Android应用开发之获取网络数据

J2SE实现网络图片的获取

public static void main(String[] args) throws Exception {
String path = "http://res.img.ifeng.com/2011/1219/xes_bb10a1495fa8e7f76415023d177585d0.jpg";

URL url = new URL(path);

HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setConnectTimeout(5*1000);
InputStream inStream = conn.getInputStream();

ByteArrayOutputStream outStream = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];

int len=0;
while((len=inStream.read(buffer))!=-1){
outStream.write(buffer,0,len);
}

byte[] data = outStream.toByteArray();

File f = new File("pic.jpg");
FileOutputStream fos = new FileOutputStream(f);
fos.write(data);
fos.close();
}

Androd中获取网络图片

<string name="btn_text">显示网络图片</string>
<string name="error">下载图片失败！！</string>

<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/btn_text"
android:id="@+id/showBtn"
/>

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView"
/>

package cn.class3g.service;
…
public class ImageService {
public static byte[] getImage(String path) throws Exception{
URL url = new URL(path);
//get //post
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
conn.setRequestMethod("GET");
conn.setConnectTimeout(5*1000);
InputStream inStream = conn.getInputStream();

ByteArrayOutputStream outStream = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len = 0;
while( (len = inStream.read(buffer)) !=-1 ){
outStream.write(buffer, 0, len);
}
byte[] data = outStream.toByteArray();//图片的二进制数据
outStream.close();
inStream.close();
return data;
}
}

public void onClick(View v) {
String path = "http://res.img.ifeng.com/2011/1221/xes_5a3a1d15ffb4b856a02237cdd79d4e41.jpg";

try {
byte[] data = ImageService.getImage(path);

Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
imgView.setImageBitmap(bitmap);

} catch (Exception e) {
//         e.printStackTrace();
Log.e("TAG", e.toString());
Toast.makeText(this, R.string.error, 1).show();
}
}

 <Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/btn_text"
android:id="@+id/showBtn"
/>

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView"
/>

public class HtmlService {
/**
* 获取给定路径的html代码
* @param path 网页路径
* @return
* @throws Exception
*/
public static String getHtml(String path) throws Exception{
URL url = new URL(path);
//get //post
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
conn.setRequestMethod("GET");
conn.setConnectTimeout(5*1000);
InputStream inStream = conn.getInputStream();

ByteArrayOutputStream outStream = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len = 0;
while( (len = inStream.read(buffer)) !=-1 ){
outStream.write(buffer, 0, len);
}
byte[] data = outStream.toByteArray();//网页的二进制数据
outStream.close();
inStream.close();
return new String(data, "gb2312");
}
}

public void onClick(View v) {
String path = pathText.getText().toString();
try {
String htmlcode = HtmlService.getHtml(path);
resultView.setText(htmlcode);
} catch (Exception e) {
Log.e(TAG, e.toString());
Toast.makeText(ShowHtmlActivity.this, R.string.error, 1).show();
}
}