jdbc链接数据库

class JdbcUtil { static String url = null; static String username = null; static String password = null; static String driverClass = null; static { try { Properties properties = new Properties(); InputStream in = JdbcUtil.class .getResourceAsStream("/jdbc.properties"); properties.load(in); url = properties.getProperty("url"); username = properties.getProperty("username"); password = properties.getProperty("password"); driverClass = properties.getProperty("driver"); System.out.println(password); Class.forName(driverClass); } catch (Exception e) { e.printStackTrace(); System.out.println("驱动加载失败！"); throw new RuntimeException(e); } } public static Connection getConnection() { try { Connection conn = DriverManager.getConnection(url, username, password); return conn; } catch (SQLException e) { e.printStackTrace(); throw new RuntimeException(e); } } public static void close(Connection conn, Statement st, ResultSet rs) { if (conn != null) { try { conn.close(); } catch (Exception e) { throw new RuntimeException(e); } } if (st != null) { try { st.close(); } catch (Exception e) { throw new RuntimeException(e); } } if (rs != null) { try { rs.close(); } catch (Exception e) { throw new RuntimeException(e); } } } public static void close(Connection conn, Statement st) { if (conn != null) { try { conn.close(); } catch (Exception e) { throw new RuntimeException(e); } } if (st != null) { try { st.close(); } catch (Exception e) { throw new RuntimeException(e); } } } /* * 释放资源 */ public static void releaseResources(ResultSet resultSet, Statement statement, Connection connection) { try { if (resultSet != null) resultSet.close(); } catch (SQLException e) { e.printStackTrace(); } finally { resultSet = null; try { if (statement != null) statement.close(); } catch (SQLException e) { e.printStackTrace(); } finally { statement = null; try { if (connection != null) connection.close(); } catch (SQLException e) { e.printStackTrace(); } finally { connection = null; } } } } }

 

 

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

import bean.QuackResults;
//存入数据库新增加功能
/**
 * 2017/10/21
 * @author lemo
 *
 */
public class DbExcute {

    private Connection connection;
    private Statement statement;
    private ResultSet resultSet;

    // 更新操作
    public void update(String sql) {
        try {
            connection = JdbcUtil.getConnection();
            statement = connection.createStatement();
            // 可执行创建、修改、删除表，添加、删除、修改元组以及查询sql语句
            boolean num=statement.execute(sql);
            System.out.println(num);
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JdbcUtil.close(connection, (com.mysql.jdbc.Statement) statement,
                    resultSet);
        }
    }

    // 查询操作
    public ResultSet Query(String sql) {
        try {
            connection = JdbcUtil.getConnection();
            statement = connection.createStatement();
            resultSet = statement.executeQuery(sql);

        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JdbcUtil.releaseResources(resultSet, statement, connection);
        }
        return resultSet;
    }

    // 添加操作
    public void addElement(String sql) {
        update(sql);
    }
    public void addElement(QuackResults aQuackResults) {
        /*String sqlStr = "select* from users where username=? and password=?"; 
        connection = JdbcUtil.getConnection();
        PreparedStatement aStatement=null;
        try {
            
            aStatement=connection.prepareStatement(sqlStr);
            aStatement.setString(1,"zhansgan");
            aStatement.setString(2, "root");
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }*/
        
        String sqlStr = "insert into mine_quack_results values(null,?,?,?,?,?)"; 
        connection = JdbcUtil.getConnection();
        PreparedStatement aStatement=null;
        try {
            
            aStatement=connection.prepareStatement(sqlStr);
            aStatement.setDouble(1,aQuackResults.getxData());
            aStatement.setDouble(2, aQuackResults.getyData());
            aStatement.setDouble(3, aQuackResults.getzData());
            aStatement.setTimestamp(4,aQuackResults.getQuackTime());
            aStatement.setDouble(5, aQuackResults.getQuackGrade());
            System.out.println(aStatement.execute());
            connection.close();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        
    }

    // 删除操作
    public void removeElement(String sql) {
        update(sql);
        
        
    }

    // 创建一个表
    public void createTable(String sql) {
        update(sql);
    }

    // 删除一个表
    public void dropTable(String sql) {
        update(sql);
    }

}

 

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/ks?useUnicode=true&characterEncoding=utf8&allowMultiQueries=true
username=root
password=root
#定义初始连接数
initialSize=0
#定义最大连接数
maxActive=20
#定义最大空闲
maxIdle=20
#定义最小空闲
minIdle=1
#定义最长等待时间
maxWait=60000

 

jdbc链接数据库

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