java利用数组随机抽取幸运观众

本文实例为大家分享了java利用数组随机抽取幸运观众的具体代码，供大家参考，具体内容如下

思想：

首先将所有观众姓名生成数组，然后获取数组元素的总数量，再在数组元素中随机抽取元素的下标，根据元素的下标得到幸运观众的名字。

import java.awt.borderlayout;
import java.awt.eventqueue;
import javax.swing.jframe;
import javax.swing.jpanel;
import javax.swing.border.emptyborder;
import javax.swing.jtextfield;
import javax.swing.jtextarea;
import javax.swing.jscrollpane;
import javax.swing.border.titledborder;
import javax.swing.jbutton;
import java.awt.event.keyadapter;
import java.awt.event.keyevent;
import java.awt.event.actionlistener;
import java.awt.event.actionevent;
import javax.swing.uimanager;
import java.awt.color;

public class arrayexample extends jframe {

  private jpanel contentpane;
  private jtextfield namefield;
  private jtextarea personnelarea;
  private jtextarea resultarea;

  /**@auther 葆宁
   * launch the application.
   */
  public static void main(string[] args) {
    try {
      uimanager
          .setlookandfeel("com.sun.java.swing.plaf.nimbus.nimbuslookandfeel");
    } catch (throwable e) {
      e.printstacktrace();
    }
    eventqueue.invokelater(new runnable() {
      public void run() {
        try {
          arrayexample frame = new arrayexample();
          frame.setvisible(true);
        } catch (exception e) {
          e.printstacktrace();
        }
      }
    });
  }

  /**
   * create the frame.
   */
  public arrayexample() {
    settitle("\u5229\u7528\u6570\u7ec4\u968f\u673a\u62bd\u53d6\u5e78\u8fd0\u89c2\u4f17");
    setdefaultcloseoperation(jframe.exit_on_close);
    setbounds(100, 100, 498, 300);
    contentpane = new jpanel();
    contentpane.setborder(new emptyborder(5, 5, 5, 5));
    setcontentpane(contentpane);
    contentpane.setlayout(null);

    jpanel panel = new jpanel();
    panel
        .setborder(new titledborder(
            null,
            "\u8f93\u5165\u5728\u573a\u89c2\u4f17\u59d3\u540d\u6309\u56de\u8f66",
            titledborder.leading, titledborder.top, null,
            new color(59, 59, 59)));
    panel.setbounds(10, 10, 174, 242);
    contentpane.add(panel);
    panel.setlayout(new borderlayout(0, 5));

    namefield = new jtextfield();
    namefield.addkeylistener(new keyadapter() {
      @override
      public void keypressed(keyevent e) {
        do_textfield_keypressed(e);
      }
    });
    panel.add(namefield, borderlayout.north);
    namefield.setcolumns(10);

    jscrollpane scrollpane = new jscrollpane();
    panel.add(scrollpane);

    personnelarea = new jtextarea();
    personnelarea.seteditable(false);
    scrollpane.setviewportview(personnelarea);

    jpanel panel_1 = new jpanel();
    panel_1.setborder(new titledborder(null,
        "\u9009\u53d6\u89c2\u4f17\u4eba\u5458\uff1a",
        titledborder.leading, titledborder.top, null, new color(59, 59,
        59)));
    panel_1.setbounds(183, 10, 219, 242);
    contentpane.add(panel_1);
    panel_1.setlayout(new borderlayout(0, 0));

    jscrollpane scrollpane_1 = new jscrollpane();
    panel_1.add(scrollpane_1);

    resultarea = new jtextarea();
    resultarea.seteditable(false);
    resultarea.setlinewrap(true);
    scrollpane_1.setviewportview(resultarea);

    jbutton button = new jbutton("\u62bd\u53d6");
    button.addactionlistener(new actionlistener() {
      public void actionperformed(actionevent e) {
        do_button_actionperformed(e);
      }
    });
    button.setbounds(407, 164, 63, 25);
    contentpane.add(button);

    jbutton button_1 = new jbutton("\u9000\u51fa");
    button_1.addactionlistener(new actionlistener() {
      public void actionperformed(actionevent e) {
        do_button_1_actionperformed(e);
      }
    });
    button_1.setbounds(407, 215, 63, 25);
    contentpane.add(button_1);
  }

  protected void do_textfield_keypressed(keyevent e) {
    if (e.getkeychar() != '\n')// 不是回车字符不做处理
      return;
    string name = namefield.gettext();
    if (name.isempty())// 如果文本框没有字符串不做处理
      return;
    personnelarea.append(name + "\n");// 把输入人名与回车符添加到人员列表
    namefield.selectall();// 选择文本框所有字符
  }

  protected void do_button_actionperformed(actionevent e) {
    string perstring = personnelarea.gettext();// 获取人员列表文本
    string[] personnelarray = perstring.split("\n{1,}");// 获取人员数组
    int index = (int) (math.random() * personnelarray.length);// 生成随机数组索引
    // 定义包含格式参数的中奖信息
    string formatarg = "本次抽取观众人员：\n\t%1$s\n恭喜%1$s成为本次观众抽奖的大奖得主。"
        + "\n\n我们将为%1$s颁发：\n\t过期的酸奶二十箱。";
    // 为中奖信息添加人员参数
    string info = string.format(formatarg, personnelarray[index]);
    resultarea.settext(info);// 在文本域显示中间信息
  }

  protected void do_button_1_actionperformed(actionevent e) {
    dispose();
  }
}

效果图：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。