Map<String, String> map = new HashMap<String, String>();  map.put("key1", "value1");  map.put("key2", "value2");  map.put("key3", "value3");    //第一种：普遍使用，二次取值  System.out.println("通过Map.keySet遍历key和value：");  for (String key : map.keySet()) {   System.out.println("key= "+ key + " and value= "http://www.mamicode.com/+ map.get(key));  }    //第二种  System.out.println("通过Map.entrySet使用iterator遍历key和value：");  Iterator<Map.Entry<String, String>> it = map.entrySet().iterator();  while (it.hasNext()) {   Map.Entry<String, String> entry = it.next();   System.out.println("key= " + entry.getKey() + " and value= "http://www.mamicode.com/+ entry.getValue());  }  <span style="color:#FF0000;">  //第三种：推荐，尤其是容量大时</span>  System.out.println("通过Map.entrySet遍历key和value");  for (Map.Entry<String, String> entry : map.entrySet()) {   System.out.println("key= " + entry.getKey() + " and value= "http://www.mamicode.com/+ entry.getValue());  }  //第四种  System.out.println("通过Map.values()遍历所有的value，但不能遍历key");  for (String v : map.values()) {   System.out.println("value= "http://www.mamicode.com/+ v);  }

public class HashMapAdapter extends BaseAdapter {    private HashMap<String, String> mData = http://www.mamicode.com/new HashMap<String, String>();    private String[] mKeys;    public HashMapAdapter(HashMap<String, String> data){        mData  = data;        mKeys = mData.keySet().toArray(new String[data.size()]);    }    @Override    public int getCount() {        return mData.size();    }    @Override    public Object getItem(int position) {        return mData.get(mKeys[position]);    }    @Override    public long getItemId(int arg0) {        return arg0;    }    @Override    public View getView(int pos, View convertView, ViewGroup parent) {        String key = mKeys[pos];        String Value = getItem(pos).toString();        //do your view stuff here        return convertView;    }}