如何关闭URLConnection对像啊?

Question

private boolean loginDomino(String strHost,String strUserName,String strPassWord)
    {
        boolean strReturn = false;
        String strNSF = "/names.nsf";
        String strLoginTarget = "";
        URL mURL = null;
        URLConnection uc = null;
        InputStream content = null;
        BufferedReader buffer = null;        try
        {
            String strResult = "";
            mURL = new URL("http://" + strHost + strNSF + "?Login&username=" + strUserName + "&password=" + strPassWord);
            uc = mURL.openConnection();
            content = (InputStream)uc.getInputStream();
            buffer = new BufferedReader(new InputStreamReader(content));
            mURL = new URL("http://" + strHost + strNSF + strLoginTarget);
            buffer = new BufferedReader(new InputStreamReader(mURL.openStream()));
            showInfo(mURL.toString());
            for(int i = 1;i < 10;i++)
            {
                strResult = buffer.readLine();
                showInfo(strResult);
                if(strResult != null)
                {
                    if(strResult.equals("0"))
                    {
                        showInfo("No." + i + "!");
                        showInfo("Login Success !");
                        strFullName = buffer.readLine();
                        strReturn = true;
                        break;
                    }
                }
            }
            buffer.close();
            content.close();
            uc = null;
            mURL = null;
        }
        catch(Exception e)
        {
            //e.printStackTrace();
            try
            {
                if(buffer != null)
                {
                    buffer.close();
                }
                if(content != null)
                {
                    content.close();
                }
                uc = null;
                mURL = null;
            }
            catch(Exception e_Err)
            {
                e_Err.printStackTrace();
            }
            showInfo("Login Domino " + strHost + " Error!");
        }
        return strReturn;
    }