Fix floating point handling in Java (#347)

Fix formatting issues, update Maven version.

Author: drinckes

.travis.yml

@@ -45,15 +45,15 @@ matrix:
         - go test -bench=. ./go -v
         - go test ./tile_server/gridserver -v
 
-    # Java implementation. Lives in java/, tested with bazel.
+    # Java implementation. Lives in java/, tested with bazel and maven.
     - language: java
       jdk: oraclejdk8
       env: OLC_PATH=java
       script:
         - wget -O install.sh "https://github.com/bazelbuild/bazel/releases/download/0.24.1/bazel-0.24.1-installer-linux-x86_64.sh"
         - chmod +x install.sh
         - ./install.sh --user && rm -f install.sh
-        - ~/bin/bazel test --test_output=all ${OLC_PATH}:all
+        - ~/bin/bazel test --test_output=all ${OLC_PATH}:all && cd ${OLC_PATH} && mvn package
 
     # Javascript Closure library implementation. Lives in js/closure, tested with bazel.
     # We use language "c" because bazel will install all the dependencies we need, and we use path "js" for the node_js tests.

java/README.md

@@ -2,6 +2,22 @@
 
 This is the Java implementation of OLC. You can build the library either with [Maven](https://maven.apache.org/) or [Bazel](https://bazel.build/).
 
+## Code Style
+
+The Java code must use the Google formatting guidelines. Format is checked using
+[google-java-format](https://github.com/google/google-java-format).
+
+The formatting is checked in the tests and formatting errors will cause tests
+to fail and comments to be added to your PR.
+
+You can ensure your files are formatted correctly either by installing
+google-java-format into your editor, or by running `mvn spotless:check`.
+
+## Static Analysis
+
+Code is checked for common flaws with [PMD](https://pmd.github.io). It can be
+executed by running `mvn pmd:pmd pmd:check`.
+
 ## Building and Testing
 
 Note: the tests read their data from the [`test_data`](https://github.com/google/open-location-code/tree/master/test_data) directory.
@@ -81,4 +97,4 @@ $
 
 The library is available to import/download via [Maven Central](https://search.maven.org/search?q=g:com.google.openlocationcode).
 
-To update the library, bump the version number in pom.xml and run "mvn clean deploy" from the java folder. See the [docs](https://central.sonatype.org/pages/apache-maven.html) for more info.
+To update the library, bump the version number in pom.xml and run "mvn clean deploy" from the java folder. See the [docs](https://central.sonatype.org/pages/apache-maven.html) for more info.

java/pom.xml

@@ -10,7 +10,7 @@
 
   <groupId>com.google.openlocationcode</groupId>
   <artifactId>openlocationcode</artifactId>
-  <version>1.0.2</version>
+  <version>1.0.4</version>
   <packaging>jar</packaging>
 
   <name>Open Location Code</name>
@@ -88,9 +88,9 @@
         </configuration>
       </plugin>
       <plugin>
-          <groupId>com.diffplug.spotless</groupId>
-          <artifactId>spotless-maven-plugin</artifactId>
-          <version>1.23.0</version>
+        <groupId>com.diffplug.spotless</groupId>
+        <artifactId>spotless-maven-plugin</artifactId>
+        <version>1.23.0</version>
         <dependencies>
           <dependency>
             <groupId>com.google.googlejavaformat</groupId>
@@ -111,9 +111,55 @@
             <trimTrailingWhitespace/>
           </java>
         </configuration>
+        <executions>
+          <execution>
+            <id>spotless</id>
+            <phase>compile</phase>
+            <goals>
+              <goal>check</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-pmd-plugin</artifactId>
+        <version>3.9.0</version>
+        <configuration>
+          <failOnViolation>true</failOnViolation>
+          <printFailingErrors>true</printFailingErrors>
+          <violationSeverity>warning</violationSeverity>
+        </configuration>
+        <executions>
+          <execution>
+            <id>pmd</id>
+            <phase>compile</phase>
+            <goals>
+              <goal>check</goal>
+            </goals>
+          </execution>
+        </executions>
       </plugin>
     </plugins>
   </build>
+  
+  <reporting>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-jxr-plugin</artifactId>
+        <version>2.3</version>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-pmd-plugin</artifactId>
+      </plugin>
+      <plugin>
+        <groupId>com.diffplug.spotless</groupId>
+        <artifactId>spotless-maven-plugin</artifactId>
+      </plugin>
+    </plugins>
+  </reporting>
 
   <distributionManagement>
     <snapshotRepository>