java-3分钟解决c3p0连接oracle数据库到使用数据库

1. 明确数据库版本

--查看oracle版本
select * from v$version

2. 明确jdk版本

java -version

3. 找寻对应的JDBC jar包
   Oracle数据库JDBC driver 版本 与 JDK版本的关系

4. 导入对应的jdbc jar包

5. 编写配置文件

• c3p0-config.xml

    
        3000
        3000
        3000
        2
        3
        2
        100
        2
        oracle.jdbc.driver.OracleDriver
        jdbc:oracle:thin:@ip地址:1521:orcl
        用户名
        密码
    

6. 编写工具类

• JDBCUtil.java

package com.utils;
import com.mchange.v2.c3p0.ComboPooledDataSource;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;


public class JDBCUtil {
    private static ComboPooledDataSource dataSource=null;
    static {

        try {
            //1.配置文件写法
            dataSource= new ComboPooledDataSource();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    
    public static Connection getConnection() throws SQLException, SQLException {
        return dataSource.getConnection();
    }

    public static void colseConnection(Connection connection, Statement statement, ResultSet resultSet){
        if(resultSet!=null){
            try {
                resultSet.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (statement!=null){
            try {
                statement.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (connection!=null){
            try {
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

• 编写使用类

package com.dao;

import com.utils.JDBCUtil;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class Query {
    public static void main(String[] args) throws SQLException {
        //获取连接对象
        Connection connection = JDBCUtil.getConnection();
        //查询sql
        String sql="select * from test where id=?";
        //预编译
        PreparedStatement preparedStatement = connection.prepareStatement(sql);
        //赋值
        preparedStatement.setInt(1,1);
        //5.获取结果集
        ResultSet resultSet = preparedStatement.executeQuery();

        while (resultSet.next()){
            System.out.println(resultSet.getInt("id"));
            System.out.println(resultSet.getString("name"));
        }
    }
}