Java进阶 - Map集合、异常处理、线程进程引入

                public
                class
                 DemoMap2 {
    
                public
                static
                void
                 main(String[] args) {
        method02();

    }

    
                private
                static
                void
                 method02() {
        
                //
                key用Person类来做，person类就必须重写Hashcode和equals方法
        HashMap<Person,String> map = new HashMap<>();
        map.put(new Person("女王",18),"英国");
        map.put(new Person("秦始皇",22),"秦国");
        map.put(new Person("普京",25),"俄国");
        map.put(new Person("女王",18),"毛里求斯");
        Set<Map.Entry<Person, String>> entrySet = map.entrySet();
        for(Map.Entry<Person,String> entry : entrySet){
            Person key = entry.getKey();
            String value = entry.getValue();
            System.out.println(value + " - - > " + key);
        }

    }

    publicstaticvoid method01(){
        //创建HashMap对象,因为String作为Key已经重写了hashcode方法和equals方法，所以key不会出现重复
        HashMap<String,Person> map = new HashMap<>();
        map.put("北京",new Person("张三",22));
        map.put("上海",new Person("李四",18));
        map.put("广州",new Person("王五",25));
    }
}

                public
                class
                 MapTest {

                public
                static
                void
                 main(String[] args) {

                //
                友情提示
System.out.println("请录入一个字符串:");
String line = new Scanner(System.in).nextLine();

// 定义 每个字符出现次数的方法findChar(line);
}
privatestaticvoid findChar(String line) {
//1:创建一个集合 存储 字符 以及其出现的次数
HashMap<Character, Integer> map = new HashMap<Character, Integer>();
//2:遍历字符串for (int i = 0; i < line.length(); i++) {
char c = line.charAt(i);
//判断 该字符 是否在键集中if (!map.containsKey(c)) {//说明这个字符没有出现过
//那就是第一次
map.put(c, 1);
} else {
//先获取之前的次数
Integer count = map.get(c);
//count++;
//再次存入 更新
map.put(c, ++count);
}
}
System.out.println(map);
}
}

                package
                 basicpart.day01.DataStructure;


                import java.util.*;

publicclass MapDouDiZhu {
    publicstaticvoid main(String[] args) {
        //通过pai方法获取牌
        Map<Integer, String> map = pai();
        System.out.println(map);
        //获取一个打乱牌的顺序
        List<Integer> order = getOrder();
        System.out.println(order);
        //遍历顺序集合去发牌        gameSet(map, order);
    }

    privatestaticvoid gameSet(Map<Integer, String> map, List<Integer> order) {
        List<String> player01 = new ArrayList<>();
        List<String> player02 = new ArrayList<>();
        List<String> player03 = new ArrayList<>();
        List<String> dipai = new ArrayList<>();
        for (int i = 0; i < order.size(); i++) {
            if(i >= 51){
                String s = map.get(order.get(i));
                dipai.add(s);
            } elseif(i %3 ==0){
                String s = map.get(order.get(i));
                player01.add(s);
            } elseif(i %3 == 1){
                String s = map.get(order.get(i));
                player02.add(s);
            } elseif(i %3 ==2){
                String s = map.get(order.get(i));
                player03.add(s);
            }
        }
        System.out.println(dipai);
        System.out.println(player01);
        System.out.println(player02);
        System.out.println(player03);
    }


    privatestatic Map<Integer, String> pai() {
        List<String> colors = List.of("?", "?", "?", "?");
        List<String> numbers = List.of("2", "A", "K", "Q", "J", "10", "9", "8", "7", "6", "5", "4", "3");
        List<String> pocker = new ArrayList<>();
        pocker.add("大王");
        pocker.add("小王");
        for (String number : numbers) {
            for (String color : colors) {
                pocker.add(color + number);
            }
        }
        Map<Integer, String> map = new HashMap<>();
        for (int i = 0; i <= 53; i++) {
            map.put(i, pocker.get(i));
        }
        return map;
    }

    publicstatic List<Integer> getOrder() {
        List<Integer> order = new ArrayList<>();
        for (int i = 0; i < 54; i++) {
            order.add(i);
        }
        Collections.shuffle(order);
        return order;
    }
}