Http Download

Http / Https 下载文件，startWith不能验证https，测试地址：https://storage.googleapis.com/golang/go1.7.3.windows-amd64.msi

private static final Logger logger = Logger.
		getLogger(MethodHandles.lookup().lookupClass());
	
	private static void sunNetSsl() {
		System.setProperty("java.protocol.handler.pkgs",
			"com.sun.net.ssl.internal.www.protocol");
		Security.addProvider(new com.sun.net.ssl.internal.ssl.Provider());
	}
	
	private static void javaxNetSsl(){
		TrustManager[] trustAllCertArr = new TrustManager[]{
			new X509TrustManager() {
				public X509Certificate[] getAcceptedIssuers() {
					return null;
				}
				public void checkServerTrusted(X509Certificate[] 
					certArr,String authType) throws CertificateException {}
				public void checkClientTrusted(X509Certificate[] 
					certArr,String authType) throws CertificateException {}
		}};
		//activate trust manager
		try {
			SSLContext sc = SSLContext.getInstance("SSL");
			sc.init(null,trustAllCertArr,new SecureRandom());
			HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
		} catch (NoSuchAlgorithmException | KeyManagementException e) {
			e.printStackTrace();
		}
	}
	
	public static void download(String downloadUrl,String fileName,boolean isHttps) throws IOException{
		if (isHttps) {
			logger.info(isHttps);
			javaxNetSsl();
			//sunNetSsl();
		}
		URL url = new URL(downloadUrl);
		try(ReadableByteChannel rbc = Channels.newChannel(url.openStream());
			FileOutputStream fos = new FileOutputStream(fileName)){
			fos.getChannel().transferFrom(rbc,0,Long.MAX_VALUE);
		}catch(IOException e){
			e.printStackTrace();
		}
	}