通过Socket访问数据库
Tip:通过socket访问数据库,分 Clinet, Display,sqlServer三个类
Client.Java
import java.awt.*;
import java.io.*;
import java.net.*;
import java.Applet.*;
public class Client extends Applet
{
public TextArea chat_txt;
private TextField sql_txt;
private Button connect,execute;
private Socket soc= null;
private PrintStream ps= null;
Listen listen;
public void init()
{
chat_txt= new TextArea();
sql_txt= new TextField(20);
connect= new Button("Connect");
execute= new Button("Execute");
execute.disable();
Panel pp= new Panel();
pp.setLayout(new FlowLayout());
pp.add(sql_txt);
pp.add(connect);
pp.add(execute);
add("North",pp);
add("Center",chat_txt);
}
public boolean action(Event evt,Object obj)
{
if(evt.target instanceof Button)
{
String label= (String)obj;
if(label.equals("Connect"))
{
try{
soc= new Socket(InetAddress.getLocalHost(),4700);
ps= new PrintStream(soc.getOutputStream());
ps.println("HELLO");
ps.flush();
listen= new Listen(this,soc);
listen.start();
}catch(Exception e)
{
chat_txt.setText(e.toString());
disconnect();
}
connect.setLabel("Disconnect");
execute.enable();
}else if(label.equals("Disconnect"))
disconnect();
else if(label.equals("Execute"))
{
if(sql_txt.getText()!= null)
{
ps.println("FIND");
ps.flush();
ps.println(sql_txt.getText());
ps.flush();
}
}
}
return false;
}
public void disconnect()
{
if(soc!= null)
{
try{
listen.stop();
ps.println("QUIT");
ps.flush();
soc.close();
}catch(Exception e){}
finally{
listen.stop();
listen= null;
soc= null;
}
execute.disable();
connect.setLabel("Disconnect");
}
}
}