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jdbcTemplate.queryForList（sql、object、classType）の戻り型

次の方法でjdbcTemplate.queryForListを使用して名前付きクエリを実行しています。

List<Conversation> conversations = jdbcTemplate.queryForList(
            SELECT_ALL_CONVERSATIONS_SQL_FULL,
            new Object[] {userId, dateFrom, dateTo});

SQLクエリは次のとおりです。

private final String SELECT_ALL_CONVERSATIONS_SQL_FULL = 
    "select conversation.conversationID, conversation.room, " +
    "conversation.isExternal, conversation.startDate, " +
    "conversation.lastActivity, conversation.messageCount " +
    "from openfire.ofconversation conversation " +
    "WHERE conversation.conversationid IN " +
    "(SELECT conversation.conversationID " +
    "FROM openfire.ofconversation conversation, " +
    "openfire.ofconparticipant participant " +
    "WHERE conversation.conversationID = participant.conversationID " +
    "AND participant.bareJID LIKE ? " +
    "AND conversation.startDate between ? AND ?)";

ただし、次の方法でリストのコンテンツを抽出する場合：

for (Conversation conversation : conversations) {
builder.append(conversation.getId());
            builder.append(",");
            builder.append(conversation.getRoom());
            builder.append(",");
            builder.append(conversation.getIsExternal());
            builder.append(",");
            builder.append(conversation.getStartDate());            
            builder.append(",");            
            builder.append(conversation.getEndDate());
            builder.append(",");  
            builder.append(conversation.getMsgCount());
            out.write(builder.toString()); 
}

エラーが発生します：

Java.util.LinkedHashMap cannot be cast to net.org.messagehistory.model.Conversation

このlinkedMapを目的のオブジェクトに変換するにはどうすればよいですか？

ありがとう

javaspring-wsjdbctemplate
19
Global Dictator

クエリの結果セットを特定のJavaクラスにマッピングするためには、おそらく、列を変換するRowMapperを使用して、他の場所でオブジェクトを使用することに興味があると仮定します）結果セットでオブジェクトインスタンスに。

行マッパーの使用方法については、 JDBCを使用したデータアクセスのセクション12.2.1.1 を参照してください。

要するに、次のようなものが必要です。

List<Conversation> actors = jdbcTemplate.query(
    SELECT_ALL_CONVERSATIONS_SQL_FULL,
    new Object[] {userId, dateFrom, dateTo},
    new RowMapper<Conversation>() {
        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;
        }
    });
34
beny23

RowMapperの例の有無にかかわらず、JdbcTemplate、NamedParameterJdbcTemplateの完全なソリューション。

// Employeeテーブルを作成します

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<String,Object> map=new HashMap<String,Object>();  
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<Map<String, Object>> rows = jdbcTemplate.queryForList(query);
       for(Map<String, Object> 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<Employee> 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<Employee> getAllEmployee1(){
    return jdbcTemplate.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.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<Employee> {

  @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<Object> {

 @Override
 public Object doInPreparedStatement(PreparedStatement ps)
        throws SQLException, DataAccessException {

     return ps.executeUpdate(); 
  } 

 }

================================================== =================== //Test.Java

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"); 

  // By calling constructor for insert
 /* 
    int status=dao.saveEmployee(new Employee(103,"Ajay",35000));  
    System.out.println(status);  
 */
 // By calling PreparedStatement
  dao.insertEmploye(new Employee(103,"Roh",25000));


 // By calling setter-getter for update
 /* 
    Employee e=new Employee(); 
    e.setId(102);
    e.setName("Rohit");
    e.setSalary(8000000);
    int status=dao.updateEmployee(e);
*/
 // By calling constructor for update
 /*
    int status=dao.updateEmployee(new Employee(102,"Sadhan",15000)); 
    System.out.println(status); 
 */ 
 // Deleting a record 
 /*      
    Employee e=new Employee(); 
    e.setId(102); 
    int status=dao.deleteEmployee(e); 
    System.out.println(status);
 */
 // Selecting single or all rows
 /*
    Employee e=new Employee(); 
    e.setId(102);
    int status=dao.selectEmployee(e);
    System.out.println(status);
*/
// Can use MyrowMapper class an implementation class for RowMapper interface

    dao.getAllEmployee();

// Can use directly a RowMapper implementation class without an object creation
 /*
    List<Employee> list=dao.getAllEmployee1();  
    for(Employee e1:list)  
    System.out.println(e1);  
  */   
   }  

 }

================================================== ================ //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"  
 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="hr" />  
 <property name="password" value="hr" />  
 </bean>  

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

<bean id="nameTemplate"   
class="org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate">  
<constructor-arg ref="ds"></constructor-arg>  
</bean>  

<bean id="edao" class="EmployeeDao"> 
<!-- Can use both --> 
<property name="nameTemplate" ref="nameTemplate"></property>
<property name="jdbcTemplate" ref="jdbcTemplate"></property> 
</bean>

================================================== =================

10
Rohit
List<Map<String, Object>> List = getJdbcTemplate().queryForList(SELECT_ALL_CONVERSATIONS_SQL_FULL, new Object[] {userId, dateFrom, dateTo});
for (Map<String, Object> rowMap : resultList) {
    DTO dTO = new DTO();
    dTO.setrarchyID((Long) (rowMap.get("ID")));
}
3
srinivas

queryForListは、LinkedHashMapオブジェクトのリストを返します。

最初に次のようにキャストする必要があります。

 
 List list = jdbcTemplate.queryForList（...）; 
 for（Object o：list）{
 Map m =（Map）o; 
 ... 
}
1
11101101b
List<Conversation> conversations = **jdbcTemplate**.**queryForList**(
            **SQL_QUERY**,
            new Object[] {userId, dateFrom, dateTo});  //placeholders values

SQLクエリは次のようなものだと仮定します

SQL_QUERY = "**select** info,count(*),IF(info is null , 'DATA' , 'NO DATA') **from** table where userId=? , dateFrom=? , dateTo=?";

**HERE userId=? , dateFrom=? , dateTo=?**

疑問符はプレースホルダーです

**SQL_QUERY**,
            new Object[] {userId, dateFrom, dateTo});

SQLクエリとともにオブジェクト配列として使用されます

0
umamaheshwar g