1 .该接口用于处理 java.sql.ResultSet，将数据按要求转换为另一种形式。
ResultSetHandler 接口提供了一个单独的方法：Object handle (java.sql.ResultSet .rs)。
2.ResultSetHandler 接口的实现类
|
ArrayHandler：把结果集中的第一行数据转成对象数组。 |
3.示例代碼如下：
1.首先定義一實體類
package com.beiwo.day05.entity;
import java.io.Serializable;
import java.sql.Date;
public class Person implements Serializable{
/**
*
*/
private static final long serialVersionUID = 1L;
private int id;
private String name;
private String password;
private String email;
private Date birthday;
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 String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public static long getSerialversionuid() {
return serialVersionUID;
}
@Override
public String toString() {
return "Person [id=" + id + ", name=" + name + ", password=" + password
+ ", email=" + email + ", birthday=" + birthday + ", getId()="
+ getId() + ", getName()=" + getName() + ", getPassword()="
+ getPassword() + ", getEmail()=" + getEmail()
+ ", getBirthday()=" + getBirthday() + ", getClass()="
+ getClass() + ", hashCode()=" + hashCode() + ", toString()="
+ super.toString() + "]";
}
}
測試查詢
package com.beiwo.day05.test;
import java.sql.SQLException;
import java.util.List;
import java.util.Map;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.ArrayHandler;
import org.apache.commons.dbutils.handlers.ArrayListHandler;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ColumnListHandler;
import org.apache.commons.dbutils.handlers.MapHandler;
import org.apache.commons.dbutils.handlers.MapListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;
import org.junit.Test;
import com.beiwo.day05.entity.Person;
import com.beiwo.day05.util.C3P0Util;
public class TestDBUtils {
@Test //把结果集中的每一行数据都转成一个数组，再存放到List中。
public void testArrayListHandler() throws SQLException{
QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());
String sql = "SELECT * FROM person";
List<Object[]> list = qr.query(sql, new ArrayListHandler());
for (Object[] objects : list) {
for (Object object : objects) {
System.out.println(object);
}
System.out.println("-----------------------------");
}
}
@Test //把结果集中的第一行数据转成对象数组。
public void testArrayHandler() throws SQLException{
QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());
String sql = "SELECT * FROM person";
Object[] object = qr.query(sql, new ArrayHandler());
for(Object object1 : object){
System.out.println(object1);
}
}
// @Test 将结果集中某一列的数据存放到List中。
public void testColumnListHandler() throws SQLException{
QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());
String sql = "SELECT name,password,email,birthday FROM person";
List<Object> persons = qr.query(sql, new ColumnListHandler(2));
for(Object object : persons){
System.out.println(object);
}
}
@Test //将结果集中的第一行数据封装到一个Map里，key是列名，value就是对应的值。
public void testMapHandler() throws SQLException{
QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());
String sql = "SELECT * FROM person WHERE id=?";
Map<String, Object> map= qr.query(sql, new MapHandler(),1);
for (Map.Entry<String, Object> m:map.entrySet()) {
System.out.println(m.getKey() + " " + m.getValue());
}
}
@Test //将结果集中的每一行数据都封装到一个Map里，然后再存放到List
public void testMapListHandler() throws SQLException{
QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());
String sql = "SELECT * FROM person ";
List<Map<String, Object>> list = qr.query(sql, new MapListHandler());
for (Map<String, Object> map : list) {
for (Map.Entry<String, Object> m : map.entrySet()) {
System.out.println(m.getKey() + " " + m.getValue());
}
System.out.println("--------------------------------------------");
}
}
@Test //查询数据库中信息的总条数
public void testScalarHandler() throws SQLException{
QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());
String sql = "SELECT COUNT(*) FROM person ";
Long l = (Long)qr.query(sql, new ScalarHandler(1));
System.out.println(l);
}
@Test //将结果集中的每一行数据都封装到一个对应的JavaBean实例中，存放到List里。
public void testBeanListHandler() throws SQLException{
QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());
String sql = "SELECT * FROM person ";
List<Person> list = qr.query(sql, new BeanListHandler<Person>(Person.class));
System.out.println(list);
}
@Test //将结果集中的第一行数据封装到一个对应的JavaBean实例中。
public void testBeanHandler() throws SQLException{
QueryRunner qr = new QueryRunner(C3P0Util.getDataSource());
String sql = "SELECT * FROM person WHERE id=?";
Person person = qr.query(sql, new BeanHandler<Person>(Person.class),1);
System.out.println(person);
}
}
測試增刪改
package com.beiwo.day05.test;
import java.sql.SQLException;
import java.util.Date;
import org.apache.commons.dbutils.QueryRunner;
import org.junit.Test;
import com.beiwo.day05.util.C3P0Util;
public class TestUpDate {
@Test
public void testInsert() throws SQLException{
QueryRunner qRunner = new QueryRunner(C3P0Util.getDataSource());
String sql = "INSERT INTO person(name,password,email,birthday)VALUES(?,?,?,?)";
qRunner.update(sql, "ccc","789","789@qq.com",new Date());
}
@Test
public void testUpDate1() throws SQLException{
QueryRunner qRunner = new QueryRunner(C3P0Util.getDataSource());
String sql = "UPDATE person SET name='www' WHERE id=2";
qRunner.update(sql);
}
@Test
public void testUpDate2() throws SQLException{
QueryRunner qRunner = new QueryRunner(C3P0Util.getDataSource());
String sql = "DELETE FROM person WHERE id=6";
qRunner.update(sql);
}
}