本文主要讲解实现了一个CSDN的安卓客户端,主要知识点如下
- java爬虫获取网页数据
- 将java程序打包成jar包
- Fragment+viewpager+TabPageIndicator实现Tab效果
- gestureImageView实现放大缩小图片
- imageLodar实现异步加载图上
- XListView实现下拉刷新
java爬虫获取网页资源
package com.zhy.biz;
import java.util.ArrayList;
import java.util.List;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
import com.zhy.bean.CommonException;
import com.zhy.bean.NewsItem;
import com.zhy.csdn.DataUtil;
import com.zhy.csdn.URLUtil;
/**
* 处理NewItem的业务类
* @author zhy
*
*/
public class NewsItemBiz
{
/**
* 业界、移动、云计算
*
* @param htmlStr
* @return
* @throws CommonException
*/
public List<NewsItem> getNewsItems( int newsType , int currentPage) throws CommonException
{
String urlStr = URLUtil.generateUrl(newsType, currentPage);
String htmlStr = DataUtil.doGet(urlStr);
List<NewsItem> newsItems = new ArrayList<NewsItem>();
NewsItem newsItem = null;
Document doc = Jsoup.parse(htmlStr);
Elements units = doc.getElementsByClass("unit");
for (int i = 0; i < units.size(); i++)
{
newsItem = new NewsItem();
newsItem.setNewsType(newsType);
Element unit_ele = units.get(i);
Element h1_ele = unit_ele.getElementsByTag("h1").get(0);
Element h1_a_ele = h1_ele.child(0);
String title = h1_a_ele.text();
String href = h1_a_ele.attr("href");
newsItem.setLink(href);
newsItem.setTitle(title);
Element h4_ele = unit_ele.getElementsByTag("h4").get(0);
Element ago_ele = h4_ele.getElementsByClass("ago").get(0);
String date = ago_ele.text();
newsItem.setDate(date);
Element dl_ele = unit_ele.getElementsByTag("dl").get(0);// dl
Element dt_ele = dl_ele.child(0);// dt
try
{// 可能没有图片
Element img_ele = dt_ele.child(0);
String imgLink = img_ele.child(0).attr("src");
newsItem.setImgLink(imgLink);
} catch (IndexOutOfBoundsException e)
{
}
Element content_ele = dl_ele.child(1);// dd
String content = content_ele.text();
newsItem.setContent(content);
newsItems.add(newsItem);
}
return newsItems;
}
}
详细实现参见链接
抓取csdn上的各类别的文章 (制作csdn app 二) - Hongyang - 博客频道 - CSDN.NET
将java项目打包成jar包
参考链接:在Eclipse中将Java项目打包为jar - 闵开慧的个人页面 - 开源中国社区
Fragment+viewpager+TabPageIndicator实现Tab效果
package com.zhy.csdndemo;
import com.viewpagerindicator.TabPageIndicator;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
public class MainActivity extends FragmentActivity
{
private TabPageIndicator mIndicator ;
private ViewPager mViewPager ;
private FragmentPagerAdapter mAdapter ;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mIndicator = (TabPageIndicator) findViewById(R.id.id_indicator);
mViewPager = (ViewPager) findViewById(R.id.id_pager);
mAdapter = new TabAdapter(getSupportFragmentManager());
mViewPager.setAdapter(mAdapter);
mIndicator.setViewPager(mViewPager, 0);
}
}
详细实现参见链接
Android 使用Fragment,ViewPagerIndicator 制作csdn app主要框架 - Hongyang - 博客频道 - CSDN.NET
viewPager的适配器
package com.zhy.csdndemo;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
public class TabAdapter extends FragmentPagerAdapter
{
public static final String[] TITLES = new String[] { "业界", "移动", "研发", "程序员杂志", "云计算" };
public TabAdapter(FragmentManager fm)
{
super(fm);
}
@Override
public Fragment getItem(int arg0)
{
MainFragment fragment = new MainFragment(arg0+1);
return fragment;
}
@Override
public CharSequence getPageTitle(int position)
{
return TITLES[position % TITLES.length];
}
@Override
public int getCount()
{
return TITLES.length;
}
}
viewPager中的Fragment实现,其中用xListView实现了获取数据与刷新等功能
package com.zhy.csdndemo;
import java.util.ArrayList;
import java.util.List;
import me.maxwin.view.IXListViewLoadMore;
import me.maxwin.view.IXListViewRefreshListener;
import me.maxwin.view.XListView;
import android.annotation.SuppressLint;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.zhy.bean.CommonException;
import com.zhy.bean.NewsItem;
import com.zhy.biz.NewsItemBiz;
import com.zhy.csdn.Constaint;
import com.zhy.csdndemo.adapter.NewsItemAdapter;
@SuppressLint("ValidFragment")
public class MainFragment extends Fragment implements IXListViewRefreshListener, IXListViewLoadMore
{
/**
* 默认的newType
*/
private int newsType = Constaint.NEWS_TYPE_YEJIE;
/**
* 当前页面
*/
private int currentPage = 1;
/**
* 处理新闻的业务类
*/
private NewsItemBiz mNewsItemBiz;
/**
* 扩展的ListView
*/
private XListView mXListView;
/**
* 数据适配器
*/
private NewsItemAdapter mAdapter;
/**
* 数据
*/
private List<NewsItem> mDatas = new ArrayList<NewsItem>();
/**
* 获得newType
* @param newsType
*/
public MainFragment(int newsType)
{
this.newsType = newsType;
mNewsItemBiz = new NewsItemBiz();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
return inflater.inflate(R.layout.tab_item_fragment_main, null);
}
@Override
public void onActivityCreated(Bundle savedInstanceState)
{
super.onActivityCreated(savedInstanceState);
mAdapter = new NewsItemAdapter(getActivity(), mDatas);
/**
* 初始化
*/
mXListView = (XListView) getView().findViewById(R.id.id_xlistView);
mXListView.setAdapter(mAdapter);
mXListView.setPullRefreshEnable(this);
mXListView.setPullLoadEnable(this);
//mXListView.NotRefreshAtBegin();
/**
* 进来时直接刷新
*/
mXListView.startRefresh();
}
@Override
public void onRefresh()
{
new LoadDatasTask().execute();
}
@Override
public void onLoadMore()
{
// TODO Auto-generated method stub
}
/**
* 记载数据的异步任务
* @author zhy
*
*/
class LoadDatasTask extends AsyncTask<Void, Void, Void>
{
@Override
protected Void doInBackground(Void... params)
{
try
{
List<NewsItem> newsItems = mNewsItemBiz.getNewsItems(newsType, currentPage);
mDatas = newsItems;
} catch (CommonException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result)
{
mAdapter.addAll(mDatas);
mAdapter.notifyDataSetChanged();
mXListView.stopRefresh();
}
}
}
xListView的adapter,其中使用了imageLoder
package com.zhy.csdndemo.adapter;
import java.util.List;
import android.content.Context;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
import com.nostra13.universalimageloader.core.display.FadeInBitmapDisplayer;
import com.nostra13.universalimageloader.core.display.RoundedBitmapDisplayer;
import com.zhy.bean.NewsItem;
import com.zhy.csdn.DataUtil;
import com.zhy.csdndemo.R;
public class NewsItemAdapter extends BaseAdapter
{
private LayoutInflater mInflater;
private List<NewsItem> mDatas;
/**
* 使用了github开源的ImageLoad进行了数据加载
*/
private ImageLoader imageLoader = ImageLoader.getInstance();
private DisplayImageOptions options;
public NewsItemAdapter(Context context, List<NewsItem> datas)
{
this.mDatas = datas;
mInflater = LayoutInflater.from(context);
imageLoader.init(ImageLoaderConfiguration.createDefault(context));
options = new DisplayImageOptions.Builder().showStubImage(R.drawable.images)
.showImageForEmptyUri(R.drawable.images).showImageOnFail(R.drawable.images).cacheInMemory()
.cacheOnDisc().displayer(new RoundedBitmapDisplayer(20)).displayer(new FadeInBitmapDisplayer(300))
.build();
}
public void addAll(List<NewsItem> mDatas)
{
this.mDatas.addAll(mDatas);
}
@Override
public int getCount()
{
return mDatas.size();
}
@Override
public Object getItem(int position)
{
return mDatas.get(position);
}
@Override
public long getItemId(int position)
{
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent)
{
ViewHolder holder = null;
if (convertView == null)
{
convertView = mInflater.inflate(R.layout.news_item_yidong, null);
holder = new ViewHolder();
holder.mContent = (TextView) convertView.findViewById(R.id.id_content);
holder.mTitle = (TextView) convertView.findViewById(R.id.id_title);
holder.mDate = (TextView) convertView.findViewById(R.id.id_date);
holder.mImg = (ImageView) convertView.findViewById(R.id.id_newsImg);
convertView.setTag(holder);
} else
{
holder = (ViewHolder) convertView.getTag();
}
NewsItem newsItem = mDatas.get(position);
holder.mTitle.setText(DataUtil.ToDBC(newsItem.getTitle()));
holder.mContent.setText(newsItem.getContent());
holder.mDate.setText(newsItem.getDate());
if (newsItem.getImgLink() != null)
{
holder.mImg.setVisibility(View.VISIBLE);
imageLoader.displayImage(newsItem.getImgLink(), holder.mImg, options);
} else
{
holder.mImg.setVisibility(View.GONE);
}
return convertView;
}
private final class ViewHolder
{
TextView mTitle;
TextView mContent;
ImageView mImg;
TextView mDate;
}
}
参考链接:
客户端上显示csdn上的各类别下的的文章列表 (制作csdn app 三) - Hongyang - 博客频道 - CSDN.NET