e) { var content = 'error: unfortunately geolocation service failed.'; } else { ...
Read more

java - Unable to make sub reports with Jasper -

-
i using jaspersoft studio create reports. having sub report in jasper main report. problem unable make work, because if add sub report detail band of main report, sub report generated number of times, row row, entire sub report repeated in number of pages. can't put in summery band due same reason. i unable put in column footer band or other footers because displays below error net.sf.jasperreports.engine.jrexception: net.sf.jasperreports.engine.jrruntimeexception: subreport overflowed on band not support overflow. @ com.jaspersoft.studio.editor.preview.view.control.reportcontroler.fillreport(reportcontroler.java:467) @ com.jaspersoft.studio.editor.preview.view.control.reportcontroler.access$18(reportcontroler.java:442) @ com.jaspersoft.studio.editor.preview.view.control.reportcontroler$4.run(reportcontroler.java:334) @ org.eclipse.core.internal.jobs.worker.run(worker.java:54) caused by: net.sf.jasperreports.engine.jrruntimeexception: subreport overflowe...
Read more

Integrity error when loading fixtures for Selenium testing in Django -

-
i want load fixture selenium testing. using fixtures successful in initial tests, know capable of loading fixtures in test setup , using them in tests. have attempted several approaches. first, generated fixtures specific models testing using dumpdata. example below: python manage.py dumpdata protocols.step --indent=2 > functional_tests/fixtures/step.json when used in test so: class signintest(functionaltest): fixtures = ['admin_user.json', 'protocol.json', 'step.json', 'protocol_element.json'] def test_login_and_view_user_data(self): ... i error: django.db.utils.integrityerror: problem installing fixtures: row in table 'protocols_protocolelement' primary key '37' has invalid foreign key: protocols_protocolelement.element_content_type_id contains value '41' not have corresponding value in django_content_type.id. second attempt involved using test data in tables, excluding contenttyp...
Read more