Example 1: 通过迭代key得到value中的值 
  
try { 
HashMap hm = new HashMap(); 
hm.put("1", "yi"); 
hm.put("2", "er"); 
hm.put("3", "san"); 
hm.put("4", "si"); 
hm.put("5", "wu"); 
Iterator it=hm.keySet().iterator(); 
while(it.hasNext()){ 
String key=(String)it.next(); 
System.out.println(hm.get(key)); 
} 
} catch (Exception e) { 
e.printStackTrace(); 
  
} 
  
Example 2:直接迭代value中的值 
  
try { 
HashMap hm = new HashMap(); 
hm.put("1", "yi"); 
hm.put("2", "er"); 
hm.put("3", "san"); 
hm.put("4", "si"); 
hm.put("5", "wu"); 
Iterator it=hm.values().iterator(); 
while(it.hasNext()){ 
System.out.println(it.next()); 
} 
} catch (Exception e) { 
e.printStackTrace(); 
} 
  
Example 3: 同时获得key和value 
try { 
HashMap hm = new HashMap(); 
hm.put("1", "yi"); 
hm.put("2", "er"); 
hm.put("3", "san"); 
hm.put("4", "si"); 
hm.put("5", "wu"); 
Iterator it=hm.entrySet().iterator(); 
while(it.hasNext()){ 
Map.Entry map=(Map.Entry)it.next(); 
System.out.println(map.getKey()+" - "+map.getValue()); 
} 
} catch (Exception e) { 
e.printStackTrace(); 
}