public class MapDemo {
public static void main(String[] args) {
// getKeyV();
// getWor();
// String str="abcdv,.,.s,.,abcda";
// charStr(str);
// show(1,3);
// Properties pro=System.getProperties();
// for(Object obj:pro.keySet())
// {
// String string=(String) pro.get(obj);
// System.out.println(obj+"------"+string);
// }
// Date date=new Date();
// System.out.println(date+"\n");
// Calendar c=Calendar.getInstance();
// System.out.println(c.get(c.YEAR)+"\n"+c);
for(int x=0; x<5; x++){
int t=(int) (Math.random()*10+1);
System.out.println(t);
}
}
public static void getKeyV()
{
Map<String,String> map=new HashMap<String, String>();
map.put("02", "beijing");
map.put("01", "tianjing");
map.put("03", "shanghai");
map.put("04", "nanjing");
Set<Map.Entry<String, String>> entrySet=map.entrySet();
Iterator<Entry<String, String>> it=entrySet.iterator();
// Set<String> keySet=map.keySet();
// Iterator<String> it1=keySet.iterator();
while(it.hasNext())
{
Map.Entry<String, String> entry=it.next();
String key=entry.getKey();
String value=entry.getValue();
System.out.println(key+"---"+value);
}
}
public static void getWor()
{
Map<Worker, String> map=new TreeMap<Worker, String>(new WorNum());
map.put(new Worker("zhaosi1",19), "shanghai");
map.put(new Worker("zhaosi2",21), "nanjing");
map.put(new Worker("zhaosi4",18), "tianjin");
map.put(new Worker("zhaosi3",32), "shanghai");
map.put(new Worker("zhaosi5",18), "tianjin");
map.put(new Worker("zhaosi5",18), "tianjin");
Set<Entry<Worker, String>> entrySet=map.entrySet();
Iterator<Entry<Worker, String>> it=entrySet.iterator();
// Set<String> keySet=map.keySet();
// Iterator<String> it1=keySet.iterator();
while(it.hasNext())
{
Entry<Worker, String> entry=it.next();
Worker worker=entry.getKey();
System.out.println(worker.getAge()+"---"+worker.getName()+"----"+worker);
}
}
public static void charStr(String str) {
char[] chs=str.toCharArray();
Map<Character,Integer> map=new TreeMap<Character,Integer>();
int count=0;
for(int x=0;x<chs.length;x++)
{
if(!(chs[x]>='a'&&chs[x]<='z'||chs[x]>='A'&&chs[x]<='Z'))
continue;
Integer value=map.get(chs[x]);
// if(value==null)
// map.put(chs[x], 1);
// else
// {
// value=value+1;
// map.put(chs[x], value);
// }
if(value!=null)
count=value;
count++;
map.put(chs[x], count);
count=0;
}
System.out.println(map);
StringBuilder sb=new StringBuilder();
Set<Map.Entry<Character, Integer>> entry=map.entrySet();
Iterator<Map.Entry<Character, Integer>> it=entry.iterator();
while(it.hasNext())
{
Map.Entry<Character, Integer> me =it.next();
sb.append(me.getKey()+"("+me.getValue()+")");
}
String string=sb.toString();
System.out.println(string);
}
public static void show(int... arr)
{
System.out.println(arr.length);
}
}
class Worker implements Comparable<Worker>
{
private String name;
private int age;
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
Worker(String name,int age)
{
this.name=name;
this.age=age;
}
public void setName(String name)
{
this.name=name;
}
public String getName()
{
return name;
}
public int compareTo(Worker o)
{
// TODO Auto-generated method stub
int num =new Integer(this.age).compareTo(new Integer(o.age));
if(num==0)
return this.name.compareTo(o.name);
return num;
}
public int hashCode()
{
return name.hashCode()+age*21;
}
public boolean equals(Object obj)
{
if(!(obj instanceof Worker))
throw new ClassCastException("类型那个不匹配");
Worker w=(Worker)obj;
return this.name.equals(w.name)&this.age==w.age;
}
}
class WorNum implements Comparator<Worker>
{
public int compare(Worker o1, Worker o2) {
// TODO Auto-generated method stub
int num=o1.getName().compareTo(o2.getName());
if(num==0)
return new Integer(o1.getAge()).compareTo(new Integer(o2.getAge()));
return num;
}
}
Map练习
最新推荐文章于 2024-05-19 10:50:58 发布