Java/Spring/Spring DAO
Spring DAO Pattern
<source lang="java">
File: context.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:util="http://www.springframework.org/schema/util" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:lang="http://www.springframework.org/schema/lang" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-2.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang-2.0.xsd">
<bean id="dataSource" class="org.apache.rumons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="org.hsqldb.jdbcDriver"/> <property name="url" value="jdbc:hsqldb:mem:."/> <property name="username" value="sa"/> <property name="password" value=""/> </bean> <bean id="abstractJdbcDao" abstract="true" class="org.springframework.jdbc.core.support.JdbcDaoSupport"> <property name="dataSource" ref="dataSource"/> </bean> <bean id="customerDao" class="JdbcCustomerDao" parent="abstractJdbcDao"/>
</beans>
File: Main.java import java.sql.Types; import java.util.Date; import java.util.List; import java.util.Map; import javax.sql.DataSource; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import org.springframework.jdbc.core.RowMapper; import org.springframework.jdbc.core.SqlParameter; import org.springframework.jdbc.core.simple.ParameterizedBeanPropertyRowMapper; import org.springframework.jdbc.core.support.JdbcDaoSupport; import org.springframework.jdbc.object.SqlQuery; class Main {
public static void main(String args[]) throws Exception { ApplicationContext ac = new ClassPathXmlApplicationContext("context.xml", Main.class); DataSource dataSource = (DataSource) ac.getBean("dataSource"); // DataSource mysqlDataSource = (DataSource) ac.getBean("mysqlDataSource"); CustomerDao customerDao = (CustomerDao)ac.getBean("customerDao"); customerDao.getAll(); customerDao.getById(1L);
}
} class JdbcCustomerDao extends JdbcDaoSupport implements CustomerDao {
private SelectCustomerById selectCustomerById; private static class SelectCustomerById extends SqlQuery { SelectCustomerById(DataSource ds) { super(ds, "select * from t_customer where id=?"); declareParameter(new SqlParameter(Types.INTEGER)); } protected RowMapper newRowMapper(Object[] parameters, Map context) { return ParameterizedBeanPropertyRowMapper.newInstance(Customer.class); } } @Override protected void initDao() throws Exception { this.selectCustomerById = new SelectCustomerById(getDataSource()); } @SuppressWarnings({"unchecked"}) public List<Customer> getAll() { return getJdbcTemplate().query("select * from t_customer", ParameterizedBeanPropertyRowMapper.newInstance(Customer.class)); } public Customer getById(long id) { return (Customer)this.selectCustomerById.findObject(id); }
} interface CustomerDao {
List<Customer> getAll(); Customer getById(long id);
}
class Customer {
private Long id; private String firstName; private String lastName; private Date lastLogin; private String comments; public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } public Date getLastLogin() { return lastLogin; } public void setLastLogin(Date lastLogin) { this.lastLogin = lastLogin; } public String getComments() { return comments; } public void setComments(String comments) { this.ruments = comments; } @Override public String toString() { final StringBuilder sb = new StringBuilder(); sb.append("Customer"); sb.append("{id=").append(id); sb.append(", firstName="").append(firstName).append("\""); sb.append(", lastName="").append(lastName).append("\""); sb.append(", lastLogin=").append(lastLogin); sb.append(", comments="").append(comments).append("\""); sb.append("}"); return sb.toString(); }
}
</source>