封装JDBC获取连接以及释放连接的两种方式

方式1：正常获取

package TTest;

import java.io.IOException;
import java.io.InputStream;
import java.sql.*;
import java.util.Properties;


public class JDBCUtils {
    static Connection getConnection(){
        Connection connection =null;
        InputStream resourceAsStream = ClassLoader.getSystemClassLoader().getResourceAsStream("jdbc.properties");
        Properties properties = new Properties();
        try {
            properties.load(resourceAsStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
             connection = DriverManager.getConnection(properties.getProperty("url"),properties.getProperty("user"),properties.getProperty("password"));
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }
        return connection;
    }

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

    static void closeConnection(Connection connection, Statement statement){
        if (null!=connection){
            try {
                connection.close();
            } catch (SQLException throwables) {
                throwables.printStackTrace();
            }
        }
        if (null!=statement){
            try {
                statement.close();
            } catch (SQLException throwables) {
                throwables.printStackTrace();
            }
        }
    }

}

方式2：利用数据库i连接池

package TTest;

import com.alibaba.druid.pool.DruidDataSourceFactory;
import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.apache.commons.dbcp2.BasicDataSourceFactory;

import javax.sql.DataSource;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;


public class JDBCUtilsNew {
    //用C3P0方式获取数据库连接
    private static ComboPooledDataSource cpds =new ComboPooledDataSource("helloc3p0");

    public static Connection getConnection(){
        Connection connection =null;
        try {
            connection = cpds.getConnection();
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }
        return connection;
    }

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

    public static void closeConnection(Connection connection, Statement statement){
        if (null!=connection){
            try {
                connection.close();
            } catch (SQLException throwables) {
                throwables.printStackTrace();
            }
        }
        if (null!=statement){
            try {
                statement.close();
            } catch (SQLException throwables) {
                throwables.printStackTrace();
            }
        }
    }


    //使用DBCP数据库连接池技术获取数据库连接
        private static DataSource source;
        static {
            Properties properties = new Properties();

//        //方式一：
//        InputStream resourceAsStream = ClassLoader.getSystemClassLoader().getResourceAsStream("DBCP.peoperties");
//        properties.load(resourceAsStream);

            //方式二：
            try {
                FileInputStream fileInputStream = new FileInputStream(new File("src/DBCP.properties"));
                properties.load(fileInputStream);

                source = BasicDataSourceFactory.createDataSource(properties);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

    public static Connection getConnection1(){
         Connection connection = null;
         try {
             connection = source.getConnection();
         } catch (SQLException throwables) {
             throwables.printStackTrace();
         }

         return connection;
    }



    //使用druid数据库连接池获取数据库连接
    private static DataSource source1;
    static {
        Properties properties = new Properties();
        InputStream resourceAsStream = ClassLoader.getSystemClassLoader().getResourceAsStream("druid.properties");
        try {
            properties.load(resourceAsStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            source1 = DruidDataSourceFactory.createDataSource(properties);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

   public static Connection getConnection2(){
        Connection connection =null;
        try {
            connection = source1.getConnection();
            if (null ==connection)
                System.out.println("数据库连接失败！");
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }
        return connection;
    }
}