上篇文章对listView 分组和字母索引导航进行了重构，重构之后，使新的实现只依赖于接口，而不是具体的Bo.但是还是要求原始的数据Bo实现接口或者继承抽象类。能不能把这一步也简化呢，只需要原始的数据Bolist? 答案是可以的，可以使用注解，也就是annnotion。
Java注解又叫java标注，java提供了一套机制，使得我们可以对方法、类、参数、包、域以及变量等添加标准(即附上某些信息)。且在以后某个时段通过反射将标注的信息提取出来以供使用。
分组listView 在上次重构后，最需要的信息就是“使用哪个字段进行分组导航”，故我们只要使用注解把这个信息标志出来即可。
另外还需要保存一些拼音等的缓存，那么可以把原始的Bo包装一下，利用泛型。下面一步步的来。
注解只要标记按照bo的哪个字段分组排序即可，且注解信息保留在运行时：
@Target(ElementType.TYPE)
@Documented
@Retention(RetentionPolicy.RUNTIME)
public @interface RulerSortStr {
String sortField();
}对Bo利用泛型对Bo进行包装，包装类实现之前的接口BoSort或者继承抽象类DefaultBoSortImp，实现方法getSortStr时利用Bo的注解信息。
public class RulerListDataWrapper<T> extends DefaultBoSortImp{
private T data;
public RulerListDataWrapper() {
super();
}
public RulerListDataWrapper(T data) {
super();
this.data = data;
}
public T getData() {
return data;
}
public void setData(T data) {
this.data = data;
}
/**
* 利用 T的注解信息实现此方法
*/
@Override
public String getSortStr() {
Class<?> temp = data.getClass();
RulerSortStr anno = temp.getAnnotation(RulerSortStr.class);
if (anno==null) {
return "";
}
String sortField = anno.sortField();
Field f;
try {
f = temp.getDeclaredField(sortField);
f.setAccessible(true);
return (String) f.get(data);
} catch (Exception e) {
e.printStackTrace();
return "";
}
}
}此工具类也重构为泛型，此类把原始数据bo列表List<T>构造为包装器类型List<RulerListDataWrapper<T>>。添加的标签也是包装器类型(RulerListDataWrapper<T>),泛型化之后，不再依赖具体的Bo.
public class RulerUtil<T> {
/**
* 列表适配??
*/
public static final String[] indexStr = { "#", "A", "B", "C", "D", "E", "F", "G", "H",
"I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U",
"V", "W", "X", "Y", "Z" };
public static final char[] letters = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U',
'V', 'W', 'X', 'Y', 'Z' };
/**
* @throws IllegalAccessException
* @throws InstantiationException
* @date 2014-7-28
* @return返回处理后的数据
* @Description:处理数据，排序，添加标签
*/
public List<RulerListDataWrapper<T>> genSortedDataAndTagLocation(List<T> myData, HashMap<String, Integer> tagLocation) throws InstantiationException, IllegalAccessException {
List<RulerListDataWrapper<T>> res = getList(myData);
//首先排序
Collections.sort(res, new Comparator<RulerListDataWrapper<T>>() {
@Override
public int compare(RulerListDataWrapper<T> lhs, RulerListDataWrapper<T> rhs) {
char firChar = checkAndGetPinyin(lhs);
char secChar = checkAndGetPinyin(rhs);
if (firChar < secChar) {
return -1;
} else if (firChar > secChar) {
return 1;
} else
return 0;
}
});
int size = res.size();
int i = 0;
char nowTag = '\0';
for (i = 0; i < size; i++) {
RulerListDataWrapper<T> temp = res.get(i);
char tempTag = checkAndGetPinyin(temp);
if(Arrays.binarySearch(letters, tempTag) < 0){
tempTag = '#';
}
if (nowTag != tempTag) {
RulerListDataWrapper<T> tagBO = new RulerListDataWrapper<T>();
tagBO.setTag(tempTag+"");
res.add(i, tagBO);
tagLocation.put(tempTag + "", i);
i++;
size++;
nowTag = tempTag;
}
}
tagLocation.put("#", 0);
return res;
}
private char checkAndGetPinyin(BoSort bo){
String pinyinStr = bo.getSortStrPinyin();
if (pinyinStr==null) {
bo.setSortStrPinYin(HanziToPinyin.getPinYin(bo.getSortStr()).toUpperCase());
pinyinStr = bo.getSortStrPinyin();
}
if(pinyinStr!=null&&pinyinStr.length()>=1){
return pinyinStr.charAt(0);
}
return '\0';
}
public List<RulerListDataWrapper<T>> getList(List<T> data){
List<RulerListDataWrapper<T>> res = new ArrayList<RulerListDataWrapper<T>>();
for (T t: data) {
res.add(new RulerListDataWrapper<T>(t));
}
return res;
}也都进行泛型化。
首先是adaptor，其所需要的数据是List<RulerListDataWrapper<T>>，泛型化之后，如下：
public class RulerAdapter<T> extends BaseAdapter{
/**
* 经过处理的数据
*/
private List<RulerListDataWrapper<T>> list;
/**
* aa
*/
private Context mContext;
/**
*
*/
public RulerAdapter() {
super();
// TODO Auto-generated constructor stub
}
/**
* @param list
*/
public RulerAdapter(List<RulerListDataWrapper<T>> list) {
super();
this.list = list;
}
/**
*
*/
public RulerAdapter(List<RulerListDataWrapper<T>> list, Context mContext) {
super();
this.list = list;
this.mContext = mContext;
}
public List<RulerListDataWrapper<T>> getList() {
return list;
}
public void setList(List<RulerListDataWrapper<T>> list) {
this.list = list;
}
public Context getmContext() {
return mContext;
}
public void setmContext(Context mContext) {
this.mContext = mContext;
}
@Override
public int getCount() {
return list.size();
}
@Override
public RulerListDataWrapper<T> getItem(int arg0) {
// TODO Auto-generated method stub
return list.get(arg0);
}
@Override
public long getItemId(int position) {
return 0;
}
/**
* @date 2014-9-3
* @Description: 需要的时候覆盖此方法，提供自己的自定义非标签视图
* @param
* @return View
*/
public View getContentView(int position,RulerListDataWrapper<T> bo){
return null;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = LayoutInflater.from(mContext).inflate(R.layout.g_ruler_list_item, null);
holder = new ViewHolder();
holder.tag = (TextView) convertView.findViewById(R.id.g_ruler_list_item_tag);
holder.content = (LinearLayout) convertView.findViewById(R.id.g_ruler_list_item);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
// 依赖于RulerListDataWrapper<T>
final RulerListDataWrapper<T> bo = getItem(position);
String tag = bo.getTag();
if(tag!=null){//是标签
holder.tag.setVisibility(View.VISIBLE);
holder.content.setVisibility(View.GONE);
holder.tag.setText(tag);
}else{//是内容
//首先取自定义视图，如果没的话就自定义一个TextView add 到content中
holder.content.removeAllViews();
holder.tag.setVisibility(View.GONE);
holder.content.setVisibility(View.VISIBLE);
View contentView = getContentView(position, bo);
if(contentView==null){
TextView textV = new TextView(mContext);
textV.setText(bo.getSortStr());
textV.setTextColor(Color.BLACK);
textV.setGravity(Gravity.CENTER_VERTICAL);
textV.setTextSize(16);
contentView = textV;
}
holder.content.addView(contentView, LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
}
return convertView;
}
static class ViewHolder{
TextView tag;
LinearLayout content;
}Activity也泛型化，主要是对RulerUtil的调用和 获取数据时泛型化，其基本代码如下：
public abstract class RulerActivity<T> extends Activity{
protected TextView noDataView;
protected TextView RulerTag;
protected ProgressBarWithText progress;
protected ListView listView;
protected RulerWidget ruler;
private RulerAdapter<T> rulerAdapter;
private List<T> originalList;
private List<RulerListDataWrapper<T>> dealedList;
private HashMap<String, Integer> tagLocation = new HashMap<String, Integer>();
/**
*
*/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.g_ruler);
findView();
initView();
initData();
}
private void findView() {
. . .
}
private void initView() {
. . .
}
private void initData() {
new GetDataAsyTask().execute();
}
/**
* @date 2014-9-4
* @Description: 需要实现这个获取数据的方法
* @param
* @return List<? extends BoSort>
*/
public abstract List<T> getDataList();
/**
* @date 2014-9-3
* @Description:
* @param
* @return void
*/
private void handleSuccessData() {
. . .
}
/**
* @Description: 获取触摸字母导航的时候，列表要滚动到的位置。如果触摸的字母，在标签tagLocation 映射中，不存,则向前寻找。
*/
private Integer getPosition(final int j) {
. . .
}
class GetDataAsyTask extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
progress.setVisibility(View.VISIBLE);
}
@Override
protected Void doInBackground(Void... params) {
originalList = getDataList();
try {
dealedList = new RulerUtil<T>().genSortedDataAndTagLocation(originalList, tagLocation);
} catch (Exception e) {
e.printStackTrace();
if (dealedList!=null) {
dealedList.clear();
dealedList = null;
}
if (originalList!=null) {
originalList.clear();
originalList = null;
}
if (tagLocation!=null) {
tagLocation.clear();
tagLocation = null;
}
}
return null;
}
@Override
protected void onPostExecute(Void result) {
progress.setVisibility(View.GONE);
super.onPostExecute(result);
if(dealedList==null){
noDataView.setVisibility(View.VISIBLE);
return;
}
handleSuccessData();
}
}
}测试使用只要继承意思activity和对Bo使用注解即可：
如下：
使用注解，@RulerSortStr(sortField="testtr"),表名使用分组索引的字段为testtr。
@RulerSortStr(sortField="testtr")
public class TestAnnotationBo {
private String testtr;
private String test2;
/**
*
*/
public TestAnnotationBo() {
super();
// TODO Auto-generated constructor stub
}
public TestAnnotationBo(String testtr, String test2) {
super();
this.testtr = testtr;
this.test2 = test2;
}
public String getTesttr() {
return testtr;
}
public void setTesttr(String testtr) {
this.testtr = testtr;
}
public String getTest2() {
return test2;
}
public void setTest2(String test2) {
this.test2 = test2;
}
}只需要继承以上activity和实现获取数据的方法接口
public class TestRulerAnnoActivity extends RulerActivity<TestAnnotationBo>{
@Override
public List<TestAnnotationBo> getDataList() {
List<TestAnnotationBo> res = new ArrayList<TestAnnotationBo>();
TestAnnotationBo a = new TestAnnotationBo("aa","sdds");
TestAnnotationBo a1 = new TestAnnotationBo("阿姨","sdds");
TestAnnotationBo b = new TestAnnotationBo("bb","sdds");
TestAnnotationBo b1 = new TestAnnotationBo("爸爸","sdds");
res.add(b1);
res.add(a);
res.add(a1);
res.add(b);
return res;
}
}
重构完毕。
原文地址：http://blog.csdn.net/windsunmoon/article/details/39315507
