import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;

public class AndroidnetimgActivity extends Activity {
    /** Called when the activity is first created. */
    //定义所使用的组件
    private Button button;
    private EditText editText;
    private ImageView imagesView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        //实例化用到的组件
        editText =(EditText)findViewById(R.id.EditText);
        imagesView = (ImageView)findViewById(R.id.ImageView);
        button = (Button)findViewById(R.id.Button);

        //为按钮添加监听事件
        button.setOnClickListener(new buttonListener());

    }

    private final class buttonListener implements OnClickListener{

        @Override
        public void onClick(View v) {
            String path = editText.getText().toString();

            System.out.println(path);

            //通过业务类ImageService的getImage方法得到数据
            try {
                byte[] data = ImageService.getImage(path);
                Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
                imagesView.setImageBitmap(bitmap);//显示图片
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                Toast.makeText(getApplicationContext(), "获取失败", 1).show();
            }

        }

    }
}

import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class ImageService {

    public static byte[] getImage(String path) throws Exception {

        URL url = new URL(path);
        //基于HTTP协议连接对象
        HttpURLConnection conn = (HttpURLConnection)url.openConnection();

        conn.setConnectTimeout(5000);
        conn.setRequestMethod("GET");

        if(conn.getResponseCode() == 200){
            InputStream inStream = conn.getInputStream();
            return StreamTool.read(inStream);
        }

        return null;
    }

}