Java 图像下载程序畸形异常

我正试图建立一个应用程序，它需要一个图像链接，并从网上下载它。每当我注册我的应用程序时，它都会给我一个错误的提示：协议未形成：url我能告诉我我做错了什么吗。我是android新手，所以我无法找出我做错了什么。非常感谢您的帮助。提前感谢：）

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链接是什么，包括http还是https？不。链接没有http或https。请告诉我们您的URL的开头是什么样的？www.something，例如。我想你必须指定协议。http://或https://我试过这样做，现在它给我一个SSL异常

     package com.img.imagedwnloader;

     import java.io.BufferedInputStream;
     import java.io.File;
     import java.io.FileOutputStream;
     import java.io.IOException;
     import java.io.InputStream;
     import java.net.HttpURLConnection;
     import java.net.URL;
     import java.net.URLConnection;

     import org.apache.http.util.ByteArrayBuffer;

     import android.app.Activity;
     import android.os.Bundle;
     import android.os.Environment;
     import android.view.View;
     import android.view.View.OnClickListener;
     import android.widget.Button;
     import android.widget.EditText;
     import android.widget.TextView;

 public class MainActivity extends Activity {
    static Button dwnload;
    static EditText link;
    static TextView textv;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    dwnload = (Button) findViewById (R.id.bstrtD);
    link = (EditText) findViewById (R.id.etlink);
    textv = (TextView) findViewById (R.id.tvUpdate);
    dwnload.setOnClickListener(new OnClickListener(){

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            textv.setText("click");

                    // TODO Auto-generated method stub
                    textv.setText("thread");
                    File storedwn = Environment.getExternalStorageDirectory();
                    File file = new File (storedwn, "downloadFile.jpg");
                    long startTime = System.currentTimeMillis();
                    try{
                        textv.setText("try");
                        String linkt = link.getText().toString();
                        URL url = new URL (linkt);
                        textv.setText(link.getText().toString());
                        URLConnection urlconnect = url.openConnection();
                        InputStream is = urlconnect.getInputStream();
                        BufferedInputStream bis = new BufferedInputStream (is);
                        ByteArrayBuffer baf = new ByteArrayBuffer(50);
                        int current = 0;
                        while ((current = bis.read()) != -1) {
                                baf.append((byte) current);
                        }
                        FileOutputStream fos = new FileOutputStream(file);
                        fos.write(baf.toByteArray());
                        fos.close();
                        textv.setText("Download Completed in" + ((System.currentTimeMillis() - startTime) / 1000) + " sec");
                } catch (IOException e) {
                     textv.setText("Error: " + e);
                }



                }

        /*      private void downloadVid() {
                    // TODO Auto-generated method stub
                    try{
                    URL url = new URL (link.getText().toString());
                    textv.setText(link.getText());
                    HttpURLConnection urlconnect = (HttpURLConnection) url.openConnection();
                    urlconnect.setRequestMethod("GET");
                    urlconnect.setDoOutput(true);
                    urlconnect.connect();
                    File storedwn = Environment.getExternalStorageDirectory();
                    File file = new File (storedwn, "downloadFile.avi");

                    } catch (Exception e){
                        textv.setText("Failed!");
                    }
                }

            }).start();;
        } */



    });
}

}