【无标题】动手实践：利用DBUtils实现增删改查
[*]搭建开发环境在数据库建表，插入数据
[*]创建JavaBean package cn.itcast.jdbc.javabean;
public class User {
private int id;
private String name;
private String password;
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;
}
}
3.创建C3P0Utils工具类
package cn.itcast.jdbc.utils;
import javax.sql.DataSource;
import com.mchange.v2.c3p0.ComboPooledDataSource;
public class C3p0Utils {
private static DataSource ds = null;
static {
ComboPooledDataSourcecpds = new ComboPooledDataSource();
try{
cpds.setDriverClass("com.mysql.cj.jdbc.Driver");
cpds.setJdbcUrl("jdbc:mysql://localhost:3306/jdbc?serverTimezone=GMT%2B8");
cpds.setUser("root");
cpds.setPassword("123456");
cpds.setInitialPoolSize(5);
cpds.setMaxPoolSize(15);
ds = cpds;
}catch (Exception e){
throw new ExceptionInInitializerError(e);
}
}
public static DataSource getDataSource(){
return ds;
}
}
4.创建InsertDao类，完成插入操作
package cn.itcast.jdbc.dao;
import java.sql.SQLException;
import org.apache.commons.dbutils.QueryRunner;
import cn.itcast.jdbc.javabean.User;
import cn.itcast.jdbc.utils.C3p0Utils;
public class InsertDao {
public staticvoid main(String[] args)throws SQLException{
QueryRunner runner = new QueryRunner(C3p0Utils.getDataSource());
String sql = "insert into user (id,name,password) values('4','hello1',123456)";
int num = runner.update(sql);
if(num>0){
System.out.println("添加成功！");
}else{
System.out.println("添加失败！");
}
}
}
5.创建UpdateDao类，完成修改操作
package cn.itcast.jdbc.dao;
import cn.itcast.jdbc.javabean.User;
import cn.itcast.jdbc.utils.C3p0Utils;
import java.sql.SQLException;
import org.apache.commons.dbutils.QueryRunner;
public class UpdateDao {
public static void main(String[] args) throws SQLException {
QueryRunner runner = new QueryRunner(C3p0Utils.getDataSource());
// 修改后的 SQL 语句
String sql = "update user set name='hello2', password='111111' where id=4";
// 打印执行的 SQL 语句，确认是否有误
System.out.println("Executing SQL: " + sql);
// 执行更新操作
int num = runner.update(sql);
// 打印影响的行数
System.out.println("Affected rows: " + num);
if (num > 0) {
System.out.println("修改成功！");
} else {
System.out.println("修改失败！");
}
}
}
6.创建DeleteDao类，完成删除操作
package cn.itcast.jdbc.dao;
import cn.itcast.jdbc.utils.C3p0Utils;
import java.sql.SQLException;
import org.apache.commons.dbutils.QueryRunner;
public class DeleteDao {
public staticvoid main(String[] args)throws SQLException{
QueryRunner runner = new QueryRunner(C3p0Utils.getDataSource());
String sql = "delete from user where name='hello2'";
int num = runner.update(sql);
if(num>0){
System.out.println("删除成功！");
}else{
System.out.println("删除失败！");
}
}
}
7.创建QueryDao类，完成查询操作
package cn.itcast.jdbc.dao;
import java.sql.SQLException;
import org.apache.commons.dbutils.QueryRunner;
import cn.itcast.jdbc.javabean.User;
import cn.itcast.jdbc.utils.C3p0Utils;
import org.apache.commons.dbutils.handlers.BeanHandler;
public class QueryDao {
public staticvoid main(String[] args)throws SQLException {
QueryRunner runner = new QueryRunner(C3p0Utils.getDataSource());
String sql = "select * from user where id=2";
User user= (User)runner.query(sql,
new BeanHandler(User.class));
System.out.println(user.getId() + "," + user.getName() + ","
+ user.getPassword());
}
}
package cn.itcast.jdbc.dao;
import java.sql.SQLException;
import org.apache.commons.dbutils.QueryRunner;
import cn.itcast.jdbc.javabean.User;
import cn.itcast.jdbc.utils.C3p0Utils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import java.util.List;
public class QueryDao {
public staticvoid main(String[] args)throws SQLException {
QueryRunner runner = new QueryRunner(C3p0Utils.getDataSource());
String sql = "select * from user ";
List<User> list = runner.query(sql, new BeanListHandler<>(User.class));
for(User user : list) {
System.out.println(user.getId() + "," + user.getName() + ","
+ user.getPassword());
}
}
}
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