I have the following situation:
I am new to hibernate and I have a project to complete within the next days.
It is about a CRUD Web application in Java.The first steps have completed but I am really stuck and I cannot find any help in internet about the following situation:
i have an a Project Table which can have many Actions from Action table. ( many-to- many Relationship).
I also have a Payments table which has a composite primary key( using the 2 foreign keys of Project and action projectId,actionId) and also some other fields like paymentMethod, price, startDate, endDate. I actually use Payments table to connect each project to each action adding some additional information like amount, etc..
I hope i clarify my thoughts about the general view.
I don't know how i have to do the mapping files? Do i have to create 2 mapping files or 3? (Project.hbm.xml , action.hbm.xml and payments.hbm.xml)
In the beginning i thought to do split the relationship into the following:
a project POJO class to have one to many relationship with payments ( and the mapping XML will the as having 1 relationship one to many) and the action POJO class to have many-to-one with payments ( also with the relevant XML mapping file).
And also have a POJO class with payments, including Objects Action and Projects, and the relevant one to many relationships in XML files.
I have not seen such an implementation to any tutorial neither to any site i don't know if that is ok ?
The only thing i found was Many-to-many relationship using annotation ( mainly) and having the mid-step table ( payments in my case ) with only the 2 foreign keys without any primary key and extra fields like these that i want.
However after some research i found something and i have done tghe following which i am not sure if it is ok:
project XML:
Code:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="com.nisid.entities.Project" table="projects">
<meta attribute="class-description"> This class contains the project records. </meta>
<id name="projectId" type="int" column="projectId">
<generator class="native">
</generator>
</id>
<many-to-one name="fkCustomer" class="com.nisid.entities.Customers"
fetch="select">
<column name="customerId" not-null="true"/>
</many-to-one>
<set name="payments"
lazy="true" fetch="select" cascade="all">
<key>
<column name="projectId" />
</key>
<one-to-many class="com.nisid.entities.Payment" />
</set>
<property name="projectName" column="projectName" type="string"/>
<property name="projectDescription" column="description" type="string"/>
</class>
</hibernate-mapping>
Action XML:
Code:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="com.nisid.entities.Action" table="actions" >
<id name="actionId" type="int">
<column name="actionId" />
<generator class="native" >
</generator>
</id>
<property name="actionName" type="string">
<column name="actionName" />
</property>
<set name="payments" inverse="true" lazy="true" fetch="select">
<key>
<column name="actionId" />
</key>
<one-to-many class="com.nisid.entities.Payment" />
</set>
</class>
</hibernate-mapping>
And payment.hbm.xml :
Code:
<class name="com.nisid.entities.Payment" table="payments">
<composite-id name="paymentId" class="com.nisid.entities.PaymentID" >
<key-property name="myproject" column="projectId" />
<key-property name="myaction" column="actionId" />
</composite-id>
<component name="myproject">
<many-to-one name="project" class="com.nisid.entities.Project"
>
<column name="projectId" not-null="true" />
</many-to-one>
</component>
<component name="myaction">
<many-to-one name="action" class="com.nisid.entities.Action"
>
<column name="actionId" not-null="true" />
</many-to-one>
</component>
<property name="amount" column="amount" type="int"/>
<property name="paymentDate" column="paymentDate" type="date"/>
<property name="paymentExpire" column="paymentExpire" type="date"/>
<property name="paymentMethod" column="paymentMethod" type="string"/>
my classes are :
Code:
public class Action {
private int actionId;
private String actionName;
private Set payments=new HashSet();
public Action(){}
public Action(String actionName) {
this.actionName = actionName;
}
public int getActionId() {
return actionId;
}
public void setActionId(int actionId) {
this.actionId = actionId;
}
public String getActionName() {
return actionName;
}
public void setActionName(String actionName) {
this.actionName = actionName;
}
public Set getPayments() {
return payments;
}
public void setPayments(Set payments) {
this.payments = payments;
}
@Override
public int hashCode() {
int hash = 5;
hash = 89 * hash + Objects.hashCode(this.actionName);
return hash;
}
@Override
public boolean equals(Object obj) {
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final Action other = (Action) obj;
if (!Objects.equals(this.actionName, other.actionName)) {
return false;
}
return true;
}
@Override
public String toString() {
return "Action{" + "=" + actionName + '}';
}
}
Code:
public class Project {
private int projectId;
private String projectName;
private String projectDescription;
private Customers fkCustomer;
private Set payments=new HashSet();
public Project(){ }
public Project( String projectName, String projectDescription) {
this.projectName = projectName;
this.projectDescription = projectDescription;
}
public int getProjectId() {
return projectId;
}
public void setProjectId(int projectId) {
this.projectId = projectId;
}
public String getProjectName() {
return projectName;
}
public void setProjectName(String projectName) {
this.projectName = projectName;
}
public String getProjectDescription() {
return projectDescription;
}
public void setProjectDescription(String projectDescription) {
this.projectDescription = projectDescription;
}
public Customers getFkCustomer() {
return fkCustomer;
}
public void setFkCustomer(Customers fkCustomer) {
this.fkCustomer = fkCustomer;
}
public Set getPayments() {
return payments;
}
public void setPayments(Set payments) {
this.payments = payments;
}
@Override
public int hashCode() {
int hash = 7;
hash = 79 * hash + Objects.hashCode(this.projectName);
return hash;
}
@Override
public boolean equals(Object obj) {
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final Project other = (Project) obj;
if (!Objects.equals(this.projectName, other.projectName)) {
return false;
}
return true;
}
@Override
public String toString() {
return "Project{" + "projectName=" + projectName + ",with description=" + projectDescription + '}';
}
}
Payment:
Code:
public class Payment {
private PaymentID paymentId=new PaymentID();
private int amount;
private Date paymentDate;
private Date paymentExpire;
private String paymentMethod;
public Payment(int fkProjectId, int fkActionId, int amount, Date paymentDate, Date paymentExpire, String paymentMethod) {
this.amount = amount;
this.paymentDate = paymentDate;
this.paymentExpire = paymentExpire;
this.paymentMethod=paymentMethod;
}
public Payment(){}
public PaymentID getPaymentId() {
return paymentId;
}
public void setPaymentId(PaymentID paymentId) {
this.paymentId = paymentId;
}
public int getAmount() {
return amount;
}
public void setAmount(int amount) {
this.amount = amount;
}
public Date getPaymentDate() {
return paymentDate;
}
public void setPaymentDate(Date paymentDate) {
this.paymentDate = paymentDate;
}
public Date getPaymentExpire() {
return paymentExpire;
}
public void setPaymentExpire(Date paymentExpire) {
this.paymentExpire = paymentExpire;
}
public String getPaymentMethod() {
return paymentMethod;
}
public void setPaymentMethod(String paymentMethod) {
this.paymentMethod = paymentMethod;
}
public Project getProject(){
return getPaymentId().getProject();
}
public Action getAction(){
return getPaymentId().getAction();
}
public void setAction(Action action){
getPaymentId().setAction(action);
}
public void setProject(Project project){
getPaymentId().setProject(project);
}
@Override
public int hashCode() {
int hash = 3;
hash = 89 * hash + this.amount;
hash = 89 * hash + Objects.hashCode(this.paymentMethod);
return hash;
}
@Override
public boolean equals(Object obj) {
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final Payment other = (Payment) obj;
if (this.amount != other.amount) {
return false;
}
if (!Objects.equals(this.paymentMethod, other.paymentMethod)) {
return false;
}
return true;
}
@Override
public String toString() {
return "Payment{" + "amount=" + amount + ", paymentMethod=" + paymentMethod + '}';
}
}
And paymentID
Code:
public class PaymentID {
private Project myproject;
private Action myaction ;
public PaymentID(){
super();}
public Project getProject() {
return myproject;
}
public void setProject(Project project) {
this.myproject = project;
}
public Action getAction() {
return myaction;
}
public void setAction(Action action) {
this.myaction = action;
}
@Override
public int hashCode() {
int hash = 3;
hash = 17 * hash + Objects.hashCode(this.myproject);
hash = 17 * hash + Objects.hashCode(this.myaction);
return hash;
}
@Override
public boolean equals(Object obj) {
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final PaymentID other = (PaymentID) obj;
if (!Objects.equals(this.myproject, other.myproject)) {
return false;
}
if (!Objects.equals(this.myaction, other.myaction)) {
return false;
}
return true;
}
}
I have done many tries but nothign works.. i get usually this error:
org.hibernate.MappingException: Could not determine type for: com.nisid.entities.Project, for columns: [org.hibernate.mapping.Column(project)]
Does my implementation seem ok ? or do i have to change anything?
Thanks in advance for your help.
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