主题：利用HTTP请求方式获取eXist查询结果的窗体程序

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.ScrollPaneConstants;

public class Exec {
    public static void main(String[] args) {
        DemoWindow dw = new DemoWindow("XQuery");
        Toolkit theKit = dw.getToolkit();
        Dimension wndSize = theKit.getScreenSize();
        dw.setBounds(wndSize.width / 3, wndSize.height / 3, wndSize.width / 3,
                wndSize.height / 3);
        dw.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        dw.setVisible(true);
    }
}

class DemoWindow extends JFrame implements ActionListener {
    JTextArea jta1 = new JTextArea();
    JTextArea jta2 = new JTextArea();
    JButton jb = new JButton("确认");
    JPanel jp = new JPanel();
    int v = ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED;
    int h = ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED;
    JScrollPane jsp = new JScrollPane(jta2, v, h);

    public DemoWindow(String title) {
        super(title);
        setLayout(new BorderLayout());
        jp.add(jb);
        jb.addActionListener(this);
        jta2.setBackground(Color.yellow);
        add(jta1, BorderLayout.NORTH);
        add(jsp, BorderLayout.CENTER);
        add(jp, BorderLayout.SOUTH);
    }

    public void actionPerformed(ActionEvent e) {
        GetXMLInfo gxi = new GetXMLInfo();
        jta2.setText(gxi.getResult(jta1.getText()));
    }
}

class GetXMLInfo {
    public String getResult(String query) {
        char[] data = null;
        FileOutputStream fos;
        URL url;
        URLConnection urlConnection;
        InputStream is;
        int i;
        try {
            fos = new FileOutputStream("results.xml");
            url = new URL("http://localhost:8080/exist/servlet/db/?_query="
                    + query);
            urlConnection = url.openConnection();
            is = urlConnection.getInputStream();

            i = is.read();
            while (i > 0) {
                fos.write(i);
                i = is.read();
            }
            fos.close();
            is.close();
            File file = new File("results.xml");
            int size = (int) file.length();
            FileReader in = new FileReader(file);
            data = new char[size];
            in.read(data, 0, size);
            in.close();
        } catch (IOException e) {
        }
        return new String(data);
    }

}