将数据从小程序文本字段插入到mysql数据库-错误

Question

我正在尝试做的是使用我的applet页面在mysql数据库上添加数据。我的想法是填充文本字段，然后当我点击保存按钮时，所有文本都会添加到mySQL数据库中。但我有个错误说

Access Denied: java.security.AccessControlException:access denied 
    (java.io.FilePermision "\C:\Program Files(x86)\MySQL\mysql-connector-java-5.1.30\mysql-connector-java-5.1.30-bin.jar‌​" "read")

提前谢谢你。这是我的代码：:((

import java.awt.*; 
import java.applet.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.SwingUtilities;
import javax.swing.JApplet;
import java.sql.*;
import java.net.*;



public class AddBook extends JApplet
{
    JButton btnSave, btnCancel;
    JLabel lblIsbn, lblTitle, lblCategory, lblAuthor, lblYPublish, lblPublisher, lblCopies, lblYear, lblMsg1;
    JTextField txtTitle, txtCategory;
    JTextField txtIsbn, txtAuthor, txtPublisher, txtCopies, txtYear;

    String ttitle, tauthor, tpublisher, tcategory, tisbn, tyear, tqty;

    public void init()
    {
        Font fonttxt = new Font("Calibri", Font.PLAIN, 16);
        Font fontlbl = new Font("Calibri",Font.BOLD, 14);
        Font fontbtn = new Font("Calibri",Font.BOLD, 16);
        Font fontTitle = new Font("Arial ",Font.BOLD,30);

        setLayout(null);
        setSize(410, 400);

        setBackground(Color.gray);

        btnSave = new JButton("Save");
        btnSave.setFont(fontbtn);
        btnCancel = new JButton("Cancel");
        btnCancel.setFont(fontbtn);

        lblMsg1 = new JLabel ("ADD BOOK");
        lblMsg1.setFont(fontbtn);
        lblIsbn = new JLabel("ISBN :");
        lblIsbn.setFont(fontlbl);
        lblTitle = new JLabel ("Title :");
        lblTitle.setFont(fontlbl);
        lblCategory = new JLabel ("Category :");
        lblCategory.setFont(fontlbl);
        lblAuthor = new JLabel ("Author :");
        lblAuthor.setFont(fontlbl);
        lblYear = new JLabel ("Year Published :");
        lblYear.setFont(fontlbl);
        lblPublisher = new JLabel ("Publisher :");
        lblPublisher.setFont(fontlbl);
        lblCopies = new JLabel ("Number of Copies :");
        lblCopies.setFont(fontlbl);

        JTextField txtIsbn = new JTextField ("",100);
        txtIsbn.setFont(fonttxt);
        JTextField txtTitle = new JTextField ("",100);
        txtTitle.setFont(fonttxt);
        JTextField txtCategory = new JTextField ("",100);
        txtCategory.setFont(fonttxt);
        JTextField txtAuthor = new JTextField ("",100);
        txtAuthor.setFont(fonttxt);
        JTextField txtPublisher = new JTextField ("",100);
        txtPublisher.setFont(fonttxt);
        JTextField txtCopies = new JTextField ("",100);
        txtCopies.setFont(fonttxt);
        JTextField txtYear = new JTextField ("",100);
        txtYear.setFont(fonttxt);

        lblMsg1.setBounds(10,10,200,40);
        lblIsbn.setBounds(10,50,250,30);
        txtIsbn.setBounds(130,50,250,30);
        lblTitle.setBounds(10,90,250,30);
        txtTitle.setBounds(130,90,250,30); 
        lblCategory.setBounds(10,130,250,30);
        txtCategory.setBounds(130,130,250,30); 
        lblAuthor.setBounds(10,165,250,30);
        txtAuthor.setBounds(130,165,250,30);  
        lblPublisher.setBounds(10,200,250,30);
        txtPublisher.setBounds(130,200,250,30);
        lblCopies.setBounds(10,240,250,30);
        txtCopies.setBounds(130,240,250,30);
        lblYear.setBounds(10,280,250,30);
        txtYear.setBounds(130,280,250,30);
        btnSave.setBounds(40,320,150,35);
        btnCancel.setBounds(200,320,150,35);

        add(lblMsg1);
        add(txtIsbn);
        add(txtTitle);
        add(txtCategory);
        add(txtAuthor);
        add(txtPublisher);
        add(txtCopies);
        add(txtYear);
        add(lblIsbn);
        add(lblTitle);
        add(lblCategory);
        add(lblAuthor);
        add(lblPublisher);
        add(lblCopies);
        add(lblYear);

        add(btnSave);
        add(btnCancel);



        tisbn = txtIsbn.getText();
        tyear = txtYear.getText();
        tqty = txtCopies.getText();
        ttitle = txtTitle.getText();
        tauthor = txtAuthor.getText();
        tcategory = txtCategory.getText();
        tpublisher = txtPublisher.getText();

        btnSave.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent ae)
            {

                //Connection con = null;
                //Statement st = null;   1
                PreparedStatement pstmt;
                Connection con; 

                if(ae.getSource() == btnSave)
                {


                    try {

                        Class.forName("com.mysql.jdbc.Driver");
                        con = DriverManager.getConnection("jdbc:mysql://localhost/library_system", "root", "password");

                        con.setAutoCommit(false);


                        pstmt = con.prepareStatement ("INSERT INTO book_records VALUES (?, ?, ?, ?, ?, ?, ?)"); 

                        pstmt.setString(1, tisbn);
                        pstmt.setString(2, ttitle);
                        pstmt.setString(3, tauthor);
                        pstmt.setString (4, tyear);
                        pstmt.setString(5, tpublisher);
                        pstmt.setString(6, tcategory);
                        pstmt.setString(7, tqty);

                        pstmt.executeUpdate();

                        con.commit();
                        pstmt.close();

                    }
                    catch(Exception err)
                    {
                        JOptionPane.showMessageDialog(null, "Access Denied: "+err );
                    }
                }

               }
            }
        });
    }
}

Answer 1

请尝试mysql连接，如下所示

Class.forName("com.mysql.jdbc.Driver");
Connection conn = null;
conn = DriverManager.getConnection("jdbc:mysql://hostname:port/dbname","username",    "password");

我想你错过港口了。

Answer 2

该错误简单地指出了从您的Java程序到MySQL jar所在目录的“访问被拒绝”问题。您不应该从Java应用程序链接(引用)另一个目录中的jar文件。

这个问题可以通过将所需的mysql-connector-java-5.1.30-bin.jar‌​添加到应用程序的类路径来简单地解决。