Switch to okhttp

[johan12345]

We are currently using Apache HTTPClient for all HTTP requests done from libopac. This has some disadvantages:

• An old version of it is bundled with older Android versions - even though we use a newer version, we need to add things like useLibrary 'org.apache.http.legacy' to make libopac work on Android
• It requires workarounds to support SNI on older Android versions
• ...

We are planning to gradually switch all APIs to use OkHttp instead. This requires a large amount of testing, especially for the library systems that require peculiar types of HTTP requests.

Systems already migrated to OkHttp:

• [x] Adis
• [x] BiBer
• [x] Bibliotheca
• [ ] Heidi
• [x] iOPAC
• [x] Littera
• [x] Open
• [x] PICA
• [ ] Primo
• [x] SISIS
• [ ] SRU
• [x] TouchPoint
• [x] VuFind
• [x] WebOpacNet
• [x] WinBiap
• [x] Zones

[raphaelm]

Do we know that we won't require the same SNI workarounds with OkHttp on older Android versions?

[johan12345]

OkHttp says it supports SNI on Android 2.3 and above: https://github.com/square/okhttp/blob/master/okhttp/src/main/java/okhttp3/internal/platform/Platform.java#L40