我正在开发一个应用程序,需要从链接获取网页的源代码,然后解析该页面的 html。

您能给我一些例子,或者从哪里开始编写这样的应用程序吗?

有帮助吗?

解决方案

可以使用 HttpClient的执行HTTP GET和检索HTML响应,是这样的:

HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet(url);
HttpResponse response = client.execute(request);

String html = "";
InputStream in = response.getEntity().getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
StringBuilder str = new StringBuilder();
String line = null;
while((line = reader.readLine()) != null)
{
    str.append(line);
}
in.close();
html = str.toString();

其他提示

我会建议 .

根据他们的网站:

获取维基百科主页,将其解析为 DOM,然后从新闻部分中选择标题到元素列表中(在线示例):

Document doc = Jsoup.connect("http://en.wikipedia.org/").get();
Elements newsHeadlines = doc.select("#mp-itn b a");

入门:

  1. 下载 jsoup jar 核心库
  2. 阅读 食谱 介绍

这个问题是有点老了,但我想我应该张贴我的答案,现在DefaultHttpClientHttpGet等已被弃用。这个函数应该给出一个URL获得并返回HTML。

public static String getHtml(String url) throws IOException {
    // Build and set timeout values for the request.
    URLConnection connection = (new URL(url)).openConnection();
    connection.setConnectTimeout(5000);
    connection.setReadTimeout(5000);
    connection.connect();

    // Read and store the result line by line then return the entire string.
    InputStream in = connection.getInputStream();
    BufferedReader reader = new BufferedReader(new InputStreamReader(in));
    StringBuilder html = new StringBuilder();
    for (String line; (line = reader.readLine()) != null; ) {
        html.append(line);
    }
    in.close();

    return html.toString();
}
public class RetrieveSiteData extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
    StringBuilder builder = new StringBuilder(100000);

    for (String url : urls) {
        DefaultHttpClient client = new DefaultHttpClient();
        HttpGet httpGet = new HttpGet(url);
        try {
            HttpResponse execute = client.execute(httpGet);
            InputStream content = execute.getEntity().getContent();

            BufferedReader buffer = new BufferedReader(new InputStreamReader(content));
            String s = "";
            while ((s = buffer.readLine()) != null) {
                builder.append(s);
            }

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    return builder.toString();
}

@Override
protected void onPostExecute(String result) {

}
}

如果你看一下 这里 或者 这里, ,你会发现你不能直接使用 android API 来做到这一点,你需要一个外部库......

如果您需要外部库,您可以在上面的两个之间进行选择。

这样称呼它

new RetrieveFeedTask(new OnTaskFinished()
        {
            @Override
            public void onFeedRetrieved(String feeds)
            {
                //do whatever you want to do with the feeds
            }
        }).execute("http://enterurlhere.com");

<强> RetrieveFeedTask.class

class RetrieveFeedTask extends AsyncTask<String, Void, String>
{
    String HTML_response= "";

    OnTaskFinished onOurTaskFinished;


    public RetrieveFeedTask(OnTaskFinished onTaskFinished)
    {
        onOurTaskFinished = onTaskFinished;
    }
    @Override
    protected void onPreExecute()
    {
        super.onPreExecute();
    }

    @Override
    protected String doInBackground(String... urls)
    {
        try
        {
            URL url = new URL(urls[0]); // enter your url here which to download

            URLConnection conn = url.openConnection();

            // open the stream and put it into BufferedReader
            BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));

            String inputLine;

            while ((inputLine = br.readLine()) != null)
            {
                // System.out.println(inputLine);
                HTML_response += inputLine;
            }
            br.close();

            System.out.println("Done");

        }
        catch (MalformedURLException e)
        {
            e.printStackTrace();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        return HTML_response;
    }

    @Override
    protected void onPostExecute(String feed)
    {
        onOurTaskFinished.onFeedRetrieved(feed);
    }
}

<强> OnTaskFinished.java

public interface OnTaskFinished
{
    public void onFeedRetrieved(String feeds);
}

一个其他的的 SO 的答案后帮我。这不逐行读取; supposingly html文件有一个行在两者之间。作为前提条件添加从项目设置的此扶养 “com.koushikdutta.ion:离子:2.2.1”实施的的AsyncTask 的验证码。如果你想返回的 -something - 的是在UI线程,它传递给交互界面

Ion.with(getApplicationContext()).
load("https://google.com/hashbrowns")
.asString()
.setCallback(new FutureCallback<String>()
 {
        @Override
        public void onCompleted(Exception e, String result) {
            //int s = result.lastIndexOf("user_id")+9;
            // String st = result.substring(s,s+5);
           // Log.e("USERID",st); //something

        }
    });
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