Question

我想在数据库中使用hibernate和struts2.But持久保存一个实体“Doctor”。每次按下按钮保存“医生”表格它会抛出空指针异常。我检查了一千次但是我不知道我在做什么错。

这是我的实体

@Entity
public class Doctor implements java.io.Serializable {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer id;

private String firstName;
private String lastName;
private String email;

public Doctor() {
}

public Doctor(String firstName, String lastName, String email) {
    this.firstName = firstName;
    this.lastName = lastName;

    this.email = email;
}

public Integer getId() {
    return this.id;
}

public void setId(Integer id) {
    this.id = id;
}

public String getFirstName() {
    return this.firstName;
}

public void setFirstName(String firstName) {
    this.firstName = firstName;
}

public String getLastName() {
    return this.lastName;
}

public void setLastName(String lastName) {
    this.lastName = lastName;
}

public String getEmail() {
    return this.email;
}

public void setEmail(String email) {
    this.email = email;
}

 }

这是我的ActionSupport类，它试图在数据库中保留医生

  public class DoctorsController extends ActionSupport implements ModelDriven<Doctor> 
   {

    private DoctorDao docDao = new DoctorDaoImpl();
    private List<Doctor> listDoc = new ArrayList<Doctor>();
    private Doctor doc = new Doctor();

    public List<Doctor> getListDoc() {
        return listDoc;
    }

    public void setListDoc(List<Doctor> listDoc) {
        this.listDoc = listDoc;
    }



 public String excute() throws Exception {
        return SUCCESS;`

    }

    public String getDoctorView() {

        return SUCCESS;
    }

    public Doctor getDoc() {
        return doc;
    }

    public void setDoc(Doctor doc) {
        this.doc = doc;
    }

 public String addDoctor() {

        this.docDao.addDoctor(this.doc);
        listDoc = docDao.listDoctor();
        return SUCCESS;

    }    

  @Override
    public Doctor getModel() {
        return doc;
    }

    public DoctorDao getDocDao() {
        return docDao;
    }


  public void setDocDao(DoctorDao docDao) {
        this.docDao = docDao;
    }
    }

这是我医生的表格

<html>
    <head>
    </head>
    <body>
        <s:form action="saveDoctor" method="post">
            <table>   
                <s:push value="doc">
                    <s:hidden name="id"  />

                    <s:textfield name="firstName" label="First Name" />

                    <s:textfield name="lastName" label="Last Name" />


                    <s:textfield name="email" label="Email" />




                </table>     
                <input type="submit" value="submit">

            </s:push>
        </s:form>
    </body>
</html>

<struts>

<package name="default" extends="struts-default">

    <action name="index" class="Controller.DoctorsController">
        <result name="success">/doctor.jsp</result>
    </action>

     <action name="addDoctorView" class="Controller.DoctorsController">
        <result name="success">/jsp/doctor.jsp</result>
    </action>

     <action name="saveDoctor" class="Controller.DoctorsController" method="addDoctor">
        <result name="success">/jsp/doctorlist.jsp</result>
    </action>

</package>
</struts>

每当我想坚持医生时，它就会抛出Nullpointer Exception。

Struts Crud Operation

0 个答案: