我正在开发一个应用程序，该应用程序需要从链接中获取网页的源代码，然后解析该页面中的 html。
你能给我一些例子，或者从哪里开始编写这样的应用程序？
【问题讨论】：
标签： html android android-emulator
您可以使用HttpClient 执行 HTTP GET 并检索 HTML 响应，如下所示：
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();
【讨论】：
new URI("http://www.google.com/")。除了“android.permission.INTERNET”之外还需要其他权限吗？
String html = EntityUtils.toString(response.getEntity());
这个问题有点老了，但我想我应该发布我的答案，因为 DefaultHttpClient、HttpGet 等已被弃用。这个函数应该获取并返回 HTML，给定一个 URL。
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();
}
【讨论】：
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) {
}
}
【讨论】：
这样称呼
new RetrieveFeedTask(new OnTaskFinished()
{
@Override
public void onFeedRetrieved(String feeds)
{
//do whatever you want to do with the feeds
}
}).execute("http://enterurlhere.com");
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);
}
}
OnTaskFinished.java
public interface OnTaskFinished
{
public void onFeedRetrieved(String feeds);
}
【讨论】：
其中一个 SO 帖子回答帮助了我。这不是逐行读取的；假设 html 文件之间有一行 null 。作为 preRequisite 从项目设置中添加此依赖项“com.koushikdutta.ion:ion:2.2.1” 在AsyncTASK 中实现此代码。如果您希望返回的 -something- 在 UI 线程中，请将其传递给相互接口。
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 } });
【讨论】：
public class DownloadTask extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
String result = "";
URL url;
HttpsURLConnection urlConnection = null;
try {
url = new URL(urls[0]);
urlConnection = (HttpsURLConnection) url.openConnection();
BufferedReader br = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
String inputLine;
while ((inputLine = br.readLine()) != null)
{
// System.out.println(inputLine);
result += inputLine;
}
br.close();
return result;
} catch (Exception e) {
e.printStackTrace();
return "failed";
}
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DownloadTask task = new DownloadTask();
String result = null;
try {
result = task.execute("https://www.example.com").get();
}catch (Exception e){
e.printStackTrace();
}
Log.i("Result", result);
}
【讨论】：