Android之WebView与URLConnection

demo

java代码：

public class MainActivity extends Activity implements View.OnClickListener {
    private TextView mTextViewDetail;
    private TextView mTextViewFalse;
    private ProgressBar mProgressBarWeb;

    private Button mButtonDetail;
    private Button mButtonUrl;

    //网页的加载需要ConnectivityManager
    private ConnectivityManager mManager;
    private WebView mWebView;
    private WebSettings mWs;

    public static final  int GET_URL_MESSAGE = 0x99;
    //handler用于接收URLConnection传递的消息
    private Handler mHandler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what){
                case GET_URL_MESSAGE:
                    mTextViewDetail.setText(msg.obj.toString());
                    break;
            }
        }
    };

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

        mTextViewDetail = (TextView) findViewById(R.id.text_detail);
        mTextViewFalse = (TextView) findViewById(R.id.text_web_false);

        mProgressBarWeb = (ProgressBar) findViewById(R.id.progressBar_web);

        mButtonDetail = (Button) findViewById(R.id.button_detail);
        mManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        mButtonDetail.setOnClickListener(this);

        mButtonUrl = (Button) findViewById(R.id.button_url);
        mButtonUrl.setOnClickListener(this);
        //WebView用来显示网页
        mWebView = (WebView) findViewById(R.id.webView_test);

        //mWs的作用是加载一个Zoom,功能是放大或缩小网页
        mWs = mWebView.getSettings();
        mWs.setSupportZoom(true);
        mWs.setBuiltInZoomControls(true);
        //监听网页加载前后和网页加载错误的事件
        mWebView.setWebViewClient(new WebViewClient() {
            @Override
            public void onPageStarted(WebView view, String url, Bitmap favicon) {
                super.onPageStarted(view, url, favicon);
                mProgressBarWeb.setVisibility(View.VISIBLE);
            }

            @Override
            public void onPageFinished(WebView view, String url) {
                super.onPageFinished(view, url);
                mProgressBarWeb.setVisibility(View.INVISIBLE);
            }

            @Override
            public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
                //super.onReceivedError(view, errorCode, description, failingUrl);
                mWebView.setVisibility(View.GONE);
                mTextViewFalse.setVisibility(View.VISIBLE);
                Toast.makeText(getApplicationContext(), "同步加载失败", Toast.LENGTH_SHORT).show();
            }

        });
        //网页加载中的监听需要调用此方法
        mWebView.setWebChromeClient(new WebChromeClient() {
            @Override
            public void onProgressChanged(WebView view, int newProgress) {
                super.onProgressChanged(view, newProgress);
                mProgressBarWeb.setProgress(newProgress);
            }
        });


    }

    @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 v) {
        switch (v.getId()) {
            case R.id.button_detail:
                //loadUrl中传入网页地址
                mWebView.loadUrl("http://www.bjlingzhuo.com/");
                //NetWorkInfo用来得到网页的一些信息
                NetworkInfo info = mManager.getActiveNetworkInfo();
                if (info != null && info.isConnected()) {
                    mTextViewDetail.setText("网络类型：" + info.getTypeName());
                } else {
                    mTextViewDetail.setText("无网络连接");
                }
                break;
            case R.id.button_url:
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        urlConnectServerLet();
                    }
                }).start();
                break;
            default:
                break;
        }
    }

    /**
     * URLConnection加载网页的方法
     */
    private void urlConnectServerLet() {
        try {
            URL url = new URL("http://www.bjlingzhuo.com");
            //需要一个URLConnection打开网页
            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) {
                buffer.append(line);
                line = br.readLine();
            }
            is.close();
            Message message = mHandler.obtainMessage();
            message.what = GET_URL_MESSAGE;
            message.obj = buffer.toString().trim();
            mHandler.sendMessage(message);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

布局：
ScrollView 中最多只能加载一个控件

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
            xmlns:tools="http://schemas.android.com/tools"
            android:layout_width="match_parent"
            android:layout_height="match_parent">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <Button
            android:id="@+id/button_detail"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="网络连接"/>

        <Button
            android:id="@+id/button_url"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="打开Url连接"/>

        <FrameLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent">

            <TextView
                android:id="@+id/text_detail"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text=""/>

            <ProgressBar
                android:id="@+id/progressBar_web"
                style="@style/Base.Widget.AppCompat.ProgressBar.Horizontal"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:visibility="invisible"/>

            <TextView
                android:id="@+id/text_web_false"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:gravity="center"
                android:text="加载失败"
                android:visibility="invisible"/>

            <WebView
                android:id="@+id/webView_test"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:visibility="visible">
            </WebView>

        </FrameLayout>
    </LinearLayout>

</ScrollView>

结果演示：
WebView

URLConnection