Android學習（48） -- 獲取xml文件並解析.

1、根據xml的格式創建JavaBean

public class News {

	private String title;
	private String detail;
	private String comment;
	private String imageUrl;
	
	@Override
	public String toString() {
		return "News [title=" + title + ", detail=" + detail + ", comment="
				+ comment + ", imageUrl=" + imageUrl + "]";
	}

	public String getTitle() {
		return title;
	}

	public void setTitle(String title) {
		this.title = title;
	}

	public String getDetail() {
		return detail;
	}

	public void setDetail(String detail) {
		this.detail = detail;
	}

	public String getComment() {
		return comment;
	}

	public void setComment(String comment) {
		this.comment = comment;
	}

	public String getImageUrl() {
		return imageUrl;
	}

	public void setImageUrl(String imageUrl) {
		this.imageUrl = imageUrl;
	}
	
}

2、創建解析xml的方法

       由於結點很多，需要創建一個List來進行存儲，在開始結點的時候初始化List、並拼裝對象

當一個對象結束後，也就是在結束結點的時候，將對象添加到List中去

     解析完一個對象結點後，繼續尋找下一個進行解析 

	List<News> newsList;
	private void parseNewsXml(InputStream is) {
		XmlPullParser xp = Xml.newPullParser();
		try {
			xp.setInput(is, "utf-8");
			//對節點的事件類型進行判斷，就可以知道當前節點是什麼節點
			int type = xp.getEventType();
			News news = null;
			while(type != XmlPullParser.END_DOCUMENT){
				switch (type) {
				case XmlPullParser.START_TAG:
					if("newslist".equals(xp.getName())){
						newsList = new ArrayList<News>();
					}
					else if("news".equals(xp.getName())){
						news = new News();
					}
					else if("title".equals(xp.getName())){
						String title = xp.nextText();
						news.setTitle(title);
					}
					else if("detail".equals(xp.getName())){
						String detail = xp.nextText();
						news.setDetail(detail);
					}
					else if("comment".equals(xp.getName())){
						String comment = xp.nextText();
						news.setComment(comment);
					}
					else if("image".equals(xp.getName())){
						String image = xp.nextText();
						news.setImageUrl(image);
					}
					break;
				case XmlPullParser.END_TAG:
					if("news".equals(xp.getName())){
						newsList.add(news);
					}
					break;

				}
				//解析完當前節點後，把指針移動至下一個節點，並返回它的事件類型
				type = xp.next();
			}
 
//			for (News n : newsList) {
//				System.out.println(n.toString());
//			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

	}

3、獲取網絡上的xml

	private void getNewsInfo() {
		Thread t = new Thread(){
			@Override
			public void run() {
				String path = "http://192.168.1.103:8080/news.xml";
				try {
					URL url = new URL(path);
					HttpURLConnection conn = (HttpURLConnection) url.openConnection();
					conn.setRequestMethod("GET");
					conn.setConnectTimeout(5000);
					conn.setReadTimeout(5000);
					//發送http GET請求，獲取相應碼
					if(conn.getResponseCode() == 200){
						InputStream is = conn.getInputStream();
						//使用pull解析器，解析這個流
						parseNewsXml(is);
					}
				} catch (Exception e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		};
		t.start();
	}

核心完整代碼

public class MainActivity extends Activity {

	List<News> newsList;
	Handler handler = new Handler(){
		public void handleMessage(android.os.Message msg) {
			ListView lv = (ListView) findViewById(R.id.lv);
			lv.setAdapter(new MyAdapter());
		}
	};
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		getNewsInfo();
//		ListView lv = (ListView) findViewById(R.id.lv);
//		//要保證在設置適配器時，新聞xml文件已經解析完畢了
//		lv.setAdapter(new MyAdapter());
	}

	class MyAdapter extends BaseAdapter{

		//得到模型層中元素的數量，用來確定listview需要有多少個條目
		@Override
		public int getCount() {
			// TODO Auto-generated method stub
			return newsList.size();
		}
		@Override
		//返回一個View對象，作爲listview的條目顯示至界面
		public View getView(int position, View convertView, ViewGroup parent) {

			News news = newsList.get(position);
			View v = null;
			ViewHolder mHolder;
			if(convertView == null){
				v = View.inflate(MainActivity.this, R.layout.item_listview, null);
				mHolder = new ViewHolder();
				//把佈局文件中所有組件的對象封裝至ViewHolder對象中
				mHolder.tv_title = (TextView) v.findViewById(R.id.tv_title);
				mHolder.tv_detail = (TextView) v.findViewById(R.id.tv_detail);
				mHolder.tv_comment = (TextView) v.findViewById(R.id.tv_comment);
				mHolder.siv = (SmartImageView) v.findViewById(R.id.iv);
				//把ViewHolder對象封裝至View對象中
				v.setTag(mHolder);
			}
			else{
				v = convertView;
				mHolder = (ViewHolder) v.getTag();
			}
			//給三個文本框設置內容
			mHolder.tv_title.setText(news.getTitle());
			
			mHolder.tv_detail.setText(news.getDetail());
			
			mHolder.tv_comment.setText(news.getComment() + "條評論");
			
			//給新聞圖片imageview設置內容
			mHolder.siv.setImageUrl(news.getImageUrl());
			return v;
		}
		
		class ViewHolder{
			//條目的佈局文件中有什麼組件，這裏就定義什麼屬性
			TextView tv_title;
			TextView tv_detail;
			TextView tv_comment;
			SmartImageView siv;
		}
		
		@Override
		public Object getItem(int position) {
			return null;
		}

		@Override
		public long getItemId(int position) {
			return 0;
		}
	}
	private void getNewsInfo() {
		Thread t = new Thread(){
			@Override
			public void run() {
				String path = "http://192.168.13.13:8080/news.xml";
				try {
					URL url = new URL(path);
					HttpURLConnection conn = (HttpURLConnection) url.openConnection();
					conn.setRequestMethod("GET");
					conn.setConnectTimeout(5000);
					conn.setReadTimeout(5000);
					//發送http GET請求，獲取相應碼
					if(conn.getResponseCode() == 200){
						InputStream is = conn.getInputStream();
						//使用pull解析器，解析這個流
						parseNewsXml(is);
					}
				} catch (Exception e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		};
		t.start();
	}
	
	List<News> newsList;
	private void parseNewsXml(InputStream is) {
		XmlPullParser xp = Xml.newPullParser();
		try {
			xp.setInput(is, "utf-8");
			//對節點的事件類型進行判斷，就可以知道當前節點是什麼節點
			int type = xp.getEventType();
			News news = null;
			while(type != XmlPullParser.END_DOCUMENT){
				switch (type) {
				case XmlPullParser.START_TAG:
					if("newslist".equals(xp.getName())){
						newsList = new ArrayList<News>();
					}
					else if("news".equals(xp.getName())){
						news = new News();
					}
					else if("title".equals(xp.getName())){
						String title = xp.nextText();
						news.setTitle(title);
					}
					else if("detail".equals(xp.getName())){
						String detail = xp.nextText();
						news.setDetail(detail);
					}
					else if("comment".equals(xp.getName())){
						String comment = xp.nextText();
						news.setComment(comment);
					}
					else if("image".equals(xp.getName())){
						String image = xp.nextText();
						news.setImageUrl(image);
					}
					break;
				case XmlPullParser.END_TAG:
					if("news".equals(xp.getName())){
						newsList.add(news);
					}
					break;

				}
				//解析完當前節點後，把指針移動至下一個節點，並返回它的事件類型
				type = xp.next();
			}
			
			//發消息，讓主線程設置listview的適配器，如果消息不需要攜帶數據，可以發送空消息
			handler.sendEmptyMessage(1);
			
//			for (News n : newsList) {
//				System.out.println(n.toString());
//			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

	}

}