第三十六天 網絡連接、單線程、多線程下載

網絡連接:MyNetwork

佈局：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/textview"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="10dp"/>
    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="網絡連接"/>
    <ProgressBar
        style="?android:attr/progressBarStyleHorizontal"
        android:layout_width="match_parent"
        android:layout_height="20dp"
        android:id="@+id/progressbar"/>
    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <WebView
            android:id="@+id/webview"
            android:layout_width="match_parent"
            android:layout_height="match_parent">
        </WebView>
        <TextView
            android:id="@+id/textview_erro"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:gravity="center"/>
    </FrameLayout>
</LinearLayout>

權限：

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>
<uses-permission android:name="android.permission.INTERNET"></uses-permission>

MainActivity

public class MainActivity extends Activity implements View.OnClickListener{
    private Button mButton;
    private TextView mTextView;
    private ConnectivityManager mManager;
    private WebView mWebView;//網頁
    private TextView mTextViewErro;//顯示網頁錯誤
    private ProgressBar mProgressBar;//網頁加載進度條
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mButton= (Button) findViewById(R.id.button);
        mTextView= (TextView) findViewById(R.id.textview);
        mWebView= (WebView) findViewById(R.id.webview);
        mTextViewErro= (TextView) findViewById(R.id.textview_erro);
        mProgressBar= (ProgressBar) findViewById(R.id.progressbar);
        mButton.setOnClickListener(this);
        mTextView.setOnClickListener(this);
        mManager= (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        mWebView.setWebViewClient(new WebViewClient());
        mWebView.getSettings().setJavaScriptEnabled(true);
        mWebView.setWebChromeClient(new WebChromeClient(){
            @Override
            public void onProgressChanged(WebView view, int newProgress) {
                super.onProgressChanged(view, newProgress);
                mProgressBar.setProgress(newProgress);//設置進度條
            }
        });

        mWebView.setWebViewClient(new WebViewClient(){

        //開始加載網頁
            @Override
            public void onPageStarted(WebView view, String url, Bitmap favicon) {
                super.onPageStarted(view, url, favicon);
                mProgressBar.setVisibility(View.VISIBLE);//顯示進度條
            }

        //網頁加載完成
            @Override
            public void onPageFinished(WebView view, String url) {
                super.onPageFinished(view, url);
                mProgressBar.setVisibility(View.INVISIBLE);//不顯示進度條
            }

            @Override
            public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
                super.onReceivedError(view, errorCode, description, failingUrl);
                mWebView.setVisibility(View.GONE);
                Toast.makeText(getApplicationContext(),"網頁錯誤",Toast.LENGTH_LONG).show();
                mTextViewErro.setText("加載失敗");//設置textview文本內容
                mTextViewErro.setVisibility(View.VISIBLE);//設置Textview可見
            }
        });
    }

    //返回上一頁面，而不會直接退出程序
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if(keyCode==KeyEvent.KEYCODE_BACK){
            if(mWebView.canGoBack()){
                mWebView.goBack();
                return true;
            }
        }else {
            MainActivity.this.finish();
        }
        return super.onKeyDown(keyCode, event);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.button:
               // mWebView.loadUrl("ht2113tp://www.b24533355aidu.com");
                mWebView.loadUrl("http://www.baidu.com");
//                NetworkInfo info=mManager.getActiveNetworkInfo();
//                if(info!=null&&info.isConnected()){
//                    Toast.makeText(getApplicationContext(),"有網絡連接",Toast.LENGTH_LONG).show();
//                    mTextView.setText("網絡連接爲："+info.getTypeName());
//                }else {
//                    Toast.makeText(getApplicationContext(),"無網絡連接",Toast.LENGTH_LONG).show();
//                    mTextView.setText("無網絡連接");
//                }
                break;
            default:
                break;
        }
    }
}

顯示網頁：

正在加載時顯示進度條：

加載完成後不顯示進度條：

Webview：(網址錯誤時)

單線程、多線程下載

多線程下載圖示：

NetworkDemo:

IndexActivity:(通過IndexActivity直接啓動其他界面)
權限:

 <uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"></uses-permission>

public class IndexActivity extends Activity implements View.OnClickListener {
    private Button mButtonHttp;
    private Button mButtonDownLoad;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_index);
        mButtonHttp= (Button) findViewById(R.id.button_http);
        mButtonDownLoad= (Button) findViewById(R.id.button_download);
        mButtonHttp.setOnClickListener(this);
        mButtonDownLoad.setOnClickListener(this);
    }
    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.button_download:
                Intent intent=new Intent(IndexActivity.this,DownloadActivity.class);
                startActivity(intent);//啓動線程下載界面
                break;
            case R.id.button_http:
                Intent intent2=new Intent(IndexActivity.this,MainActivity.class);
                startActivity(intent2);//啓動URL連接界面
                break;
        }
    }
}

MainActivity：（URL連接界面）

public class MainActivity extends Activity implements View.OnClickListener{
    private Button mButton;
    private TextView mTextView;
    public static final int URL_CONTENT=0X23;
    private Handler handler=new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            switch (msg.what){
                case URL_CONTENT:
                    String content= (String) msg.obj;
                    mTextView.setText(content);
                    break;
            }
        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mButton= (Button) findViewById(R.id.button);
        mTextView= (TextView) findViewById(R.id.textview);
        mButton.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.button:
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        urlConnection();
                    }
                }).start();
                break;
            default:
                break;
        }
    }
    public void urlConnection(){
        try {
            //URL url=new URL("http://www.360.com");
            URL url=new URL("http://192.168.0.85:8080/JavaEE");
            URLConnection connection=url.openConnection();
            InputStream is=connection.getInputStream();
            BufferedReader br=new BufferedReader(new InputStreamReader(is));
            String line=br.readLine();
            StringBuffer buffer=new StringBuffer();
            while(line!=null){
                Log.d("line",line);
                buffer.append(line);
                line=br.readLine();
            }
            Message message=handler.obtainMessage();
            message.what=URL_CONTENT;
            message.obj=buffer.toString().trim();
            handler.sendMessage(message);
            is.close();
            br.close();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

URL url=new URL(“http://www.360.com“)

URL url=new URL(“http://192.168.0.85:8080/JavaEE“)

DownLoadActivity:

public class DownloadActivity extends Activity implements View.OnClickListener{
    private Button mButtonSingle;
    private ProgressBar mProgressBar;
    private Button mButtonMore;
    private static final int MESSAGE_THREAD=0X23;
    private int length;

     //多線程下載，用handler實現
    private Handler handler=new Handler(){
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what){
                case MESSAGE_THREAD:
                    mProgressBar.setProgress (msg.arg1*100/length);//設置多線程下載進度條
                    break;
            }

        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_download);
        mButtonSingle= (Button) findViewById(R.id.button_single);
        mProgressBar= (ProgressBar) findViewById(R.id.progressbar);
        mButtonMore= (Button) findViewById(R.id.button_more);
        mButtonSingle.setOnClickListener(this);
        mButtonMore.setOnClickListener(this);
    }

    //AsynTask實現單線程下載
    class MyTask extends AsyncTask<String,Integer,String>{
        @Override
        protected String doInBackground(String... strings) {
            try {
                URL url=new URL("http://192.168.0.85:8080/JavaEE/photo/view.png");
                URLConnection connection=url.openConnection();
                length=connection.getContentLength();
                InputStream is=connection.getInputStream();
                File file=new File(Environment.getExternalStorageDirectory(),"view.png");
                if(!file.exists()){
                    file.createNewFile();
                }
                FileOutputStream os=new FileOutputStream(file);
                byte[] array=new byte[1024];
                int sum=0;
                int i=is.read(array);
                while(i!=-1){
                    os.write(array,0,i);
                    sum+=i;
                    publishProgress(sum,length);
                    i=is.read(array);
                }
                os.flush();
                os.close();
                is.close();
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }
        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);
        }
        @Override
        protected void onProgressUpdate(Integer... values) {
            super.onProgressUpdate(values);
            mProgressBar.setProgress((int) (values[0]*100.0/values[1]));//設置單線程下載進度條
        }
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.button_single:
                MyTask task=new MyTask();
                task.execute();
                break;
            case R.id.button_more:
                //多線程下載
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        String urlPath="http://192.168.0.85:8080/JavaEE/photo/view.png";
                        try {
                            URL url=new URL(urlPath);
                            URLConnection connection=url.openConnection();
                            int length=connection.getContentLength();
                            File file=new File(Environment.getExternalStorageDirectory(),"a.png");
                            if(!file.exists()){
                                file.createNewFile();
                            }
                            MultiThread[] threads=new MultiThread[5];
                            for(int i=0;i<5;i++){
                                MultiThread thread=null;
                                if(i==4){
                                    thread=new MultiThread(length/5*4,length,urlPath,file.getAbsolutePath());
                                }else {
                                    thread=new MultiThread(length/5*i,length/5*(i+1),urlPath,file.getAbsolutePath());
                                }
                                thread.start();
                                threads[i]=thread;
                            }
                            boolean isFinish=true;
                            while(isFinish){
                                int  sum=0;
                                for(MultiThread thread:threads){
                                    sum+=thread.getSum();
                                }
                                Message message=handler.obtainMessage();
                                message.what=MESSAGE_THREAD;
                                message.arg1=sum;
                                handler.sendMessage(message);
                                if(sum+10>=length){
                                    isFinish=false;
                                }
                                Thread.sleep(1000);
                            }
                        } catch (MalformedURLException e) {
                            e.printStackTrace();
                        } catch (IOException e) {
                            e.printStackTrace();
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                    }
                }).start();
                break;
        }
    }
}

MultiThraed:(多線程下載)

public class MultiThread extends Thread {
    private long start;
    private long end;
    private String urlPath;
    private String filePath;
    private int sum=0;

    public int getSum() {
        return sum;
    }

    public MultiThread(long start, long end, String urlPath, String filePath) {
        this.start = start;
        this.end = end;
        this.urlPath = urlPath;
        this.filePath = filePath;
    }

    @Override
    public void run() {
        try {
            URL url=new URL(urlPath);
            URLConnection connection=url.openConnection();
            connection.setRequestProperty("Range","bytes="+start+"-"+end);
            InputStream is=connection.getInputStream();
            File file=new File(filePath);
            if(!file.exists()){
                file.createNewFile();
            }
            RandomAccessFile randomAccessFile=new RandomAccessFile(file,"rw");
            randomAccessFile.seek(start);
            byte[] array=new byte[1024];
            int i=is.read(array);
            while(i!=-1){
                randomAccessFile.write(array,0,i);
                sum+=i;
                i=is.read(array);
            }
            randomAccessFile.close();
            is.close();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        super.run();
    }
}

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