1.解析網站並顯示

因為要處理網頁讀取，需要開啟執行緒，並在UI上更新，則要使用handler

注意Handler匯入的是os包

下面是MainActivity

private WebView webView;
    private WebView webView;
    private Handler handler=new Handler();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_http_url_connection);
        webView=(WebView)findViewById(R.id.webview);
        
        new HttpThread("http://www.baidu.com",handler,webView).start();
        
    }
 

public class HttpThread extends Thread {
    private String url=null;
    private Handler handler;
    private WebView webView;
    StringBuffer sb;

    public HttpThread(String url,Handler handler,WebView webView){
        this.url=url;
        this.handler=handler;
        this.webView=webView;
    }

    @Override
    public void run() {

        try {
            //獲取URL物件
            URL httpUrl=new URL(url);
            //通過URL物件獲取連線
            HttpURLConnection conn= (HttpURLConnection) httpUrl.openConnection();
            //設定 連線讀取時長
            conn.setReadTimeout(5000);
            //設定以get形式請求
            conn.setRequestMethod("GET");
            //字串流
            sb=new StringBuffer();
            //獲得連線的位元組輸入流
            InputStream is=conn.getInputStream();
            //將位元組輸入流轉換為字元輸入流
            InputStreamReader isr=new InputStreamReader(is);
            //載入到快取流中,只有快取流可以直接讀一行
            BufferedReader reader=new BufferedReader(isr);
            String str;
            while ((str=reader.readLine())!=null){
                sb.append(str);
            }

            //使用post(),在runable中更新UI
            handler.post(new Runnable() {
                @Override
                public void run() {
                   webView.loadData(sb.toString(),"text/html;charset=utf-8",null);
                }
            });


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

    }
}
 

在MainActivity中開啟執行緒

下面的網址一定要是一個圖片網址，即字尾以,jpg或其他圖片格式顯示

new HttpThread("http://pic.sc.chinaz.com/files/pic/pic9/201512/apic17727.jpg",handler,imageView).start();

public class HttpThread extends Thread {
    private String url=null;
    private Handler handler;
    private ImageView imageView;


    public HttpThread(String url,Handler handler,ImageView imageView){
        this.url=url;
        this.handler=handler;
        this.imageView=imageView;
    }

    @Override
    public void run() {
        try {
            URL httpUrl=new URL(url);
            //通過URL物件獲取連線
            HttpURLConnection conn= (HttpURLConnection) httpUrl.openConnection();
            //設定 連線讀取時長
            conn.setReadTimeout(5000);
            //設定以get形式請求
            conn.setRequestMethod("GET");
            //文件上只是寫著設定連線允許輸入，不知道是什麼意思
            conn.setDoInput(true);
            InputStream in=conn.getInputStream();
            FileOutputStream out=null;
            File downloadFile=null;

            Log.i("info","進入到HttpThread中");
            String fileName=String.valueOf(System.currentTimeMillis());
            //只有在SD卡狀態為MEDIA_MOUNTED時,/mmt/sdcard目錄才是可讀可寫的，並且可以建立目錄及檔案
            if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {

                //獲取外部儲存路徑，外部儲存不一定是sd卡，還包括手機自帶的記憶體，內部儲存是指data/data/包名下的
                File parent=Environment.getExternalStorageDirectory();
                //在獲取的目錄下新建檔名為fileName的檔案
                downloadFile=new File(parent,fileName);
                //檔案輸出流
                out=new FileOutputStream(downloadFile);

            }
            byte[] b=new byte[2*1024];
            int len;

            if(out!=null){
                //通過位元組流的讀取方法，以陣列為快取
                while((len=in.read(b))!=-1){
                    out.write(b,0,len);
                }

            }

            //通過指定sd卡圖片檔案路徑來獲取bitmap
            final Bitmap bitmap= BitmapFactory.decodeFile(downloadFile.getAbsolutePath());
            handler.post(new Runnable() {
                @Override
                public void run() {
                    Log.i("info","寫入成功");
                    imageView.setImageBitmap(bitmap);
                }
            });
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}
 

上面獲取網頁圖片是先存到外部儲存中，然後在將圖片從外部儲存中取出來，當然可以直接通過網頁來獲取，下面的程式碼只是將獲取的方式從檔案改為了流

URL httpUrl=new URL(url);
            HttpURLConnection connection=(HttpURLConnection)httpUrl.openConnection();
            connection.setReadTimeout(5000);
            connection.setRequestMethod("GET");
            InputStream in=connection.getInputStream();
            //通過獲取網上的輸入流，來將圖片傳給Bitmap
            final Bitmap bitmap= BitmapFactory.decodeStream(in);

            //同樣通過post更新UI
            handler.post(new Runnable() {
                @Override
                public void run() {
                    imageView.setImageBitmap(bitmap);
                }
            });