Java Tutorial/JPA/Cascade Action

Cascade Type: REFRESH

File: Employee.java

   <source lang="java">

import java.util.ArrayList; import java.util.Collection; import javax.persistence.CascadeType; import javax.persistence.Entity; import javax.persistence.Id; import javax.persistence.ManyToOne; import javax.persistence.OneToMany; @Entity public class Employee {

 @Id
 private int id;
 private String name;
 @ManyToOne(cascade = { CascadeType.REFRESH })
 private Employee manager;
 @OneToMany(mappedBy = "manager")
 private Collection<Employee> directs = new ArrayList<Employee>();
 public int getId() {
   return id;
 }
 public void setId(int id) {
   this.id = id;
 }
 public String getName() {
   return name;
 }
 public void setName(String name) {
   this.name = name;
 }
 public Collection<Employee> getDirects() {
   return directs;
 }
 public void addDirect(Employee employee) {
   if (!getDirects().contains(employee)) {
     getDirects().add(employee);
     if (employee.getManager() != null) {
       employee.getManager().getDirects().remove(employee);
     }
     employee.setManager(this);
   }
 }
 public Employee getManager() {
   return manager;
 }
 public void setManager(Employee manager) {
   this.manager = manager;
 }

}</source>

With Cascade.All Linked Entity Auto Save

File: Helper.java

   <source lang="java">

import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; public class Helper {

 public static void checkData() throws Exception {
   Class.forName("org.hsqldb.jdbcDriver");
   Connection conn = DriverManager.getConnection("jdbc:hsqldb:data/tutorial", "sa", "");
   Statement st = conn.createStatement();
   ResultSet mrs = conn.getMetaData().getTables(null, null, null, new String[] { "TABLE" });
   while (mrs.next()) {
     String tableName = mrs.getString(3);
     System.out.println("\n\n\n\nTable Name: "+ tableName);
     ResultSet rs = st.executeQuery("select * from " + tableName);
     ResultSetMetaData metadata = rs.getMetaData();
     while (rs.next()) {
       System.out.println(" Row:");
       for (int i = 0; i < metadata.getColumnCount(); i++) {
         System.out.println("    Column Name: "+ metadata.getColumnLabel(i + 1)+ ",  ");
         System.out.println("    Column Type: "+ metadata.getColumnTypeName(i + 1)+ ":  ");
         Object value = rs.getObject(i + 1);
         System.out.println("    Column Value: "+value+"\n");
       }
     }
   }
 }

}</source>