< 16 >jdbc_ using dbutils to write generic DAO

Interface: Dao<t>.java

Import java.sql.Connection;
Import java.sql.SQLException;
Import java.util.List;

/*
* DAO interface for accessing data.
* @param types of entity classes processed by T:dao
* */
Public interface Dao<t> {

/*
* Method of batch Processing
* @param con: Database connection
* @param sql:sql statement
* @param args: Variable parameters for object[] types filled with placeholders
* @return
* */
void Batch (Connection con,string Sql,object[]...args);

/*
* Returns a specific value, eg. total number of people, average salary ...
* @param con: Database connection
* @param sql:sql statement
* @param args: Variable parameters for fill placeholders
* @return
* */
<E> E getforvalue (Connection con,string Sql,object...args);

/*
* Returns a collection of T
* @param con: Database connection
* @param sql:sql statement
* @param args: Variable parameters for fill placeholders
* @return
* */
List<t> getforlist (Connection con,string Sql,object...args);

/*
* Returns an object of T
* @param con: Database connection
* @param sql:sql statement
* @param args: Variable parameters for fill placeholders
* @return
* */
T Get (Connection con,string Sql,object...args) throws SQLException;

/*
* INSERT, UPDATE, delete
* @param con: Database connection
* @param sql:sql statement
* @param args: Variable parameters for fill placeholders
* */
void Update (Connection con,string Sql,object...args);
}

DAO interface Implementation class: Jdbcdaoimpl.java

Import java.sql.Connection;
Import java.sql.SQLException;
Import java.util.List;
Import Org.apache.commons.dbutils.QueryRunner;
Import Org.apache.commons.dbutils.handlers.BeanHandler;
Import Com.kk.jdbc.ReflectionUtils;

/*
* Use Queryrunner to provide its specific implementation
* @param <t>: Subclasses need to pass in a generic type
* */
public class Jdbcdaoimpl<t> implements dao<t> {

Private Queryrunner Qr=null;
Private class<t> type;

Public Jdbcdaoimpl () {

Qr=new Queryrunner ();
Type=reflectionutils.getsupergenerictype (GetClass ());
}

@Override
public void Batch (Connection con, String sql, object[] ... args) {
TODO auto-generated Method Stub

}

@Override
Public <E> E getforvalue (Connection con, String sql, Object ... args) {
TODO auto-generated Method Stub
return null;
}

@Override
Public list<t> getforlist (Connection con, String sql, Object ... args) {
TODO auto-generated Method Stub
return null;
}

@Override
Public T get (Connection con, String sql, Object ... args) throws SQLException {

Return qr.query (Con, SQL, New beanhandler<> (type), args);
}

@Override
public void update (Connection con, String sql, Object ... args) {
TODO auto-generated Method Stub
}
}

Sub-class of Jdbcdaoimpl Customerdao.java

public class Customerdao extends Jdbcdaoimpl<customer> {

}

Test class: Customerdaotest.java

Import static org.junit.assert.*;
Import java.sql.Connection;
Import Org.junit.Test;
Import Com.kk.jdbc.JDBCTools;

public class Customerdaotest {

Customerdao customerdao=new Customerdao ();

@Test
public void Testbatch () {
Fail ("not yet implemented");
}

@Test
public void Testgetforvalue () {
Fail ("not yet implemented");
}

@Test
public void Testgetforlist () {
Fail ("not yet implemented");
}

@Test
public void Testget () {

Connection con = null;
try {

Con=jdbctools.getconnection ();
String sql = "Select Id,name,email from Customers where id=?";
Customer customer=customerdao.get (Con, SQL, 6);
SYSTEM.OUT.PRINTLN (customer);
} catch (Exception e) {
E.printstacktrace ();
}finally{
Jdbctools.release (null, NULL, con);
}
}

@Test
public void Testupdate () {
Fail ("not yet implemented");
}
}

< 16 >jdbc_ using dbutils to write generic DAO