PARQUET-2142: parquet-cli without hadoop throws java.lang.NoSuchMetho…

…dError on any parquet file access command (#990)

parquet-cli/README.md

@@ -31,13 +31,13 @@ mvn clean install -DskipTests
 The build produces a shaded Jar that can be run using the `hadoop` command:
 
 ```
-hadoop jar parquet-cli-1.9.1-runtime.jar org.apache.parquet.cli.Main
+hadoop jar parquet-cli-1.12.3-runtime.jar org.apache.parquet.cli.Main
 ```
 
 For a shorter command-line invocation, add an alias to your shell like this:
 
 ```
-alias parquet="hadoop jar /path/to/parquet-cli-1.9.1-runtime.jar org.apache.parquet.cli.Main --dollar-zero parquet"
+alias parquet="hadoop jar /path/to/parquet-cli-1.12.3-runtime.jar org.apache.parquet.cli.Main --dollar-zero parquet"
 ```
 
 ### Running without Hadoop
@@ -51,9 +51,14 @@ mvn dependency:copy-dependencies
 Then, run the command-line and add `target/dependencies/*` to the classpath:
 
 ```
-java -cp 'target/*:target/dependency/*' org.apache.parquet.cli.Main
+java -cp 'target/parquet-cli-1.12.3.jar:target/dependency/*' org.apache.parquet.cli.Main
 ```
 
+Note that you shouldn't include the runtime jar used above into the classpath in this case.
+In that jar, the `org.apache.avro package` is relocated for avoiding conflict with Hadoop's one.
+That relocation changes method signatures, so it can cause `NoSuchMethodError` depending on the class loading order.
+See PARQUET-2142 for details.
+
 
 ### Help
 
@@ -100,7 +105,7 @@ Usage: parquet [options] [command] [command options]
   Examples:
 
     # print information for create
-    parquet help create
+    parquet help meta
 
   See 'parquet help <command>' for more information on a specific command.
 ```