import java.sql.*;
public class DataBase {
public Connection conn;
public Statement stmt;
public ResultSet rs=null;
public String sqlStr=""; public DataBase() {
this.connect();//构造函数中调用connect方法 !1
}
public boolean connect(){
try{
Class.forName("org.gjt.mm.mysql.Driver").newInstance();
String url ="jdbc:mysql://localhost/BookStore?user=wxy&useUnicode=true&characterEncoding=8859_1";
conn=DriverManager.getConnection(url);
stmt = conn.createStatement ();
}catch(Exception ee){
System.out.println("connect db error:"+ee.getMessage());
return false;
}
return true;
}
public static void main(String[] args) {
try{
DataBase db = new DataBase();//!2
db.connect();//!3
}catch(Exception e){
e.printStackTrace();
}
}
}在database的构造函数中有调用connect方法,而在构造对象后又一次调用connect方法。上面标记的三个步骤是否有重复呢。这样对吗?请高手帮忙解释。
public class DataBase {
public Connection conn;
public Statement stmt;
public ResultSet rs=null;
public String sqlStr=""; public DataBase() {
this.connect();//构造函数中调用connect方法 !1
}
public boolean connect(){
try{
Class.forName("org.gjt.mm.mysql.Driver").newInstance();
String url ="jdbc:mysql://localhost/BookStore?user=wxy&useUnicode=true&characterEncoding=8859_1";
conn=DriverManager.getConnection(url);
stmt = conn.createStatement ();
}catch(Exception ee){
System.out.println("connect db error:"+ee.getMessage());
return false;
}
return true;
}
public static void main(String[] args) {
try{
DataBase db = new DataBase();//!2
db.connect();//!3
}catch(Exception e){
e.printStackTrace();
}
}
}在database的构造函数中有调用connect方法,而在构造对象后又一次调用connect方法。上面标记的三个步骤是否有重复呢。这样对吗?请高手帮忙解释。
db.connect()肯定重复了