JavaWeb之DBUtils
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2024-02-29 12:05:22
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CREATE DATABASE day0528;
USE day0528;
CREATE TABLE t_user(
id INT PRIMARY KEY AUTO_INCREMENT,
NAME VARCHAR(40),
PASSWORD VARCHAR(40),
email VARCHAR(40),
birthday DATE
);
INSERT INTO t_user(NAME,PASSWORD,email,birthday) VALUES('小龙女','16','[email protected]','2001-1-1');
INSERT INTO t_user(NAME,PASSWORD,email,birthday) VALUES('姬如雪','17','[email protected]','2002-2-2');
INSERT INTO t_user(NAME,PASSWORD,email,birthday) VALUES('女帝','18','[email protected]','2003-3-3');
SELECT * FROM t_user;User.java
package zh.jdbc.demo;
import java.util.Date;
public class User {
private Integer id;
private String name;
private String password;
private String email;
private Date birthday;// java.util.Date
public User() {
}
public User(Integer id, String name, String password, String email,
Date birthday) {
super();
this.id = id;
this.name = name;
this.password = password;
this.email = email;
this.birthday = birthday;
}
public Integer getId() {
return id;
}
public void setId(Integer 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;
}
@Override
public String toString() {
return "User [id=" + id + ", name=" + name + ", password=" + password
+ ", email=" + email + ", birthday=" + birthday + "]";
}
}DBUtilsDemo.java
package zh.dbutils.demo;
import java.sql.SQLException;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import javax.sql.DataSource;
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.BeanMapHandler;
import org.apache.commons.dbutils.handlers.ColumnListHandler;
import org.apache.commons.dbutils.handlers.KeyedHandler;
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 zh.jdbc.demo.User;
import com.mchange.v2.c3p0.ComboPooledDataSource;
/**
* DBUtils使用：QueryRunner类和ResultSetHandler接口
*
* @author ZH
*
*/
public class DBUtilsDemo {
// c3p0连接池
private DataSource dataSource = new ComboPooledDataSource();
/**
* ArrayHandler:将单行结果集封装成数组
*
* @throws SQLException
*/
@Test
public void query1() throws SQLException {
QueryRunner queryRunner = new QueryRunner(dataSource);
String sql = "select * from t_user where id = ?";
Object[] array = queryRunner.query(sql, new ArrayHandler(), 1);
System.out.println(Arrays.toString(array));
// [1, 小龙女, 16, [email protected], 2001-01-01]
}
/**
* ArrayListHandler:将结果集中每一行数据封装到一个数组，再把数组添加到List集合
*
* @throws SQLException
*/
@Test
public void query2() throws SQLException {
QueryRunner queryRunner = new QueryRunner(dataSource);
String sql = "select * from t_user";
List<Object[]> arrayList = queryRunner.query(sql,
new ArrayListHandler());
for (Object[] array : arrayList) {
System.out.println(Arrays.toString(array));
}
// [1, 小龙女, 16, [email protected], 2001-01-01]
// [2, 姬如雪, 17, [email protected], 2002-02-02]
// [3, 女帝, 18, [email protected], 2003-03-03]
}
/**
* BeanHandler:将单行结果集封装到JavaBean
*
* @throws SQLException
*/
@Test
public void query3() throws SQLException {
QueryRunner queryRunner = new QueryRunner(dataSource);
String sql = "select * from t_user where id = ?";
User user = queryRunner
.query(sql, new BeanHandler<User>(User.class), 1);
System.out.println(user);
// User [id=1, name=小龙女, password=16, [email protected],
// birthday=2001-01-01]
}
/**
* BeanListHanlder:将结果集中每一行数据封装到一个JavaBean对象，再将对象添加到List集合
*
* @throws SQLException
*/
@Test
public void query4() throws SQLException {
QueryRunner queryRunner = new QueryRunner(dataSource);
String sql = "select * from t_user";
List<User> userList = queryRunner.query(sql, new BeanListHandler<User>(
User.class));
for (User user : userList) {
System.out.println(user);
}
// User [id=1, name=小龙女, password=16, [email protected],
// birthday=2001-01-01]
// User [id=2, name=姬如雪, password=17, [email protected],
// birthday=2002-02-02]
// User [id=3, name=女帝, password=18, [email protected],
// birthday=2003-03-03]
}
/**
* BeanMapHandler:将结果集中每一行数据封装到一个JavaBean对象，再根据指定的key将对象添加到Map集合
*
* @throws SQLException
*/
@Test
public void query5() throws SQLException {
QueryRunner queryRunner = new QueryRunner(dataSource);
String sql = "select * from t_user";
Map<Integer, User> userMap = queryRunner.query(sql,
new BeanMapHandler<Integer, User>(User.class, "id"));
Set<Entry<Integer, User>> entrySet = userMap.entrySet();
for (Entry<Integer, User> entry : entrySet) {
System.out.println(entry.getKey() + ":" + entry.getValue());
}
// 1:User [id=1, name=小龙女, password=16, [email protected],
// birthday=2001-01-01]
// 2:User [id=2, name=姬如雪, password=17, [email protected],
// birthday=2002-02-02]
// 3:User [id=3, name=女帝, password=18, [email protected],
// birthday=2003-03-03]
}
/**
* MapHandler:将单行结果集数据封装到Map集合，key是列名，value是对应的值
*
* @throws SQLException
*/
@Test
public void query6() throws SQLException {
QueryRunner queryRunner = new QueryRunner(dataSource);
String sql = "select * from t_user where id = ?";
Map<String, Object> map = queryRunner.query(sql, new MapHandler(), 1);
System.out.println(map);
// {id=1, name=小龙女, password=16, [email protected], birthday=2001-01-01}
}
/**
* MapListHandler:将单行结果集数据封装到Map集合，key是列名，value是对应的值；再将Map集合添加到List集合
*
* @throws SQLException
*/
@Test
public void query7() throws SQLException {
QueryRunner queryRunner = new QueryRunner(dataSource);
String sql = "select * from t_user";
List<Map<String, Object>> mapList = queryRunner.query(sql,
new MapListHandler());
for (Map<String, Object> map : mapList) {
System.out.println(map);
}
// {id=1, name=小龙女, password=16, [email protected], birthday=2001-01-01}
// {id=2, name=姬如雪, password=17, [email protected], birthday=2002-02-02}
// {id=3, name=女帝, password=18, [email protected], birthday=2003-03-03}
}
/**
* ColumnListHandler:将结果集中某一列添加到List集合
*
* @throws SQLException
*/
@Test
public void query8() throws SQLException {
QueryRunner queryRunner = new QueryRunner(dataSource);
String sql = "select * from t_user";
List<String> columnList = queryRunner.query(sql,
new ColumnListHandler<String>("name"));
System.out.println(columnList);
// [小龙女, 姬如雪, 女帝]
}
/**
* ScalarHandler:将单行结果集中某一列字段值封装到Object
*
* @throws SQLException
*/
@Test
public void query9() throws SQLException {
QueryRunner queryRunner = new QueryRunner(dataSource);
String sql = "select * from t_user where id = ?";
String hang = queryRunner.query(sql, new ScalarHandler<String>("name"),
1);
System.out.println(hang);
// 小龙女
}
/**
* KeyedHandler:将结果集中每一行封装到一个Map集合，再根据指定key，将各个Map集合封装到一个Map集合
*
* @throws SQLException
*/
@Test
public void query10() throws SQLException {
QueryRunner queryRunner = new QueryRunner(dataSource);
String sql = "select * from t_user";
Map<Integer, Map<String, Object>> map = queryRunner.query(sql,
new KeyedHandler<Integer>("id"));
Set<Entry<Integer, Map<String, Object>>> entrySet = map.entrySet();
for (Entry<Integer, Map<String, Object>> entry : entrySet) {
Integer key = entry.getKey();
Map<String, Object> value = entry.getValue();
System.out.println(key + ":" + value.toString());
}
// 1:{id=1, name=小龙女, password=16, [email protected], birthday=2001-01-01}
// 2:{id=2, name=姬如雪, password=17, [email protected], birthday=2002-02-02}
// 3:{id=3, name=女帝, password=18, [email protected], birthday=2003-03-03}
}
}