Java完成Map集合二级联合浮动,javamap联合浮动

Map集合能够保存键值映射关系,那特别切合本实例所须要的数据结构,全数省区消息方可保留为Map会集的键,而各类键能够保存对应的都市新闻,本实例就是利用Map集结完结了省市级联选拔框,当选用省份音讯时,将改蒙特雷会下拉挑选框对应的内容。

思路拆解分析:

1. 创办全国(省,直辖市,自治区)映射集结,即LinkedHashMap对象,使用Map接口的put()方法向聚集中加上钦赐的省与都市的投射关系,在那之中值为String型一维数组。

 1 import java.util.LinkedHashMap;
 2 import java.util.Map;
 3  
 4 public class CityMap {
 5     /**
 6      * 全国(省,直辖市,自治区)映射集合
 7      */
 8     public static Map<String,String[]> model=new LinkedHashMap<String, String[]>();
 9     static{
10         model.put("北京", new String[]{"北京"});
11         model.put("上海", new String[]{"上海"});
12         model.put("天津", new String[]{"天津"});
13         model.put("重庆", new String[]{"重庆"});
14         model.put("黑龙江", new String[]{"哈尔滨","齐齐哈尔","牡丹江","大庆","伊春","双鸭山","鹤岗","鸡西","佳木斯","七台河","黑河","绥化","大兴安岭"});
15         model.put("吉林", new String[]{"长春","延边","吉林","白山","白城","四平","松原","辽源","大安","通化"});
16         model.put("辽宁", new String[]{"沈阳","大连","葫芦岛","旅顺","本溪","抚顺","铁岭","辽阳","营口","阜新","朝阳","锦州","丹东","鞍山"});
17         model.put("内蒙古", new String[]{"呼和浩特","呼伦贝尔","锡林浩特","包头","赤峰","海拉尔","乌海","鄂尔多斯","通辽"});
18         model.put("河北", new String[]{"石家庄","唐山","张家口","廊坊","邢台","邯郸","沧州","衡水","承德","保定","秦皇岛"});
19         model.put("河南", new String[]{"郑州","开封","洛阳","平顶山","焦作","鹤壁","新乡","安阳","濮阳","许昌","漯河","三门峡","南阳","商丘","信阳","周口","驻马店"});
20         model.put("山东", new String[]{"济南","青岛","淄博","威海","曲阜","临沂","烟台","枣庄","聊城","济宁","菏泽","泰安","日照","东营","德州","滨州","莱芜","潍坊"});
21         model.put("山西", new String[]{"太原","阳泉","晋城","晋中","临汾","运城","长治","朔州","忻州","大同","吕梁"});
22         model.put("江苏", new String[]{"南京","苏州","昆山","南通","太仓","吴县","徐州","宜兴","镇江","淮安","常熟","盐城","泰州","无锡","连云港","扬州","常州","宿迁"});
23         model.put("安徽", new String[]{"合肥","巢湖","蚌埠","安庆","六安","滁州","马鞍山","阜阳","宣城","铜陵","淮北","芜湖","毫州","宿州","淮南","池州"});
24         model.put("陕西", new String[]{"西安","韩城","安康","汉中","宝鸡","咸阳","榆林","渭南","商洛","铜川","延安"});
25         model.put("宁夏", new String[]{"银川","固原","中卫","石嘴山","吴忠"});
26         model.put("甘肃", new String[]{"兰州","白银","庆阳","酒泉","天水","武威","张掖","甘南","临夏","平凉","定西","金昌"});
27         model.put("青海", new String[]{"西宁","海北","海西","黄南","果洛","玉树","海东","海南"});
28         model.put("湖北", new String[]{"武汉","宜昌","黄冈","恩施","荆州","神农架","十堰","咸宁","襄樊","孝感","随州","黄石","荆门","鄂州"});
29         model.put("湖南", new String[]{"长沙","邵阳","常德","郴州","吉首","株洲","娄底","湘潭","益阳","永州","岳阳","衡阳","怀化","韶山","张家界"});
30         model.put("浙江", new String[]{"杭州","湖州","金华","宁波","丽水","绍兴","雁荡山","衢州","嘉兴","台州","舟山","温州"});
31         model.put("江西", new String[]{"南昌","萍乡","九江","上饶","抚州","吉安","鹰潭","宜春","新余","景德镇","赣州"});
32         model.put("福建", new String[]{"福州","厦门","龙岩","南平","宁德","莆田","泉州","三明","漳州"});
33         model.put("贵州", new String[]{"贵阳","安顺","赤水","遵义","铜仁","六盘水","毕节","凯里","都匀"});
34         model.put("四川", new String[]{"成都","泸州","内江","凉山","阿坝","巴中","广元","乐山","绵阳","德阳","攀枝花","雅安","宜宾","自贡","甘孜州","达州","资阳","广安","遂宁","眉山","南充"});
35         model.put("广东", new String[]{"广州","深圳","潮州","韶关","湛江","惠州","清远","东莞","江门","茂名","肇庆","汕尾","河源","揭阳","梅州","中山","德庆","阳江","云浮","珠海","汕头","佛山"});
36         model.put("广西", new String[]{"南宁","桂林","阳朔","柳州","梧州","玉林","桂平","贺州","钦州","贵港","防城港","百色","北海","河池","来宾","崇左"});
37         model.put("云南", new String[]{"昆明","保山","楚雄","德宏","红河","临沧","怒江","曲靖","思茅","文山","玉溪","昭通","丽江","大理"});
38         model.put("海南", new String[]{"海口","三亚","儋州","琼山","通什","文昌"});
39         model.put("新疆", new String[]{"乌鲁木齐","阿勒泰","阿克苏","昌吉","哈密","和田","喀什","克拉玛依","石河子","塔城","库尔勒","吐鲁番","伊宁"});
40     }
41 }

2. 概念获取省份的办法,成立二个Map集结,将上一步获得的映照会集赋值给它,使用Map集结的keySet()方法获得该集合中的全体键对象组成的Set集结,即为省分集合,创制四个Object型一维数组,使用Set接口的toArray()方法将Set集结转换为数组,再次回到此数组作为省份采取下拉列表的参数。

3. 选择JComboBox类的setModel()方法为省份下拉列表加多省份音信,参数即为上一步中的获取省份方法。

4. 概念依据省份获取市/县的措施,创设一个Map会集,将步骤第11中学赢得的投射集结赋值给它,使用Map集合的get()方法获得钦定键的值,即为市/县会集,成立贰个String[]型一维数组,将市/县会集赋值给该数组。

5. 概念省份下拉列表的选用处境改换事件,在该事件中通过JComboBox类的getSelectedItem()方法赢得选中的省区,默以为省份群集中的第贰个值,然后选拔JComboBox类的removeAllItems()方法清空市/县列表,依照选中的省区获取市/县数组,最后动用JComboBox的setModel()方法重新扩大加市/县列表的值。

 1 import java.awt.Graphics;
 2 import java.awt.Image;
 3  
 4 import javax.swing.JPanel;
 5  
 6 /**
 7  * 带背景的面板组件
 8  *
 9  * @author ZhongWei Lee
10  */
11 public class BackgroundPanel extends JPanel {
12  
13     /**
14      *
15      */
16     private static final long serialVersionUID = 7758689434195492602L;
17     /**
18      * 背景图片
19      */
20     private Image image;
21  
22     /**
23      * 构造方法
24      */
25     public BackgroundPanel() {
26         super();
27         setOpaque(false);
28         setLayout(null);
29     }
30  
31     /**
32      * 设置图片的方法
33      */
34     public void setImage(Image image) {
35         this.image = image;
36     }
37  
38     @Override
39     protected void paintComponent(Graphics g) {// 重写绘制组件外观
40         if (image != null) {
41             int width = getWidth();// 获取组件大小
42             int height = getHeight();
43             g.drawImage(image, 0, 0, width, height, this);// 绘制图片与组件大小相同
44         }
45         super.paintComponent(g);// 执行超类方法
46     }
47 }

  1 import java.awt.Image;
  2 import java.awt.Toolkit;
  3 import java.io.BufferedInputStream;
  4 import java.io.ByteArrayOutputStream;
  5 import java.io.FileInputStream;
  6 import java.io.IOException;
  7 import java.io.InputStream;
  8 import java.util.HashMap;
  9 import java.util.Iterator;
 10 import javax.swing.ImageIcon;
 11  
 12 /**
 13  * Utility class for managing resources such as colors, fonts, images, etc.
 14  *
 15  * This class may be freely distributed as part of any application or plugin.
 16  * <p>
 17  * Copyright (c) 2003 - 2004, Instantiations, Inc. <br>All Rights Reserved
 18  *
 19  * @author scheglov_ke
 20  */
 21 public class SwingResourceManager {
 22      
 23     /**
 24      * Maps image names to images
 25      */
 26     private static HashMap<String, Image> m_ClassImageMap = new HashMap<String, Image>();
 27      
 28     /**
 29      * Returns an image encoded by the specified input stream
 30      * @param is InputStream The input stream encoding the image data
 31      * @return Image The image encoded by the specified input stream
 32      */
 33     private static Image getImage(InputStream is) {
 34         try {
 35             ByteArrayOutputStream baos = new ByteArrayOutputStream();
 36             byte buf[] = new byte[1024 * 4];
 37             while (true) {
 38                 int n = is.read(buf);
 39                 if (n == -1)
 40                     break;
 41                 baos.write(buf, 0, n);
 42             }
 43             baos.close();
 44             return Toolkit.getDefaultToolkit().createImage(baos.toByteArray());
 45         } catch (Throwable e) {
 46             return null;
 47         }
 48     }
 49      
 50     /**
 51      * Returns an image stored in the file at the specified path relative to the specified class
 52      * @param clazz Class The class relative to which to find the image
 53      * @param path String The path to the image file
 54      * @return Image The image stored in the file at the specified path
 55      */
 56     public static Image getImage(Class<?> clazz, String path) {
 57         String key = clazz.getName() + '|' + path;
 58         Image image = m_ClassImageMap.get(key);
 59         if (image == null) {
 60             if ((path.length() > 0) && (path.charAt(0) == '/')) {
 61                 String newPath = path.substring(1, path.length());
 62                 image = getImage(new BufferedInputStream(clazz.getClassLoader().getResourceAsStream(newPath)));
 63             } else {
 64                 image = getImage(clazz.getResourceAsStream(path));
 65             }
 66             m_ClassImageMap.put(key, image);
 67         }
 68         return image;
 69     }
 70      
 71     /**
 72      * Returns an image stored in the file at the specified path
 73      * @param path String The path to the image file
 74      * @return Image The image stored in the file at the specified path
 75      */
 76     public static Image getImage(String path) {
 77         return getImage("default", path); //$NON-NLS-1$
 78     }
 79      
 80     /**
 81      * Returns an image stored in the file at the specified path
 82      * @param section String The storage section in the cache
 83      * @param path String The path to the image file
 84      * @return Image The image stored in the file at the specified path
 85      */
 86     public static Image getImage(String section, String path) {
 87         String key = section + '|' + SwingResourceManager.class.getName() + '|' + path;
 88         Image image = m_ClassImageMap.get(key);
 89         if (image == null) {
 90             try {
 91                 FileInputStream fis = new FileInputStream(path);
 92                 image = getImage(fis);
 93                 m_ClassImageMap.put(key, image);
 94                 fis.close();
 95             } catch (IOException e) {
 96                 return null;
 97             }
 98         }
 99         return image;
100     }
101      
102     /**
103      * Clear cached images in specified section
104      * @param section the section do clear
105      */
106     public static void clearImages(String section) {
107         for (Iterator<String> I = m_ClassImageMap.keySet().iterator(); I.hasNext();) {
108             String key = I.next();
109             if (!key.startsWith(section + '|'))
110                 continue;
111             Image image = m_ClassImageMap.get(key);
112             image.flush();
113             I.remove();
114         }
115     }
116      
117     /**
118      * Returns an icon stored in the file at the specified path relative to the specified class
119      * @param clazz Class The class relative to which to find the icon
120      * @param path String The path to the icon file
121      * @return Icon The icon stored in the file at the specified path
122      */
123     public static ImageIcon getIcon(Class<?> clazz, String path) {
124         return getIcon(getImage(clazz, path));
125     }
126      
127     /**
128      * Returns an icon stored in the file at the specified path
129      * @param path String The path to the icon file
130      * @return Icon The icon stored in the file at the specified path
131      */
132     public static ImageIcon getIcon(String path) {
133         return getIcon("default", path); //$NON-NLS-1$
134     }
135      
136     /**
137      * Returns an icon stored in the file at the specified path
138      * @param section String The storage section in the cache
139      * @param path String The path to the icon file
140      * @return Icon The icon stored in the file at the specified path
141      */
142     public static ImageIcon getIcon(String section, String path) {
143         return getIcon(getImage(section, path));
144     }
145  
146     /**
147      * Returns an icon based on the specified image
148      * @param image Image The original image
149      * @return Icon The icon based on the image
150      */
151     public static ImageIcon getIcon(Image image) {
152         if (image == null)
153             return null;
154         return new ImageIcon(image);
155     }
156 }

  1 import java.awt.EventQueue;
  2 import java.awt.event.ItemEvent;
  3 import java.awt.event.ItemListener;
  4 import java.util.Map;
  5 import java.util.Set;
  6  
  7 import javax.swing.DefaultComboBoxModel;
  8 import javax.swing.JButton;
  9 import javax.swing.JComboBox;
 10 import javax.swing.JFrame;
 11 import javax.swing.JLabel;
 12 import javax.swing.JPanel;
 13 import javax.swing.JTextField;
 14 import javax.swing.SwingConstants;
 15 import javax.swing.UIManager;
 16 import javax.swing.border.TitledBorder;
 17  
 18  
 19 public class MainFrame extends JFrame {
 20  
 21     /**
 22      *
 23      */
 24     private static final long serialVersionUID = -4595347311922711984L;
 25     private JTextField textField_3;
 26     private JTextField textField_1;
 27     private JComboBox comboBox_1;
 28     private JTextField textField;
 29     private JComboBox cityComboBox;
 30     private JComboBox comboBox;
 31  
 32     /**
 33      * Launch the application
 34      *
 35      * @param args
 36      */
 37     public static void main(String args[]) {
 38         EventQueue.invokeLater(new Runnable() {
 39             public void run() {
 40                 try {
 41                     UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
 42                     MainFrame frame = new MainFrame();
 43                     frame.setVisible(true);
 44                 } catch (Exception e) {
 45                     e.printStackTrace();
 46                 }
 47             }
 48         });
 49     }
 50  
 51     /**
 52      * Create the frame
 53      */
 54     public MainFrame() {
 55         getContentPane().setLayout(null);
 56         setBounds(100, 100, 518, 379);
 57         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 58         //获取默认的市/县
 59         String province=(String)getProvince()[0];
 60         setTitle("输入指定省/直辖市查询对应的市县");
 61  
 62         final BackgroundPanel backgroundPanel = new BackgroundPanel();
 63         backgroundPanel.setImage(SwingResourceManager.getImage(MainFrame.class, "/images/background.jpg"));
 64         backgroundPanel.setBounds(0, 0, 510, 380);
 65         getContentPane().add(backgroundPanel);
 66  
 67         final JPanel panel = new JPanel();
 68         panel.setOpaque(false);
 69         panel.setBounds(36, 126, 438, 70);
 70         backgroundPanel.add(panel);
 71         panel.setLayout(null);
 72         panel.setBorder(new TitledBorder(null, "居住地", TitledBorder.DEFAULT_JUSTIFICATION, TitledBorder.DEFAULT_POSITION, null, null));
 73         cityComboBox = new JComboBox();
 74         cityComboBox.setBounds(245, 25, 124, 27);
 75         panel.add(cityComboBox);
 76          
 77         cityComboBox.setModel(new DefaultComboBoxModel(getCity(province)));
 78  
 79         comboBox = new JComboBox();
 80         comboBox.setBounds(25, 25, 124, 27);
 81         panel.add(comboBox);
 82         comboBox.addItemListener(new ItemListener() {
 83             public void itemStateChanged(final ItemEvent e) { // 选项状态更改事件
 84                 itemChange();
 85             }
 86         });
 87         comboBox.setModel(new DefaultComboBoxModel(getProvince())); // 添加省份信息
 88  
 89         final JLabel label = new JLabel();
 90         label.setText("省/直辖市");
 91         label.setBounds(155, 30, 66, 18);
 92         panel.add(label);
 93  
 94         final JLabel label_1 = new JLabel();
 95         label_1.setText("市/县");
 96         label_1.setBounds(375, 30, 37, 18);
 97         panel.add(label_1);
 98  
 99         final JLabel label_2 = new JLabel();
100         label_2.setBounds(36, 43, 65, 18);
101         backgroundPanel.add(label_2);
102         label_2.setHorizontalAlignment(SwingConstants.RIGHT);
103         label_2.setHorizontalTextPosition(SwingConstants.LEADING);
104         label_2.setText("姓    名:");
105  
106         textField = new JTextField();
107         textField.setBounds(113, 38, 154, 28);
108         backgroundPanel.add(textField);
109  
110         final JLabel label_3 = new JLabel();
111         label_3.setBounds(36, 84, 65, 18);
112         backgroundPanel.add(label_3);
113         label_3.setHorizontalAlignment(SwingConstants.RIGHT);
114         label_3.setHorizontalTextPosition(SwingConstants.LEADING);
115         label_3.setText("性    别:");
116  
117         comboBox_1 = new JComboBox();
118         comboBox_1.setBounds(113, 81, 66, 25);
119         backgroundPanel.add(comboBox_1);
120         comboBox_1.setModel(new DefaultComboBoxModel(new String[] {"男", "女"}));
121  
122         final JLabel label_4 = new JLabel();
123         label_4.setBounds(36, 212, 65, 18);
124         backgroundPanel.add(label_4);
125         label_4.setHorizontalAlignment(SwingConstants.RIGHT);
126         label_4.setHorizontalTextPosition(SwingConstants.LEADING);
127         label_4.setText("详细地址:");
128  
129         textField_1 = new JTextField();
130         textField_1.setBounds(113, 208, 367, 28);
131         backgroundPanel.add(textField_1);
132  
133         final JLabel label_4_1 = new JLabel();
134         label_4_1.setBounds(36, 252, 65, 18);
135         backgroundPanel.add(label_4_1);
136         label_4_1.setHorizontalTextPosition(SwingConstants.LEADING);
137         label_4_1.setHorizontalAlignment(SwingConstants.RIGHT);
138         label_4_1.setText("E-mail:");
139  
140         textField_3 = new JTextField();
141         textField_3.setBounds(113, 248, 367, 27);
142         backgroundPanel.add(textField_3);
143  
144         final JButton button = new JButton();
145         button.setBounds(159, 289, 75, 28);
146         backgroundPanel.add(button);
147         button.setText("保存");
148  
149         final JButton button_1 = new JButton();
150         button_1.setBounds(265, 289, 75, 28);
151         backgroundPanel.add(button_1);
152         button_1.setText("重置");
153         //
154     }
155  
156     /**
157      * 获取省、直辖市,自治区
158      *
159      * @return
160      */
161     public Object[] getProvince() {
162         Map<String, String[]> map = CityMap.model;// 获取省份信息保存到Map中
163         Set<String> set = map.keySet(); // 获取Map集合中的键,并以Set集合返回
164         Object[] province = set.toArray(); // 转换为数组
165         return province; // 返回获取的省份信息
166     }
167  
168     /**
169      * 获取指定省对应的市/县
170      *
171      * @param selectProvince
172      * @return
173      */
174     public String[] getCity(String selectProvince) {
175         Map<String, String[]> map = CityMap.model; // 获取省份信息保存到Map中
176         String[] arrCity = map.get(selectProvince); // 获取指定键的值
177         return arrCity; // 返回获取的市/县
178     }
179  
180     private void itemChange() {
181         String selectProvince = (String) comboBox.getSelectedItem();
182         cityComboBox.removeAllItems(); // 清空市/县列表
183         String[] arrCity = getCity(selectProvince); // 获取市/县
184         cityComboBox.setModel(new DefaultComboBoxModel(arrCity)); // 重新添加市/县列表的值
185     }
186  
187 }

必发88官网,效果与利益如图:

必发88官网 1

 

Map会集能够保存键值映射关系,那非常切合本实例所急需的数据结构,全数省份新闻能够保存为Map集结…

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