Andriod从网络上读入文件

来源：互联网发布：js获取网页源代码编辑：程序博客网时间：2024/06/08 07:11

class TxtDownLoadOnClickListener implements View.OnClickListener{        @Override        public void onClick(View view) {            //TxtDown txtDown = new TxtDown();            //String string = txtDown.downLoad("http://dampce032.iteye.com/blog/975642");            //System.out.println(string);            new Thread(){                @Override                public void run() {                    TxtDown txtDown = new TxtDown();                    String string = txtDown.downLoad("http://dampce032.iteye.com/blog/975642");                    System.out.println(string);                    super.run();                }            }.start();        }    }

看的是Mars老师的Andriod教程，因为教程比较早，在文件下载的时候出现NullPointerException异常，崩掉程序。在Andriod4.0以后，对网络的访问不能写在主线程中了。可以在监听器中设置线程。

网络的读写要用到IO流,下面代码可以实现对string类型的读入。在Mars老师讲解时，网站用Tomcat模拟，我没弄这个，但是也没有找到TXT文件的网站，所以就直接找的随机一个网站读入，能成功读入。听别人说用PHPStudy也能实现这个功能。

public class TxtDown {    private URL url = null;    //urlString是下载地址    public String downLoad(String urlString){        StringBuffer stringBuffer = new StringBuffer();        BufferedReader bufferedReader = null;        String line = null;        try {            //初始化URL对象            url = new URL(urlString);            // 创建http连接            HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();            //用IO流读取数据            bufferedReader = new BufferedReader(new InputStreamReader(httpURLConnection.getInputStream()));            while ((line = bufferedReader.readLine()) != null){                stringBuffer.append(line);            }            bufferedReader.close();        } catch (Exception e) {            e.printStackTrace();        }        return stringBuffer.toString();    }}

另外又写了一个读入网络图片的程序，和上面的基本上差不多，如果可能的话我再试试能不能封装成一个方法。

class JPGOnClickListener implements View.OnClickListener{        @Override        public void onClick(View view) {            //DownJPG downJPG = new DownJPG();            //downJPG.GetJPG("http://f.hiphotos.baidu.com/image/w%3D2048/sign=3b06d28fc91349547e1eef6462769358/d000baa1cd11728b22c9e62ccafcc3cec2fd2cd3.jpg");            //System.out.println("OnClick");            new Thread(){                @Override                public void run() {                    DownJPG downJPG = new DownJPG();                    downJPG.GetJPG("http://f.hiphotos.baidu.com/image/w%3D2048/sign=3b06d28fc91349547e1eef6462769358/d000baa1cd11728b22c9e62ccafcc3cec2fd2cd3.jpg");                    System.out.println("OnClick");                    super.run();                }            }.start();        }    }

public class DownJPG {    protected URL url = null;    Bitmap bitmap = null;    public Bitmap GetJPG(String urlJPG){        try {            url = new URL(urlJPG);            //使用HttpURLConnect建立连接            HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();            httpURLConnection.setDoInput(true);//??以后就可以使用conn.getInputStream().read()            httpURLConnection.connect();            //get数据            InputStream inputStream = httpURLConnection.getInputStream();            bitmap = BitmapFactory.decodeStream(inputStream);            inputStream.close();            System.out.println("DownLoad");        } catch (MalformedURLException e) {            // TODO Auto-generated catch block            System.out.println("[getNetWorkBitmap->]MalformedURLException");            e.printStackTrace();        } catch (Exception e) {            System.out.println("[getNetWorkBitmap->]IOException");            e.printStackTrace();        }        return bitmap;    }}

在AndriodManifest.xml文件里面要加入访问网络的权限

  <!-- 访问网络的权限 --><uses-permission android:name="android.permission.INTERNET"></uses-permission>

阅读全文

0 0