i am using template interface to cast to the required DAO, but i need to place it in the bean xml file so that i can inject the datasource in the required implemented class.
SimpleInterfaceDao.java
package com.dao;
import java.util.List;
import com.connection.impl.QuerySpecifierWrapperList;
public interface SimpleInterfaceDao<T> {
public List<String> loadColumnNames(String query);
public List<T> loadAll(String query);
}
ClusterInfoDaoImpl.java
package com.dao.impl;
import java.util.List;
import javax.sql.DataSource;
import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import com.common.CommonConstants;
import com.connection.impl.QueryExecutorImpl;
import com.connection.impl.QuerySpecifierWrapperList;
import com.dao.ClusterInfo;
import com.dao.SimpleInterfaceDao;
public class ClusterInfoDaoImpl <T> implements SimpleInterfaceDao <T> {
#Autowired
DataSource GlobalcashmanmdataSource;
static Logger log = Logger.getLogger(ClusterInfoDaoImpl.class.getName());
public List<T> loadAll(String query){
List<ClusterInfo> listClusterinfo = null;
log.info("Executing query loadAll:" + query);
//JdbcTemplate jdbcTemplate = (JdbcTemplate) GlobalcashmanmdataSource;
JdbcTemplate jdbcTemplate = new JdbcTemplate(GlobalcashmanmdataSource);
listClusterinfo = jdbcTemplate.query(query,new BeanPropertyRowMapper<ClusterInfo>(ClusterInfo.class));
return (List <T>) listClusterinfo;
}
public List<String> loadColumnNames(String query){
List<String> columnNames = null;
//TODO to be removed or commented once the testing is done.
//callContextToSetDataSource();
JdbcTemplate jdbcTemplate = new JdbcTemplate(GlobalcashmanmdataSource);
columnNames = jdbcTemplate.queryForList(query,String.class);
return columnNames;
}
public void insert(ClusterInfo customer){
}
}
call to the function
public class QueryExecutorImpl {
public QueryExecutionResults executeQueryWrapperByQueryID(String queryID){
......
......
SimpleInterfaceDao <ClusterInfo> daoInterface = new ClusterInfoDaoImpl<ClusterInfo>();
queryColumnNames = daoInterface.loadColumnNames(querySpecifier.getColumnQuery());
queryRowColResult = (List) daoInterface.loadAll(querySpecifier.getColumnQuery());
......
}
bean.xml
<bean id="queryexecutorimplbean" class="com.connection.impl.QueryExecutorImpl">
</bean>
Question is not clear, However you could try this way
If ClusterInfoDaoImpl bean, already been created then it's simple, inject this directly into QueryExecutorImpl (have a instance ClusterInfoDaoImpl<?> daoInterface; and it's setter property)
<bean id="queryexecutorimplbean" class="com.connection.impl.QueryExecutorImpl">
<property name="ClusterInfoDao" ref="ClusterInfoDaoImpl" />
</bean>
I think nothing much to do with templates here.
Related
I am trying to Implement InitializingBean on my StudentDaoImpl.class and in the function afterPropertiesSet() trying to execute an expression using ExpressionParser, but Spring is saying that property config is not found or is null even if I have declared config in my App.propperties.
AppConfig.class(Configuration Class)
package config;
import dao.StudentDAOImpl;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import javax.sql.DataSource;
#Configuration
#PropertySource("classpath:App.properties")
public class AppConfig {
#Bean("jdbcTemplete")
public JdbcTemplate jdbcTemplate() {
JdbcTemplate template = new JdbcTemplate();
template.setDataSource(dataSource());
return template;
}
#Bean("dataSource")
public DataSource dataSource() {
DriverManagerDataSource ds = new DriverManagerDataSource();
ds.setDriverClassName("com.mysql.cj.jdbc.Driver");
ds.setUrl("jdbc:mysql://localhost:3306/springjdbc");
ds.setUsername("root");
ds.setPassword("root");
return ds;
}
#Bean("StudentDaoImpl")
public StudentDAOImpl studentDaoImpl() {
StudentDAOImpl studentdao = new StudentDAOImpl(jdbcTemplate());
return studentdao;
}
#Bean("getProperties")
public static PropertySourcesPlaceholderConfigurer getProperties() {
return new PropertySourcesPlaceholderConfigurer();
}
}
StudentDaoImpl.class (I have removed methods of StudentDao Interface from the code below for you to see properly)
package dao;
import entities.Student;
import mapper.StudentMapper;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.expression.Expression;
import org.springframework.expression.ExpressionParser;
import org.springframework.expression.spel.standard.SpelExpressionParser;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import java.util.List;
public class StudentDAOImpl implements StudentDAO, InitializingBean {
private JdbcTemplate jdbcTemplate;
#Value("${config}")
String s;
public StudentDAOImpl(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}
#Override
public void afterPropertiesSet() throws Exception {
ExpressionParser expressionParser = new SpelExpressionParser();
System.out.println(s);
Expression expression = expressionParser.parseExpression("config");
String result = (String)expression.getValue();
System.out.println(result);
// if(result == true) {
// System.out.println("[Configuration]: Java Configuration");
// } else {
// System.out.println("[Configuration]: XML Configuration");
// }
}
}
App.properties
config=java
Also, I have seen that I was able to access the property from App.properties using #Value but not with ExpressionParser, Please help me solve this issue.
?
You are parsing a String, not the field; use
Expression expression = expressionParser.parseExpression(config);
to parse an expression in field config - however the value java is not a valid expression.
It is not at all clear what you are trying to do.
I am trying to create a maven project to access Oracle database with more than one datasource configurations. Here is my code:
First DataSource Config:
package com.business.data.datasource;
import javax.sql.DataSource;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.autoconfigure.jdbc.DataSourceProperties;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
#Configuration
public class FirstDbConfig {
#Primary
#Bean(name = "firstDataSourceProperties")
#ConfigurationProperties("first.datasource")
public DataSourceProperties dataSourceProperties() {
return new DataSourceProperties();
}
#Primary
#Bean(name = "firstDataSource")
#ConfigurationProperties(prefix = "first.datasource")
public DataSource dataSource(#Qualifier("firstDataSourceProperties") DataSourceProperties properties) {
return DataSourceBuilder.create().build();
}
#Bean(name = "firstSessionFactory")
#Primary
public SqlSessionFactoryBean firstSessionFactory(#Qualifier("firstDataSource") final DataSource firstDataSource)
throws Exception {
final SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
sqlSessionFactoryBean.setDataSource(firstDataSource);
sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:./mapper/FirstDbMapper.xml"));
sqlSessionFactoryBean.setTypeAliasesPackage("com.business.data.model");
return sqlSessionFactoryBean;
}
}
Second DataSource Config:
package com.business.data.datasource;
import javax.sql.DataSource;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.autoconfigure.jdbc.DataSourceProperties;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
#Configuration
public class SecondDbConfig {
#Primary
#Bean(name = "secondDataSourceProperties")
#ConfigurationProperties("second.datasource")
public DataSourceProperties dataSourceProperties() {
return new DataSourceProperties();
}
#Bean(name = "secondDataSource")
#ConfigurationProperties(prefix = "second.datasource")
public DataSource dataSource(#Qualifier("secondDataSourceProperties") DataSourceProperties properties) {
return DataSourceBuilder.create().build();
}
#Bean(name = "secondSessionFactory")
public SqlSessionFactoryBean secondSessionFactory(#Qualifier("secondDataSource") final DataSource firstDataSource)
throws Exception {
final SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
sqlSessionFactoryBean.setDataSource(firstDataSource);
sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:./mapper/SecondDbMapper.xml"));
sqlSessionFactoryBean.setTypeAliasesPackage("com.business.data.model");
return sqlSessionFactoryBean;
}
}
First Mapper interface:
package com.business.data.repository;
import java.util.List;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import com.business.data.model.PersonDetail;
import org.springframework.stereotype.Repository;
#Repository
#Mapper
public interface FirstDbMapper {
public List<PersonDetail> getUserData(#Param("firstName") String firstName, #Param("lastName") String lastName);
}
Second Mapper interface:
package com.business.data.repository;
import java.util.List;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import com.business.data.model.PersonDetail;
import org.springframework.stereotype.Repository;
#Repository
#Mapper
public interface SecondDbMapper {
public List<PersonDetail> getStaffData(#Param("firstName") String firstName, #Param("lastName") String lastName);
}
src/main/resources/mapper/FirstMapper.xml
<?xml version = "1.0" encoding = "UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!-- namespace must indicate mapper interface full package path . It is an alias here-->
<mapper namespace = "com.business.data.repository.FirstDbMapper">
<select id = "getUserData" parameterType = "map" resultMap = "personDetailMap">
SELECT *
FROM user
WHERE UPPER(first_name) LIKE UPPER(#{firstName}||'%')
AND UPPER(last_name) LIKE UPPER(#{lastName}||'%')
</select>
...
</mapper>
src/main/resources/mapper/SecondMapper.xml
<?xml version = "1.0" encoding = "UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!-- namespace must indicate mapper interface full package path . It is an alias here-->
<mapper namespace = "com.business.data.repository.SecondDbMapper">
<select id = "getStaffData" parameterType = "map" resultMap = "personDetailMap">
SELECT *
FROM staff
WHERE UPPER(first_name) LIKE UPPER(#{firstName}||'%')
AND UPPER(last_name) LIKE UPPER(#{lastName}||'%')
</select>
...
</mapper>
Service class is like
#Autowired
FirstDbMapper firstDbMapper;
public List<PersonDetail> getUser(String fName, String lName) throws MyServiceException {
...
try {
userList = firstDbMapper.getUserData(fName, lName);
} catch (Exception e) {
...
}
return userList;
}
application.properties:
first.datasource.jdbc-url=jdbc:oracle:thin:#host01:1561:db1
first.datasource.username=user1
first.datasource.password=password1
second.datasource.jdbc-url=jdbc:oracle:thin:#host02:1561:db2
second.datasource.username=user2
second.datasource.password=password2
I also have #MapperScan("com.business.data.repository") in my spring boot application java.
I can only make one datasource work, which is the one with #Primary annotation. I swapped #Primary between the two configuration, always the one with #Primary worked, the other got "Invalid bound statement (not found)" error.
Can anyone help me out?
Thanks!
You can use the #MapperScan annotation on a configuration class to attach mappers to the different session factories. I find it convenient to place mappers in different packages like this:
#MapperScan(basePackages="mapper.package1", sqlSessionFactoryRef="firstSessionFactory")
#MapperScan(basePackages="mapper.package2", sqlSessionFactoryRef="secondSessionFactory")
The issue was resolved by using HikariDataSource.
#Primary
#Bean(name = FIRST_DATASOURCE)
#ConfigurationProperties(prefix = "first.datasource")
public DataSource dataSourceFirst() {
return DataSourceBuilder.create().type(HikariDataSource.class).build();
}
I have an issue with detecting adding a new row to the table. I want to trigger a method from some service (Spring boot) when somebody executes an insert query on the database (Postgres)
Somebody told me I can use #Scheduled annotation and check if something was added using a repository. I have to make some changes instantly (by using another method). The scheduled method should run every 5 seconds to do this instantly. Of course, this is a really bad idea because it will kill the database someday and it's not efficient.
How can I do this better?
You can write concrete implementer of org.hibernate.integrator.spi.Integrator. and give it to hibernate.integrator_provider
From ServiceRegistry we can get EventListenerRegistry and then append listener of type EventType.POST_INSERT. More events here.
Main Reference Hibernate Integrator Ref
As per the query, I have also added how to call the service method from the listener class.
Here is how I have done it:
package com.example.samplejdbctemplatecall;
import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import lombok.extern.slf4j.Slf4j;
import org.hibernate.boot.Metadata;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.event.service.spi.EventListenerGroup;
import org.hibernate.event.service.spi.EventListenerRegistry;
import org.hibernate.event.spi.EventType;
import org.hibernate.event.spi.PostInsertEvent;
import org.hibernate.event.spi.PostInsertEventListener;
import org.hibernate.integrator.spi.Integrator;
import org.hibernate.jpa.boot.spi.IntegratorProvider;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.service.spi.SessionFactoryServiceRegistry;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.orm.jpa.HibernatePropertiesCustomizer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Repository;
import org.springframework.stereotype.Service;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import java.util.Collections;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
#RequestMapping(path = "/entity-listener")
#RestController
public class SampleLogController {
private final SampleLogRepository sampleLogRepository;
private final SampleLogEntries sampleLogEntiries;
#Autowired
public SampleLogController(SampleLogRepository sampleLogRepository, SampleLogEntries sampleLogEntiries) {
this.sampleLogRepository = sampleLogRepository;
this.sampleLogEntiries = sampleLogEntiries;
}
// This is usually post method but for test purpose creating new log with uuid random and inserting
#GetMapping(path = "insert")
public SampleLog insertNewEntry() {
final String uuid = UUID.randomUUID().toString();
final SampleLog sampleLog = new SampleLog();
sampleLog.setMessage(uuid);
return sampleLogRepository.save(sampleLog);
}
#GetMapping(path = "list-recent-inserts")
public Map<Long, String> entries() {
return sampleLogEntiries.data();
}
}
#Slf4j
#Component
class HibernateConfig implements HibernatePropertiesCustomizer {
private final JpaEventListenerIntegrator jpaEventListenerIntegrator;
#Autowired
HibernateConfig(JpaEventListenerIntegrator jpaEventListenerIntegrator) {
this.jpaEventListenerIntegrator = jpaEventListenerIntegrator;
}
#Override
public void customize(Map<String, Object> hibernateProperties) {
log.warn("Called hibernate configuration");
hibernateProperties.put("hibernate.integrator_provider",
(IntegratorProvider) () -> Collections.singletonList(jpaEventListenerIntegrator));
}
}
#Configuration
class SampleConfiguration {
#Bean
SampleLogEntries sampleEntries() {
return new SampleLogEntries();
}
}
class SampleLogEntries {
private final ConcurrentMap<Long, String> map = new ConcurrentHashMap<>();
public void add(SampleLog sampleLog) {
this.map.put(sampleLog.getId(), sampleLog.getMessage());
}
public Map<Long, String> data() {
return Collections.unmodifiableMap(this.map);
}
}
#Repository
interface SampleLogRepository extends CrudRepository<SampleLog, Long> {
}
#Getter
#Setter
#NoArgsConstructor
#AllArgsConstructor
#Entity
class SampleLog {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String message;
}
#Service
#Slf4j
class JpaEventListenerIntegrator implements Integrator, PostInsertEventListener {
private final SampleLogEntries sampleLogEntiries;
#Autowired
JpaEventListenerIntegrator(SampleLogEntries sampleLogEntiries) {
this.sampleLogEntiries = sampleLogEntiries;
}
#Override
public void integrate(Metadata metadata, SessionFactoryImplementor sessionFactory, SessionFactoryServiceRegistry serviceRegistry) {
final EventListenerRegistry eventListenerRegistry = serviceRegistry.getService(EventListenerRegistry.class);
eventListenerRegistry
.appendListeners(EventType.POST_INSERT, this);
}
#Override
public void disintegrate(SessionFactoryImplementor sessionFactory, SessionFactoryServiceRegistry serviceRegistry) {
final EventListenerRegistry eventListenerRegistry = serviceRegistry.getService(EventListenerRegistry.class);
EventListenerGroup<PostInsertEventListener> eventListenerGroup = eventListenerRegistry
.getEventListenerGroup(EventType.POST_INSERT);
log.info("listener attached were: " + eventListenerGroup.getClass().getSimpleName());
log.error("disintegrate : " + getClass().getCanonicalName());
eventListenerGroup.clearListeners();
}
#Override
public void onPostInsert(PostInsertEvent event) {
log.info("Inserted : " + event.getEntity());
final Object entity = event.getEntity();
if (entity instanceof SampleLog) {
sampleLogEntiries.add((SampleLog) entity);
}
}
#Override
public boolean requiresPostCommitHanding(EntityPersister persister) {
return false;
}
}
The answer from #silentsudo is the best one if you only ever use JPA to update the table in question, and if you only have one process updating it.
The issue is that since you are being notified via the JPA interceptor, you won't be notified of any updates that happen outside of your JAP repository.
If you need these other notifications, then you can use Postgres' LISTEN/NOTIFY without polling by using an alternate postgresql JDBC driver, pgjdbc-ng, which implements async notifications.
With this method, you create a trigger in the database to send the notification, so you will be notified of other's updates as well. See https://www.openmakesoftware.com/postgresql-listen-notify-events-example
I have to create multiple beans of same type for different property value which is to be injected using constructor.
Currently I have used Bean scope as Prototype & created multiple methods to read different properties to create new object. How to combine all the different methods into single method and to supply different values at run time to create new bean.
package com.demo.service;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.Environment;
#Configuration
public class ConfigClass {
#Bean(name="RC")
public JavaClient getClient(#Autowired Environment env)
{
String sName=env.getProperty("RCSName");
String aUrl=env.getProperty("RCAUrl");
String dUrl=env.getProperty("RCDUrl");
return new JavaClient(sName,aUrl,dUrl);
}
#Bean(name="O")
public JavaClient getOClient(#Autowired Environment env)
{
String sName=env.getProperty("OSName");
String aUrl=env.getProperty("OAUrl");
String dUrl=env.getProperty("ODUrl");
return new JavaClient(sName,aUrl,dUrl);
}
}
Now it is creating 2 beans as per above code. Expectation: How to combine getClient & getOClient into single method, but the property to be supplied in a loop to create multiple beans of same type JavaClient
I have modified my ConfigClass as below & created ApplicationContextAware to inject beans by reading file properties.
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Scope;
import org.springframework.scheduling.annotation.EnableScheduling;
#Configuration
#EnableScheduling
public class ConfigClass {
#Bean
#Scope("prototype")
public JavaClient getClient(String sName,String aUrl,String dUrl)
{
return new JavaClient(sName,aUrl,dUrl);
}
}
Then Have created ApplicationContextAware to create Beans.
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.util.Iterator;
import java.util.List;
import javax.annotation.PostConstruct;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.stereotype.Component;
#Component
public class ApplicationContextProvider implements ApplicationContextAware {
private ApplicationContext applicationContext;
#Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.applicationContext = applicationContext;
}
public ApplicationContext getContext() {
return applicationContext;
}
#PostConstruct
public void init()
{
try {
String fileName = "Url.txt";
Resource resource = new ClassPathResource(fileName);
File file = resource.getFile();
List<String> lines = Files.readAllLines(file.toPath());
for (Iterator<String> iterator = lines.iterator(); iterator.hasNext();) {
String line = (String) iterator.next();
String[] s = line.split(",");
applicationContext.getBean(JavaClient.class,s[0], s[1], s[2]);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
By mean of Spring libraries I have to develope a DAL (Data Access Layer) in the form of a jar library which will be imported into the main application.
I want to use Hibernate to access a MySQL DB and DBCP for the management of the connections pool.
I have written the config file DALConfig.java which contains the configuration of the DAL beans:
package my.dal.config;
import java.util.Properties;
import javax.annotation.Resource;
import org.apache.commons.dbcp2.BasicDataSource;
import org.apache.commons.dbcp2.BasicDataSourceFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor;
import org.springframework.orm.hibernate4.HibernateTransactionManager;
// Needed by Spring to add this class to the ApplicationContext's configuration
#Configuration
#ComponentScan(basePackages = { "my.dal.config" })
// Property file in which are written the MySQL connection properties
#PropertySource("classpath:dbconnection.properties")
public class DALConfig {
private static final String PROPERTY_NAME_DATABASE_DRIVER = "db.driver";
private static final String PROPERTY_NAME_DATABASE_PASSWORD = "db.password";
private static final String PROPERTY_NAME_DATABASE_URL = "db.url";
private static final String PROPERTY_NAME_DATABASE_USERNAME = "db.username";
private static final String PROPERTY_NAME_POOL_INITIAL_SIZE = "pool.initialsize";
private static final String PROPERTY_NAME_POOL_MAX_IDLE = "pool.maxidle";
// Needed to access property file
#Resource
private Environment environment;
// The bean which defines the BasicDataSource (DBCP)
#Bean
public BasicDataSource dataSource() throws Exception
{
Properties props = new Properties();
props.put("driverClassName", environment.getProperty(PROPERTY_NAME_DATABASE_DRIVER));
props.put("url", environment.getProperty(PROPERTY_NAME_DATABASE_URL));
props.put("username", environment.getProperty(PROPERTY_NAME_DATABASE_USERNAME));
props.put("password", environment.getProperty(PROPERTY_NAME_DATABASE_PASSWORD));
props.put("initialSize", environment.getProperty(PROPERTY_NAME_POOL_INITIAL_SIZE));
props.put("maxIdle", environment.getProperty(PROPERTY_NAME_POOL_MAX_IDLE));
BasicDataSource bds = BasicDataSourceFactory.createDataSource(props);
return bds;
}
// Bean used to translate Hibernate's exceptions into Spring's ones
#Bean
public PersistenceExceptionTranslationPostProcessor persistenceExceptionTranslationPostProcessor()
{
PersistenceExceptionTranslationPostProcessor b = new PersistenceExceptionTranslationPostProcessor();
return b;
}
}
Then I wrote the HibernateConfig.java config file which contains the Hibernate configuration stuff
package my.dal.hibernateconfig;
import java.util.Properties;
import javax.annotation.Resource;
import javax.sql.DataSource;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.orm.hibernate4.HibernateTransactionManager;
import org.springframework.orm.hibernate4.LocalSessionFactoryBean;
#Configuration
#ComponentScan(basePackages = { "my.dal.hibernatesessionfactory" })
#PropertySource("classpath:dbconnection.properties")
public class HibernateConfig {
private static final String PROPERTY_NAME_DAL_CLASSES_PACKAGE = "hibernate.dal.package";
private static final String PROPERTY_NAME_HIBERNATE_DIALECT = "hibernate.dialect";
#Resource
private Environment environment;
#Autowired
DataSource dataSource;
// Bean which defines the FactoryBean for the SessionBean
#Bean
public LocalSessionFactoryBean sessionFactory()
{
LocalSessionFactoryBean lsfb = new LocalSessionFactoryBean();
lsfb.setPackagesToScan(PROPERTY_NAME_DAL_CLASSES_PACKAGE);
Properties hibernateProperties = new Properties();
hibernateProperties.put("dialect", PROPERTY_NAME_HIBERNATE_DIALECT);
lsfb.setHibernateProperties(hibernateProperties);
lsfb.setDataSource(dataSource);
return lsfb;
}
#Bean
public HibernateTransactionManager transactionManager()
{
// THE EXCEPTION IS THROWN AT THIS LINE
HibernateTransactionManager htm = new HibernateTransactionManager((SessionFactory) sessionFactory());
return htm;
}
}
Next I wrote the UserDAO.java class which is a DAO for the User class which models the DB's User table.
package my.dal.dao;
import my.models.User;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;
#Component
#Repository
#Transactional
public class UserDAO
{
private SessionFactory sessionFactory;
#Autowired
public UserDAO(SessionFactory sessionFactory) {
this.sessionFactory=sessionFactory;
}
public int insert(User user) {
return (Integer) sessionFactory.getCurrentSession().save(user);
}
public User getByUsername(String username) {
return (User) sessionFactory.getCurrentSession().get(User.class, username);
}
public void update(User user) {
sessionFactory.getCurrentSession().merge(user); // .update(user);
}
public void delete(String username) {
User u = getByUsername(username);
sessionFactory.getCurrentSession().delete(u);
}
}
The mapping class User.java (generated using the Eclipse's Hibernate tools) is
package my.models;
public class User implements java.io.Serializable {
private String username;
private String idUserKeystone;
private String firstName;
private String lastName;
private String password;
private String email;
private String emailRef;
private String employer;
private boolean confirmed;
// Getters, setters and full constructor
}
Now I want to test the DAL. The testing class is DALTest.java
package my.dal.tests;
import static org.junit.Assert.assertTrue;
import my.dal.config.DALConfig;
import my.dal.dao.UserDAO;
import my.dal.hibernateconfig.HibernateConfig;
import my.models.User;
import org.hibernate.SessionFactory;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
#ContextConfiguration(classes = { DALConfig.class, HibernateConfig.class})
#RunWith(SpringJUnit4ClassRunner.class)
public class DALTest {
#Autowired
UserDAO userDAO;
#Test
public void testGetUser() {
User user = null;
// Let's see if the user "myuser" is into the database
user = userDAO.getByUsername("myuser");
assertTrue(null != user);
}
}
When I run the test it throws the following exceptions
java.lang.IllegalStateException: Failed to load ApplicationContext
...
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionManager' defined in class my.dal.hibernateconfig.HibernateConfig: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.springframework.orm.hibernate4.HibernateTransactionManager my.dal.hibernateconfig.HibernateConfig.transactionManager()] threw exception; nested exception is java.lang.ClassCastException: org.springframework.orm.hibernate4.LocalSessionFactoryBean$$EnhancerBySpringCGLIB$$d866ed45 cannot be cast to org.hibernate.SessionFactory
...
Caused by: java.lang.ClassCastException: org.springframework.orm.hibernate4.LocalSessionFactoryBean$$EnhancerBySpringCGLIB$$d866ed45 cannot be cast to org.hibernate.SessionFactory
at my.dal.hibernateconfig.HibernateConfig.transactionManager(HibernateConfig.java:55)
at my.dal.hibernateconfig.HibernateConfig$$EnhancerBySpringCGLIB$$bd53a036.CGLIB$transactionManager$1(<generated>)
at my.dal.hibernateconfig.HibernateConfig$$EnhancerBySpringCGLIB$$bd53a036$$FastClassBySpringCGLIB$$119f2c5b.invoke(<generated>)
...
It seems like the problem is the cast at the line
HibernateTransactionManager htm = new HibernateTransactionManager((SessionFactory) sessionFactory())
On the contrary, the Internet is full of example writing that line that way.
What could be the problem?
Thank you in advance
A FactoryBean<Foo> is a bean that creates objects of type Foo. It's not, itself, of type Foo (as the javadoc would show you). To get the Foo it creates, you simply call getObject() on the factory bean:
HibernateTransactionManager htm =
new HibernateTransactionManager(sessionFactory().getObject());