JAVAEE -- spring03: spring integrates JDBC and aop transactions, javaeespring03

JAVAEE -- spring03: spring integrates JDBC and aop transactions, javaeespring03
I. Integrate spring with JDBC 1. spring provides a lot of Dao technology for template Integration

　　

2. spring provides an object for database operations. The object encapsulates the jdbc technology.

JDBCTemplate => JDBC template object

It is very similar to QueryRunner in DBUtils.

// 0 prepare the connection pool ComboPooledDataSource dataSource = new ComboPooledDataSource (); dataSource. setDriverClass ("com. mysql. jdbc. driver "); dataSource. setJdbcUrl ("jdbc: mysql: // xieyupeng"); dataSource. setUser ("root"); dataSource. setPassword ("1234"); // 1 create the JDBC template object JdbcTemplate jt = new JdbcTemplate (); jt. setDataSource (dataSource); // 2 Write the SQL statement and run String SQL = "insert into t_user values (null, 'Rose ')"; jt. update (SQL );

3. Integration Step 3.1 import package

4 + 2: 4 represents:

2 representative: com.springsource.org. apache. commons. logging-1.1.1.jar, com.springsource.org. apache. log4j-1.2.15.jar (the old version to import, the import can be guaranteed to run)

Spring-test, spring-aop, and junit4 Class Libraries

C3p0 connection pool, JDBC driver

Spring-jdbc and spring-tx transactions

3.2 prepare the database (two Field IDS (auto-increment) and name) 3.3 write Dao

// Use the JDBC template to add, delete, modify, and query 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 into the 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. put JDBCTemplate into the spring container --> <bean name = "jdbcTemplate" class = "org. springframework. jdbc. core. jdbcTemplate "> <property name =" dataSource "ref =" dataSource "> </property> </bean> <! -- 3. Add UserDao to the 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

// Demonstrate the 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 content 4.1 JDBCDaoSupport

public class UserDaoImpl extends JdbcDaoSupport

<! -- 3. Add UserDao to the spring container (inherit from JDBCDaoSupport and directly inject into sponse) --> <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 external Properties configuration

Db. properties pay attention to prefix (better differentiation to prevent duplicate names)

jdbc.jdbcUrl=jdbc:mysql:///hibernate_32jdbc.driverClass=com.mysql.jdbc.Driverjdbc.user=rootjdbc.password=1234

<! -- Specify spring to read db. properties configuration --> <context: property-placeholder location = "classpath: db. properties"/> <! -- 1. put the connection pool into the 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>

Ii. Use annotations to configure spring 1. Transaction review

Transaction Features: acid

Transaction concurrency problems: dirty reads, non-repeated reads, Phantom reads

Transaction isolation level: 1 read uncommitted, 2 read committed, 4 Repeatable read, 8 serialize

2. spring encapsulates the Transaction Management Code

Transaction operations: open transactions, commit transactions, roll back transactions

Transaction operation object

Because the code for operating transactions varies on different platforms. spring provides an interface

2.1 PlatformTransactionManager Interface

DataSourceTransactionManager

HibernateTransitionmanager

Note: In spring, the most important object is the TransactionManager object.

2.2 Introduction to spring's transaction management attributes

Transaction isolation level: 1 read uncommitted, 2 read committed, 4 Repeatable read, 8 serialize

Read-Only: true; read-only; false; operable

Propagation Behavior of transactions:

　　

3. spring transaction management method

　　

 

3.1 understand (understand) 3.1.1 configure the core Transaction Manager to the spring container

<! -- The core Transaction Manager encapsulates all transaction operations. dependent on the connection pool --> <bean name = "transactionManager" class = "org. springframework. jdbc. datasource. dataSourceTransactionManager "> <property name =" dataSource "ref =" dataSource "> </property> </bean>

3.1.2 configure the TransactionTemplate Template

<! -- Transaction template object --> <bean name = "transactionTemplate" class = "org. springframework. transaction. support. transactionTemplate "> <property name =" transactionManager "ref =" transactionManager "> </property> </bean>

3.1.3 inject the transaction Template into the 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.exe cute (new TransactionCallbackWithoutResult () {@ Override protected void doInTransactionWithoutResult (TransactionStatus arg0) {// deduct money ad. decreaseMoney (from, money); int I = 1/0; // trigger an error to verify whether the code is correct // Add money to ad. increaseMoney (to, money );}});}

3.2 xml configuration (aop) 3.2.1 import package

Aop, aspect, aop alliance, and weaving

3.2.2 import new constraints (tx)

　　

Beans: Basic
Context: Read properties configuration
Aop: Configure aop
Tx: Configure transaction notifications

3.2.3 configuration notification

<! -- Configure transaction notification --> <tx: advice id = "txAdvice" transaction-manager = "transactionManager"> <tx: attributes> <! -- In the unit of method, specify the transaction attribute isolation used by the method: isolation level propagation: propagation Behavior read-only: read-only --> <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 configure to route notifications to the target

<! -- Configure woven --> <aop: config> <! -- Configure the cut expression --> <aop: pointcut expression = "execution (* cn. itcast. service. * ServiceImpl. *(..)) "id =" txPc "/> <! -- Configuration aspect: Notification + cut point advice-ref: Notification name pointcut-ref: Cut Point name --> <aop: advisor advice-ref = "txAdvice" pointcut-ref = "txPc"/> </aop: config>

3.3 annotation configuration (aop) pilot package, tx constraint, and xml configuration (aop) Same 3.3.1 enable annotation management transaction

<! -- Enable the use of annotations to manage aop transactions --> <tx: annotation-driven/>

3.3.2 Annotation

@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) {