1. spring Integration JDBC
1.spring provides many templates to integrate Dao Technology
2.spring provides an object that can operate database. Objects encapsulate jdbc technology.
JDBCTemplate => JDBC template object
It is very similar to Query Runner in DBUtils.
//0 Prepare connection pool ComboPooledDataSource dataSource = new ComboPooledDataSource(); dataSource.setDriverClass("com.mysql.jdbc.Driver"); dataSource.setJdbcUrl("jdbc:mysql:///xieyupeng"); dataSource.setUser("root"); dataSource.setPassword("1234"); //1 Establish JDBC Template object JdbcTemplate jt = new JdbcTemplate(); jt.setDataSource(dataSource); //2 write sql,And execute String sql = "insert into t_user values(null,'rose') "; jt.update(sql);
3. Integration steps
3.1 Guide
4+2:4 stands for:
2 Representatives: com.springsource.org.apache.commons.logging-1.1.1.jar, com.springsource.org.apache.log4j-1.2.15.jar.
Spr-test, spring-aop, junit4 Libraries
c3p0 connection pool, JDBC driver
Spr-jdbc, spring-tx transactions
3.2 Prepare the database (two fields id (self-growth) and name will do)
3.3 Writing Dao
//Use JDBC Template for Addition, Deletion, Change and Check public class UserDaoImpl extends JdbcDaoSupport implements UserDao { @Override public void save(User u) { String sql = "insert into t_user values(null,?) "; super.getJdbcTemplate().update(sql, u.getName()); } @Override public void delete(Integer id) { String sql = "delete from t_user where id = ? "; super.getJdbcTemplate().update(sql,id); } @Override public void update(User u) { String sql = "update t_user set name = ? where id=? "; super.getJdbcTemplate().update(sql, u.getName(),u.getId()); } @Override public User getById(Integer id) { String sql = "select * from t_user where id = ? "; return super.getJdbcTemplate().queryForObject(sql,new RowMapper<User>(){ @Override public User mapRow(ResultSet rs, int arg1) throws SQLException { User u = new User(); u.setId(rs.getInt("id")); u.setName(rs.getString("name")); return u; }}, id); } @Override public int getTotalCount() { String sql = "select count(*) from t_user "; Integer count = super.getJdbcTemplate().queryForObject(sql, Integer.class); return count; } @Override public List<User> getAll() { String sql = "select * from t_user "; List<User> list = super.getJdbcTemplate().query(sql, new RowMapper<User>(){ @Override public User mapRow(ResultSet rs, int arg1) throws SQLException { User u = new User(); u.setId(rs.getInt("id")); u.setName(rs.getString("name")); return u; }}); return list; } }
3.4 spring configuration
Dependency
<!-- 1.Put the connection pool in spring container --> <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" > <property name="jdbcUrl" value="${jdbc.jdbcUrl}" ></property> <property name="driverClass" value="${jdbc.driverClass}" ></property> <property name="user" value="${jdbc.user}" ></property> <property name="password" value="${jdbc.password}" ></property> </bean> <!-- 2.take JDBCTemplate Put in spring container --> <bean name="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate" > <property name="dataSource" ref="dataSource" ></property> </bean> <!-- 3.take UserDao Put in spring container --> <bean name="userDao" class="cn.itcast.a_jdbctemplate.UserDaoImpl" > <!-- <property name="jt" ref="jdbcTemplate" ></property> --> <property name="dataSource" ref="dataSource" ></property> </bean>
3.5 Test
//Demonstration JDBC Template @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration("classpath:applicationContext.xml") public class Demo { @Resource(name="userDao") private UserDao ud; @Test public void fun2() throws Exception{ User u = new User(); u.setName("tom"); ud.save(u); } @Test public void fun3() throws Exception{ User u = new User(); u.setId(2); u.setName("jack"); ud.update(u); } @Test public void fun4() throws Exception{ ud.delete(2); } @Test public void fun5() throws Exception{ System.out.println(ud.getTotalCount()); } @Test public void fun6() throws Exception{ System.out.println(ud.getById(1)); } @Test public void fun7() throws Exception{ System.out.println(ud.getAll()); } }
4. Advanced Contents
4.1 JDBCDaoSupport
public class UserDaoImpl extends JdbcDaoSupport
<!-- 3.take UserDao Put in spring container(inherit JDBCDaoSupport，Direct injection dataSourse that will do) --> <bean name="userDao" class="cn.itcast.a_jdbctemplate.UserDaoImpl" > <!-- <property name="jt" ref="jdbcTemplate" ></property> --> <property name="dataSource" ref="dataSource" ></property> </bean>
4.1 Read the external Proerties configuration
Attention should be paid to prefixing db.properties (better distinction, avoid renaming)
jdbc.jdbcUrl=jdbc:mysql:///hibernate_32
jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.user=root
jdbc.password=1234
<!-- Appoint spring read db.properties To configure --> <context:property-placeholder location="classpath:db.properties" /> <!-- 1.Put the connection pool in spring container --> <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" > <property name="jdbcUrl" value="${jdbc.jdbcUrl}" ></property> <property name="driverClass" value="${jdbc.driverClass}" ></property> <property name="user" value="${jdbc.user}" ></property> <property name="password" value="${jdbc.password}" ></property> </bean>
Configuring spring with annotations
1. Business Review
Transaction characteristics: acid
Transaction Concurrency Problems: Dirty Reading, Non-repeatable Reading, Illusive Reading
Transaction isolation level: 1 read uncommitted, 2 read submitted, 4 repeatable read, 8 serialization
2.spring encapsulates transaction management code
Transaction operation: Open transaction, commit transaction, rollback transaction
Transaction Operating Objects
Because the code for operating transactions varies from platform to platform. spring provides an interface
2.1 Platform Transaction Manager interface
DataSourceTransactionManager
HibernateTransitionmanager
Note: Play transaction management in spring. The core object is the Transaction Manager object.
2.2 Introduction to the attributes of spring management transactions
Transaction isolation level: 1 read uncommitted, 2 read submitted, 4 repeatable read, 8 serialization
Read-Only: true Read-Only, false Operational
Transaction communication behavior:
3.spring Management Transaction Mode
3.1 Encoding Formula (Understanding)
3.1.1 Configure the core transaction manager to the spring container
<! - Transaction Core Manager, which encapsulates all transaction operations. Depends on connection pools - >.
<bean name="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager" >
<property name="dataSource" ref="dataSource" ></property>
</bean>
3.1.2 Configure the Transaction Template template
<!-- Transaction template object --> <bean name="transactionTemplate" class="org.springframework.transaction.support.TransactionTemplate" > <property name="transactionManager" ref="transactionManager" ></property> </bean>
3.1.3 Injecting Transaction Template into Service
<!-- 3.Service--> <bean name="accountService" class="cn.itcast.service.AccountServiceImpl" > <property name="ad" ref="accountDao" ></property> <property name="tt" ref="transactionTemplate" ></property> </bean>
3.1.4 Call Template in Service
public void transfer(final Integer from,final Integer to,final Double money) { tt.execute(new TransactionCallbackWithoutResult() { @Override protected void doInTransactionWithoutResult(TransactionStatus arg0) { //Reduce money ad.decreaseMoney(from, money); int i = 1/0;//Trigger an error to verify that the code is correct //Add money ad.increaseMoney(to, money); } }); }
3.2 xml configuration (aop)
3.2.1 Guide
aop, aspect, aop alliance and weaving weaving package
3.2.2 Import new constraints (tx)
beans: Basically
context: Read the properties configuration
aop: Configure aop
tx: Configuration transaction notification
3.2.3 Configuration Notification
<!-- Configuration transaction notification --> <tx:advice id="txAdvice" transaction-manager="transactionManager" > <tx:attributes> <!-- In terms of methods,Specify what transaction attributes the method applies isolation:Isolation level propagation:Communication behavior read-only:readOnly --> <tx:method name="save*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" /> <tx:method name="persist*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" /> <tx:method name="update*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" /> <tx:method name="modify*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" /> <tx:method name="delete*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" /> <tx:method name="remove*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" /> <tx:method name="get*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="true" /> <tx:method name="find*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="true" /> <tx:method name="transfer" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" /> </tx:attributes> </tx:advice>
3.2.4 configuration will inform weaving target
<! - Configuration weaving - >
<aop:config >
<! - Configure the tangent expression - >
<aop:pointcut expression="execution(* cn.itcast.service.*ServiceImpl.*(..))" id="txPc"/>
<! - Configuration Aspect: Notification + Cut Point
advice-ref: Name of notification
pointcut-ref: The name of the pointcut
-->
<aop:advisor advice-ref="txAdvice" pointcut-ref="txPc" />
</aop:config>
3.3 Annotation Configuration (aop)
Guide packages, tx constraints, and xml configuration (aop) are the same
3.3.1 Open Annotation Management Services
<! - Open the use of annotations to manage aop transactions - > <tx:annotation-driven/>
3.3.2 Use of annotations
@Transactional(isolation=Isolation.REPEATABLE_READ,propagation=Propagation.REQUIRED,readOnly=true) public class AccountServiceImpl implements AccountService { private AccountDao ad ; private TransactionTemplate tt; @Override @Transactional(isolation=Isolation.REPEATABLE_READ,propagation=Propagation.REQUIRED,readOnly=false) public void transfer(final Integer from,final Integer to,final Double money) {