爬网入门：JAVA抓取网站网页内容

最近在用JAVA研究下爬网技术,呵呵，入了个门,把自己的心得和大家分享下
以下提供二种方法，一种是用apache提供的包．另一种是用JAVA自带的.
代码如下:


// 第一种方法
//这种方法是用apache提供的包,简单方便
//但是要用到以下包:commons-codec-1.4.jar
//    commons-httpclient-3.1.jar
//    commons-logging-1.0.4.jar


    public static String createhttpClient(String url, String param) {
        HttpClient client = new HttpClient();
        String response = null;
        String keyword = null;
        PostMethod postMethod = new PostMethod(url);

 
//        try {
//            if (param != null)
//                keyword = new String(param.getBytes("gb2312"), "ISO-8859-1");
//        } catch (UnsupportedEncodingException e1) {
//            // TODO Auto-generated catch block
//            e1.printStackTrace();
//        }

        // NameValuePair[] data = { new NameValuePair("keyword", keyword) };
        // // 将表单的值放入postMethod中
        // postMethod.setRequestBody(data);
        //    以上部分是带参数抓取,我自己把它注销了．大家可以把注销消掉研究下         

        try {
            int statusCode = client.executeMethod(postMethod);
            response = new String(postMethod.getResponseBodyAsString()
                    .getBytes("ISO-8859-1"), "gb2312");//这里要注意下 gb2312要和你抓取网页的编码要一样
          
            String p = response.replaceAll("\\&[a-zA-Z]{1,10};", "")
                    .replaceAll("<[^>]*>", "");//去掉网页中带有html语言的标签
            System.out.println(p);
        } catch (Exception e) {

            e.printStackTrace();
        }
        return response;

    }

    // 第二种方法
    // 这种方法是JAVA自带的URL来抓取网站内容


    public String getPageContent(String strUrl, String strPostRequest,
            int maxLength) {
        // 读取结果网页
        StringBuffer buffer = new StringBuffer();
        System.setProperty("sun.net.client.defaultConnectTimeout", "5000");
        System.setProperty("sun.net.client.defaultReadTimeout", "5000");
        try {
            URL newUrl = new URL(strUrl);
            HttpURLConnection hConnect = (HttpURLConnection) newUrl
                    .openConnection();
            // POST方式的额外数据
            if (strPostRequest.length() > 0) {
                hConnect.setDoOutput(true);
                OutputStreamWriter out = new OutputStreamWriter(hConnect
                        .getOutputStream());
                out.write(strPostRequest);
                out.flush();
                out.close();
            }
            // 读取内容
          
            BufferedReader rd = new BufferedReader(new InputStreamReader(
                    hConnect.getInputStream()));
            int ch;
            for (int length = 0; (ch = rd.read()) > -1
                    && (maxLength <= 0 || length < maxLength); length++)
                buffer.append((char) ch);
            String s = buffer.toString();
            s.replaceAll("\\&[a-zA-Z]{1,10};", "").replaceAll("<[^>]*>", "");
            System.out.println(s);
          
            rd.close();
            hConnect.disconnect();
            return buffer.toString().trim();
        } catch (Exception e) {
            // return "错误:读取网页失败！";
            //
            return null;

            
        }
    }

然后写个测试类:


public static void main(String[] args) {

        String url = "http://www.liuzm.com";
        String keyword = "刘志猛博客";
        createhttpClient p = new createhttpClient();
        String response = p.createhttpClient(url, keyword); // 第一种方法
        // p.getPageContent(url, "post", 100500);//第二种方法
    }

呵呵，看看控制台吧,是不是把网页的内容获取了

http://blog.csdn.net/fzhlee/archive/2011/03/30/6288654.aspx