package cn.itcast.demo17; import java.util.HashMap; import java.util.Map; import java.util.Map.Entry; import java.util.Set; public class Test { public static void main(String[] args) { //定义网络组集合 Map<String,String> wangluozu = new HashMap<String,String>(); wangluozu.put("001", "liupc"); wangluozu.put("002", "lijing"); //定义电磁组集合 Map<String,String> diancizu = new HashMap<String,String>(); diancizu.put("001", "liubo"); diancizu.put("002", "guoshaoying"); //定义四室集合 Map<String,Map<String,String>> sishi = new HashMap<String,Map<String,String>>(); sishi.put("网络组", wangluozu); sishi.put("电磁组", diancizu); //查看四室网络组001号学生 String str = sishi.get("网络组").get("001"); System.out.println(str); System.out.println("--------------"); //遍历四室电磁组的学生:keySet()方式 for(String no : sishi.get("电磁组").keySet()){ System.out.println(no + "..." + sishi.get("电磁组").get(no)); } System.out.println("--------------"); //遍历四室电磁组的学生:entry方式 Set<Entry<String,String>> set = sishi.get("电磁组").entrySet(); for(Entry<String,String> entry:set){ System.out.println(entry.getKey()+"..."+entry.getValue()); } System.out.println("--------------"); //遍历四室的学生:keySet()方式 Set<String> set_sishi = sishi.keySet(); for(String zuName :set_sishi){ Map<String,String> map = sishi.get(zuName); Set<String> set_zu = map.keySet(); for(String no:set_zu){ String name = map.get(no); System.out.println(zuName + "..." + no + "..." + name); } } System.out.println("--------------"); //遍历四室的学生:Entry方式 Set<Map.Entry<String,Map<String,String>>> entrySet1 = sishi.entrySet(); for(Map.Entry<String,Map<String,String>> entry2:entrySet1){ String zuName1 = entry2.getKey(); Map<String,String> map2 = entry2.getValue(); Set<Map.Entry<String,String>> entrySet2 = map2.entrySet(); for(Map.Entry<String,String> entry3:entrySet2){ String no1 = entry3.getKey(); String name1 = entry3.getValue(); System.out.println(zuName1 + "..." + no1 + "..." + name1); } } } } |