Spring Ders16 - Database ( Veritabanı ) - RowMapper

   RowMapper arayüzü (interface), ResultSetExtractor arayüzünde olduğu gibi JdbcTemplate sınıfının query metoduyla veritabanından verileri çekmeye yarayan bir arayüzdür.

query metodunun imzası (signatur) aşağıdaki gibidir.

public T query(String sql,RowMapper<T> rm)

 RowMapper arayüzünün  ResultSetExtractor arayüzüne göre avantajı ResultSet verilerinin dahili bir şekilde yer almasıdır. Böylece daha az koda ihtiyaç duyar.

Şimdi örnek programımızı yapalım.

Main.java

package test;

import java.util.List;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Main {
 public static void main(String[] args) {

  ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");

  BilgiIslem bilgici = (BilgiIslem) context.getBean("bilgiislem");

  List <Personel> list = bilgici.getPersoneller();
 
  System.out.println("ID\tAD\tMAAS\n");
  
  for(Personel p:list){
   System.out.println(p.getId()+"\t"+p.getAd()+"\t"+p.getMaas());
  }
  
  
 }

}

Personel.java

package test;

public class Personel {

 private int id;
 private int maas;
 private String ad;

 public Personel() {
 }

 public Personel(int id, String ad, int maas) {
  this.id = id;
  this.ad = ad;
  this.maas = maas;
 }

 public int getId() {
  return id;
 }

 public void setId(int id) {
  this.id = id;
 }

 public int getMaas() {
  return maas;
 }

 public void setMaas(int maas) {
  this.maas = maas;
 }

 public String getAd() {
  return ad;
 }

 public void setAd(String ad) {
  this.ad = ad;
 }

}

BilgiIslem.java

package test;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;

public class BilgiIslem {

 private JdbcTemplate jdbcTemplate;

 public JdbcTemplate getJdbcTemplate() {
  return jdbcTemplate;
 }

 public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
  this.jdbcTemplate = jdbcTemplate;
 }

 public List<Personel> getPersoneller() {
  return jdbcTemplate.query("select * from bilgiislem", new RowMapper<Personel>() {

   @Override
   public Personel mapRow(ResultSet rs, int satirNumarasi) throws SQLException {
    Personel p = new Personel();
    p.setId(rs.getInt(1));
    p.setAd(rs.getString(2));
    p.setMaas(rs.getInt(3));
    return p;
   }
  });

 }
}

applicationContext.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"
 xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

 <bean id="ds"
  class="org.springframework.jdbc.datasource.DriverManagerDataSource">
  <property name="driverClassName" value="oracle.jdbc.driver.OracleDriver" />
  <property name="url" value="jdbc:oracle:thin:@localhost:1521:xe" />
  <property name="username" value="system" />
  <property name="password" value="****" />
 </bean>

 <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
  <property name="dataSource" ref="ds"></property>
 </bean>

 <bean id="bilgiislem" class="test.BilgiIslem">
  <property name="jdbcTemplate" ref="jdbcTemplate" />
 </bean>
 
 
</beans>

test.sql

create table bilgiislem(
id int,
ad varchar(255),
maas int
);