政府與android 的互鬥: android 9 SSLHandshakeException: Handshake failed

From Android 9 Pie now, requests without encryption will never work.
And by default, the System will expect you to use TLS by default.

簡單講就是:android 9.0後一定要用https, 偏偏政府機構的ssl憑證有問題,
但政府機構不承認他們有問題...所以opendata 資料會取不到.
可說是政府與android的互鬥.

OkHttp或 urlconnect 報錯javax.net.ssl.SSLHandshakeException: Handshake failed

error message:
Failure in SSL library, usually a protocol errorerror:100000f0:SSL
routines:OPENSSL_internal:UNSUPPORTED_PROTOCOL

problem: Error when connecting from Android to a server that does not support TLS 1.0

solution step 1:  

OkHttpClient client = new OkHttpClient.Builder() .connectionSpecs(Arrays.asList(ConnectionSpec.COMPATIBLE_TLS)) .build();

Request request = new Request.Builder()
         .url(url)
         .build();

Response responses = null;
responses = client.newCall(request).execute();

return responses.body().string();
  
but got another error:

javax.net.ssl.SSLHandshakeException: 
java.security.cert.CertPathValidatorException: 
Trust anchor for certification path not found.javax.net.ssl.SSLHandshakeException:

so, 判斷: 直接在電腦chrome看憑證，憑證是由 政府憑證管理中心所簽發，判斷是自訂簽章，導致android不支援
證書鏈配置錯誤，沒有安裝中間證書（intermediate certificate).

 
注意:以上方法太複雜,不用.因為對憑證的問題去竄改都不是好方法.

我們還是改用http取代https,

所以要用下面的方法solution2. 
 
solution 2: 

CLEARTEXT communication to server not permitted by network security policy
問題原因： Android P 限制了明文流量的網絡請求，

非加密的流量請求都會被系統禁止掉
W/System.err: java.io.IOException: Cleartext HTTP traffic to **** not permitted
 

不可以像其他人一樣信任所有證書的改法.這太危險且複雜.
改用http,不用https...當利用到政府opentata時.

Fix Cleartext Traffic Error in Android 9 Pie
To do this in Android 9 Pie you will have to set a networkSecurityConfig in your Manifest application tag like this:

https://developer.android.com/training/articles/security-config 

在res下新增一個 xml 目錄，然後創建一個名為：network_security_config.xml 文件
url部分改成你呼叫url domain: 

 

然後在APP的AndroidManifest.xml文件下的application標籤增加以下屬性
<application
...
android:networkSecurityConfig="@xml/network_security_config"

> 
run.. app

成功.在android 9系統 call http url.