javamysql连接全分析Java 连接 MySQL 需要驱动

import java.sql.*;

public class Test2 {

    public static void main(String[] args) throws Exception {
        // 1.加载数据访问驱动
        Class.forName("com.mysql.jdbc.Driver");
        //2.连接到数据"库"上去
        Connection conn= DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb?characterEncoding=GBK", "root", "");
        //3.构建SQL命令
        Statement state=conn.createStatement();
        String s="insert into xs values(‘008‘,‘李丽‘,‘四中‘)";
        state.executeUpdate(s);
    }

}

    1、驱动：配置pom 2、测试单链接 3、使用dbcp数据池连接    
1、驱动：配置pom

<dependencies>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.46</version>
    </dependency>
    <!--microsoft acess数据库连接器 ucanaccess注意使用的版本问题  -->
    <dependency>
    <groupId>net.sf.ucanaccess</groupId>
    <artifactId>ucanaccess</artifactId>
    <version>4.0.1</version>
    </dependency>

2、测试单链接：

public static void sqltest() throws ClassNotFoundException, SQLException {
    //1、加载驱动
    Class.forName("com.mysql.jdbc.Driver");
    //2、用户信息和url
    String url = "jdbc:mysql://localhost:3306/book?useUnicode=true&characterEncoding=utf8&useSSL=false";
    String name = "root";
    String password = "shiyw11shuzi";
    //3、连接成功，数据库对象  connection代表数据库
    Connection connection = DriverManager.getConnection(url, name, password);
    //4、执行sql的对象   statement 执行sql的对象
    Statement statement = connection.createStatement();
    //5、执行sql的对象去执行sql，可能存在返回结果，查看返回结果
    String sql = "select * from `mingxi`";
    ResultSet resultSet = statement.executeQuery(sql);
    while (resultSet.next()){
        System.out.print("id = " + resultSet.getObject("id")+" ;\t ");
        System.out.print("name = " + resultSet.getObject("name")+" ;\t ");
        System.out.println("mima = " + resultSet.getObject("mima")+" ;\t ");
    }
    //6、关闭连接
    resultSet.close();
    statement.close();
    connection.close();
    System.out.println( MySQLConnTest.class.getResource("/").getPath() + "druid.properties" );
}

    3、使用dbcp数据池连接: 项目主目录下的配置文件：D:\IntelliJIDEA20\workspace\mysqltest\dbmysql.properties

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/book?useUnicode=true&useSSL=false&characterEncoding=utf8
username=rootbook
password=book2020shuzihua


4、使用dbcp数据池连接数据池:

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



public class MysqlJDBCUtils {
    private static String driver = null;
    private static String url = null;
    private static String username = null;
    private static String password = null;
    static {
        try {

            String propfile = System.getProperty("user.dir")+File.separator+ "dbmysql.properties";
            System.out.println( 33+MysqlJDBCUtils.class.getResource("/").getPath() + "dbmysql.properties");
            System.out.println( 66+propfile);
            //// 66D:\IntelliJIDEA2018\ideawork2020\ddp2023pa\dbmysql.properties
            InputStream is = new BufferedInputStream(new FileInputStream(propfile));
            //// InputStream error = MysqlJDBCUtils.class.getClassLoader().getResourceAsStream("dbmysql.properties");
            Properties properties = new Properties();
            properties.load(is);
            driver = properties.getProperty("driver");
            url = properties.getProperty("url");
            username = properties.getProperty("username");
            password = properties.getProperty("password");
            //1、加载驱动  只加载一次
            Class.forName(driver);
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }

//获取连接
public static Connection getConnection()  {
    ////return DriverManager.getConnection(url, username, password);
    Connection getConn=null;
    try {
        getConn=DriverManager.getConnection(url, username, password); 
    }catch (Exception e){   }
    return getConn;
}

//释放连接资源
public static void release(Connection conn, Statement st, ResultSet rs) {
    if (rs != null){
        try {
            rs.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    if (st != null){
        try {
            st.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    if (conn != null){
        try {
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

5、链接测试：

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

public class JDBCUtilsTestSelect {
    public static void main(String[] args) {
        ///////////  testConn();     ////////获取数据库连接///////
        Connection  conn = JDBCUtils.getConnection();
        conn = MysqlJDBCUtils.getConnection();
        testConn(conn);
    }


    private static void testConn(Connection conn) {
        //// Connection  conn = JDBCUtils.getConnection();  ////获取数据库连接 testConn(conn); ////
        PreparedStatement st = null;
        ResultSet rs = null;
        try {
            /////  Connection  conn = JDBCUtils.getConnection();    //获取数据库连接
            String sql = "select * from `mingxi` where `id` = ?";
            sql = "select * from temp ";
            //预编译sql但不执行
            st = conn.prepareStatement(sql);
            //手动设置sql参数            st.setInt(1, 3);
            //执行sql
            rs = st.executeQuery();
            while (rs.next()){
                System.out.print("name = " + rs.getObject("name") +"\t" );
                System.out.print("mima = " + rs.getObject("mima") +"\t" );
                System.out.println("author = " + rs.getObject("author") +"\t" );
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            //释放资源
            JDBCUtils.release(conn, st, rs);
        }
    }

    private static void testConn() {
        Connection conn = null;
        PreparedStatement st = null;
        ResultSet rs = null;

        try {
            conn = JDBCUtils.getConnection();    //获取数据库连接
            String sql = "select * from `mingxi` where `id` = ?";
            sql = "select * from temp ";
            //预编译sql但不执行
            st = conn.prepareStatement(sql);
            //手动设置sql参数            st.setInt(1, 3);
            //执行sql
            rs = st.executeQuery();
            while (rs.next()){
                System.out.print("name = " + rs.getObject("name") +"\t" );
                System.out.print("mima = " + rs.getObject("mima") +"\t" );
                System.out.println("author = " + rs.getObject("author") +"\t" );
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            //释放资源
            JDBCUtils.release(conn, st, rs);
        }
    }

                   

javamysql连接全分析Java 连接 MySQL 需要驱动

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