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  • Java c3p0 连接 MySQL

    <?xml version="1.0" encoding="UTF-8"?>
    <!-- 需要导入c3p0驱动jar包和mysql驱动jar包 -->
    <!-- c3p0-config.xml配置文件放在src包下 -->
    <c3p0-config>
        <named-config name="mysqlConnection">
            <property name="user">root</property>
            <property name="password"></property>
            <property name="jdbcUrl">jdbc:mysql://localhost:3306/test</property>
            <property name="driverClass">com.mysql.jdbc.Driver</property>
            
            <property name="initialPoolSize">20</property>
            <property name="maxPoolSize">25</property>
            <property name="minPoolSize">5</property>
        </named-config>
    </c3p0-config>
    package cn.zr.testfilter.pojo;
    
    public class User {
        private String name;
        private Integer age;
        public String getName() {
            return name;
        }
        public void setName(String name) {
            this.name = name;
        }
        public Integer getAge() {
            return age;
        }
        public void setAge(Integer age) {
            this.age = age;
        }
        
        public User() {
            super();
        }
        public User(String name, Integer age) {
            super();
            this.name = name;
            this.age = age;
        }
        @Override
        public String toString() {
            return "User [name=" + name + ", age=" + age + "]";
        }
        
        
        
    }
    package cn.zr.testfilter.Utils;
    
    import java.sql.Connection;
    import java.sql.PreparedStatement;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.util.ArrayList;
    import java.util.List;
    
    import javax.sql.DataSource;
    
    import cn.zr.testfilter.pojo.User;
    
    import com.mchange.v2.c3p0.ComboPooledDataSource;
    
    public class ConnectionUtils {
        
        public static void main(String[] args) {
            ConnectionUtils utils = new ConnectionUtils();
            List<User> list = utils.getData();
            System.out.println(list);
        }
        
        public List<User> getData(){
            List<User> list = new ArrayList<User>();
            Connection connection  = ConnectionUtils.getConnection();
            String sql = "SELECT NAME,AGE FROM USERTEST";
            PreparedStatement pStatement = null;
            ResultSet rSet = null;
            try {
                pStatement = (PreparedStatement) connection.prepareStatement(sql);
                rSet = pStatement.executeQuery();
                while (rSet.next()) {
                    User user = new User(rSet.getString("name"), rSet.getInt("age"));
                    list.add(user);
                }
                return list;
            } catch (SQLException e) {
                e.printStackTrace();
            }finally{
                try {
                    if (rSet != null) {
                        rSet.close();
                    }
                    if (pStatement != null) {
                        pStatement.close();
                    }
                    if (connection != null) {
                        connection.close();
                    }
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            return null;
        }
        
        
        public static Connection getConnection() {
            
            DataSource ds = new ComboPooledDataSource("mysqlConnection");
            try {
                Connection connection = ds.getConnection();
                return connection;
            } catch (SQLException e) {
                e.printStackTrace();
            }
            
            return null;
            
            /*String driver = "com.mysql.jdbc.Driver";
            String url = "jdbc:mysql://localhost:3306/mysql";
            String user = "root";
            String password = "";
            try {
                Class.forName("com.mysql.jdbc.Driver");
            } catch (ClassNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            Connection connection = null;
            try {
                connection = DriverManager.getConnection(url, user, password);
            } catch (SQLException e) {
                e.printStackTrace();
            }        
            return connection;*/
            
                    
        }
        
    }
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  • 原文地址:https://www.cnblogs.com/lantu1989/p/6379565.html
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