spring - Getting java.lang.NumberFormatException when displaying data in JSP page -

i using hibernate , spring mvc. trying fetch information 2 tables , display in jsp page . here tables:

table name : student

student_id    studentname   1.           jason stathum 

table name : studentdetails

studentdetailsid   fathername   mothername    student_id    1                 mr.x          mrs. y        1 

in jsp page trying display data this:

 sl#   student              father     mother  1     jason stathum        mr.x       mrs.y 

when run application see data following error message:

http status 500 - exception occurred processing jsp page /web-inf/views/studentlist.jsp @ line 29 root cause java.lang.numberformatexception: input string: "fathername" java.lang.numberformatexception.forinputstring(unknown source) java.lang.integer.parseint(unknown source) java.lang.integer.parseint(unknown source).... , many other lines...

i have included codes below, please tell me doing wrong?

thank much

entity: student

@entity @table(name = "student") public class student {  @id  @generatedvalue(strategy = generationtype.auto) @column(name="student_id", nullable= false) private integer studentid; private string studentname;  @onetomany(cascade = cascadetype.all) @joincolumn(name="student_id", referencedcolumnname="student_id") private list<studentdetails> studentdetails = new arraylist<studentdetails>();  // getters , setters  public integer getstudentid() {     return studentid; } public void setstudentid(integer studentid) {     this.studentid = studentid; } public string getstudentname() {     return studentname; }  public void setstudentname(string studentname) {     this.studentname = studentname; } public list<studentdetails> getstudentdetails() {     return studentdetails; } public void setstudentdetails(list<studentdetails> studentdetails) {     this.studentdetails = studentdetails; } 

entity : studentdetails

@entity @table(name = "studentdetails") public class studentdetails {  @id @generatedvalue(strategy = generationtype.auto) private integer studentdetailsid; private string fathername; private string mothername;  // getters , setters  public integer getstudentdetailsid() {     return studentdetailsid; } public void setstudentdetailsid(integer studentdetailsid) {     this.studentdetailsid = studentdetailsid; } public string getfathername() {     return fathername; } public void setfathername(string fathername) {     fathername = fathername; } public string getmothername() {     return mothername; } public void setmothername(string mothername) {     mothername = mothername; } 

controller

@requestmapping(value="studentlist", method = requestmethod.get) public string getrecords(model map) {            list<student> student = studentservice.getall();     map.addattribute("student", student);     return "studentlist";        } 

studentdaoimpl

@override @suppresswarnings("unchecked") public list<student> getall() {     return getsessionfactory().opensession().createquery("from student").list(); } 

jsp page: studentlist

<c:if test="${!empty student}"> <table class="studenttable"> <tr>     <th>sl#</th>     <th>name</th>     <th>father</th>     <th>mother</th>               </tr> <c:set var="count" value="0" scope="page" /> <c:foreach items="${student}" var="row">      <c:set var="count" value="${count + 1}" scope="page"/>     <tr>         <td>${count}</td>         <td>${row.studentname}</td>                  <td>${row.studentdetails.fathername}</td> <--- line 29         <td>${row.studentdetails.mothername}</td>     </tr>  </c:foreach> </table> </c:if> 

the problem trying reference property of list object.

${row.studentdetails} = list<studentdetails>

jstl trying convert fathername number can index in list<studentdetails>.

to fix ${row.studentdetails[0].fathername} or put method in student called getdefaultstudentdata() return first or "preffered" student details object reference ${row.defaultstudentdata.fathername}. or of course change output deal multiple student details per student ☺