2016-04-11 24 views
0

私はhibernateとspring mvcを使ってDBからデータを読み込むグリッドライブラリを作っています。私はEPMID、EMPNAME、EMPAGE、SALARY、ADDRESS、department_idの2つのテーブルemployeeを持っています。部門表におけるDEPARTMENT_ID)とDEPARTMENT_IDと名前たdepartment ...ここDepartment.javaデータベースに外部キーを追加する

public class Department { 

@Id 
@GeneratedValue(strategy = GenerationType.AUTO) 

@Column(name = "department_id") 
private int depId; 

@Column(name = "name") 
private String depName; 

@OneToMany(mappedBy="department",cascade = { CascadeType.ALL }, orphanRemoval=true) 
private List<Employee> employees;} 

Employee.java

public class Employee { 

@Id 
@GeneratedValue(strategy = GenerationType.AUTO) 
@Column(name = "EMPID") 
private int empId; 

@Column(name = "EMPNAME") 
private String empName; 

@Column(name = "ADDRESS") 
private String empAddress; 

@Column(name = "SALARY") 
private String salary; 

@Column(name = "EMPAGE") 
private int empAge; 

@ManyToOne(cascade={CascadeType.ALL}) 
@JoinColumn(name="department_id") 
private Department department;} 

とサービス

01でtehの従業員を追加する機能です
public void addEmployee(String[] list, Employee employee) { 
    employee.getDepartment().setDepId(Integer.parseInt(list[3])); 

    employee.setEmpName(list[2]); 
    employee.setEmpAge(Integer.parseInt(list[4])); 
    employee.setEmpAddress(list[6]); 
    employee.setSalary(list[1]); 
    this.employeeDao.addOrEditEmployee(employee); 

すべてがそのラインemployee.getDepartment().setDepId(Integer.parseInt(list[3]));せずに罰金行くが、私は主1に参照するために外部キーを追加したい.. ここでは、例外

SEVERE: Servlet.service() for servlet [sdnext] in context with path [/Spring3HibernateApp1] threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause 
 
java.lang.NullPointerException 
 
\t at com.dineshonjava.service.EmployeeServiceImpl.addEmployee(EmployeeServiceImpl.java:27) 
 
\t at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
 
\t at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) 
 
\t at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) 
 
\t at java.lang.reflect.Method.invoke(Unknown Source) 
 
\t at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317) 
 
\t at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190) 
 
\t at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) 
 
\t at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98) 
 
\t at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:266) 
 
\t at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95) 
 
\t at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) 
 
\t at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207) 
 
\t at com.sun.proxy.$Proxy30.addEmployee(Unknown Source) 
 
\t at com.dineshonjava.controller.EmployeeController.doPostSave(EmployeeController.java:65) 
 
\t at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
 
\t at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) 
 
\t at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) 
 
\t at java.lang.reflect.Method.invoke(Unknown Source) 
 
\t at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215) 
 
\t at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132) 
 
\t at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) 
 
\t at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:781) 
 
\t at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:721) 
 
\t at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83) 
 
\t at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:943) 
 
\t at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:877) 
 
\t at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961) 
 
\t at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852) 
 
\t at javax.servlet.http.HttpServlet.service(HttpServlet.java:620) 
 
\t at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837) 
 
\t at javax.servlet.http.HttpServlet.service(HttpServlet.java:727) 
 
\t at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) 
 
\t at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) 
 
\t at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) 
 
\t at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) 
 
\t at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) 
 
\t at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) 
 
\t at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) 
 
\t at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) 
 
\t at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170) 
 
\t at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) 
 
\t at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) 
 
\t at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) 
 
\t at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) 
 
\t at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040) 
 
\t at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607) 
 
\t at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:313) 
 
\t at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) 
 
\t at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) 
 
\t at java.lang.Thread.run(Unknown Source)

答えて

0

ませを実行していますこのようなものを使用して外部キーを維持する

employee.getDepartment().setDepId(Integer.parseInt(list[3])); 

は、代わりに

Department dept = departmentDao.findById(Integer.parseInt(list[3])); 
employee.setDepartment(dept); 

Hibernateは今、従業員表にDEPARTMENT_IDを挿入することにより、部門と従業員間のデータベースの関係を作成しますか。

P.S.私はあなたのコードのすべてを持っていないので、いくつかのクラスとメソッドの名前を仮定しています。 NPE

について

私は従業員がその時点での部門を持っていないので、あなたがnullポインタ例外を受け取ったと信じています。

employee.getDepartment().setDepId(... 
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