{"id":197,"date":"2016-02-11T23:08:20","date_gmt":"2016-02-11T23:08:20","guid":{"rendered":"http:\/\/kaizen-koka.com\/?p=197"},"modified":"2018-11-22T00:28:29","modified_gmt":"2018-11-22T00:28:29","slug":"hibernate","status":"publish","type":"post","link":"https:\/\/kaizen-koka.com\/?p=197","title":{"rendered":"Hibernate"},"content":{"rendered":"

\n\tDOCS : https:\/\/docs.jboss.org\/hibernate\/orm\/5.2\/userguide\/html_single\/Hibernate_User_Guide.html<\/a>
\n\tPOSTGRES: https:\/\/mvnrepository.com\/artifact\/org.postgresql\/postgresql<\/a><\/span><\/span>
\n\tHIBERNATE REPOS: https:\/\/mvnrepository.com\/artifact\/org.hibernate<\/a><\/span>\n<\/p>\n

\n\tIf you encounter any compatabile issues. pick the right version of postgres..<\/span> \n<\/p>\n

\n\t \n<\/p>\n

\r\n <dependency>\r\n    <groupId>org.postgresql<\/groupId>\r\n    <artifactId>postgresql<\/artifactId>\r\n    <version>42.2.1<\/version>\r\n  <\/dependency>\r\n  <dependency>\r\n    <groupId>org.hibernate<\/groupId>\r\n    <artifactId>hibernate-core<\/artifactId>\r\n    <version>5.2.2.Final<\/version>\r\n  <\/dependency>\r\n  <dependency>\r\n    <groupId>org.hibernate<\/groupId>\r\n    <artifactId>hibernate-ehcache<\/artifactId>\r\n    <version>5.2.2.Final<\/version>\r\n  <\/dependency>\r\n  <dependency>\r\n    <groupId>net.sf.ehcache<\/groupId>\r\n    <artifactId>ehcache<\/artifactId>\r\n    <version>2.10.1<\/version>\r\n    <type>pom<\/type>\r\n  <\/dependency>\r\n  <dependency>\r\n    <groupId>net.sf.ehcache<\/groupId>\r\n    <artifactId>ehcache-core<\/artifactId>\r\n    <version>2.6.9<\/version>\r\n  <\/dependency>\r\n  <dependency>\r\n    <groupId>org.slf4j<\/groupId>\r\n    <artifactId>slf4j-simple<\/artifactId>\r\n    <version>1.7.5<\/version>\r\n  <\/dependency>\r\n<\/dependencies><\/pre>\n
\n\t.What is Hibernate? Advantage over other persistent implementations?<\/strong>
\n\t   As per as persistent implementation is concered hibernate is the best ORM tool because of the following feature<\/span><\/span>\n<\/p>\n
\n\t– Auto DDL( Data Defination Language ) support
\n\t– HQL Support (DB independent Queries)
\n\t– Cache Support
\n\t– PK(primary key) generator support
\n\t– Data Validation Support (using Annotations)
\n\t– All exceptions are runtime exceptions in Hibernate
\n\t– ORM(Object-relational Mapping) Support Collections, inheritance, polymorphism and (uni and bidirectional relationship). And also supports one-to-one, one-to-many and many-to-many associations.
\n\t– Batch updates
\n\t– Lazy Initialization 
\n\t– OGM(Object-graph Mapping) (for DataBases like NO SQL)
\n\t– Search Feature
\n\t– in-Built connection-pool support.
\n\t– Support for native queries based on the dialect used. 
\n\t– Support criteria queries (We can do join and compilated queries easily using criterial queries)
\n\t– No source code retranslation or byte code retranslation.
\n\t– Supports transaction management and concurrency control.
\n\t– No need to write jdbc statements.<\/span><\/span>\n<\/p>\n
\n\tHigh level APIs:<\/strong>
\n\t . <\/strong>Transient Object (normal java object )
\n\t . <\/strong>Persistent Object (once object is attched to Hibernate)
\n\t . <\/strong>Detached Object (once object removed from Hibernate)
\n\t . <\/strong>Session Factory
\n\t . <\/strong>Session
\n\t . <\/strong>Transaction<\/span><\/span>\n<\/p>\n
\n\tLow level API:(Used by hibernate API internally)<\/strong>
\n\t. <\/strong>TransactionFactory (normal java object )
\n\t. <\/strong>ConnectionProvider(Factory)
\n\t. <\/strong>JTA(Java Transaction API)
\n\t. <\/strong>JNDI API
\n\t. <\/strong>JDBC API<\/span><\/span>\n<\/p>\n
\n\tSessionFactory :(org.hibernate.SessionFactory)<\/strong>
\n\t – SessionFactory is a thread-safe
\n\t – Once SessionFactory for one DB for the entire Application
\n\t – It's factory for session.
\n\t – It acts as a client for ConnectionProvider<\/span><\/span>\n<\/p>\n
\n\tSession :(org.hibernate.Session)<\/strong>
\n\t – Session is single threaded short lived object represents a conversation between application and database.
\n\t – Its a factory for Transactions<\/span><\/span>\n<\/p>\n
\n\tTransaction: (org.hibernate.Transaction)<\/strong>
\n\t – Transaction is a single threaded shortlived object used by the application to specify the atomic untis of work.
\n\t – Abstracts or hides the application from JDBC, JTA Transactions
\n\t – A session might span serval transactions in some cases.<\/span><\/span>\n<\/p>\n
\n\tConnectionProvider (org.hibernate.connection.ConnectionProvider)<\/strong>
\n\t -Its a factory of JDBC connections.
\n\t -Hides the application from underlying datasource and driver manager.
\n\t -Its not exposed to applications, i.e used by hibernate framework internally<\/span><\/span>\n<\/p>\n
\n\tTransactionFactory (org.hibernate.TransactionFactory)<\/strong>
\n\t – It's a factory for transaction object and its not exposed to Application<\/span><\/span>\n<\/p>\n
\n\tPersistent Object <\/strong>: 
\n\t – These are shortlived single threaded objects containing persistent state. These might be oridnary java beans or pojo(plain old java objects)
\n\t – The only special thing about these objects is that – they assoicates with exactly one session.
\n\t – As soon as the session is closed they will be detached and free to use any where<\/span><\/span>\n<\/p>\n
\n\t Transient and Detached Obejects:<\/strong>
\n\t – These objects are not associated with the session
\n\t – The transient instance has never been assoicated with any persistent context i.e it has not persistent identity<\/span><\/span>\n<\/p>\n
\n\t
\n\tIn order to develop Hibernate Application<\/strong>
\n\t1. pojo class 
\n\t2. mapping file
\n\t3. configuration file <\/span><\/span>\n<\/p>\n
\n\tRules:<\/strong>
\n\t..Pojo class must contain required persistent fields
\n\t..Pojo class must contain default constructor
\n\t..In Pojo, each property should contain public setter\/getter<\/span><\/span>\n<\/p>\n
\n\t..Mapping file<\/strong>
\n\t${tablename\/objectname}.hbm.xml
\n\tstudent.hbm.xml<\/span><\/span>
\n\t \n<\/p>\n
\r\n<?xml version="1.0"?>\r\n<!DOCTYPE hibernate-mapping PUBLIC "-\/\/Hibernate\/Hibernate Mapping DTD 3.0\/\/EN"\r\n        "http:\/\/hibernate.sourceforge.net\/hibernate-mapping-3.0.dtd">\r\n\r\n<hibernate-mapping>\r\n    <class name="com.bellinfo.hibernate.Student" table="STUDENT" schema="hibernate1">\r\n      <id name="studentId"\/>\r\n      <property name="name"\/>\r\n      <property name="createdDate"\/>\r\n    <\/class>\r\n<\/hibernate-mapping><\/pre>\n
\n\t <\/span><\/span>\n<\/p>\n
\n\t..Configuration file<\/strong>
\n\thibernate.cfg.xml
\n\t -DB Driver proerpties
\n\t -DB ConnectionPool properties
\n\t -hibernate Commands
\n\t -Attach mapping file<\/span><\/span>\n<\/p>\n
\r\n<?xml version="1.0" encoding="utf-8"?>\r\n<!DOCTYPE hibernate-configuration PUBLIC\r\n        "-\/\/Hibernate\/Hibernate Configuration DTD 3.0\/\/EN"\r\n        "http:\/\/hibernate.sourceforge.net\/hibernate-configuration-3.0.dtd">\r\n\r\n<hibernate-configuration>\r\n    <session-factory>\r\n        <property name="hibernate.connection.driver_class">org.postgresql.Driver<\/property>\r\n        <property name="hibernate.connection.url">jdbc:postgresql:\/\/localhost\/hibernate1<\/property>\r\n        <property name="hibernate.connection.username">postgres<\/property>\r\n        <property name="hibernate.connection.password">bellinfo<\/property>\r\n        <property name="hibernate.dialect">org.hibernate.dialect.ProgressDialect<\/property>\r\n      <!-- create, update, create-drop, validate -->\r\n        <property name="hbm2ddl.auto">create<\/property>\r\n        <property name="hibernate.default_schema">hibernate1<\/property>\r\n        <property name="show_sql">true<\/property>\r\n\r\n        <mapping resource="student.hbm.xml"\/>\r\n    <\/session-factory>\r\n<\/hibernate-configuration><\/pre>\n
\n\tEquivalent Java Code for CFG file<\/strong>\n<\/p>\n
\r\n  public static SessionFactory newSessionFactory() {\r\n\r\n        Properties properties = new Properties();\r\n        properties.put("hibernate.dialect", "org.hibernate.dialect.PostgreSQLDialect");\r\n        properties.put("hibernate.hbm2ddl.auto", "update");\r\n        properties.put("hibernate.show_sql", "true");\r\n        properties.put("hibernate.connection.driver_class", "org.postgresql.Driver");\r\n        properties.put("hibernate.connection.url", "jdbc:postgresql:\/\/127.0.0.1:5432\/mydb");\r\n        properties.put("hibernate.connection.username", "admin");\r\n        properties.put("hibernate.connection.password", "IscanU#1");\r\n\r\n        return new Configuration()\r\n                .addProperties(properties)\r\n                .addAnnotatedClass(Customer.class)\r\n                .addAnnotatedClass(Department.class)\r\n                .addAnnotatedClass(Employee.class)\r\n                .buildSessionFactory(\r\n                        new StandardServiceRegistryBuilder()\r\n                                .applySettings(properties)\r\n                                .build()\r\n                );\r\n    }<\/pre>\n
\n\tJava Code to connect<\/strong>\n<\/p>\n
\r\n public static void main(String args[]){\r\n\r\n       Student std = new Student();\r\n       std.setStudentId(1);\r\n       std.setName("siva");\r\n       std.setCreatedDate(new Date());\r\n       \/\/student state is transient\r\n       Configuration cfg = new Configuration().configure("hibernate.cfg.xml");\r\n       SessionFactory sf = cfg.buildSessionFactory();\r\n       Session session = sf.openSession();\r\n       Transaction transaction = session.beginTransaction();\r\n       session.save(std);\r\n       \/\/object state is persistent\r\n       transaction.commit();\r\n       \/\/object will be moved to database\r\n       session.evict(std);\r\n       \/\/from here object is eligible for garbage collection.\r\n\r\n       session.close();\r\n\r\n       sf.close();\r\n   }<\/pre>\n
\n\thbm2ddl.auto allows the following options:<\/span><\/span><\/strong>\n<\/p>\n
\n\tcreate<\/strong> – drop exsisting tables and create new tables
\n\tupdate<\/strong> – If any table required, it just creates. If required, it will do alter operation. else it will as is
\n\tcreate-drop <\/strong>– drop-create-drop  when you call sessionfactory.close() then it will drop the tables.
\n\tvalidate<\/strong> – validates mapping schema against table schema. Required column not found in table.<\/span><\/span>\n<\/p>\n
\n\t..insert record:<\/strong>
\n\tsave(object)   -> rt primary key(Integer)
\n\tpersist(object)  -> rt void 
\n\tsession.saveOrUpdate(object) -> rt void  -> if data avaliable in RDB and if your object modified for any attribute then it will just update column (which means select and update or insert)<\/span><\/span>\n<\/p>\n
\n\t..update record: <\/strong>(possible on non-pk feilds, update will update entire column)
\n\tsession.update(object)   ->If your session contains already the update record then update() doesn't work
\n\tsession.merge(object) – it will update the data at any cost<\/span><\/span>\n<\/p>\n
\n\t..delete record:<\/strong>
\n\t-session.delete(object)<\/span><\/span>\n<\/p>\n
\n\t..select record:<\/strong> (Transaction is not required)
\n\tObject get(Class var1, Serializable var2)<\/strong>
\n\t– select will be called whenever you trigger the get() method
\n\t– earger loading and it gurantee the record
\n\t– if record not found, then it will return null and end-up getting null pointer exception.
\n\tObject load(Class var1, Serializable var2)<\/strong>
\n\t– select will be called whenever you try to access non-pk attribute
\n\t– so, you don't any null pointer exception.
\n\t– lazy loading and it doesn't gurantee the record until you call whether the record is avaliable or not.<\/span><\/span>\n<\/p>\n
\n\t..Primary Key Auto Generators<\/strong>– <\/span><\/span>\n<\/p>\n
\n\t– assigned (default) * user is responsible
\n\t– increment  * auto +1 increment
\n\t– sequence (DataBase and Application responsible)
\n\t– identity (DataBase should support) 
\n\t– native ( sequence, identity, or hilo)
\n\t– foreign (
\n\t– hilo  (increment by 32768)
\n\t– seqhilo 
\n\t– custom generators<\/span><\/span>\n<\/p>\n
\n\tPostgres Dialects avalaible:<\/strong>
\n\torg.hibernate.dialect.PostgreSQL82Dialect
\n\torg.hibernate.dialect.ProgressDialect<\/span><\/span>\n<\/p>\n
\r\nCREATE SEQUENCE hibschema.hibernate_sequence1\r\n  INCREMENT 1\r\n  MINVALUE 1\r\n  MAXVALUE 9223372036854775807\r\n  START 5\r\n  CACHE 1;<\/pre>\n
\r\n      <id name="studentId" >\r\n          <generator class="sequence">\r\n              <param name="sequence">registration_sequence<\/param>\r\n          <\/generator>\r\n      <\/id><\/pre>\n
\n
\n\tHQL: for crud operations<\/strong>
\n\t – Database independent
\n\t – Need to write queries based on your bean class and its attribute<\/span><\/span>\n<\/p>\n
\n\tDUL: 
\n\t    executeUpdate()
\n\tDRL :
\n\t    uiqueResult()
\n\t    list()<\/span><\/span>\n<\/p>\n
\n\tInsert :<\/span><\/span><\/strong>\n<\/p>\n
\r\n \t   String hql = "insert into StudentNew(studentId, name, createdDate) select s.studentId,s.name, s.createdDate from Student s";\r\n       Query q = session.createQuery(hql);\r\n       int rows = q.executeUpdate();\r\n       System.out.println("no. of rows afftected :" + rows);\r\n       transaction.commit();\r\n       session.close();<\/pre>\n
\n\tUpdate : <\/span><\/span><\/strong>\n<\/p>\n
\r\n       String hql_update = "update Student set name='teju' where studentId='1'";\r\n       Query q = session.createQuery(hql_update);\r\n       int rows = q.executeUpdate();\r\n       System.out.println("no. of rows afftected :" + rows);\r\n       transaction.commit();\r\n       session.close();<\/pre>\n
\n\t
\n\tDelete :<\/span><\/span><\/strong>\n<\/p>\n
\r\n       String hql_delete = "delete Student where studentId='1'";\r\n       Query q = session.createQuery(hql_delete);\r\n       int rows = q.executeUpdate();\r\n       System.out.println("no. of rows afftected :" + rows);\r\n       transaction.commit();\r\n       session.close();<\/pre>\n
\n\t
\n\tRead :<\/span><\/span><\/strong>\n<\/p>\n
\n\tRetrieve Student record where student id is 4\n<\/p>\n
\r\n       \/* Retrieve Student record where student id is 4*\/\r\n       String hql_select ="from Student where studentId='4'";\r\n       Query q = session.createQuery(hql_select);\r\n       Student sd = (Student)q.uniqueResult();\r\n       System.out.println(sd);\r\n       session.close(); <\/pre>\n
\n\tRetrive all the student records\n<\/p>\n
\r\n       String hql_select ="from Student";\r\n       Query q = session.createQuery(hql_select);\r\n       List<Student> sdList = q.list();\r\n       for(Student s:sdList){\r\n           System.out.println(s);\r\n       }\r\n       transaction.commit();\r\n       session.close();<\/pre>\n
\n\tRetrive student names from Student\n<\/p>\n
\r\n       String hql_select ="select name from Student ";\r\n       Query q = session.createQuery(hql_select);\r\n       List<String> nameList = q.list();\r\n       for(String s:nameList){\r\n           System.out.println(s);\r\n       }\r\n       session.close();<\/pre>\n
\n\tTo Extract more then one column\n<\/p>\n
\r\n       String hql_select ="select studentId, name from Student ";\r\n       Query q = session.createQuery(hql_select);\r\n       List<Object> list = q.list();\r\n       for(Object obj:list){\r\n           Object[] array = (Object[]) obj;\r\n           System.out.println(array[0]);\r\n           System.out.println(array[1]);\r\n       }\r\n       session.close();\r\n<\/pre>\n
\n\tAggregate Functions avg, count, first, last, max, min, sum\n<\/p>\n
\r\n       String hql_select ="select avg(studentId) from Student";\r\n       Query q = session.createQuery(hql_select);\r\n       Double maxID = (Double)q.uniqueResult();\r\n       System.out.println(maxID.doubleValue());\r\n       session.close();<\/pre>\n
\n
\n\tCriteria Queries :<\/strong> 
\n\t-used for select operation by applying conditions
\n\t-Restrcitions are for conditions (eq, gt, )
\n\t-Projections are for particular column operations and aggregate functions
\n\t <\/span><\/span>\n<\/p>\n
\n\tSimple Criteria to retrive all records from Student table<\/span><\/span>\n<\/p>\n
\r\nCriteria c = session.createCriteria(Student.class);\r\n       List<Student> studList = c.list();\r\n       for(Student s:studList){\r\n        System.out.println(s);\r\n       }\r\n       session.close();<\/pre>\n
\n\textract a student data where studentId equals 4<\/span><\/span>\n<\/p>\n
\r\n       Criteria c = session.createCriteria(Student.class);\r\n       Criterion cr  = Restrictions.eq("studentId", 4);\r\n       c.add(cr);\r\n       Student s =(Student) c.uniqueResult();\r\n       System.out.println(s);\r\n       session.close();<\/pre>\n
\n\t <\/span><\/span>extract all the student objects where studentid greater than 4 <\/span><\/span>\n<\/p>\n
\r\n      Criteria c = session.createCriteria(Student.class);\r\n       Criterion cr  = Restrictions.gt("studentId", 4);\r\n       c.add(cr);\r\n       List<Student> list = c.list();\r\n       for(Student s:list)\r\n       System.out.println(s);\r\n       session.close();<\/pre>\n
\n\textract all the student names where studentid greater than 4<\/span><\/span>\n<\/p>\n
\r\n       Criteria c = session.createCriteria(Student.class);\r\n       Projection p = Projections.property("name");\r\n       Criterion cr  = Restrictions.gt("studentId", 4);\r\n       c.setProjection(p);\r\n       c.add(cr);\r\n       List<String> list = c.list();\r\n       for(String s:list)\r\n       System.out.println(s);\r\n       session.close();<\/pre>\n
\n\textract all the student names and studentId where studentid greater than 4<\/span><\/span>\n<\/p>\n
\r\n       \/* extract all the student names and studentId where studentid greater than 4*\/\r\n       Criteria c = session.createCriteria(Student.class);\r\n       Projection pName = Projections.property("name");\r\n       Projection pId = Projections.property("studentId");\r\n       Criterion cr  = Restrictions.gt("studentId", 4);\r\n       ProjectionList pl = Projections.projectionList();\r\n       pl.add(pName);\r\n       pl.add(pId);\r\n       c.setProjection(pl);\r\n       c.add(cr);\r\n       List<Object> list = c.list();\r\n       for(Object o:list){\r\n           Object[] arr = (Object[]) o;\r\n           System.out.println(arr[0]);\r\n           System.out.println(arr[1]);\r\n       }\r\n       session.close();\r\n<\/pre>\n
\n\tAggregate functions: get average of studentID<\/span><\/span>\n<\/p>\n
\r\n       \/* Aggregate functions: get average of studentID *\/\r\n       Criteria c = session.createCriteria(Student.class);\r\n       Projection pAvg = Projections.avg("studentId");\r\n       c.setProjection(pAvg);\r\n       double d = ((Double)c.uniqueResult()).doubleValue();\r\n       System.out.println(d);\r\n       session.close();  <\/span><\/span>\r\n<\/pre>\n
\n
\n\tORM Relations:<\/span><\/span><\/strong>\n<\/p>\n
\n\t1. Inheritance ( Is-a releation)<\/strong>
\n\t   – table-per-class <\/span><\/span>\n<\/p>\n
\r\n<hibernate-mapping>\r\n    <class name="com.bellinfo.hib.inheritance.Payment" table="PAYMENT" schema="hibschema" >\r\n     <id name="paymentId">\r\n         <generator class="increment"\/>\r\n             <\/id>\r\n        <discriminator column="PAYMENT_TYPE" type="string"\/>\r\n        <property name="amount" column="AMOUNT"\/>\r\n\r\n     <subclass name="com.bellinfo.hib.inheritance.CreditCardPayment" discriminator-value="CREDIT">\r\n         <property name="cardNumber" column="CARD_NUMBER"\/>\r\n         <property name="cvv" column="CVV"\/>\r\n     <\/subclass>\r\n     <subclass name="com.bellinfo.hib.inheritance.ChequePayment" discriminator-value="CHEQUE">\r\n         <property name="chequeNo" column="CHEQUE_NUMBER"\/>\r\n         <property name="chequeBy" column="CHEQUE_BY"\/>\r\n     <\/subclass>\r\n  <\/class>\r\n<\/hibernate-mapping><\/pre>\n
\n\t
\n\t   – table-per-subclass <\/span><\/span>\n<\/p>\n
\r\n<hibernate-mapping>\r\n    <class name="com.bellinfo.hib.inheritance.Payment" table="PAYMENT" schema="hibschema" >\r\n     <id name="paymentId" column="PAYMENT_ID">\r\n         <generator class="increment"\/>\r\n             <\/id>\r\n        <property name="amount" column="AMOUNT"\/>\r\n     <joined-subclass name="com.bellinfo.hib.inheritance.CreditCardPayment" table="CREDIT_PAYMENT">\r\n         <key column="PAYMENT_ID"\/>\r\n         <property name="cardNumber" column="CARD_NUMBER"\/>\r\n         <property name="cvv" column="CVV"\/>\r\n     <\/joined-subclass>\r\n     <joined-subclass name="com.bellinfo.hib.inheritance.ChequePayment" table="CHEQUE_PAYMENT">\r\n         <key column="PAYMENT_ID"\/>\r\n         <property name="chequeNo" column="CHEQUE_NUMBER"\/>\r\n         <property name="chequeBy" column="CHEQUE_BY"\/>\r\n     <\/joined-subclass>\r\n  <\/class>\r\n<\/hibernate-mapping><\/pre>\n
\n\t
\n\t   – table-per-concrete class<\/span><\/span>\n<\/p>\n
\r\n<hibernate-mapping>\r\n    <class name="com.bellinfo.hib.inheritance.Payment" table="PAYMENT" schema="hibschema" >\r\n        <cache usage="read-write"\/>\r\n        <id name="paymentId" column="PAYMENT_ID">\r\n         <generator class="increment"\/>\r\n             <\/id>\r\n        <property name="amount" column="AMOUNT"\/>\r\n\r\n    <union-subclass name="com.bellinfo.hib.inheritance.CreditCardPayment" table="CREDIT_PAYMENT">\r\n\r\n         <property name="cardNumber" column="CARD_NUMBER"\/>\r\n         <property name="cvv" column="CVV"\/>\r\n\r\n    <\/union-subclass>\r\n    <union-subclass name="com.bellinfo.hib.inheritance.ChequePayment" table="CHEQUE_PAYMENT">\r\n        <property name="chequeNo" column="CHEQUE_NUMBER"\/>\r\n        <property name="chequeBy" column="CHEQUE_BY"\/>\r\n    <\/union-subclass>\r\n\r\n  <\/class>\r\n<\/hibernate-mapping><\/pre>\n
\n\tReference : https:\/\/docs.jboss.org\/hibernate\/orm\/3.5\/reference\/en\/html\/inheritance.html<\/a><\/span><\/span>\n<\/p>\n
\n\t
\n\t2. Assocaition ( Has-a )<\/strong>
\n\t   – one-to-many<\/span><\/span>\n<\/p>\n
\r\n<hibernate-mapping>\r\n    <class name="com.bellinfo.hib.associations.onetomany.Product" table="PRODUCT" schema="hibschema" >\r\n\r\n      <id name="productId" column="PRODUCT_ID" >\r\n          <generator class="increment">\r\n          <\/generator>\r\n      <\/id>\r\n      <property name="productName" column="PRODUCT_NAME"\/>\r\n      <set name="parts" cascade="all"><\/strong>\r\n          <key column="PRODUCT_ID" not-null="true"<\/strong>><\/key>\r\n          <one-to-many class="com.bellinfo.hib.associations.onetomany.Part"\/>\r\n      <\/set>\r\n\r\n    <\/class>\r\n<\/hibernate-mapping><\/pre>\n
\n\t
\n\t   – one-to-many
\n\t   – many-to-many
\n\t   – one-to-one<\/span><\/span>\n<\/p>\n
\n
\n\tPagination<\/strong> : using HQL and Criteria<\/span><\/span>\n<\/p>\n
\n\tHQL <\/span><\/span><\/strong>\n<\/p>\n
\r\n        String hql_retirve ="from CreditCardPayment";\r\n        Query q =session.createQuery(hql_retirve);\r\n        int initial = 1;\r\n        int max =3;\r\n        int count =1;\r\n        HashMap<Integer, List<CreditCardPayment>> hmPagination = new HashMap<>();\r\n        System.out.println(q.list().size());\r\n        for(int i=0;i<q.list().size();i++){\r\n            q.setFirstResult(initial);\r\n            q.setMaxResults(max);\r\n<\/strong>            List<CreditCardPayment> listcc = q.list();\r\n            hmPagination.put(count, listcc);\r\n            count++;\r\n            initial = max+1;\r\n            max = max +3;\r\n        }\r\n\r\n        for(Map.Entry<Integer, List<CreditCardPayment>> entry:hmPagination.entrySet()){\r\n            System.out.println(entry.getKey());\r\n            for(CreditCardPayment ccp:entry.getValue()){\r\n            System.out.println(ccp);\r\n            }\r\n\r\n        }\r\n<\/pre>\n
\n\tCriteria :   <\/strong>     <\/span><\/span>
\n\t        criteria.setFirstResult(1);\n<\/p>\n
\n\t       criteria.setMaxResults(5);\n<\/p>\n
\n
\n\tCache Support:<\/strong>
\n\t    – Reduce database calls
\n\t    – Improve application performance<\/span><\/span>
\n\t1. Session level   – per user and its a default cache<\/span><\/span><\/strong>\n<\/p>\n
\r\nSession ses1 = sf.openSession();\r\nStudent c1 = (Student)ses1.load(Student.class, 5);\r\n\/\/This one is coming from session\r\nc1 = (Student)ses1.load(Student.class, 5);\r\n<\/pre>\n
\n\t2. SessionFactory level  – per entire application<\/strong>
\n\t    a.Enable second-level cache
\n\t    b.Configure cache factory class
\n\t    c.Define ehcache
\n\t    d.configure ehcache
\n\t    e.configure cache usage in hbm file<\/span><\/span>\n<\/p>\n
\n\tPOM FILE<\/span><\/span>\n<\/p>\n
\r\n    <dependencies>\r\n        <dependency>\r\n            <groupId>org.postgresql<\/groupId>\r\n            <artifactId>postgresql<\/artifactId>\r\n            <version>9.3-1100-jdbc41<\/version>\r\n        <\/dependency>\r\n        <dependency>\r\n            <groupId>org.hibernate<\/groupId>\r\n            <artifactId>hibernate-core<\/artifactId>\r\n            <version>4.3.2.Final<\/version>\r\n        <\/dependency>\r\n        <dependency>\r\n            <groupId>org.hibernate<\/groupId>\r\n            <artifactId>hibernate-ehcache<\/artifactId>\r\n            <version>4.3.2.Final<\/version>\r\n        <\/dependency>\r\n        <dependency>\r\n            <groupId>net.sf.ehcache<\/groupId>\r\n            <artifactId>ehcache<\/artifactId>\r\n            <version>2.10.1<\/version>\r\n            <type>pom<\/type>\r\n        <\/dependency>\r\n        <dependency>\r\n            <groupId>net.sf.ehcache<\/groupId>\r\n            <artifactId>ehcache-core<\/artifactId>\r\n            <version>2.6.9<\/version>\r\n        <\/dependency>\r\n        <dependency>\r\n            <groupId>org.slf4j<\/groupId>\r\n            <artifactId>slf4j-simple<\/artifactId>\r\n            <version>1.7.5<\/version>\r\n        <\/dependency>\r\n\r\n    <\/dependencies><\/pre>\n
\n\tCFG FILE\n<\/p>\n
\n\t      \n<\/p>\n
\r\n <!-- enable second-level cache -->\r\n        <property name="hibernate.cache.use_second_level_cache">true<\/property>\r\n        <property name="hibernate.cache.use_query_cache">true<\/property>\r\n        <property name="hibernate.cache.region.factory_class">org.hibernate.cache.ehcache.EhCacheRegionFactory<\/property>\r\n        <property name="net.sf.ehcache.configurationResourceName">ehcache.xml<\/property><\/pre>\n
\n\tEHCACHE.XML\n<\/p>\n
\r\n<?xml version='1.0' encoding='UTF-8'?>\r\n<ehcache xmlns:xsi='http:\/\/www.w3.org\/2001\/XMLSchema-instance'\r\n         xsi:noNamespaceSchemaLocation='http:\/\/ehcache.org\/ehcache.xsd'  updateCheck="true"\r\n         monitoring="autodetect" dynamicConfig="true">\r\n\r\n    <diskStore path="java.io.tmpdir\/ehcache" \/>\r\n\r\n    <defaultCache maxEntriesLocalHeap="10000" eternal="false"\r\n                  timeToIdleSeconds="120" timeToLiveSeconds="120" diskSpoolBufferSizeMB="30"\r\n                  maxEntriesLocalDisk="10000000" diskExpiryThreadIntervalSeconds="120"\r\n                  memoryStoreEvictionPolicy="LRU" statistics="true">\r\n        <persistence strategy="localTempSwap" \/>\r\n    <\/defaultCache>\r\n\r\n\r\n    <cache name="com.bellinfo.hib.inheritance.CreditCardPayment" maxEntriesLocalHeap="10000" eternal="false"\r\n           timeToIdleSeconds="60" timeToLiveSeconds="60">\r\n        <persistence strategy="localTempSwap" \/>\r\n    <\/cache>\r\n\r\n     <cache name="org.hibernate.cache.internal.StandardQueryCache"\r\n            maxEntriesLocalHeap="5" eternal="false" timeToLiveSeconds="120">\r\n         <persistence strategy="localTempSwap" \/>\r\n     <\/cache>\r\n\r\n     <cache name="org.hibernate.cache.spi.UpdateTimestampsCache"\r\n            maxEntriesLocalHeap="5000" eternal="true">\r\n         <persistence strategy="localTempSwap" \/>\r\n     <\/cache>\r\n<\/ehcache><\/pre>\n
\n\tHBM FILE \n<\/p>\n
\r\n<hibernate-mapping>\r\n    <class name="com.bellinfo.hibernate.Student" table="STUDENT" schema="hibschema" >\r\n       <cache usage="read-only"\/>\r\n      <id name="studentId" >\r\n          <generator class="native">\r\n          <\/generator>\r\n      <\/id>\r\n      <property name="name"\/>\r\n      <property name="createdDate"\/>\r\n\r\n    <\/class>\r\n<\/hibernate-mapping><\/pre>\n
\n\t3. Query Cache – <\/span><\/span>\n<\/p>\n
\n\tReferences  : https:\/\/docs.jboss.org\/hibernate\/orm\/3.6\/reference\/en-US\/html\/collections.html<\/a><\/span><\/span>\n<\/p>\n
\n\t \n<\/p>\n
\n\tAnnnotation Based Configuration:\n<\/p>\n
\n\tTABLE-PER-SUBCLASS (JOINED)\n<\/p>\n
\r\n@Entity\r\n@Table(name = "Payment")\r\n@Inheritance(strategy=InheritanceType.JOINED)\r\npublic class Payment {\r\n\r\n    @Id\r\n    @GeneratedValue(strategy=GenerationType.IDENTITY)\r\n    @Column(name = "id")\r\n    protected int id;\r\n\r\n    @Column(name="amount")\r\n    protected String amount;\r\n\r\n    public Payment(String amount) {\r\n        this.amount = amount;\r\n    }\r\n\r\n}<\/pre>\n
\n\t \n<\/p>\n
\r\n@Entity\r\n@Table(name="credit_card")\r\npublic class CreditCardPayment extends Payment{\r\n\r\n    @Column\r\n    private String ccNumber;\r\n\r\n    @Column\r\n    private String cccvv;\r\n\r\n    public CreditCardPayment(String amount, String ccNumber, String cccvv) {\r\n        super(amount);\r\n        this.ccNumber = ccNumber;\r\n        this.cccvv = cccvv;\r\n    }\r\n\r\n}\r\n<\/pre>\n
\r\n@Entity\r\n@Table(name="check_pay")\r\npublic class ChequePayment extends Payment {\r\n\r\n    @Column(name="chequeNo")\r\n    private String chequeNo;\r\n\r\n    @Column(name="chequeBy")\r\n    private String chequeBy;\r\n\r\n\r\n    public ChequePayment(String amount, String chequeNo, String chequeBy) {\r\n        super(amount);\r\n        this.chequeNo = chequeNo;\r\n        this.chequeBy = chequeBy;\r\n    }\r\n\r\n}<\/pre>\n
\n\t \n<\/p>\n
\n\tONE TABLE\n<\/p>\n
\r\n@Entity\r\n@Inheritance(strategy = InheritanceType.SINGLE_TABLE)\r\n@DiscriminatorColumn(\r\n        name="personType",\r\n        discriminatorType=DiscriminatorType.STRING\r\n)\r\n@DiscriminatorValue("Person")\r\n@Table(name="person")\r\npublic class Person implements Serializable {\r\n\r\n}<\/pre>\n
\n\t \n<\/p>\n
\r\n@Entity\r\n@Table(name="student")\r\n@DiscriminatorValue("Student")\r\npublic class Student extends Person implements Serializable {\r\n    private static final long serialVersionUID = 1L;\r\n    @Column(name="class_name")\r\n    private String className;\r\n\r\n}<\/pre>\n
\n\t \n<\/p>\n
\n\tTABLE-PER-CLASS\n<\/p>\n
\r\n@Entity\r\n@Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)\r\n@Table(name="person")\r\npublic class Person implements Serializable {\r\n private static final long serialVersionUID = 1L;\r\n\r\n}<\/pre>\n
\n\t \n<\/p>\n
\r\n@Entity\r\npublic class Student extends Person implements Serializable {\r\n\tprivate static final long serialVersionUID = 1L;\r\n\t@Column(name="class_name")\r\n\tprivate String className;\r\n\r\n}<\/pre>\n
\n\t \n<\/p>\n
\n\tASSOCIATIONS\n<\/p>\n
\n\tONE-TO-MANY\n<\/p>\n
\r\npackage com.bellinfo.advanced.hibernate.entity;\r\n\r\nimport javax.persistence.*;\r\nimport java.util.Set;\r\n\r\n@Entity\r\npublic class Cart {\r\n\r\n    @Id\r\n    @GeneratedValue(strategy = GenerationType.IDENTITY)\r\n    @Column(name="cart_id")\r\n    int id;\r\n\r\n    @Column\r\n    String name;\r\n\r\n    @OneToMany\r\n    Set<Items> items;\r\n\r\n    public Set<Items> getItems() {\r\n        return items;\r\n    }\r\n\r\n    public void setItems(Set<Items> items) {\r\n        this.items = items;\r\n    }\r\n\r\n    public Cart() {\r\n    }\r\n\r\n    public Cart(String name) {\r\n        this.name = name;\r\n    }\r\n\r\n    public int getId() {\r\n        return id;\r\n    }\r\n\r\n    public void setId(int id) {\r\n        this.id = id;\r\n    }\r\n\r\n    public String getName() {\r\n        return name;\r\n    }\r\n\r\n    public void setName(String name) {\r\n        this.name = name;\r\n    }\r\n\r\n    @Override\r\n    public String toString() {\r\n        return "Cart{" +\r\n                "id=" + id +\r\n                ", name='" + name + '\\'' +\r\n                '}';\r\n    }\r\n}\r\n<\/pre>\n
\n\t \n<\/p>\n
\r\npackage com.bellinfo.advanced.hibernate.entity;\r\n\r\nimport javax.persistence.*;\r\n\r\n@Entity\r\npublic class Items {\r\n\r\n    @Id\r\n    @GeneratedValue(strategy = GenerationType.IDENTITY)\r\n    int id;\r\n\r\n    @Column\r\n    String itemId;\r\n\r\n    @Column\r\n    double cost;\r\n\r\n    @ManyToOne\r\n    @JoinColumn(name="cart_id", nullable = false)\r\n    Cart cart1;\r\n\r\n    public Items() {\r\n    }\r\n\r\n    public Items(String itemId, double cost, Cart cart1) {\r\n        this.itemId = itemId;\r\n        this.cost = cost;\r\n        this.cart1 = cart1;\r\n    }\r\n\r\n    public int getId() {\r\n        return id;\r\n    }\r\n\r\n    public void setId(int id) {\r\n        this.id = id;\r\n    }\r\n\r\n    public String getItemId() {\r\n        return itemId;\r\n    }\r\n\r\n    public void setItemId(String itemId) {\r\n        this.itemId = itemId;\r\n    }\r\n\r\n    public double getCost() {\r\n        return cost;\r\n    }\r\n\r\n    public void setCost(double cost) {\r\n        this.cost = cost;\r\n    }\r\n\r\n    public Cart getCart1() {\r\n        return cart1;\r\n    }\r\n\r\n    public void setCart1(Cart cart1) {\r\n        this.cart1 = cart1;\r\n    }\r\n\r\n    @Override\r\n    public String toString() {\r\n        return "Items{" +\r\n                "id=" + id +\r\n                ", itemId='" + itemId + '\\'' +\r\n                ", cost=" + cost +\r\n                ", cart1=" + cart1 +\r\n                '}';\r\n    }\r\n}\r\n\r\nDemo:<\/pre>\n
\r\npackage com.bellinfo.advanced.hibernate.inheritance;\r\n\r\nimport com.bellinfo.advanced.hibernate.entity.Bike;\r\nimport com.bellinfo.advanced.hibernate.entity.Cart;\r\nimport com.bellinfo.advanced.hibernate.entity.Items;\r\nimport com.bellinfo.advanced.hibernate.entity.Vehicle;\r\nimport com.bellinfo.advanced.hibernate.util.HibernateUtil;\r\nimport org.hibernate.HibernateException;\r\nimport org.hibernate.Session;\r\nimport org.hibernate.SessionFactory;\r\nimport org.hibernate.Transaction;\r\n\r\nimport java.util.HashSet;\r\nimport java.util.Set;\r\n\r\npublic class OneToMany {\r\n\r\n    public static void main(String[] args) {\r\n        SessionFactory sf = null;\r\n        Session s = null;\r\n        Transaction tx = null;\r\n        try {\r\n            sf = HibernateUtil.newSessionFactory();\r\n            s = sf.openSession();\r\n            tx = s.beginTransaction();\r\n\r\n            Cart cart = new Cart("fruits");\r\n\r\n            Items item1 = new Items("1",200,cart);\r\n            Items item2 = new Items("2",400,cart);\r\n            Set<Items> itemsSet = new HashSet<Items>();\r\n            itemsSet.add(item1);\r\n            itemsSet.add(item2);\r\n            cart.setItems(itemsSet);\r\n\r\n            s.save(cart);\r\n            s.save(item1);\r\n            s.save(item2);\r\n\r\n            tx.commit();\r\n        } catch (HibernateException e) {\r\n            e.printStackTrace();\r\n        } finally {\r\n            s.close();\r\n            sf.close();\r\n        }\r\n    }\r\n}\r\n<\/pre>\n
\n\t <\/p>\n","protected":false},"excerpt":{"rendered":"
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