public class CreateConn {
Connection conn=null;
public Connection getConnection(){
try {
Class.forName("org.gjt.mm.mysql.Driver");
} catch (Exception e) {
// TODO Auto-generated catch block
System.out.println("加载驱动失败!"+e.getMessage());
}
String url = "jdbc:mysql://localhost/customer?user=root&password=123&useUnicode=true&characterEncoding=utf-8";//customer为数据库名,root为用户名,123为密码
try {
conn = DriverManager.getConnection(url);
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.println("获取数据库连接时出错了"+e.getMessage());
}
return conn;
本人初学者,哪位高手给解释下这段代码的意思?最好是逐句解释!!谢谢了。
Connection conn=null;
public Connection getConnection(){
try {
Class.forName("org.gjt.mm.mysql.Driver");
} catch (Exception e) {
// TODO Auto-generated catch block
System.out.println("加载驱动失败!"+e.getMessage());
}
String url = "jdbc:mysql://localhost/customer?user=root&password=123&useUnicode=true&characterEncoding=utf-8";//customer为数据库名,root为用户名,123为密码
try {
conn = DriverManager.getConnection(url);
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.println("获取数据库连接时出错了"+e.getMessage());
}
return conn;
本人初学者,哪位高手给解释下这段代码的意思?最好是逐句解释!!谢谢了。
http://book.csdn.net/bookfiles/317/10031712984.shtml
你自己去看吧,讲的很详细
public class CreateConn {
Connection conn=null;
public Connection getConnection(){
try {
Class.forName("org.gjt.mm.mysql.Driver"); //加载驱动程序,数据库是要有驱动程序才能有java代码做连接的
} catch (Exception e) {
// TODO Auto-generated catch block
System.out.println("加载驱动失败!"+e.getMessage()); //如果数据库驱动程序加载过程中有异常,加载失败打印失败信息
}
String url = "jdbc:mysql://localhost/customer?
user=root&password=123&useUnicode=true&characterEncoding=utf-8";//customer为数据库名,root为用户名,123为密码
try {
conn = DriverManager.getConnection(url); //过得一个数据库连接,获得了连接才能操作数据库
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.println("获取数据库连接时出错了"+e.getMessage()); //如果获得连接这个过程中有异常产生,打印过得连接失败信息
}
return conn;
Connection conn=null;
public Connection getConnection(){
try {
Class.forName("org.gjt.mm.mysql.Driver"); --------将驱动加载到Java虚拟机中
} catch (Exception e) {
// TODO Auto-generated catch block
System.out.println("加载驱动失败!"+e.getMessage());
}
String url = "jdbc:mysql://localhost/customer?user=root&password=123&useUnicode=true&characterEncoding=utf-8";//customer为数据库名,root为用户名,123为密码
try {
conn = DriverManager.getConnection(url);------------------------ 加载驱动,与数据库建立连接
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.println("获取数据库连接时出错了"+e.getMessage());
}
return conn;
conn = cc.getConnection();
那这里面用到的getConnection()方法是干什么啊?
是你写的connection工具类阿,用来取得connection的,
你没必要每次想要的到connection都写上
try {
Class.forName("org.gjt.mm.mysql.Driver"); //加载驱动程序,数据库是要有驱动程序才能有java代码做连接的
} catch (Exception e) {
// TODO Auto-generated catch block
System.out.println("加载驱动失败!"+e.getMessage()); //如果数据库驱动程序加载过程中有异常,加载失败打印失败信息
}
String url = "jdbc:mysql://localhost/customer?
user=root&password=123&useUnicode=true&characterEncoding=utf-8";//customer为数据库名,root为用户名,123为密码
try {
conn = DriverManager.getConnection(url); //过得一个数据库连接,获得了连接才能操作数据库
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.println("获取数据库连接时出错了"+e.getMessage()); //如果获得连接这个过程中有异常产生,打印过得连接失败信息
}
这么大串吧.驱动程序加载一次就够了,
这个是干什么啊?
import java.sql.DriverManager;
import java.sql.SQLException;/**
*
* <p>标题:连接工厂</p>
* <p>描述:平台测试</p>
* @version 1.0
* @author zhq
*
*/
public class ConnectionFactory {
//相关的连接信息
private String userName="scott";
private String passWord="tiger";
private String address="localhost";
private String connStr="jdbc:oracle:thin:@localhost:1521:ZHQ";
//静态加载驱动
static{
try{
Class.forName("oracle.jdbc.driver.OracleDriver");
}catch(Exception e){
System.out.println("Oracle驱动加载失败..");
}
}
//构造方法私有化
private ConnectionFactory(){
}
//只允许有一个对象存在
private final static ConnectionFactory cf = new ConnectionFactory();
//取得this
public static ConnectionFactory newInstance(){
return cf;
}
//取得连接
public Connection getConnection()throws SQLException{
return DriverManager.getConnection(this.connStr,this.userName,this.passWord);
}
//关闭连接
public void closeConnection(Connection conn){
if(conn!=null){
try{
conn.close();
}catch(SQLException e){
}
}
}
//测试
// public static void main(String[] args)throws Exception{
// System.out.println(ConnectionFactory.newInstance().getConnection());
// }
}