1、JdbcTemplate操作数据库
Spring对数据库的操作在jdbc上面做了深层次的封装,使用spring的注入功能,可以把DataSource注册到JdbcTemplate之 中。同时,为了支持对properties文件的支持,spring提供了类似于EL表达式的方式,把dataSource.properties的文件 参数引入到参数配置之中,<context:property-placeholder location="classpath:jdbc.properties" />。
实例代码如下:
提供数据源的相关配置信息:jdbc.properties
driverClassName=sql.Driver
url=jdbc\:mysql\://localhost\:3306/stanley?useUnicode\=true&characterEncoding\=UTF-8
username=root
password=123456
initialSize=1
maxActive=500
url=jdbc\:mysql\://localhost\:3306/stanley?useUnicode\=true&characterEncoding\=UTF-8
username=root
password=123456
initialSize=1
maxActive=500
maxIdle=2
minIdle=1
minIdle=1
提供spring的配置文件,将jdbc.properties与JdbcTemplate粘合起来的配置文件:l
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="/schema/beans"
xmlns:xsi="/2001/XMLSchema-instance"
xmlns:context="/schema/context"
xmlns:aop="/schema/aop"
xmlns:tx="/schema/tx"
xsi:schemaLocation="/schema/beans
/schema/beans/spring-beans-2.5.xsd
/schema/context /schema/context/spring-context-2.5.xsd
/schema/aop /s
<beans xmlns="/schema/beans"
xmlns:xsi="/2001/XMLSchema-instance"
xmlns:context="/schema/context"
xmlns:aop="/schema/aop"
xmlns:tx="/schema/tx"
xsi:schemaLocation="/schema/beans
/schema/beans/spring-beans-2.5.xsd
/schema/context /schema/context/spring-context-2.5.xsd
/schema/aop /s
chema/aop/spring-aop-2.5.xsd
/schema/tx /schema/tx/spring-tx-2.5.xsd">
<context:property-placeholder location="classpath:jdbc.properties"/>
<bean id="dataSource" class="org.apachemons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="${driverClassName}"/>
<property name="url" value="${url}"/>
<property name="username" value="${username}"/>
<property name="password" value="${password}"/>
<!-- 连接池启动时的初始值 -->
<property name="initialSize" value="${initialSize}"/>
<!-- 连接池的最大值 -->
<property name="maxActive" value="${maxActive}"/>
/schema/tx /schema/tx/spring-tx-2.5.xsd">
<context:property-placeholder location="classpath:jdbc.properties"/>
<bean id="dataSource" class="org.apachemons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="${driverClassName}"/>
<property name="url" value="${url}"/>
<property name="username" value="${username}"/>
<property name="password" value="${password}"/>
<!-- 连接池启动时的初始值 -->
<property name="initialSize" value="${initialSize}"/>
<!-- 连接池的最大值 -->
<property name="maxActive" value="${maxActive}"/>
<!-- 最大空闲值.当经过一个高峰时间后,连接池可以慢慢将已经用不到的连接慢慢释放一部分,一直减少到maxIdle为止 -->
<property name="maxIdle" value="${maxIdle}"/>
<!-- 最小空闲值.当空闲的连接数少于阀值时,连接池就会预申请去一些连接,以免洪峰来时来不及申请 -->
jdbctemplate查询一条数据<property name="minIdle" value="${minIdle}"/>
</bean>
<bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"/>
</bean>
<aop:config>
<aop:pointcut id="transactionPointcut" expression="execution(* cnp.service..*.*(..)
<property name="maxIdle" value="${maxIdle}"/>
<!-- 最小空闲值.当空闲的连接数少于阀值时,连接池就会预申请去一些连接,以免洪峰来时来不及申请 -->
jdbctemplate查询一条数据<property name="minIdle" value="${minIdle}"/>
</bean>
<bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"/>
</bean>
<aop:config>
<aop:pointcut id="transactionPointcut" expression="execution(* cnp.service..*.*(..)
)"/>
<aop:advisor advice-ref="txAdvice" pointcut-ref="transactionPointcut"/>
</aop:config>
<tx:advice id="txAdvice" transaction-manager="txManager">
<tx:attributes>
<tx:method name="get*" read-only="true" propagation="NOT_SUPPORTED"/>
<tx:method name="*"/>
</tx:attributes>
</tx:advice>
<bean id="personService" class="cnp.service.impl.PersonServiceBean">
<property name="dataSource" ref="dataSource"/>
</bean>
</beans>
<aop:advisor advice-ref="txAdvice" pointcut-ref="transactionPointcut"/>
</aop:config>
<tx:advice id="txAdvice" transaction-manager="txManager">
<tx:attributes>
<tx:method name="get*" read-only="true" propagation="NOT_SUPPORTED"/>
<tx:method name="*"/>
</tx:attributes>
</tx:advice>
<bean id="personService" class="cnp.service.impl.PersonServiceBean">
<property name="dataSource" ref="dataSource"/>
</bean>
</beans>
提供POJO的java类:Person.java
public class Person {
private Integer id;
private String name;
public Person(){}
public Person(String name) {
this.name = name;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
private Integer id;
private String name;
public Person(){}
public Person(String name) {
this.name = name;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
return name;
}
public void setName(String name) {
this.name = name;
}
}
提供对Person的操作接口:PersonService.java
public interface PersonService {
public void save(Person person);
public void update(Person person);
public void save(Person person);
public void update(Person person);
public Person getPerson(Integer personid);
public List<Person> getPersons();
public void delete(Integer personid) throws Exception;
}
public List<Person> getPersons();
public void delete(Integer personid) throws Exception;
}
提供对接口的实现类:PersonServiceBean.java
public class PersonServiceBean implements PersonService {
private JdbcTemplate jdbcTemplate;
public void setDataSource(DataSource dataSource) {
this.jdbcTemplate = new JdbcTemplate(dataSource);
}
private JdbcTemplate jdbcTemplate;
public void setDataSource(DataSource dataSource) {
this.jdbcTemplate = new JdbcTemplate(dataSource);
}
public void delete(Integer personid) throws Exception{
jdbcTemplate.update("delete from person where id=?", new Object[]{personid},
new int[]{java.sql.Types.INTEGER});
}
public Person getPerson(Integer personid) {
return (Person)jdbcTemplate.queryForObject("select * from person where id=?", new Object[]{personid},
new int[]{java.sql.Types.INTEGER}, new PersonRowMapper());
}
@SuppressWarnings("unchecked")
public List<Person> getPersons() {
return (List<Person>)jdbcTemplate.query("select * from person", new PersonRowMapper());
jdbcTemplate.update("delete from person where id=?", new Object[]{personid},
new int[]{java.sql.Types.INTEGER});
}
public Person getPerson(Integer personid) {
return (Person)jdbcTemplate.queryForObject("select * from person where id=?", new Object[]{personid},
new int[]{java.sql.Types.INTEGER}, new PersonRowMapper());
}
@SuppressWarnings("unchecked")
public List<Person> getPersons() {
return (List<Person>)jdbcTemplate.query("select * from person", new PersonRowMapper());
}
public void save(Person person) {
jdbcTemplate.update("insert into person(name) values(?)", new Object[]{Name()},
new int[]{java.sql.Types.VARCHAR});
}
public void update(Person person) {
jdbcTemplate.update("update person set name=? where id=?", new Object[]{Name(), Id()},
new int[]{java.sql.Types.VARCHAR, java.sql.Types.INTEGER});
}
}
public void save(Person person) {
jdbcTemplate.update("insert into person(name) values(?)", new Object[]{Name()},
new int[]{java.sql.Types.VARCHAR});
}
public void update(Person person) {
jdbcTemplate.update("update person set name=? where id=?", new Object[]{Name(), Id()},
new int[]{java.sql.Types.VARCHAR, java.sql.Types.INTEGER});
}
}
提供在查询对象时,记录的映射回调类:PersonRowMapper.java
public class PersonRowMapper implements RowMapper {
public Object mapRow(ResultSet rs, int index) throws SQLException {
Person person = new String("name"));
person.Int("id"));
return person;
}
}
public Object mapRow(ResultSet rs, int index) throws SQLException {
Person person = new String("name"));
person.Int("id"));
return person;
}
}
【注意】:由于dbcp的jar包对common-pool和commons-collections的jar包有依赖,所有需要把他们一起引入到工程中。【 commons-dbcp-1.2.1.jar, commons-pool-1.2.jar, commons-collections-3.1.jar】, 参考文档《JDBC高级部分》:tianya23.blog.51cto/1081650/270849
2、JdbcTemplate事务
事务的操作首先要通过配置文件,取得spring的支持, 再在java程序中显示的使用@Transa
ctional注解来使用事务操作。
在xml配置文件中增加对事务的支持:
<bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"/>
</bean>
<tx:annotation-driven transaction-manager="txManager"/>
<bean id="personService" class="cnp.service.impl.PersonServiceBean">
<property name="dataSource" ref="dataSource"/>
</bean>
<property name="dataSource" ref="dataSource"/>
</bean>
<tx:annotation-driven transaction-manager="txManager"/>
<bean id="personService" class="cnp.service.impl.PersonServiceBean">
<property name="dataSource" ref="dataSource"/>
</bean>
在java程序中显示的指明是否需要事务,当出现运行期异常Exception或一般的异常Exception是否需要回滚
@Transactional
public class PersonServiceBean implements PersonService {
private JdbcTemplate jdbcTemplate;
public void setDataSource(DataSource dataSource) {
this.jdbcTemplate = new JdbcTemplate(dataSource);
}
// unchecked ,
// checked
@Transactional(noRollbackFor=RuntimeException.class)
public void delete(Integer personid) throws Exception{
jdbcTemplate.update("delete from person where id=?", new Object[]{personid},
new int[]{java.sql.Types.INTEGER});
throw new RuntimeException("运行期例外");
}
public class PersonServiceBean implements PersonService {
private JdbcTemplate jdbcTemplate;
public void setDataSource(DataSource dataSource) {
this.jdbcTemplate = new JdbcTemplate(dataSource);
}
// unchecked ,
// checked
@Transactional(noRollbackFor=RuntimeException.class)
public void delete(Integer personid) throws Exception{
jdbcTemplate.update("delete from person where id=?", new Object[]{personid},
new int[]{java.sql.Types.INTEGER});
throw new RuntimeException("运行期例外");
}
@Transactional(propagation=Propagation.NOT_SUPPORTED)
public Person getPerson(Integer personid) {
return (Person)jdbcTemplate.queryForObject("select * from person where id=?", new Object[]{personid},
new int[]{java.sql.Types.INTEGER}, new PersonRowMapper());
}
@Transactional(propagation=Propagation.NOT_SUPPORTED)
@SuppressWarnings("unchecked")
public List<Person> getPersons() {
return (List<Person>)jdbcTemplate.query("select * from person", new PersonRowMapper());
}
public void save(Person person) {
public Person getPerson(Integer personid) {
return (Person)jdbcTemplate.queryForObject("select * from person where id=?", new Object[]{personid},
new int[]{java.sql.Types.INTEGER}, new PersonRowMapper());
}
@Transactional(propagation=Propagation.NOT_SUPPORTED)
@SuppressWarnings("unchecked")
public List<Person> getPersons() {
return (List<Person>)jdbcTemplate.query("select * from person", new PersonRowMapper());
}
public void save(Person person) {
jdbcTemplate.update("insert into person(name) values(?)", new Object[]{Name()},
new int[]{java.sql.Types.VARCHAR});
}
public void update(Person person) {
jdbcTemplate.update("update person set name=? where id=?", new Object[]{Name(), Id()},
new int[]{java.sql.Types.VARCHAR, java.sql.Types.INTEGER});
}
}
new int[]{java.sql.Types.VARCHAR});
}
public void update(Person person) {
jdbcTemplate.update("update person set name=? where id=?", new Object[]{Name(), Id()},
new int[]{java.sql.Types.VARCHAR, java.sql.Types.INTEGER});
}
}
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