Tipo de retorno para jdbcTemplate.queryForList (sql, object, classType)

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Solución:

Para mapear un conjunto de resultados de la consulta a una clase particular de Java, probablemente será mejor (suponiendo que esté interesado en usar el objeto en otro lugar) con un RowMapper para convertir las columnas en el conjunto de resultados en una instancia de objeto.

Consulte la Sección 12.2.1.1 de Acceso a datos con JDBC sobre cómo utilizar un mapeador de filas.

En resumen, necesitará algo como:

List actors = jdbcTemplate.query(
    SELECT_ALL_CONVERSATIONS_SQL_FULL,
    new Object[] userId, dateFrom, dateTo,
    new RowMapper() 
        public Conversation mapRow(ResultSet rs, int rowNum) throws SQLException 
            Conversation c = new Conversation();
            c.setId(rs.getLong(1));
            c.setRoom(rs.getString(2));
            [...]
            return c;
        
    );

Una solución completa para JdbcTemplate, NamedParameterJdbcTemplate con o sin RowMapper Example.

// Crea una tabla de empleados

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

================================================ ===================== //Employee.java

public class Employee 
private int id;  
private String name;  
private float salary;  

//no-arg and parameterized constructors  

public Employee();

public Employee(int  id, String name, float salary)
    this.id=id;
    this.name=name;
    this.salary=salary;


//getters and setters  
public int getId() 
    return id;

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

public String getName() 
    return name;

public void setName(String name) 
    this.name = name;

public float getSalary() 
    return salary;

public void setSalary(float salary) 
    this.salary = salary;

public String toString()  
   return id+" "+name+" "+salary;  
   

================================================ ======================= //EmployeeDao.java

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;

public class EmployeeDao   
  private JdbcTemplate jdbcTemplate;  
  private NamedParameterJdbcTemplate nameTemplate;  

  public void setnameTemplate(NamedParameterJdbcTemplate template)   
    this.nameTemplate = template;  
    

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

 // BY using JdbcTemplate
 public int saveEmployee(Employee e)  
 int id = e.getId();
 String name = e.getName();
 float salary = e.getSalary();
 Object p[] = id, name, salary;
    String query="insert into employee values(?,?,?)";
      return jdbcTemplate.update(query, p);
    /*String query="insert into employee     values('"+e.getId()+"','"+e.getName()+"','"+e.getSalary()+"')"; 
      return jdbcTemplate.update(query);
    */

  

//By using NameParameterTemplate
public void insertEmploye(Employee e)   
String query="insert into employee values (:id,:name,:salary)";  
Map map=new HashMap();  
map.put("id",e.getId());  
map.put("name",e.getName());  
map.put("salary",e.getSalary());  

nameTemplate.execute(query,map,new MyPreparedStatement());

 
// Updating Employee
public int updateEmployee(Employee e)  
String query="update employee set  name='"+e.getName()+"',salary='"+e.getSalary()+"' where id='"+e.getId()+"' ";  
  return jdbcTemplate.update(query);  
 
 // Deleting a Employee row
 public int deleteEmployee(Employee e)  
 String query="delete from employee where id='"+e.getId()+"' ";  
 return jdbcTemplate.update(query);  
   
 //Selecting Single row with condition and also all rows
    public int selectEmployee(Employee e)  
     //String query="select * from employee where id='"+e.getId()+"' ";
      String query="select * from employee";
      List> rows = jdbcTemplate.queryForList(query);
       for(Map row : rows)
          String id = row.get("id").toString();
          String name = (String)row.get("name");
          String salary = row.get("salary").toString();
          System.out.println(id + " " + name + " " + salary );
        

      return 1;
     

   // Can use MyrowMapper class an implementation class for RowMapper interface
    public void getAllEmployee()
    

    String query="select * from employee";
    List l = jdbcTemplate.query(query, new MyrowMapper());

    Iterator it=l.iterator();
    while(it.hasNext())
    
      Employee e=(Employee)it.next();
      System.out.println(e.getId()+" "+e.getName()+" "+e.getSalary());
    
     

  //Can use directly a RowMapper implementation class without an object creation
  public List getAllEmployee1()
    return jdbcTemplate.query("select * from employee",new RowMapper()  
      @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.getFloat(3));  
            return e;  
            
      );  
      
     // End of all the function

     

================================================ ============== //MyrowMapper.java

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

 public class MyrowMapper implements RowMapper 

  @Override  
  public Employee mapRow(ResultSet rs, int rownumber) throws SQLException 
     
    System.out.println("mapRow()====:"+rownumber);
    Employee e=new Employee();  
     e.setId(rs.getInt("id"));  
     e.setName(rs.getString("name"));  
     e.setSalary(rs.getFloat("salary"));  
     return e;  
      
     

================================================ ======== //MyPreparedStatement.java

import java.sql.PreparedStatement;
import java.sql.SQLException;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.PreparedStatementCallback;


 public class MyPreparedStatement implements  PreparedStatementCallback