Javaサンプル(数字チェックとメッセージダイアログ)

//Sample07
import java.awt.Button;
import java.awt.Dialog;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.Label;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
public class Sample07 extends Frame implements ActionListener {
  private static final String btnNumericCheck_code = "Integer Check";
  private static final String btnNumberRangeCheck_code = "1 - 5 Check";
  private static final String window_title = "数字チェックとメッセージダイアログ";
  private static final int window_width = 640;
  private static final int window_height = 400;
  private static final int tf01_size = 5;
  private static final int tf02_size = 1;
  private static final long serialVersionUID = 1L;
  TextField tf01 = new TextField("", Sample07.tf01_size);
  TextField tf02 = new TextField("", Sample07.tf02_size);
  int pc = -1;
  // 主処理
  public static void main(final String ar[]) {
    final Frame f = new Sample07();
    f.setTitle(Sample07.window_title);
    f.setSize(Sample07.window_width, Sample07.window_height);
    f.setVisible(true);
  }
  // 部品セット
  Sample07() {
    this.setLayout(new FlowLayout());
    final Button btnNumberCheck = new Button(Sample07.btnNumericCheck_code);
    final Button btnNumberRangeCheck = new Button(
        Sample07.btnNumberRangeCheck_code);
    btnNumberCheck.addActionListener(this);
    btnNumberRangeCheck.addActionListener(this);
    this.add(this.tf01);
    this.add(btnNumberCheck);
    this.add(this.tf02);
    this.add(btnNumberRangeCheck);
    this.addWindowListener(new WinAdapter());
  }
  // 閉じる
  class WinAdapter extends WindowAdapter {
    @Override
    public void windowClosing(final WindowEvent we) {
      System.exit(0);
    }
  }
  // イベント
  public void actionPerformed(final ActionEvent ae) {
    int i;
    String str;
    final String strnum = "0123456789";
    final String str1to5 = "12345";
    final String ErrorDialog_title = "Error Message";
    final String message01 = "数字を入力してください";
    final String message02 = "１〜５の数字を入力してください";
    if (ae.getActionCommand() == Sample07.btnNumericCheck_code) {
      str = this.tf01.getText();
      if (str.length() == 0) {
        final ErrDialog dia = new ErrDialog(this, ErrorDialog_title,
            message01, true);
        return;
      }
      for (i = 0; i < str.length(); i++) {
        if (strnum.indexOf(str.substring(i, i + 1)) == -1) {
          final ErrDialog dia = new ErrDialog(this,
              ErrorDialog_title, message01, true);
          return;
        }
      }
    }
    if (ae.getActionCommand() == Sample07.btnNumberRangeCheck_code) {
      str = this.tf02.getText();
      if (str.length() != 1) {
        final ErrDialog dia = new ErrDialog(this, ErrorDialog_title,
            message02, true);
        return;
      }
      if (str1to5.indexOf(str) == -1) {
        final ErrDialog dia = new ErrDialog(this, ErrorDialog_title,
            message02, true);
        return;
      }
    }
  }
  // ダイアログ
  class ErrDialog extends Dialog implements ActionListener {
    private static final String Dialog_button_title = "Close";
    private static final long serialVersionUID = 1L;
    ErrDialog(final Frame f, final String title, final String msg,
        final boolean modal) {
      super(f, title, modal);
      this.setLayout(new FlowLayout());
      this.setSize(200, 100);
      final Label lbl = new Label(msg);
      this.add(lbl);
      final Button btc = new Button(ErrDialog.Dialog_button_title);
      this.add(btc);
      btc.addActionListener(this);
      this.setVisible(true);
    }
    // イベント
    public void actionPerformed(final ActionEvent e) {
      this.dispose();
    }
  }
}