网络图片查看器

 1 public class MainActivity extends Activity implements OnClickListener {  2  3 private static final String TAG = "MainActivity";  4 protected static final int ERROR = 1;  5 private EditText etUrl;  6 private ImageView ivIcon;  7 private final int SUCCESS = 0;  8  9 private Handler handler = new Handler() {  10  11 /**  12  * 接收消息  13 */  14  @Override  15 public void handleMessage(Message msg) {  16 super.handleMessage(msg);  17  18 Log.i(TAG, "what = " + msg.what);  19 if(msg.what == SUCCESS) { // 当前是访问网络, 去显示图片  20 ivIcon.setImageBitmap((Bitmap) msg.obj); // 设置imageView显示的图片  21 } else if(msg.what == ERROR) {  22 Toast.makeText(MainActivity.this, "抓取失败", 0).show();  23  }  24  }  25  };  26  27  @Override  28 protected void onCreate(Bundle savedInstanceState) {  29 super.onCreate(savedInstanceState);  30  setContentView(R.layout.activity_main);  31  32 ivIcon = (ImageView) findViewById(R.id.iv_icon);  33 etUrl = (EditText) findViewById(R.id.et_url);  34  35 findViewById(R.id.btn_submit).setOnClickListener(this);  36  }  37  38  @Override  39 public void onClick(View v) {  40 final String url = etUrl.getText().toString();  41  42 new Thread(new Runnable() {  43  44  @Override  45 public void run() {  46 Bitmap bitmap = getImageFromNet(url);  47  48 // ivIcon.setImageBitmap(bitmap); // 设置imageView显示的图片  49 if(bitmap != null) {  50 Message msg = new Message();  51 msg.what = SUCCESS;  52 msg.obj = bitmap;  53  handler.sendMessage(msg);  54 } else {  55 Message msg = new Message();  56 msg.what = ERROR;  57  handler.sendMessage(msg);  58  }  59  }}).start();  60  61  }  62  63 /**  64  * 根据url连接取网络抓去图片返回  65  * @param url  66  * @return url对应的图片  67 */  68 private Bitmap getImageFromNet(String url) {  69 HttpURLConnection conn = null;  70 try {  71 URL mURL = new URL(url); // 创建一个url对象  72  73 // 得到http的连接对象  74 conn = (HttpURLConnection) mURL.openConnection();  75  76 conn.setRequestMethod("GET"); // 设置请求方法为Get  77 conn.setConnectTimeout(10000); // 设置连接服务器的超时时间, 如果超过10秒钟, 没有连接成功, 会抛异常  78 conn.setReadTimeout(5000); // 设置读取数据时超时时间, 如果超过5秒, 抛异常  79  80 conn.connect(); // 开始链接  81  82 int responseCode = conn.getResponseCode(); // 得到服务器的响应码  83 if(responseCode == 200) {  84 // 访问成功  85 InputStream is = conn.getInputStream(); // 获得服务器返回的流数据  86  87 Bitmap bitmap = BitmapFactory.decodeStream(is); // 根据 流数据 创建一个bitmap位图对象  88  89 return bitmap;  90 } else {  91 Log.i(TAG, "访问失败: responseCode = " + responseCode);  92  }  93 } catch (Exception e) {  94  e.printStackTrace();  95 } finally {  96 if(conn != null) {  97 conn.disconnect(); // 断开连接  98  }  99  } 100 return null; 101  } 102 }