在寫之前首先得感謝JAVA1234的小峯老師,是看了他的視頻再開始的學習,非常感謝
package class1;
import java.sql.DriverManager;
import com.mysql.jdbc.Connection;
public class Demo2 {
private static String dburl="jdbc:mysql://localhost:3306/db_text";
private static String dbusername="root";
private static String dbpassword="876986919";//這是我QQ號,有想一起探討的朋友可以加一下
private static String dbjdbcname="com.mysql.jdbc.Driver";
public static void main(String[] args) throws Exception {
try {
Class.forName(dbjdbcname);
System.out.println("加載數據庫成功!");
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
System.out.println("加載數據庫失敗!");
}
try {
Connection con=(Connection) DriverManager.getConnection(dburl, dbusername, dbpassword);
System.out.println("連接數據庫成功!");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
System.out.println("連接數據庫失敗!");
}
}
}
之前瞭解了try catch 現在看代碼就明白多了,這裏面能讓我疑惑的就是這句: Connection con=(Connection) DriverManager.getConnection(dburl, dbusername, dbpassword);在視頻中代碼是Connection con= DriverManager.getConnection(dburl, dbusername, dbpassword); 但是爲啥我的DriverManager前面就要加一個(Connection)呢?剛剛纔發現,原來我少了java.sql.Connection 的接口····暈死················,所以新的代碼就變成:
package class1;
import java.sql.DriverManager;
import java.sql.Connection ;
public class Demo2 {
private static String dburl="jdbc:mysql://localhost:3306/db_text";
private static String dbusername="root";
private static String dbpassword="876986919";
private static String dbjdbcname="com.mysql.jdbc.Driver";
public static void main(String[] args) throws Exception {
try {
Class.forName(dbjdbcname);
System.out.println("加載數據庫成功!");
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
System.out.println("加載數據庫失敗!");
}
try {
DriverManager.getConnection(dburl, dbusername, dbpassword);
System.out.println("連接數據庫成功!");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
System.out.println("連接數據庫失敗!");
}
}
}