1>从网络上获取数据（图片，网页，xml,json等）
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A.从网络上获取一张图片，然后显示到手机上
这是在java中
public class ImageRequest {
?/**
? * @param args
? */
?public static void main(String[] args) throws Exception {
??URL url = new URL("http://i3.itc.cn/20100707/76c_0969b700_d5b4_41cd_8243_9b486be92cc4_0.jpg");
??HttpURLConnection conn = (HttpURLConnection)url.openConnection();
??conn.setRequestMethod("GET");
??conn.setConnectTimeout(5 * 1000);
??InputStream inStream = conn.getInputStream();//通过输入流获取图片数据
??byte[] data = readInputStream(inStream);//得到图片的二进制数据
??File imageFile = new File("itcast.jpg");//保存在项目下
??FileOutputStream outStream = new FileOutputStream(imageFile);
??outStream.write(data);
??outStream.close();
?}
?public static byte[] readInputStream(InputStream inStream) throws Exception{
??ByteArrayOutputStream outStream = new ByteArrayOutputStream();
??byte[] buffer = new byte[1024];//定义一个1k的缓冲区
??int len = 0;
??while( (len=inStream.read(buffer)) != -1 ){//返回的是实际的字节数
???outStream.write(buffer, 0, len);//将缓冲区的数据写入到内存中
??}
??inStream.close();
??return outStream.toByteArray();
?}
}
在手机上
?button.setOnClickListener(new View.OnClickListener() {
???@Override
???public void onClick(View v) {
????String path = pathText.getText().toString();
????try {
?????byte[] data = ImageService.getImage(path);
?????Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);//生成位图
?????imageView.setImageBitmap(bitmap);//显示图片?????
????} catch (Exception e) {
?????Toast.makeText(ImageShowActivity.this, R.string.error, 1).show();
?????Log.e(TAG, e.toString());
????}
???}});
<!-- 访问网络的权限 -->
<uses-permission android:name="android.permission.INTERNET"/>
public class StreamTool {
?/**
? * 从输入流中获取数据
? * @param inStream 输入流
? * @return
? * @throws Exception
? */
?public static byte[] readInputStream(InputStream inStream) throws Exception{
??ByteArrayOutputStream outStream = new ByteArrayOutputStream();
??byte[] buffer = new byte[1024];
??int len = 0;
??while( (len=inStream.read(buffer)) != -1 ){
???outStream.write(buffer, 0, len);
??}
??inStream.close();
??return outStream.toByteArray();
?}
}
-----------------------------------------------------------------------------------------------------
public class ImageService {
?
?public static byte[] getImage(String path) throws Exception {
??URL url = new URL("http://i3.itc.cn/20100707/76c_0969b700_d5b4_41cd_8243_9b486be92cc4_0.jpg");
??HttpURLConnection conn = (HttpURLConnection)url.openConnection();
??conn.setRequestMethod("GET");
??conn.setConnectTimeout(5 * 1000);
??InputStream inStream = conn.getInputStream();//通过输入流获取图片数据
??return StreamTool.readInputStream(inStream);//得到图片的二进制数据
?}
}
B.从网络上获取网页(用的比较少)
byte[] data = readInputStream(inStream);//得到网页的二进制数据
String html = new String(data,"gb2312");
C.从网络上获取xml数据，然后显示在手机上
?android手机模拟器本身绑定在模拟器上，所以访问web service的时候不能用local host
?或者用127.0.0.1。而应该使用局域网上的ip地址。
public class VideoService {
?/**
? * 获取最新的视频资讯
? * @return
? * @throws Exception
? */
?public static List<Video> getLastVideos() throws Exception{
??String path = "http://192.168.1.100:8080/videoweb/video/list.do";
??URL url = new URL(path);
??HttpURLConnection conn = (HttpURLConnection)url.openConnection();
??conn.setReadTimeout(5*1000);
??conn.setRequestMethod("GET");
??InputStream inStream = conn.getInputStream();
??return parseXML(inStream);
?}
/**
? * 解析服务器返回的协议，得到视频资讯
? * @param inStream
? * @return
? * @throws Exception
? */
?private static List<Video> parseXML(InputStream inStream) throws Exception{
??List<Video> videos = null;
??Video video = null;
??XmlPullParser parser = Xml.newPullParser();
??parser.setInput(inStream, "UTF-8");
??int eventType = parser.getEventType();//产生第一个事件
??while(eventType!=XmlPullParser.END_DOCUMENT){//只要不是文档结束事件
???switch (eventType) {
???case XmlPullParser.START_DOCUMENT:
????videos = new ArrayList<Video>();
????break;
?
???case XmlPullParser.START_TAG:
????String name = parser.getName();//获取解析器当前指向的元素的名称
????if("video".equals(name)){
?????video = new Video();
?????video.setId(new Integer(parser.getAttributeValue(0)));
????}
????if(video!=null){
?????if("title".equals(name)){
??????video.setTitle(parser.nextText());//获取解析器当前指向元素的下一个文本节点的值
?????}
?????if("timelength".equals(name)){
??????video.setTime(new Integer(parser.nextText()));
?????}
????}
????break;
????
???case XmlPullParser.END_TAG:
????if("video".equals(parser.getName())){
?????videos.add(video);
?????video = null;
????}
????break;
???}
???eventType = parser.next();
??}
??return videos;
?}
}
D.从网络上获取json数据，然后显示在手机上
public class VideoService {
?/**
? * 获取最新的视频资讯
? * @return
? * @throws Exception
? */
?
?public static List<Video> getJSONLastVideos() throws Exception{
??List<Video> videos = new ArrayList<Video>();
??String path = "http://192.168.1.100:8080/videoweb/video/list.do?format=json";
??URL url = new URL(path);
??HttpURLConnection conn = (HttpURLConnection)url.openConnection();
??conn.setReadTimeout(5*1000);
??conn.setRequestMethod("GET");
??InputStream inStream = conn.getInputStream();
??byte[] data = StreamTool.readInputStream(inStream);
??String json = new String(data);
??JSONArray array = new JSONArray(json);
??for(int i=0 ; i < array.length() ; i++){
???JSONObject item = array.getJSONObject(i);
???int id = item.getInt("id");
???String title = item.getString("title");
???int timelength = item.getInt("timelength");
???videos.add(new Video(id, title, timelength));
??}
??return videos;
?}
?
}