My gradle file:
apply plugin: \'com.android.application\'
android {
useLibrary \'org.apache.http.legacy\'
compileSdkVersion 23
buildToolsVersion \
Why? If you use Android Studio on Windows then optional.json file should be not only in \Program Files (x86)\...\platforms\android-23\optional\ .
So: go to Android Studio Settings -> Appearence & Behavior -> System Settings and look for Android SDK Location, copy (or create) optional.json in corresponding folder.
Or just edit Android SDK Location to \Program Files (x86)\...
In my case Android SDK Location was C:\Users\Usernade\AppData\Local\Android\sdk and there was no optional.json file.
Settings -> Appearence & Behavior -> System Settings and look for Android SDK Location
platforms/Android 23/optional/
org.apache.http.legacy jar file is copy and paste your android studio project lib and this jar file gradle compile files('libs/org.apache.http.legacy.jar')
The error is that the optional.json file is not in the <sdk-path>\platforms\android-23\optional\ folder.
I solved this by the following:
I guess, the easier way to solve this issue without having to reinstall the SDK is to create a file called optional.json in <sdk-path>\platforms\android-23\optional\ directory with the following content:
[
{
"name": "org.apache.http.legacy",
"jar": "org.apache.http.legacy.jar",
"manifest": false
}
]
It solved the problem for me.
EDIT: Information taken from @domoch's answer below on how to locate your SDK location
Go to Android Studio Settings -> Appearence & Behavior -> System Settings and look for Android SDK Location. In Windows, it usually would be pointing to C:\Users\<username>\AppData\Local\Android\sdk.
I had exactly the same issue. Please check if you have android-sdk-windows\platforms\android-23\optional\optional.json file in place. If not then just reinstall API 23 (remove and install again).