办法查找工具[Java编程]

//: DisplayMethods.java
// Display the methods of any class inside
// a window. Dynamically narrows your search.
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import java.lang.reflect.*;
import java.io.*;

public class DisplayMethods extends Applet {
  Class cl;
  Method[] m;
  Constructor[] ctor;
  String[] n = new String[0];
  TextField 
    name = new TextField(40),
    searchFor = new TextField(30);
  Checkbox strip = 
    new Checkbox("Strip Qualifiers");
  TextArea results = new TextArea(40, 65);
  public void init() {
    strip.setState(true);
    name.addTextListener(new NameL());
    searchFor.addTextListener(new SearchForL());
    strip.addItemListener(new StripL());
    Panel 
      top = new Panel(),
      lower = new Panel(),
      p = new Panel();
    top.add(new Label("Qualified class name:"));
    top.add(name);
    lower.add(
      new Label("String to search for:"));
    lower.add(searchFor);
    lower.add(strip);
    p.setLayout(new BorderLayout());
    p.add(top, BorderLayout.NORTH);
    p.add(lower, BorderLayout.SOUTH);
    setLayout(new BorderLayout());
    add(p, BorderLayout.NORTH);
    add(results, BorderLayout.CENTER);
  }
  class NameL implements TextListener {
    public void textValueChanged(TextEvent e) {
      String nm = name.getText().trim();
      if(nm.length() == 0) {
        results.setText("No match");
        n = new String[0];
        return;
      }
      try {
        cl = Class.forName(nm);
      } catch (ClassNotFoundException ex) {
        results.setText("No match");
        return;
      }
      m = cl.getMethods();
      ctor = cl.getConstructors();
      // Convert to an array of Strings:
      n = new String[m.length + ctor.length];
      for(int i = 0; i < m.length; i++)
        n[i] = m[i].toString();
      for(int i = 0; i < ctor.length; i++)
        n[i + m.length] = ctor[i].toString();
      reDisplay();
    }
  }
  void reDisplay() {
    // Create the result set:
    String[] rs = new String[n.length];
    String find = searchFor.getText();
    int j = 0;
    // Select from the list if find exists:
    for (int i = 0; i < n.length; i++) {
      if(find == null)
        rs[j++] = n[i];
      else if(n[i].indexOf(find) != -1)
          rs[j++] = n[i];
    }
    results.setText("");
    if(strip.getState() == true)
      for (int i = 0; i < j; i++)
        results.append(
          StripQualifiers.strip(rs[i]) + "\n");
    else // Leave qualifiers on
      for (int i = 0; i < j; i++)
        results.append(rs[i] + "\n");
  }
  class StripL implements ItemListener {
    public void itemStateChanged(ItemEvent e) {
      reDisplay();
    }
  }
  class SearchForL implements TextListener {
    public void textValueChanged(TextEvent e) {
      reDisplay();
    }
  }
  public static void main(String[] args) {
    DisplayMethods applet = new DisplayMethods();
    Frame aFrame = new Frame("Display Methods");
    aFrame.addWindowListener(
      new WindowAdapter() {
        public void windowClosing(WindowEvent e) {
          System.exit(0);
        }
      });
    aFrame.add(applet, BorderLayout.CENTER);
    aFrame.setSize(500,750);
    applet.init();
    applet.start();
    aFrame.setVisible(true);
  }
}

class StripQualifiers {
  private StreamTokenizer st;
  public StripQualifiers(String qualified) {
      st = new StreamTokenizer(
        new StringReader(qualified));
      st.ordinaryChar(' ');
  }
  public String getNext() {
    String s = null;
    try {
      if(st.nextToken() !=
            StreamTokenizer.TT_EOF) {
        switch(st.ttype) {
          case StreamTokenizer.TT_EOL:
            s = null;
            break;
          case StreamTokenizer.TT_NUMBER:
            s = Double.toString(st.nval);
            break;
          case StreamTokenizer.TT_WORD:
            s = new String(st.sval);
            break;
          default: // single character in ttype
            s = String.valueOf((char)st.ttype);
        }
      }
    } catch(IOException e) {
      System.out.println(e);
    }
    return s;
  }
  public static String strip(String qualified) {
    StripQualifiers sq = 
      new StripQualifiers(qualified);
    String s = "", si;
    while((si = sq.getNext()) != null) {
      int lastDot = si.lastIndexOf('.');
      if(lastDot != -1)
        si = si.substring(lastDot + 1);
      s += si;
    }
    return s;
  }
} ///:~