ZOOKEEPER-3786: Simplify version generation

Simplify generation of VersionInfoMain.java and Info.java by using
maven-resource-plugin's built-in resource filtering at build time.

This eliminates the need to use VerGen to generate java source files
during the build.

Also make other slight pom improvements:
1. Remove trailing tab character in Ted's name in pom.xml
2. Simplify spotbugs skipping in contrib pom.xml
3. Add m2e configuration for build plugin executions to be ignored by
   Eclipse, for developers (like me) using Eclipse IDE
4. Format build time in a more international-friendly and less ambiguous
   way (year first, then month, then day, using UTC instead of GMT)

Link to issue: https://issues.apache.org/jira/browse/ZOOKEEPER-3786

Author: Christopher Tubbs <[email protected]>

Reviewers: Enrico Olivelli <[email protected]>, Mate Szalay-Beko <[email protected]>

Closes apache#1310 from ctubbsii/use-resource-filtering-for-version-info

pom.xml

@@ -117,7 +117,7 @@
   <developers>
     <developer>
       <id>tdunning</id>
-      <name>Ted Dunning	</name>
+      <name>Ted Dunning</name>
       <email>[email protected]</email>
       <timezone>-8</timezone>
     </developer>

zookeeper-contrib/pom.xml

@@ -49,18 +49,13 @@
     </profile>
   </profiles>
 
+  <properties>
+    <spotbugs.skip>true</spotbugs.skip>
+  </properties>
+
   <build>
     <pluginManagement>
       <plugins>
-        <plugin>
-          <groupId>com.github.spotbugs</groupId>
-          <artifactId>spotbugs-maven-plugin</artifactId>
-          <version>3.1.9</version>
-          <configuration>
-            <!-- No spotbugs for contrib modules -->
-            <skip>true</skip>
-          </configuration>
-        </plugin>
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-compiler-plugin</artifactId>

zookeeper-server/pom.xml

@@ -166,22 +166,29 @@
 
   <build>
     <plugins>
-      <plugin> <!-- ${maven.build.timestamp} does not support timezone :( -->
+      <plugin>
         <groupId>org.codehaus.mojo</groupId>
         <artifactId>build-helper-maven-plugin</artifactId>
         <executions>
           <execution>
+            <!-- ${maven.build.timestamp} does not support timezone :( -->
             <id>tbuild-time</id>
             <goals>
               <goal>timestamp-property</goal>
             </goals>
             <configuration>
               <name>build.time</name>
-              <pattern>MM/dd/yyyy HH:mm zz</pattern>
+              <pattern>yyyy-MM-dd HH:mm zz</pattern>
               <locale>en_US</locale>
-              <timeZone>GMT</timeZone>
+              <timeZone>UTC</timeZone>
             </configuration>
           </execution>
+          <execution>
+            <id>parse-version</id>
+            <goals>
+              <goal>parse-version</goal>
+            </goals>
+          </execution>
           <execution>
             <phase>generate-sources</phase>
             <goals>
@@ -197,44 +204,22 @@
       </plugin>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-compiler-plugin</artifactId>
+        <artifactId>maven-resources-plugin</artifactId>
         <executions>
           <execution>
-            <id>pre-compile-vergen</id>
-            <phase>generate-sources</phase>
-            <configuration>
-              <includes>
-                <include>org/apache/zookeeper/version/**/*.java</include>
-              </includes>
-            </configuration>
+            <id>prepare-filtered-java-source</id>
             <goals>
-              <goal>compile</goal>
+              <goal>copy-resources</goal>
             </goals>
-          </execution>
-        </executions>
-      </plugin>
-      <plugin>
-        <groupId>org.codehaus.mojo</groupId>
-        <artifactId>exec-maven-plugin</artifactId>
-        <executions>
-          <execution>
-            <id>generate-version-info</id>
             <phase>generate-sources</phase>
-            <goals>
-              <goal>exec</goal>
-            </goals>
             <configuration>
-              <workingDirectory>${project.basedir}/src/main/java/</workingDirectory>
-              <executable>java</executable>
-              <arguments>
-                <argument>-classpath</argument>
-                <classpath />
-                <argument>org.apache.zookeeper.version.util.VerGen</argument>
-                <argument>${project.version}</argument>
-                <argument>${mvngit.commit.id}</argument>
-                <argument>${build.time}</argument>
-                <argument>${project.basedir}/target/generated-sources/java</argument>
-              </arguments>
+              <outputDirectory>${project.build.directory}/generated-sources/java</outputDirectory>
+              <resources>
+                <resource>
+                  <directory>src/main/java-filtered</directory>
+                  <filtering>true</filtering>
+                </resource>
+              </resources>
             </configuration>
           </execution>
         </executions>

zookeeper-server/src/main/java-filtered/org/apache/zookeeper/version/Info.java

@@ -0,0 +1,29 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.zookeeper.version;
+
+public interface Info {
+    int MAJOR=${parsedVersion.majorVersion};
+    int MINOR=${parsedVersion.minorVersion};
+    int MICRO=${parsedVersion.incrementalVersion};
+    String QUALIFIER="${parsedVersion.qualifier}".isEmpty() ? null : "${parsedVersion.qualifier}";
+    int REVISION=-1; //@deprecated, please use REVISION_HASH
+    String REVISION_HASH="${mvngit.commit.id}";
+    String BUILD_DATE="${build.time}";
+}

zookeeper-server/src/main/java-filtered/org/apache/zookeeper/version/VersionInfoMain.java

@@ -0,0 +1,25 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.zookeeper.version;
+
+public class VersionInfoMain implements org.apache.zookeeper.version.Info {
+    public static void main(String[] args) {
+        System.out.println("Apache ZooKeeper, version ${project.version} ${build.time}");
+    }
+}