用applet、jdbc和socket进行数据库访问？

Question

我做过一个
applet、jdbc和servlet进行数据库访问
可以吗[email protected]

Answer 1

不好意思我忘了留自己的信箱了。
[email protected]
还请大家多多帮助呀！

Answer 2

主要就是applet和servlet的通讯问题！
下面是两个很简单的程序，只要将访问数据库的代码加在servlet中就行了，显示图形的代码加在applet中。DbServlet.java
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;public class DbServlet extends HttpServlet
{
  private static final String CONTENT_TYPE = "text/html";
  /**Initialize global variables*/
  public void init() throws ServletException
  {
  }
  /**Process the HTTP Get request*/
  public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
  {
    response.setContentType(CONTENT_TYPE);
    PrintWriter out = response.getWriter();    String query=request.getParameter("query");
    try
    {
      out.println("Succeed!"+query);
    }
    catch(Exception e)
    {
    }
    out.println();
    out.close();
  }
  /**Clean up resources*/
  public void destroy()
  {
  }
}DbSearchApplet.java
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import javax.swing.*;
import java.net.*;
import java.io.*;public class DbSearchApplet extends JApplet implements Runnable
{
  boolean isStandalone = false;
  JPanel panel1=new JPanel();
  JTextField searchfield=new JTextField("",25);
  JButton excutebutton=new JButton("GO");
  JLabel searchlabel = new JLabel("Search:");
  JScrollPane jScrollPane1 = new JScrollPane();
  JTextArea resultarea = new JTextArea(10,80);
  /**Get a parameter value*/
  public String getParameter(String key, String def)
  {
    return isStandalone ? System.getProperty(key, def) :
      (getParameter(key) != null ? getParameter(key) : def);
  }  /**Construct the applet*/
  public DbSearchApplet()
  {
  }
  /**Initialize the applet*/
  public void init()
  {
    try
    {
      jbInit();
    }
    catch(Exception e)
    {
      e.printStackTrace();
    }
  }
  /**Component initialization*/
  private void jbInit() throws Exception
  {
    this.setSize(new Dimension(400,300));
    panel1.setLayout(new FlowLayout(FlowLayout.LEFT));    excutebutton.addActionListener(new java.awt.event.ActionListener()
    {
      public void actionPerformed(ActionEvent e)
      {
        excutebutton_actionPerformed(e);
      }
    });
    resultarea.setEditable(false);
    panel1.add(searchlabel, null);
    panel1.add(searchfield);    panel1.add(excutebutton);
    this.getContentPane().add(jScrollPane1,  BorderLayout.CENTER);
    jScrollPane1.getViewport().add(resultarea, null);
    this.getContentPane().add(panel1,  BorderLayout.NORTH);
  }
  /**Get Applet information*/
  public String getAppletInfo()
  {
    return "Applet Information";
  }
  /**Get parameter info*/
  public String[][] getParameterInfo()
  {
    return null;
  }
  /**Execute Query*/
  public void executeQuery()
  {
    String input=searchfield.getText();
    try
    {
      URL url=new URL("http://localhost:7001/DbServlet");
      String query=URLEncoder.encode("query")+"="+URLEncoder.encode(input);      URLConnection uc=url.openConnection();
      uc.setDoInput(true);
      uc.setDoOutput(true);
      uc.setUseCaches(false);
      uc.setRequestProperty("Content-type","application/x-www-form-urlencoded");      DataOutputStream dos=new DataOutputStream(uc.getOutputStream());
      dos.writeBytes(query);
      dos.flush();
      dos.close();      InputStreamReader in=new InputStreamReader(uc.getInputStream());      int chr=in.read();
      while(chr!=-1)
      {
resultarea.append(String.valueOf((char)chr));
chr=in.read();
      }
      in.close();
    }
    catch(Exception e)
    {
      resultarea.setText(e.toString());
    }
    //resultarea.append(input);
  }
   //static initializer for setting look & feel
  static
  {
    try
    {
      //UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
      //UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassName());
    }
    catch(Exception e)
    {
    }
  }  void excutebutton_actionPerformed(ActionEvent e)
  {
    executeQuery();
  }
}

Answer 3

//DataOutputStream dos=new DataOutputStream(uc.getOutputStream());
      
该行出错！！java.net.UnknownServiceException: protocol doesn't support output为什么？？？