求解决FATAL EXCEPTION: main

private Spinner province,city,area;
private Map>> data=null;
/**当前的选择的省份**/
private String currentProvince;
/**当前的选择的城市**/
private String currentCity;
private PullProvince pullProvince;

// /**当前的选择的区**/
// private String currentArea;
private Handler mHandler=new Handler(){
@SuppressWarnings("unchecked")
@Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
switch (msg.what) {
case PullProvince.PARSESUCCWSS://数据解析完毕，加载数据
data=(Map>>) msg.obj;
initData();
break;
default:
break;
}
super.handleMessage(msg);
}
};

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_user2);

    province=(Spinner)findViewById(R.id.province);
    city=(Spinner)findViewById(R.id.city);
    area=(Spinner)findViewById(R.id.area);  
    pullProvince=new PullProvince(mHandler);
    AssetManager asset = getAssets();
    InputStream input;
    try {
        input = asset.open("province_data.xml");
        pullProvince.getProvinces(input);
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    initView();
    initParams();
    initListnner();

}


  /**
 * 初始化数据
 */
private void initData(){        
  if (data!=null) {
    String[]arrStrings= data.keySet().toArray(new String[0]);
    System.out.println(arrStrings);         
    //将省份信息填充到 province Spinner
    province.setAdapter(new ArrayAdapter<String>(this, 
        android.R.layout.simple_expandable_list_item_1,arrStrings));
    currentProvince=getCurrentProvince();   
    bindCityAdapter(currentProvince);
    currentCity=getCurrentCity();           
    bindAreaAdapter(currentCity);           
    setOnItemSelectedListener();            
  }
}
private void bindAreaAdapter(String currentCity) {
  // TODO Auto-generated method stub
  //根据当前显示的城市将对应的区填充到area Spinner     
  area.setAdapter(new ArrayAdapter<String>(this, 
      android.R.layout.simple_expandable_list_item_1,
      data.get(currentProvince).get(currentCity)));
}
private void bindCityAdapter(String currentProvince) {
  // TODO Auto-generated method stub
  //根据当前显示的省份将对应的城市填充到city Spinner
  city.setAdapter(new ArrayAdapter<String>(this, 
      android.R.layout.simple_expandable_list_item_1,data.
      get(currentProvince).keySet().toArray(new String[0])));
}
/**
 * 为Spinner设置监听器
 */
private void setOnItemSelectedListener() {
  // TODO Auto-generated method stub
  province.setOnItemSelectedListener(new OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView<?> arg0, View arg1,
        int arg2, long arg3) {
      // TODO Auto-generated method stub
      currentProvince=getCurrentProvince();
      bindCityAdapter(currentProvince);
    }

    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
      // TODO Auto-generated method stub

    }
  });
  city.setOnItemSelectedListener(new OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView<?> arg0, View arg1,
        int arg2, long arg3) {
      // TODO Auto-generated method stub
      currentCity=getCurrentCity();
      bindAreaAdapter(currentCity);
    }

    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
      // TODO Auto-generated method stub

    }
  });
  area.setOnItemSelectedListener(new OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView<?> arg0, View arg1,
        int arg2, long arg3) {
      // TODO Auto-generated method stub

// Toast.makeText(MainActivity.this,area.getSelectedItem().toString(),
// Toast.LENGTH_SHORT).show();
}

    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
      // TODO Auto-generated method stub

    }
  });   
}

/**获取当前选择的省份
 * @return String:当前选择的省份
 */
private String getCurrentProvince() {
  // TODO Auto-generated method stub
  return province.getSelectedItem().toString();
}
/**获取当前选择的城市
 * @return String:当前选择的城市
 */
private String getCurrentCity() {
  // TODO Auto-generated method stub
  return city.getSelectedItem().toString();
}