我接触的个人感觉很简单,和超哥聊完发现。在hibernate4.0.getCurrentSession()这种方法几乎不常用,就是一个hibernate映射表的一个小例子吧
step:
1、建工程
2、导入需要的jar包
3、创建映射实体类
4、创建配置hibernate的配置文件hibernate.cfg.xml,即配置hibernate 模板
5、配置 hibernate 的基本属性 二级缓存相关
6、创建Spring的bean配置文件,配置到sessionfactorybean实例,创建测试类,运行、完成表映射
7,修改生成的*.hbm.xml
8、写接口实现类,继续配置bean
直接上代码了:
实体类:
package com.spring.bean.entity;
public class Account {
private Integer id;
String username;
private int balance;
public Integer getId() {
return id;
}
void setId(Integer id) {
this.id = String getUsername() {
username;
}
setUsername(String username) {
this.username = getBalance() {
balance;
}
void setBalance( balance) {
this.balance = balance;
}
}
Book {
String bookName;
String isbn;
price;
stock;
String getBookName() {
bookName;
}
setBookName(String bookName) {
this.bookName = String getIsbn() {
isbn;
}
setIsbn(String isbn) {
this.isbn = getPrice() {
price;
}
void setPrice( price) {
this.price = getStock() {
stock;
}
void setStock( 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="hibernate.show_sql">true="hibernate.format_sql"="hibernate.hbm2ddl.auto">update>
映射生成的*.hbm,xml
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-mappingclass ="com.spring.bean.entity.Account" table="Account"id ="id" type="java.lang.Integer">
column ="ID" />
generator ="native" />
id="username"="java.lang.String"="username" ="balance"="int"="balance" >
="com.spring.bean.entity.Book"="Book"="bookName"="bookName" ="isbn"="isbn" ="price"="price" ="stock"="stock" >
接口不上了只上实现类(bookshaodao)
com.spring.bean.respistory;
import org.hibernate.Session;
org.hibernate.SessionFactory;
org.springframework.beans.factory.annotation.Autowired;
org.springframework.stereotype.Repository;
@Repository("bookShopDao")
class BookShopDaoImpl implements BookShopDao {
@Autowired
SessionFactory session;
Session getCurrentSession(){
session.getCurrentSession();
}
@Override
findBookPriceByIsbn(String isbn) {
String hsql = "SELECT b.price FROM Book b WHERE b.isbn = ?";
int price = (int) getCurrentSession().createQuery(hsql).setString(0,isbn).uniqueResult();
price;
}
@Override
updateBookStock(String isbn) {
//检查书的库存是否足够,若不够,则抛出异常
String hsql2 = "SELECT b.stock FROM Book b WHERE b.isbn = ?"int stock = (int) getCurrentSession().createQuery(hsql2).setString(0if(stock == 0){
throw new BookStockException("库存不足!");
}
String hsql = "UPDATE Book b SET b.stock = b.stock -1 WHERE b.isbn = ?";
getCurrentSession().createQuery(hsql).setString(0void updateUserAccount(String username,验证余额是否足够,若不足,则抛出异常
String hsql2 = "SELECT a.balance FROM Account a WHERE a.username = ?"int balance = (if(balance < price){
new UserAccountException("余额不足!");
}
String hsql = "UPDATE Account a SET a.balance = a.balance - ? WHERE a.username = ?";
getCurrentSession().createQuery(hsql).setInteger(0,price).setString(1
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" 自动扫描需要的包 -->
context:component-scan base-package="com.spring.bean"></context:component-scan 加载外部资源文件 context:property-placeholder location="classpath:db.properties"/>
配置mysql bean ="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource" value="${jdbc.user}"="password"="${jdbc.password}"="url"="${jdbc.jdbcUrl}"="driverClassName"="${jdbc.driverClass}"bean hibernate的sessionFactory实例 ="sessionFactoryBean"="org.springframework.orm.hibernate4.LocalSessionFactoryBean" 配置数据源 -->
ref="dataSource" 配置文件名称及位置 --><!-- 也可以通过hibernateProperties配置 <property name="configLocation" value="classpath:hibernate.cfg.xml"></property> ="hibernateProperties"props>
prop keyprop 配置映射文件名称和位置 ="mappingLocations"="classpath:com/spring/bean/entity/*.hbm.xml" 配置声明式事务管理器 ="transactionManager"="org.springframework.orm.hibernate4.HibernateTransactionManager"="sessionFactory"="sessionFactoryBean" 配置事物属性 tx:advice ="taAdvice" transaction-manager="transactionManager"tx:attributestx:method ="get*" read-only="true"="purchase" propagation="REQUIRES_NEW"="*"tx:advice 配置事物切点 aop:configaop:pointcut expression="execution(* com.spring.bean.services.*.*(..))" id="pointcut"aop:advisor advice-ref pointcut-ref>
beans>
在实现类中有几个细节吧
1、sql必须写成这样的如:
SELECT b.price FROM Book b WHERE b.isbn = ?即表明必须与生成的hbm.xml中的table中的名字一致
<class name="com.spring.bean.entity.Book" table="Book">
要是写成不一致sql会报错:
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.<init>(HQLQueryPlan.java:105) at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:80) 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、调用dao层里面的任何接口实现方法都会报错:
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)
?超哥说是因为用getCurrentSession(),hibernate4.0不常用导致的,建议我换成opensession(),试验完发现dao层的所有方法都没问题,批量购书的接口加的事物required_new添加的注解无效了,提示余额不足,
?
?
?
度娘后,才明白
1 getCurrentSession创建的session会和绑定到当前线程,而openSession不会。
2 getCurrentSession创建的线程会在事务回滚或事物提交后自动关闭,而openSession必须手动关闭
这里getCurrentSession本地事务(本地事务:jdbc)时 要在配置文件里进行如下设置
??? * 如果使用的是本地事务(jdbc事务) ?<property name="hibernate.current_session_context_class">thread</property> ?? * 如果使用的是全局事务(jta事务) ?<property name="hibernate.current_session_context_class">jta</property>?
? getCurrentSession () 使用当前的session ? openSession()???????? 重新建立一个新的session (编辑:李大同)
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