java连接数据库

public Connection conn=null;
public PreparedStatement pst=null;
public ResultSet rs=null;
String Driver=com.mysql.cj.jdbc.Driver;//注意:该版本为8.0.22
String url=jdbc:mysql://localhost:3306/mydb?serverTimezone=GMT%2B8;//
String user=root;//填你的mysql用户名
String password=ok;//填你的mysql密码
public void getConn(){
try {
Class.forName(Driver);
conn= DriverManager.getConnection(url,user,password);
}catch (Exception e){
e.printStackTrace();
}
}
public void closeAll(){
try {
if (rs!=null){
rs.close();
}
if (pst!=null){
pst.close();
}
if (conn!=null){
pst.close();
}
}catch (Exception e){
e.printStackTrace();
}
}
public int update(String sql,Object[]parms){
getConn();
try {
pst=conn.prepareStatement(sql);
for (int i = 0; i < parms.length; i++) {
pst.setObject(i+1,parms[i]);
}
return pst.executeUpdate();
}catch (Exception e){
e.printStackTrace();
}
return -1;
}
public void select(String sql,Object[]parms){
getConn();
try {
pst=conn.prepareStatement(sql);
for (int i = 0; i < parms.length; i++) {
pst.setObject(i+1,parms[i]);
}
rs= pst.executeQuery();
}catch (Exception e){
e.printStackTrace();
}
}