Map接口的类实现
public class MapText { public static void main(String[] args) { // TODO Auto-generated method stub Map<String, String>map = new HashMap<>(); Emp emp = new Emp("351", "张三"); Emp emp2 = new Emp("512", "李四"); Emp emp3 = new Emp("853", "王一"); Emp emp4 = new Emp("125", "赵六"); Emp emp5 = new Emp("341", "黄七"); map.put(emp.getE_id(), emp.getE_name()); map.put(emp2.getE_id(), emp2.getE_name()); map.put(emp3.getE_id(), emp3.getE_name()); map.put(emp4.getE_id(), emp4.getE_name()); map.put(emp5.getE_id(), emp5.getE_name()); Set<String>set = map.keySet(); Iterator<String> it = set.iterator(); System.out.println("HashMap类实现Map集合,无序:"); while(it.hasNext()){ String str = (String)it.next(); String name = (String)map.get(str); System.out.println(str + " " + name); } TreeMap<String, String> treeMap = new TreeMap<>(); treeMap.putAll(map); Iterator<String> iter = treeMap.keySet().iterator(); System.out.println("TreeMap类实现的Map集合,键对象升序: "); while(iter.hasNext()){ String str = (String)iter.next(); String name = (String)treeMap.get(str); System.out.println(str + " " + name); } } }