My personal experience is very simple, and I found out after chatting with Brother Chao. In hibernate4.0.getCurrentSession(), this method is rarely used. It is a small example of a hibernate mapping table.
step:
1. Construction project
2. Import the required jar packages
3. Create a mapping entity class
4. Create the configuration file hibernate.cfg.xml to configure hibernate, that is, configure the hibernate template
5. Configure the basic properties of hibernate related to the second level cache
6. Create Spring bean configuration file, configure it to sessionfactorybean instance, create test class, run and complete table mapping
7. Modify the generated *.hbm.xml
8. Write the interface implementation class and continue to configure the beans
Just upload the code:
Entity class:
package com.spring.bean.entity;
public class Account {
private Integer id;
private String username;
private int balance;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public int getBalance() {
return balance;
}
public void setBalance(int balance) {
this.balance = balance;
}
}
package com.spring.bean.entity;
public class Book {
private Integer id;
private String bookName;
private String isbn;
private int price;
private int stock;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getBookName() {
return bookName;
}
public void setBookName(String bookName) {
this.bookName = bookName;
}
public String getIsbn() {
return isbn;
}
public void setIsbn(String isbn) {
this.isbn = isbn;
}
public int getPrice() {
return price;
}
public void setPrice(int price) {
this.price = price;
}
public int getStock() {
return stock;
}
public void setStock(int stock) {
this.stock = stock;
}
}
hibernate.cfg.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
<property name="hibernate.show_sql">true</property>
<property name="hibernate.format_sql">true</property>
<property name="hibernate.hbm2ddl.auto">update</property>
</session-factory>
</hibernate-configuration>
*.hbm,xml generated by mapping
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2017-1-25 19:42:09 by Hibernate Tools 3.5.0.Final -->
<hibernate-mapping>
<class name="com.spring.bean.entity.Account" table="Account">
<id name="id" type="java.lang.Integer">
<column name="ID" />
<generator class="native" />
</id>
<property name="username" type="java.lang.String">
<column name="username" />
</property>
<property name="balance" type="int">
<column name="balance" />
</property>
</class>
</hibernate-mapping>
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2017-1-25 19:42:09 by Hibernate Tools 3.5.0.Final -->
<hibernate-mapping>
<class name="com.spring.bean.entity.Book" table="Book">
<id name="id" type="java.lang.Integer">
<column name="ID" />
<generator class="native" />
</id>
<property name="bookName" type="java.lang.String">
<column name="bookName" />
</property>
<property name="isbn" type="java.lang.String">
<column name="isbn" />
</property>
<property name="price" type="int">
<column name="price" />
</property>
<property name="stock" type="int">
<column name="stock" />
</property>
</class>
</hibernate-mapping>
The interface is not up, only the implementation class is up (bookshaodao)
package com.spring.bean.respistory;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;
@Repository("bookShopDao")
public class BookShopDaoImpl implements BookShopDao {
@Autowired
private SessionFactory session;
public Session getCurrentSession(){
return session.getCurrentSession();
}
@Override
public int findBookPriceByIsbn(String isbn) {
String hsql = "SELECT b.price FROM Book b WHERE b.isbn = ?";
int price = (int) getCurrentSession().createQuery(hsql).setString(0, isbn).uniqueResult();
return price;
}
@Override
public void updateBookStock(String isbn) {
//Check whether the book inventory is sufficient, if not, throw an exception
String hsql2 = "SELECT b.stock FROM Book b WHERE b.isbn = ?";
int stock = (int) getCurrentSession().createQuery(hsql2).setString(0, isbn).uniqueResult();
if(stock == 0){
throw new BookStockException("Insufficient stock!");
}
String hsql = "UPDATE Book b SET b.stock = b.stock -1 WHERE b.isbn = ?";
getCurrentSession().createQuery(hsql).setString(0, isbn).executeUpdate();
}
@Override
public void updateUserAccount(String username, int price) {
//Verify whether the balance is sufficient, if not, throw an exception
String hsql2 = "SELECT a.balance FROM Account a WHERE a.username = ?";
int balance = (int) getCurrentSession().createQuery(hsql2).setString(0, username).uniqueResult();
if(balance < price){
throw new UserAccountException("Insufficient balance!");
}
String hsql = "UPDATE Account a SET a.balance = a.balance - ? WHERE a.username = ?";
getCurrentSession().createQuery(hsql).setInteger(0, price).setString(1, username).executeUpdate();
}
}
bean.xml
<?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:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.1.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.1.xsd">
<!-- Automatically scan required packages -->
<context:component-scan base-package="com.spring.bean"></context:component-scan>
<!-- Load external resource files -->
<context:property-placeholder location="classpath:db.properties"/>
<!-- Configure mysql -->
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="username" value="${jdbc.user}"></property>
<property name="password" value="${jdbc.password}"></property>
<property name="url" value="${jdbc.jdbcUrl}"></property>
<property name="driverClassName" value="${jdbc.driverClass}"></property>
</bean>
<!-- hibernate sessionFactory instance -->
<bean id="sessionFactoryBean" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<!-- Configure data source -->
<property name="dataSource" ref="dataSource"></property>
<!-- Configuration file name and location --><!-- It can also be configured through hibernateProperties -->
<!-- <property name="configLocation" value="classpath:hibernate.cfg.xml"></property> -->
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</prop>
<prop key="hibernate.show_sql">true</prop>
<prop key="hibernate.format_sql">true</prop>
<prop key="hibernate.hbm2ddl.auto">update</prop>
</props>
</property>
<!-- Configuration mapping file name and location -->
<property name="mappingLocations" value="classpath:com/spring/bean/entity/*.hbm.xml"></property>
</bean>
<!-- Configure declarative transaction manager -->
<bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactoryBean"></property>
</bean>
<!-- Configure thing properties -->
<tx:advice id="taAdvice" transaction-manager="transactionManager">
<tx:attributes>
<tx:method name="get*" read-only="true"/>
<tx:method name="purchase" propagation="REQUIRES_NEW"/>
<tx:method name="*"/>
</tx:attributes>
</tx:advice>
<!-- Configure transaction point -->
<aop:config>
<aop:pointcut expression="execution(* com.spring.bean.services.*.*(..))" id="pointcut"/>
<aop:advisor advice-ref="taAdvice" pointcut-ref="pointcut"/>
</aop:config>
</beans>
There are a few details in the implementation class
1. The sql must be written like this:
SELECT b.price FROM Book b WHERE b.isbn = ? means it must be consistent with the name in the table in the generated hbm.xml
<class name="com.spring.bean.entity.Book" table="Book">
<br>If the SQL is written inconsistently, an error will be reported:
org.hibernate.hql.internal.ast.QuerySyntaxException: book is not mapped [SELECT price FROM book WHERE isbn = ?]
at org.hibernate.hql.internal.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:180)
at org.hibernate.hql.internal.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:110)
at org.hibernate.hql.internal.ast.tree.FromClause.addFromElement(FromClause.java:93)
at org.hibernate.hql.internal.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:324)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3291)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:3180)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:706)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:562)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:299)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:247)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:248)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:183)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:136)
at org.hibernate.engine.query.spi.HQLQueryPlan.
at org.hibernate.engine.query.spi.HQLQueryPlan.
at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:168)
at org.hibernate.internal.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:219)
at org.hibernate.internal.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:197)
at org.hibernate.internal.SessionImpl.createQuery(SessionImpl.java:1736)
at com.spring.bean.respistory.BookShopDaoImpl.findBookPriceByIsbn(BookShopDaoImpl.java:21)
at com.spring.bean.services.BookShopServiceImpl.purchase(BookShopServiceImpl.java:18)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:266)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
at com.sun.proxy.$Proxy14.purchase(Unknown Source)
at com.spring.bean.services.CashierImpl.checkout(CashierImpl.java:19)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:266)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
at com.sun.proxy.$Proxy15.checkout(Unknown Source)
at com.spring.bean.entity.MainTest.run(MainTest.java:32)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
2. Calling any interface implementation method in the dao layer will report an error:
org.hibernate.HibernateException: Could not obtain transaction-synchronized Session for current thread
at org.springframework.orm.hibernate4.SpringSessionContext.currentSession(SpringSessionContext.java:134)
at org.hibernate.internal.SessionFactoryImpl.getCurrentSession(SessionFactoryImpl.java:941)
at com.spring.bean.respistory.BookShopDaoImpl.getCurrentSession(BookShopDaoImpl.java:15)
at com.spring.bean.respistory.BookShopDaoImpl.findBookPriceByIsbn(BookShopDaoImpl.java:21)
at com.spring.bean.services.BookShopServiceImpl.purchase(BookShopServiceImpl.java:18)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:266)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
at com.sun.proxy.$Proxy14.purchase(Unknown Source)
at com.spring.bean.services.CashierImpl.checkout(CashierImpl.java:19)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:266)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
at com.sun.proxy.$Proxy15.checkout(Unknown Source)
at com.spring.bean.entity.MainTest.run(MainTest.java:32)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Brother Chao said that it was caused by using getCurrentSession(), which is not commonly used in hibernate4.0. He suggested that I switch to opensession(). After testing, I found that all the methods in the dao layer were fine. The annotation added by required_new for the bulk book purchase interface was invalid. , it prompts that the balance is insufficient.
Only after marrying my mother did I understand
1 The session created by getCurrentSession will be bound to the current thread, but openSession will not.
2 The thread created by getCurrentSession will be automatically closed after the transaction is rolled back or the thing is committed, while openSession must be closed manually.
Here, when gettingCurrentSession local transaction (local transaction: jdbc), the following settings must be made in the configuration file
* If you are using local transactions (jdbc transactions)
getCurrentSession () uses the current session
openSession() re-establishes a new session
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