jdbc

package com.sxt;

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

/**
* jdbc工具类 jdbc java数据库连接 executeQuery – 执行查询 返回查询结果集合（select） execute –
* 执行事物，数据库，对象操作 executeUpdate – 执行更新（插入，删除，修改）返回执行了几条
*
* @author Administrator
*
*/
public class JDBCUtil {
private static String url = “jdbc:oracle:thin:@127.0.0.1:1521:orcl”;
private static String username = “scott”;
private static String userpwd = “tiger”;
private static Connection conn;
private static Statement st;
private static ResultSet rs;

static {
    // 1.加载驱动（通过反射）
    try {
        Class.forName("oracle.jdbc.driver.OracleDriver");
        // 2.通过驱动管理器获取连接
        conn = DriverManager.getConnection(url, username, userpwd);
        st = conn.createStatement();
        System.out.println("数据库连接成功");
    } catch (Exception e) {
        e.printStackTrace();
    }
}

private JDBCUtil() {

}

public static int update(String sql) {
    System.out.println("sql:" + sql);
    // 3.通过连接获取一个声明
    try {

        int i = st.executeUpdate(sql);
        System.out.println("更新成功：" + i);
        return i;
    } catch (SQLException e) {
        e.printStackTrace();
    } finally {
        try {
            st.close();
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    return 0;
}

public static ResultSet query(String sql) {
    System.out.println("sql:" + sql);
    try {
        rs = st.executeQuery(sql);
        return rs;
    } catch (SQLException e) {
        e.printStackTrace();
    }
    return null;
}

public static void close() {
    try {
        rs.close();
        st.close();
        conn.close();
        System.out.println("数据库关闭成功");
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

}