Update from 1.25.0 to 1.26.0 causes NoClassDefFoundError on 'Preconditions'

[geri-m]

Environment details

• OS: OSX 10.12.6
• Java version: 1.8.0_111-b14, 64 bit
• google-http-java-client version: 1.25.0/1.26.0

Steps to reproduce

1. The Statement Preconditions.checkState(true); works fine in 1.25.0.
2. Then switch to Version 1.26.0.
3. Now you will get a NoClassDefFoundError
4. Then add guava (version 20.0) and everything is good again.

Stacktrace

java.lang.NoClassDefFoundError: com/google/common/base/Preconditions

	at com.google.api.client.util.Preconditions.checkState(Preconditions.java:81)
	at org.soundtouch4j.ZoneApiTest.testPrecondition(ZoneApiTest.java:172)
	at java.util.ArrayList.forEach(ArrayList.java:1249)
	at java.util.ArrayList.forEach(ArrayList.java:1249)
Caused by: java.lang.ClassNotFoundException: com.google.common.base.Preconditions
	at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 41 more

Any additional information below

Making sure to follow these steps will guarantee the quickest resolution possible.

In the class Preconditions there is a change from com.google.api.client.repackaged.com.google.common.base.Preconditions.checkArgument(expression); to com.google.common.base.Preconditions.checkArgument(expression); . And this package is not part of the JAR File.

[chingor13]

Guava has been a "provided" dependency for a long time, meaning that it's up to you to add a dependency (or be using another library with a guava dependency). This library supports guava 20+.

That said, we are looking at possibly setting up dependency ranges for these libraries (google-http-java-client, google-oauth-java-client, and google-api-java-client).

[elharo]

1. Please do not use version ranges for reasons elaborated in https://github.com/GoogleCloudPlatform/cloud-opensource-java/blob/master/library-best-practices/JLBP-14.md

2. Guava doesn't fit the use case of a provided dependency. It should be explicit.

[garrettjonesgoogle]

@ejona86 might have context on why Guava is a provided dependency - do the original reasons for it still hold? With Guava's higher surface stability these days, I suspect the situation is different now.

[ejona86]

That's because Guava isn't actually a dependency at this level. It looks like it is supposed to be jarjar'd: https://github.com/googleapis/google-http-java-client/blob/master/google-http-client/pom.xml#L44

That said, I do remember that guava was an actual dependency somewhere (maybe oauth?), because of all the guava-jdk5 nastiness, but I don't remember precisely where.