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如何從Java Netbeans8連接http(虛擬主機)mysql數據庫? 我使用jdbc Driver。Java NetBeans8連接到HTTP mysql數據庫
package javaswimingapplication;
public class JavaSwimingApplication {
public static void main(String[] args) {
DBConnect connect = new DBConnect();
connect.getData();
}
}
package javaswimingapplication;
import java.sql.*;
public class DBConnect {
private Connection con;
private Statement st;
private ResultSet rs;
public DBConnect(){
try{
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection("jdbc:mysql://web server ip/database name","database user","password");
st = con.createStatement();
}catch(Exception ex){
System.out.println("Error: "+ex);
}
}
public void getData(){
try{
String query = "select * from persons";
rs = st.executeQuery(query);
System.out.println("Rexords from database");
while(rs.next()){
String name = rs.getString("name");
String age = rs.getString("age");
//String name = rs.getString("name");
System.out.println("Name: "+name+" "+"Age: "+age);
}
}catch(Exception ex){
System.out.println(ex);
}
}
}
錯誤:
運行:
錯誤:com.mysql.jdbc.exceptions.jdbc4.CommunicationsException:通信鏈路故障
的最後一個數據包發送成功服務器是0毫秒前。驅動程序尚未收到來自服務器的任何數據包。 顯示java.lang.NullPointerException СБОРКАУСПЕШНОЗАВЕРШЕНА(общеевремя:22секунды)
Class.forName(「com.mysql.jdbc.Driver」); con = DriverManager.getConnection(「jdbc:mysql // 91.212.89.57/tutorials_uz_employe」,「tutor_employe」,「K8cns9#2」); st = con.createStatement(); – Unnamed
錯誤:java.sql.SQLException中:找到了JDBC沒有合適的驅動程序:MySQL的// 91.212.89.57/tutorials_uz_employe 顯示java.lang.NullPointerException СБОРКАУСПЕШНОЗАВЕРШЕНА(общеевремя:0секунд) – Unnamed
首先:您剛纔交數據庫憑據?並且錯誤消息表明,現在你缺少類路徑中的MySQL連接器庫,或者數據庫服務器沒有在其默認端口上偵聽,或者(正如我在第一條評論中所說的),根本沒有偵聽其外部IP。 –