十六、从网络中获取网页数据

从网络中获取网页数据时，网页有可能使用GZIP压缩技术对页面进行压缩，这样就会减小通过网络传输的数据量，提高浏览的速度。因此在获取网络数据时要对其进行判断，对GZIP格式的数据使用GZIPInputStream对其特殊处理，否则在获取数据可能出现乱码哦.

以下为网络中获取网页数据的案例代码

public class InternetTest2 {public static void main(String[] args) throws Exception{String result = "";    //URL url = new URL("http://www.sohu.com");    URL url = new URL("http://www.ku6.com/");        HttpURLConnection conn = (HttpURLConnection) url.openConnection();        conn.setConnectTimeout(6* 1000);//设置连接超时        if (conn.getResponseCode() != 200) throw new RuntimeException("请求url失败");        InputStream is = conn.getInputStream();//得到网络返回的输入流        if("gzip".equals(conn.getContentEncoding())){            result = new InternetTest2().readDataForZgip(is, "GBK");        }else {            result = new InternetTest2().readData(is, "GBK");        }        conn.disconnect();        System.out.println(result);        System.err.println("ContentEncoding: " + conn.getContentEncoding());}//第一个参数为输入流,第二个参数为字符集编码    public static String readData(InputStream inStream, String charsetName) throws Exception{        ByteArrayOutputStream outStream = new ByteArrayOutputStream();        byte[] buffer = new byte[1024];        int len = -1;        while( (len = inStream.read(buffer)) != -1 ){            outStream.write(buffer, 0, len);        }        byte[] data = outStream.toByteArray();        outStream.close();        inStream.close();        return new String(data, charsetName);    }        //第一个参数为输入流,第二个参数为字符集编码    public static String readDataForZgip(InputStream inStream, String charsetName) throws Exception{        GZIPInputStream gzipStream = new GZIPInputStream(inStream);        ByteArrayOutputStream outStream = new ByteArrayOutputStream();        byte[] buffer =new  byte[1024];        int len = -1;        while ((len = gzipStream.read(buffer))!=-1) {            outStream.write(buffer, 0, len);        }        byte[] data = outStream.toByteArray();        outStream.close();        gzipStream.close();        inStream.close();        return new String(data, charsetName);    }}