Android Http基础：图片下载并显示和WebView的应用，android实战视频教程

Android Http基础：图片下载并显示和WebView的应用，android实战视频教程

public class MainActivity extends ActionBarActivity {

private WebView webView;

private ImageView imageView;

public static final int SHOW_WEDVIEW = 0;

private Handler handler = new Handler();

@Override

protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);

    webView = (WebView) findViewById(R.id.wedView);

    imageView = (ImageView) findViewById(R.id.image);

    //通过网络加载图片

    new ImageThread("http://gb.cri.cn/mmsource/images/2013/02/22/35/14607758026320856623.jpg",imageView,handler).start();

    //在WebView中显示百度主页

    new HttpThread("http://www.baidu.com",webView,handler).start();

}

}

ImageThread（加载图片的线程）:

---

public class ImageThread extends Thread {

//声明要传递的参数

private String url;

private ImageView imageView;

private Handler handler;

//创建构造方法，对参数进行初始化

public ImageThread(String url, ImageView imageView, Handler handler) {

    this.url = url;

    this.imageView = imageView;

    this.handler = handler;

}

@Override

public void run() {

    try {

        //定义一个URL对象

        URL httpUrl = new URL(url);

        //获取HttpURLConnection的实例，表示到URL所引用的远程对象的连接

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

        //设置读取超时时间

        connection.setReadTimeout(5000);

        //设置请求方法，GET表示希望从服务器那里获取数据，而POST则表示提交数据给服务器

        connection.setRequestMethod("GET");

        //设置该URLConnection的doOutput请求头字段的值

        connection.setDoInput(true);

        //用时间作为下载的图片的文件名

        String fileName = String.valueOf(System.currentTimeMillis());

        File downloadFile = null;

        InputStream inputStream = connection.getInputStream();

        //要把文件写到SD卡，所以用FileOutputStream

        FileOutputStream fileOutputStream = null;

        //判断SD卡是否存在，存在就创建文件

        if (Environment.getExternalStorageState().equals(

                Environment.MEDIA_MOUNTED)) {

            File parent = Environment.getExternalStorageDirectory();

            downloadFile = new File(parent,fileName);

            fileOutputStream = new FileOutputStream(downloadFile);

        }

        //创建一个2K的缓冲区

        byte[] bytes = new byte[2 * 1024];

        int length;

        if (fileOutputStream != null) {

            while ((length = inputStream.read(bytes)) != -1) {

                fileOutputStream.write(bytes,0,length);

            }

        }

        final Bitmap bitmap = BitmapFactory.decodeFile(downloadFile.getAbsolutePath());

        //通过handler去更新UI

        handler.post(new Runnable() {

            @Override

            public void run() {

                imageView.setImageBitmap(bitmap);

            }

        });

    } catch (MalformedURLException e) {

        e.printStackTrace();

    } catch (IOException e) {

        e.printStackTrace();

    }

}

}

HttpThread（加载WebView的线程）:

---

public class HttpThread extends Thread {

//声明要传递的参数

private String url;

private WebView webView;

private Handler handler;

//创建构造方法，对参数进行初始化

public HttpThread(String url, WebView webView, Handler handler) {

    this.url = url;

    this.webView = webView;

    this.handler = handler;

}

@Override

public void run() {

    try {

        //定义一个URL对象

        URL httpUrl = new URL(url);

        //获取HttpURLConnection的实例，表示到URL所引用的远程对象的连接

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

        //设置读取超时时间

        connection.setReadTimeout(5000);

        //设置请求方法，GET表示希望从服务器那里获取数据，而POST则表示提交数据给服务器

        connection.setRequestMethod("GET");

        final StringBuffer stringBuffer = new StringBuffer();

        InputStream inputStream = connection.getInputStream();

        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));

        String str;

        while ((str=bufferedReader.readLine())!=null) {

            stringBuffer.append(str);