Spring DAO Pattern : DAO « Spring « Java Tutorial

1. Java Tutorial
2. Spring
3. DAO

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.commons.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.comments = 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();
  }
}

28.42.DAO
	28.42.1.	Inject DataSource to DAO
	28.42.2.	Spring DAO Pattern