Cant instantiate class: org.primefaces.examples.view.TableBean

Cant instantiate class: org.primefaces.examples.view.TableBean

i have JSF 2 web Page that user choose from menu class_id and data FROM ,
TO .
then prees button that redirects to MainReports page thats have and ready
database Queries that taking Arguments from the Previous page .
but when just choose menu item and and Data FROM and To , o getting that
error in MainReports Page .
Note : MainReports Pgae = TableBean class . Method " doitforclass() " it's
for Menu and Date FROM and TO fileds .
it tells me :
com.sun.faces.mgbean.ManagedBeanCreationException: Cant instantiate class:
org.primefaces.examples.view.TableBean.
at com.sun.faces.mgbean.BeanBuilder.newBeanInstance(BeanBuilder.java:193)
at com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:102)
at com.sun.faces.mgbean.BeanManager.createAndPush(BeanManager.java:409)
at com.sun.faces.mgbean.BeanManager.create(BeanManager.java:269)
at
com.sun.faces.el.ManagedBeanELResolver.resolveBean(ManagedBeanELResolver.java:244)
at
com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:116)
at
com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
at
com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
at org.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:72)
at org.apache.el.parser.AstValue.getValue(AstValue.java:161)
at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:185)
at
com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)
at
javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:194)
at
javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:182)
at javax.faces.component.UIData.getValue(UIData.java:730)
at org.primefaces.component.datatable.DataTable.getValue(DataTable.java:867)
at org.primefaces.component.api.UIData.getDataModel(UIData.java:579)
at javax.faces.component.UIData.getRowCount(UIData.java:355)
at
org.primefaces.component.datatable.DataTableRenderer.encodeTbody(DataTableRenderer.java:629)
at
org.primefaces.component.datatable.DataTableRenderer.encodeRegularTable(DataTableRenderer.java:234)
at
org.primefaces.component.datatable.DataTableRenderer.encodeMarkup(DataTableRenderer.java:196)
at
org.primefaces.component.datatable.DataTableRenderer.encodeEnd(DataTableRenderer.java:82)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1786)
at javax.faces.render.Renderer.encodeChildren(Renderer.java:168)
at
javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1779)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782)
at
com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:437)
at
com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:124)
at
com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:594)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1008)
at
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
at
org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:724)
Caused by: java.lang.NullPointerException
at org.primefaces.examples.view.TableBean.<init>(TableBean.java:92)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at java.lang.Class.newInstance(Class.java:374)
at com.sun.faces.mgbean.BeanBuilder.newBeanInstance(BeanBuilder.java:188)
... 50 more
Method that passing values TO and FROM and Class_id :
public String doitforclass(){
int class_id = 0 ;
try{
Dbconnection NewConnect = new Dbconnection();
Connection con = NewConnect.MakeConnect();
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("select class_id from
class where class_name ='" + classname + "'" );
while(rs.next()){
class_id = rs.getInt(1);
}
//classname = String.valueOf(class_id);
System.out.println(String.valueOf(class_id));
System.out.println(from);
System.out.println(to);
return "MainReports.xhtml?faces-redirect=true&class_id=" +
String.valueOf(class_id)
+ "&from=" + from + "&to=" + to;
} catch(Exception ex){
System.out.println(ex);
}
return "MainReports.xhtml?faces-redirect=true&class_id=" +
String.valueOf(class_id)
+ "&from=" + from + "&to=" + to;
}
TableBean Constractor:
public TableBean() {
String SID = FacesContext.getCurrentInstance().getExternalContext()
.getRequestParameterMap().get("SID");
String from = FacesContext.getCurrentInstance().getExternalContext()
.getRequestParameterMap().get("from");
String to = FacesContext.getCurrentInstance().getExternalContext()
.getRequestParameterMap().get("to");
String class_id = FacesContext.getCurrentInstance()
.getExternalContext().getRequestParameterMap().get("class_id");
if (SID.equalsIgnoreCase("null")) {
try {
Dbconnection NewConnect = new Dbconnection();
Connection con = NewConnect.MakeConnect();
Statement stmt = con.createStatement();
ResultSet rs = stmt
.executeQuery("SELECT a.course_id, a.teacher_id,
a.class_id, a.day_id, a.state, a.apssent_date,
a.interval_id,s.student_id,s.first_name FROM Student
AS s INNER JOIN Apsent AS a ON s.student_id =
a.student_id where apssent_date between '"
+ from
+ "' and '"
+ to
+ "' and a.class_id = "
+ Integer.parseInt(class_id));
List<Integer> ids = new ArrayList<Integer>();
List<String> names = new ArrayList<String>();
List<Integer> intervals = new ArrayList<Integer>();
List<Integer> teachers = new ArrayList<Integer>();
List<String> dates = new ArrayList<String>();
final List<String> state = new ArrayList<String>();
while (rs.next()) {
ids.add(rs.getInt(8));
names.add(rs.getString(9));
intervals.add(rs.getInt(7));
teachers.add(rs.getInt(2));
dates.add(rs.getString(6));
state.add(rs.getString(5));
}
} catch (Exception ex) {
System.out.println(ex);
}
}
System.out.println(SID + from + class_id + to);
if (Integer.parseInt(SID) > 0) {
try {
Dbconnection NewConnect = new Dbconnection();
Connection con = NewConnect.MakeConnect();
Statement stmt = con.createStatement();
ResultSet rs = stmt
.executeQuery("SELECT a.course_id, a.teacher_id,
a.class_id, a.day_id, a.state, a.apssent_date,
a.interval_id,s.student_id,s.first_name FROM Student
AS s INNER JOIN Apsent AS a ON s.student_id =
a.student_id where apssent_date between '"
+ from
+ "' and '"
+ to
+ "' and s.student_id = " + SID);
List<Integer> ids = new ArrayList<Integer>();
List<String> names = new ArrayList<String>();
List<Integer> intervals = new ArrayList<Integer>();
List<Integer> teachers = new ArrayList<Integer>();
List<String> dates = new ArrayList<String>();
final List<String> state = new ArrayList<String>();
while (rs.next()) {
// System.out.println(rs.getInt(1));
ids.add(rs.getInt(8));
names.add(rs.getString(9));
intervals.add(rs.getInt(7));
teachers.add(rs.getInt(2));
dates.add(rs.getString(6));
state.add(rs.getString(5));
}
carsSmall = new ArrayList<Car>();
populateRandomCars(carsSmall, ids.size(), ids, names,
intervals, teachers, dates, state);
} catch (Exception ex) {
System.out.println(ex);
}
}
}