Hints
CriteriaQuery and CriteriaBuilder of EntityManager using with JPA.
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Tomcat Console Log
Hibernate: insert into STUDENT_INFO (STUDENT_NAME) values (?)
Hibernate: insert into STUDENT_INFO (STUDENT_NAME) values (?)
Hibernate: insert into STUDENT_INFO (STUDENT_NAME) values (?)
Hibernate: insert into STUDENT_INFO (STUDENT_NAME) values (?)
Hibernate: insert into STUDENT_INFO (STUDENT_NAME) values (?)
Hibernate: insert into STUDENT_INFO (STUDENT_NAME) values (?)
Hibernate: insert into STUDENT_INFO (STUDENT_NAME) values (?)
Hibernate: insert into STUDENT_INFO (STUDENT_NAME) values (?)
Hibernate: insert into STUDENT_INFO (STUDENT_NAME) values (?)
Hibernate: insert into STUDENT_INFO (STUDENT_NAME) values (?)
Hibernate: select studentinf0_.STUDENT_ID as STUDENT1_0_, studentinf0_.STUDENT_NAME as STUDENT2_0_ from STUDENT_INFO studentinf0_ where studentinf0_.STUDENT_NAME=? limit ?
{"studentId":7,"StudentName":"Student 7"}
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package com.knowledgewalls.entity;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
@Entity(name="STUDENT_INFO")
public class StudentInfo {
@Id @GeneratedValue(strategy=GenerationType.AUTO)
@Column(name="STUDENT_ID")
private int studentId;
@Column(name="STUDENT_NAME")
private String StudentName;
public StudentInfo(){}
public StudentInfo(int studentId,String StudentName){
this.studentId = studentId;
this.StudentName = StudentName;
}
public int getStudentId() {
return studentId;
}
public void setStudentId(int studentId) {
this.studentId = studentId;
}
public String getStudentName() {
return StudentName;
}
public void setStudentName(String studentName) {
StudentName = studentName;
}
}
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package com.knowledgewalls.dao;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;
import com.knowledgewalls.entity.StudentInfo;
@Repository
@Transactional
public class StudentInfoDAO {
@PersistenceContext
EntityManager em;
public void save10Students(){
try {
for (int i=1;i<=10;i++){
StudentInfo studentInfo = new StudentInfo();
studentInfo.setStudentName("Student "+i);
em.persist(studentInfo);
}
}
catch(Exception e){
System.out.println("Insertion Failure.");
e.printStackTrace();
}
}
public StudentInfo getStudentByName(String studentName){
try {
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery<StudentInfo> criteria = builder.createQuery(StudentInfo.class);
Root<StudentInfo> studentInfo = criteria.from(StudentInfo.class);
criteria.where(builder.equal(studentInfo.get("StudentName"), studentName));
return (StudentInfo) em.createQuery(criteria.select(studentInfo)).getSingleResult();
}
catch (Exception e){
e.printStackTrace();
return null;
}
}
}
package com.knowledgewalls.dao;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;
import com.knowledgewalls.entity.StudentInfo;
@Repository
@Transactional
public class StudentInfoDAO {
@PersistenceContext
EntityManager em;
public void save10Students(){
try {
for (int i=1;i<=10;i++){
StudentInfo studentInfo = new StudentInfo();
studentInfo.setStudentName("Student "+i);
em.persist(studentInfo);
}
}
catch(Exception e){
System.out.println("Insertion Failure.");
e.printStackTrace();
}
}
public StudentInfo getStudentByName(String studentName){
try {
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery<StudentInfo> criteria = builder.createQuery(StudentInfo.class);
Root<StudentInfo> studentInfo = criteria.from(StudentInfo.class);
criteria.where(builder.equal(studentInfo.get("StudentName"), studentName));
return (StudentInfo) em.createQuery(criteria.select(studentInfo)).getSingleResult();
}
catch (Exception e){
e.printStackTrace();
return null;
}
}
}
package com.knowledgewalls.dao;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;
import com.knowledgewalls.entity.StudentInfo;
@Repository
@Transactional
public class StudentInfoDAO {
@PersistenceContext
EntityManager em;
public void save10Students(){
try {
for (int i=1;i<=10;i++){
StudentInfo studentInfo = new StudentInfo();
studentInfo.setStudentName("Student "+i);
em.persist(studentInfo);
}
}
catch(Exception e){
System.out.println("Insertion Failure.");
e.printStackTrace();
}
}
public StudentInfo getStudentByName(String studentName){
try {
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery<StudentInfo> criteria = builder.createQuery(StudentInfo.class);
Root<StudentInfo> studentInfo = criteria.from(StudentInfo.class);
criteria.where(builder.equal(studentInfo.get("StudentName"), studentName));
return (StudentInfo) em.createQuery(criteria.select(studentInfo)).getSingleResult();
}
catch (Exception e){
e.printStackTrace();
return null;
}
}
}
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StudentInfoController.java
package com.knowledgewalls.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import com.google.gson.Gson;
import com.knowledgewalls.dao.StudentInfoDAO;
@Controller
public class StudentInfoController {
@Autowired
StudentInfoDAO studentInfoDAO;
private void displayObject(Object object) {
if (object == null)
System.out.println("Null");
else
System.out.println(new Gson().toJson(object));
}
@RequestMapping(value="/doRun",method=RequestMethod.GET)
public @ResponseBody String addUsers(){
{
studentInfoDAO.save10Students();
displayObject(studentInfoDAO.getStudentByName("Student 7"));
}
return "Saved and Retrieved by HQL";
}
}
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<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd" >
<persistence-unit name="hibernatePersistenceUnit">
<properties>
<property name="hibernate.hbm2ddl.auto" value="create" />
</properties>
</persistence-unit>
</persistence>
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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:util="http://www.springframework.org/schema/util"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd">
<context:component-scan base-package="com.knowledgewalls" />
<mvc:annotation-driven />
<tx:annotation-driven transaction-manager="transactionManager" />
<bean id="emf" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="persistenceXmlLocation" value="classpath*:persistence.xml" />
<property name="persistenceUnitName" value="hibernatePersistenceUnit" />
<property name="dataSource" ref="dataSource"/>
<property name="jpaVendorAdapter" ref="jpaVendorAdapter"/>
</bean>
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/test" />
<property name="username" value="root" />
<property name="password" value="mysql" />
<property name="initialSize" value="5" />
<property name="maxActive" value="10" />
</bean>
<bean id="jpaVendorAdapter" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<property name="database" value="MYSQL"></property>
<property name="showSql" value="true"></property>
<property name="generateDdl" value="false"></property>
<property name="databasePlatform" value="org.hibernate.dialect.MySQL5InnoDBDialect"></property>
</bean>
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="emf" />
</bean>
<bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter" />
<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"/>
<bean class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor"/>
</beans>
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<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>Hibernate024_CriteriaQueries</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>beans</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>beans</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
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drop table if exists STUDENT_INFO;
create table STUDENT_INFO (STUDENT_ID integer not null auto_increment, STUDENT_NAME varchar(255), primary key (STUDENT_ID)) ENGINE=InnoDB;
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