dependency problem with com.google.guava when using maven as build-tool

[marc0olo]

Problem

for some reason maven loads guava 18.0 instead of 27.0.1-jre and that leads to the following error:

Exception in thread "main" java.lang.NoSuchMethodError: com.google.common.base.Preconditions.checkArgument(ZLjava/lang/String;Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)V
	at net.consensys.cava.bytes.ArrayWrappingBytes.<init>(ArrayWrappingBytes.java:39)
	at net.consensys.cava.bytes.Bytes.wrap(Bytes.java:83)
	at net.consensys.cava.bytes.Bytes.wrap(Bytes.java:58)
	at net.consensys.cava.bytes.Bytes.<clinit>(Bytes.java:46)
	at net.consensys.cava.rlp.RLPWriter.writeBigInteger(RLPWriter.java:102)
	at com.kryptokrauts.aeternity.sdk.service.transaction.impl.TransactionServiceImpl.lambda$spendTxNative$0(TransactionServiceImpl.java:96)
	at net.consensys.cava.rlp.AccumulatingRLPWriter.writeList(AccumulatingRLPWriter.java:67)
	at net.consensys.cava.rlp.DelegatingRLPWriter.writeList(DelegatingRLPWriter.java:76)
	at net.consensys.cava.rlp.RLP.encodeList(RLP.java:83)
	at com.kryptokrauts.aeternity.sdk.service.transaction.impl.TransactionServiceImpl.spendTxNative(TransactionServiceImpl.java:87)
	at com.kryptokrauts.aeternity.sdk.service.transaction.impl.TransactionServiceImpl.createSpendTx(TransactionServiceImpl.java:48)
	at AeppsTest.main(AeppsTest.java:60)

Workarounds

1. include the current guava version in the maven project
2. use gradle ;-)

[mitch-lbw]

The problem is class path pollution due to duplicated dependencies to guava transitively coming from the bitcoinj and cava-crypto.
Solution is to use maven dependencyManagement and declare the current version in a uniform manner

<dependencyManagement>
	<dependencies>
		<dependency>
			<groupId>com.google.guava</groupId>
			<artifactId>guava</artifactId>
			<version>27.1-jre</version>
		</dependency>
	</dependencies>
</dependencyManagement>

Add this explanation to the wiki

[marc0olo]

@mitch-lbw in order to make sure our SDK always uses the right guava version we explicitely want to add the specific version as dependency in our project so that maven users wouldn't need that workaround