问题

Sure, here is the translated code:

Your Code:

package com.example.guesstheceleb;

import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Button;
import android.widget.ImageView;

import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.concurrent.ExecutionException;

public class MainActivity extends AppCompatActivity {

    ImageView celebrityImageView;
    Button button0;
    Button button1;
    Button button2;
    Button button3;

    public class DownloadTask extends AsyncTask<String, Void, String> {
        @Override
        protected String doInBackground(String... urls) {
            String result = "";
            URL url;
            HttpURLConnection urlConnection = null;
            try {
                url = new URL(urls[0]);
                urlConnection = (HttpURLConnection)url.openConnection();
                InputStream in = urlConnection.getInputStream();
                InputStreamReader reader = new InputStreamReader(in);
                int data = reader.read();
                while (data != -1) {
                    char current = (char) data;
                    result += current;
                    data = reader.read();
                }
                return result;
            } catch (Exception e) {
                e.printStackTrace();
            }
            return "failed";
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        celebrityImageView = (ImageView) findViewById(R.id.celebrityImageView);
        button0 = (Button) findViewById(R.id.button0);
        button1 = (Button) findViewById(R.id.button1);
        button2 = (Button) findViewById(R.id.button2);
        button3 = (Button) findViewById(R.id.button3);

        DownloadTask taskURL = new DownloadTask();
        String code = "";
        try {
            code = taskURL.execute("http://www.posh24.se/kandisar").get();
        } catch (ExecutionException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        Log.i("prout", code);
    }
}

Teacher's Code:

package com.example.robpercival.guessthecelebrity;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Random;
import java.util.concurrent.ExecutionException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class MainActivity extends Activity {

    ArrayList<String> celebURLs = new ArrayList<String>();
    ArrayList<String> celebNames = new ArrayList<String>();
    int chosenCeleb = 0;
    int locationOfCorrectAnswer = 0;
    String[] answers = new String[4];

    ImageView imageView;
    Button button0;
    Button button1;
    Button button2;
    Button button3;

    public void celebChosen(View view) {
        // Celeb chosen logic
    }

    public class ImageDownloader extends AsyncTask<String, Void, Bitmap> {
        @Override
        protected Bitmap doInBackground(String... urls) {
            // ImageDownloader logic
        }
    }

    public class DownloadTask extends AsyncTask<String, Void, String> {
        @Override
        protected String doInBackground(String... urls) {
            // DownloadTask logic
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        imageView = (ImageView) findViewById(R.id.imageView);
        button0 = (Button) findViewById(R.id.button);
        button1 = (Button) findViewById(R.id.button2);
        button2 = (Button) findViewById(R.id.button3);
        button3 = (Button) findViewById(R.id.button4);

        DownloadTask task = new DownloadTask();
        String result = null;

        try {
            result = task.execute("http://www.posh24.se/kandisar").get();
            // Parsing logic for celebURLs and celebNames
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (ExecutionException e) {
            e.printStackTrace();
        }

        createNewQuestion();
    }

    public void createNewQuestion() {
        // createNewQuestion logic
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // onCreateOptionsMenu logic
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // onOptionsItemSelected logic
    }
}

Please note that the translations might not be 100% accurate, but I've tried to preserve the structure and content of the code as accurately as possible. If you have any specific questions about the translated code or need further assistance, feel free to ask.

英文:

I'm following a course about Android Studio and of my task is to use the DownloadTask class to extract the HTML code of this website http://www.posh24.se/kandisar

But even when I almost copy the code of the teacher, it doesn't work for me (meanwhile, if I download his whole project and launch it, it works perfectly) but for this specific part of extraction it doesn't work and I don't know why...

Note that I indeed wrote the Internet permission in my AndroidManifest.xml file :
<uses-permission android:name="android.permission.INTERNET" />

What I get is "Failed" statement, meaning there was a problem in the DownloadTask but I don't know what !

Here is my java code, where I try to test that I can show the HTML code in the log:


package com.example.guesstheceleb;

import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Button;
import android.widget.ImageView;

import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.concurrent.ExecutionException;

public class MainActivity extends AppCompatActivity {

    ImageView celebrityImageView;
    Button button0;
    Button button1;
    Button button2;
    Button button3;

    public class DownloadTask extends AsyncTask&lt;String, Void, String&gt; {


        @Override
        protected String doInBackground(String... urls) {

            String result = &quot;&quot;;
            URL url;
            HttpURLConnection urlConnection = null;

            try {

                url = new URL(urls[0]);

                urlConnection = (HttpURLConnection)url.openConnection();

                InputStream in = urlConnection.getInputStream();

                InputStreamReader reader = new InputStreamReader(in);

                int data = reader.read();

                while (data != -1) {

                    char current = (char) data;

                    result += current;

                    data = reader.read();
                }

                return result;

            }
            catch (Exception e) {

                e.printStackTrace();

            }

            return &quot;failed&quot;;
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        celebrityImageView = (ImageView) findViewById(R.id.celebrityImageView);
        button0 = (Button) findViewById(R.id.button0);
        button1 = (Button) findViewById(R.id.button1);
        button2 = (Button) findViewById(R.id.button2);
        button3 = (Button) findViewById(R.id.button3);

        DownloadTask taskURL = new DownloadTask();
        String code = &quot;&quot;;
        try {
            code = taskURL.execute(&quot;http://www.posh24.se/kandisar&quot;).get();
        } catch (ExecutionException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        Log.i(&quot;prout&quot;,code);

    }
}

Now here is the code of the teacher. But really what matters is the DownloadTask class and the use of it in the onCreate method, but I'm gonna put it all entirely just in case

package com.example.robpercival.guessthecelebrity;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Random;
import java.util.concurrent.ExecutionException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;


public class MainActivity extends Activity {

    ArrayList&lt;String&gt; celebURLs = new ArrayList&lt;String&gt;();
    ArrayList&lt;String&gt; celebNames = new ArrayList&lt;String&gt;();
    int chosenCeleb = 0;
    int locationOfCorrectAnswer = 0;
    String[] answers = new String[4];

    ImageView imageView;
    Button button0;
    Button button1;
    Button button2;
    Button button3;

    public void celebChosen(View view) {

        if (view.getTag().toString().equals(Integer.toString(locationOfCorrectAnswer))) {

            Toast.makeText(getApplicationContext(), &quot;Correct!&quot;, Toast.LENGTH_LONG).show();

        } else {

            Toast.makeText(getApplicationContext(), &quot;Wrong! It was &quot; + celebNames.get(chosenCeleb), Toast.LENGTH_LONG).show();

        }

        createNewQuestion();

    }

    public class ImageDownloader extends AsyncTask&lt;String, Void, Bitmap&gt; {


        @Override
        protected Bitmap doInBackground(String... urls) {

            try {

                URL url = new URL(urls[0]);

                HttpURLConnection connection = (HttpURLConnection) url.openConnection();

                connection.connect();

                InputStream inputStream = connection.getInputStream();

                Bitmap myBitmap = BitmapFactory.decodeStream(inputStream);

                return myBitmap;


            } catch (MalformedURLException e) {

                e.printStackTrace();

            } catch (IOException e) {

                e.printStackTrace();

            }

            return null;
        }
    }


    public class DownloadTask extends AsyncTask&lt;String, Void, String&gt; {


        @Override
        protected String doInBackground(String... urls) {

            String result = &quot;&quot;;
            URL url;
            HttpURLConnection urlConnection = null;

            try {

                url = new URL(urls[0]);

                urlConnection = (HttpURLConnection)url.openConnection();

                InputStream in = urlConnection.getInputStream();

                InputStreamReader reader = new InputStreamReader(in);

                int data = reader.read();

                while (data != -1) {

                    char current = (char) data;

                    result += current;

                    data = reader.read();
                }

                return result;

            }
            catch (Exception e) {

                e.printStackTrace();

            }

            return null;
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        imageView = (ImageView) findViewById(R.id.imageView);
        button0 = (Button) findViewById(R.id.button);
        button1 = (Button) findViewById(R.id.button2);
        button2 = (Button) findViewById(R.id.button3);
        button3 = (Button) findViewById(R.id.button4);

        DownloadTask task = new DownloadTask();
        String result = null;

        try {

            result = task.execute(&quot;http://www.posh24.se/kandisar&quot;).get();

            String[] splitResult = result.split(&quot;&lt;div class=\&quot;sidebarContainer\&quot;&gt;&quot;);

            Pattern p = Pattern.compile(&quot;&lt;img src=\&quot;(.*?)\&quot;&quot;);
            Matcher m = p.matcher(splitResult[0]);

            while (m.find()) {

                celebURLs.add(m.group(1));

            }

            p = Pattern.compile(&quot;alt=\&quot;(.*?)\&quot;&quot;);
            m = p.matcher(splitResult[0]);

            while (m.find()) {

                celebNames.add(m.group(1));

            }


        } catch (InterruptedException e) {

            e.printStackTrace();

        } catch (ExecutionException e) {

            e.printStackTrace();

        }

        createNewQuestion();

    }

    public void createNewQuestion() {

        Random random = new Random();
        chosenCeleb = random.nextInt(celebURLs.size());

        ImageDownloader imageTask = new ImageDownloader();

        Bitmap celebImage;

        try {

            celebImage = imageTask.execute(celebURLs.get(chosenCeleb)).get();

            imageView.setImageBitmap(celebImage);

            locationOfCorrectAnswer = random.nextInt(4);

            int incorrectAnswerLocation;

            for (int i=0; i&lt;4; i++) {

                if (i == locationOfCorrectAnswer) {

                    answers[i] = celebNames.get(chosenCeleb);

                } else {

                    incorrectAnswerLocation = random.nextInt(celebURLs.size());

                    while (incorrectAnswerLocation == chosenCeleb) {

                        incorrectAnswerLocation = random.nextInt(celebURLs.size());

                    }

                    answers[i] = celebNames.get(incorrectAnswerLocation);


                }


            }

            button0.setText(answers[0]);
            button1.setText(answers[1]);
            button2.setText(answers[2]);
            button3.setText(answers[3]);


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




    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

Thank you for your patience

答案1

得分: 0

我检查了你的代码并找到了问题。如果你想获取 http://www.posh24.se/kandisar 网址的 Html 内容，你应该使用代理。你的代码是正确的，你可以用这个网址进行验证：http://info.cern.ch，然后查看结果。

英文:

I checked your code and find the problem. You should use a proxy if you want to get the Html of http://www.posh24.se/kandisar URL. Your code is correct and you can check it with this URL: http://info.cern.ch and see the result.

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