Java/Spring/ResultSetExtractor
Implements ResultSetExtractor to get the data from first column
<source lang="java">
File: context.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:util="http://www.springframework.org/schema/util" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:lang="http://www.springframework.org/schema/lang" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-2.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang-2.0.xsd">
<bean id="dataSource" class="org.apache.rumons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="org.hsqldb.jdbcDriver"/> <property name="url" value="jdbc:hsqldb:mem:."/> <property name="username" value="sa"/> <property name="password" value=""/> </bean>
<bean id="lobHandler" class="org.springframework.jdbc.support.lob.OracleLobHandler"> <property name="nativeJdbcExtractor" ref="nativeJdbcExtractor"/> </bean> <bean id="nativeJdbcExtractor" class="org.springframework.jdbc.support.nativejdbc.rumonsDbcpNativeJdbcExtractor"/> <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"> <property name="dataSource" ref="dataSource"/> </bean>
</beans>
File: Main.java import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import javax.sql.DataSource; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import org.springframework.dao.DataAccessException; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.jdbc.core.PreparedStatementSetter; import org.springframework.jdbc.core.ResultSetExtractor; class Main {
public static void main(String args[]) throws Exception { ApplicationContext ac = new ClassPathXmlApplicationContext("context.xml", Main.class); DataSource dataSource = (DataSource) ac.getBean("dataSource"); // DataSource mysqlDataSource = (DataSource) ac.getBean("mysqlDataSource"); JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource); String firstCustomersName = (String) jdbcTemplate.query( "select first_name from t_customer where id=?", new PreparedStatementSetter() { public void setValues(PreparedStatement preparedStatement) throws SQLException { preparedStatement.setLong(1, 1L); } }, new FirstColumnStringExtractor()); System.out.println(firstCustomersName); }
} class FirstColumnStringExtractor implements ResultSetExtractor {
public Object extractData(ResultSet resultSet) throws SQLException, DataAccessException { if (resultSet.next()) { return resultSet.getString(1); } return null; }
}
</source>
PreparedStatementCreator And ResultSetExtractor
<source lang="java">
File: context.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:util="http://www.springframework.org/schema/util" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:lang="http://www.springframework.org/schema/lang" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-2.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang-2.0.xsd">
<bean id="dataSource" class="org.apache.rumons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="org.hsqldb.jdbcDriver"/> <property name="url" value="jdbc:hsqldb:mem:."/> <property name="username" value="sa"/> <property name="password" value=""/> </bean>
<bean id="lobHandler" class="org.springframework.jdbc.support.lob.OracleLobHandler"> <property name="nativeJdbcExtractor" ref="nativeJdbcExtractor"/> </bean> <bean id="nativeJdbcExtractor" class="org.springframework.jdbc.support.nativejdbc.rumonsDbcpNativeJdbcExtractor"/> <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"> <property name="dataSource" ref="dataSource"/> </bean>
</beans>
File: Main.java import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import javax.sql.DataSource; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import org.springframework.dao.DataAccessException; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.jdbc.core.PreparedStatementCreator; import org.springframework.jdbc.core.PreparedStatementSetter; import org.springframework.jdbc.core.ResultSetExtractor; class Main {
public static void main(String args[]) throws Exception { ApplicationContext ac = new ClassPathXmlApplicationContext("context.xml", Main.class); DataSource dataSource = (DataSource) ac.getBean("dataSource"); // DataSource mysqlDataSource = (DataSource) ac.getBean("mysqlDataSource"); JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource); Long maxId = (Long) jdbcTemplate.query(new PreparedStatementCreator() { public PreparedStatement createPreparedStatement(Connection connection) throws SQLException { return connection.prepareStatement("select max(id) from customer"); } }, new ResultSetExtractor() { public Object extractData(ResultSet resultSet) throws SQLException, DataAccessException { if (resultSet.next()) { return resultSet.getLong(1); } return null; } }); System.out.println(maxId); }
}
</source>
ResultSetExtractor With Aggregate Function
<source lang="java">
File: context.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:util="http://www.springframework.org/schema/util" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:lang="http://www.springframework.org/schema/lang" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-2.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang-2.0.xsd">
<bean id="dataSource" class="org.apache.rumons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="org.hsqldb.jdbcDriver"/> <property name="url" value="jdbc:hsqldb:mem:."/> <property name="username" value="sa"/> <property name="password" value=""/> </bean>
<bean id="lobHandler" class="org.springframework.jdbc.support.lob.OracleLobHandler"> <property name="nativeJdbcExtractor" ref="nativeJdbcExtractor"/> </bean> <bean id="nativeJdbcExtractor" class="org.springframework.jdbc.support.nativejdbc.rumonsDbcpNativeJdbcExtractor"/> <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"> <property name="dataSource" ref="dataSource"/> </bean>
</beans>
File: Main.java import java.sql.ResultSet; import java.sql.SQLException; import javax.sql.DataSource; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import org.springframework.dao.DataAccessException; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.jdbc.core.ResultSetExtractor; class Main {
public static void main(String args[]) throws Exception { ApplicationContext ac = new ClassPathXmlApplicationContext("context.xml", Main.class); DataSource dataSource = (DataSource) ac.getBean("dataSource"); // DataSource mysqlDataSource = (DataSource) ac.getBean("mysqlDataSource"); JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource); Long count = (Long) jdbcTemplate.query("select count(*) from customer", new ResultSetExtractor() { public Object extractData(ResultSet resultSet) throws SQLException, DataAccessException { if (resultSet.next()) { return resultSet.getLong(1); } return null; } }); System.out.println(count); }
}
</source>