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Spring Tutorial

RowMapper example | Retrieve records using Spring JdbcTemplate

Just like ResultSetExtractor, we can use the RowMapper interface to JdbcTemplate class query()The method retrieves records from the database. During the execution, we now need to pass an instance of RowMapper.

Syntax of query methods using RowMapper

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

RowMapper interface

RowMapper The interface allows the use of instances of user-defined classes to map rows of the relationship. It internally iterates over the ResultSet and adds them to the collection. Therefore, we do not need to write a lot of code to get the records as ResultSetExtractor.

RowMapper is superior to ResultSetExtractor

RowMapper can save a lot of code because

Methods of the RowMapper interface

It only defines a method MapRow, which accepts ResultSet instance and int as parameter list. The syntax of the method is as follows: 

public T mapRow(ResultSet rs, int rowNumber)throws SQLException

An example of the RowMapper interface that displays all records of the table

We assume that you have already installed Oracle10The following table was created in g database. 

create table employee(
id number(10)
name varchar2(100),
salary number(10)
);

Employee.java

This class includes3an attribute with a constructor, setter and getter properties, and an additional toString() method. 

package com.w3codebox;
public class Employee {
private int id;
private String name;
private float salary;
//no-arg and parameterized constructors
//getters and setters
public String toString(){
    return id+" "+name+" "+salary;

EmployeeDao.java

It contains the properties jdbcTemplate and a method getAllEmployeesRowMapper. 

package com.w3codebox;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.ResultSetExtractor;
import org.springframework.jdbc.core.RowMapper;
public class EmployeeDao {
private JdbcTemplate template;
public void setTemplate(JdbcTemplate template) {
    this.template = template;

public List<Employee> getAllEmployeesRowMapper(){
 return template.query("select * from employee",new RowMapper<Employee>(){
    @Override
    public Employee mapRow(ResultSet rs, int rownumber) throws SQLException {
        Employee e=new Employee();
        e.setId(rs.getInt(1));
        e.setName(rs.getString(2));
        e.setSalary(rs.getInt(3));
        return e;
    
    });

applicationContext.xml

DriverManagerDataSource used to contain information about the database, such as the driver class name, connection URL, username, and password.

In the JdbcTemplate class of type DriverManagerDataSource, there is a named datasource The attribute. Therefore, we need to provide a reference to the DriverManagerDataSource object for the data source attribute in the JdbcTemplate class.

Here, we use the JdbcTemplate object in the EmployeeDao class, so we pass it through the setter method, but you can also use the constructor. 

<?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:p="http://www.springframework.org/schema/p
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
http://www.springframework.org/schema/beans/spring-beans-3.0.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="oracle"> />
</bean>
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="ds"></property>
</bean>
<bean id="edao" class="com.w3codebox.EmployeeDao">
<property name="jdbcTemplate" ref="jdbcTemplate"></property>
</bean>
</beans>

Test.java

This class retrieves Beans from the applicationContext.xml file and calls the getAllEmployeesRowMapper() method of the EmployeeDao class. 

package com.w3codebox;
import java.util.List;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Test {
public static void main(String[] args) {
    ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
    EmployeeDao dao = (EmployeeDao)ctx.getBean("edao");
    List<Employee> list = dao.getAllEmployeesRowMapper();
    for(Employee e:list)
        System.out.println(e);
Spring NamedParameterJdbcTemplate ExampleResultSetExtractor Example | Retrieve Records through Spring JdbcTemplate