Require Java 11, use modules, and prepare for release

.github/workflows/test.yml

@@ -8,7 +8,7 @@ jobs:
       matrix:
         distribution: ['zulu']
         os: [ubuntu-latest, windows-latest, macos-latest]
-        version: [ 8, 9, 10, 11, 12, 13, 14, 15 ]
+        version: [ 11, 12, 13, 14, 15, 16, 17, 18, 19 ]
     steps:
       - uses: actions/checkout@v3
         with:

CHANGELOG.md

@@ -1,12 +1,18 @@
 CHANGELOG
 =========
 
+3.0.0
+------------------
+
+* Java 11 or greater is now required.
+* This library is now a Java module.
+
 2.1.0 (2022-10-31)
 ------------------
 
 * Messages for `DeserializationException` have been improved, and the cause
- is included, if any. Moreover, the message provides detail about the involved
- types, if the exception is caused by an `IllegalArgumentException`.
+  is included, if any. Moreover, the message provides detail about the involved
+  types, if the exception is caused by an `IllegalArgumentException`.
 
 2.0.0 (2020-10-13)
 ------------------
@@ -101,7 +107,6 @@ CHANGELOG
 * Several optimizations have been made to reduce allocations when decoding a
   record. Pull requests by Viktor Szathmáry. GitHub #16 & #17.
 
-
 1.0.0 (2014-09-29)
 ------------------
 

README.md

@@ -185,7 +185,7 @@ specific to this reader, please [contact MaxMind support](https://www.maxmind.co
 
 ## Requirements  ##
 
-This API requires Java 8 or greater.
+This API requires Java 11 or greater.
 
 ## Contributing ##
 
@@ -198,6 +198,6 @@ The MaxMind DB Reader API uses [Semantic Versioning](https://semver.org/).
 
 ## Copyright and License ##
 
-This software is Copyright (c) 2014-2020 by MaxMind, Inc.
+This software is Copyright (c) 2014-2022 by MaxMind, Inc.
 
 This is free software, licensed under the Apache License, Version 2.0.

checkstyle-suppressions.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0"?>
+
+<!DOCTYPE suppressions PUBLIC
+        "-//Checkstyle//DTD SuppressionFilter Configuration 1.0//EN"
+        "https://checkstyle.org/dtds/suppressions_1_0.dtd">
+
+<suppressions>
+    <suppress checks="AbbreviationAsWordInName" files="CHMCache.java" lines="11"/>
+</suppressions>

pom.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.maxmind.db</groupId>
     <artifactId>maxmind-db</artifactId>
@@ -45,6 +46,33 @@
     </dependencies>
     <build>
         <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-checkstyle-plugin</artifactId>
+                <version>3.2.0</version>
+                <configuration>
+                    <consoleOutput>true</consoleOutput>
+                    <configLocation>checkstyle.xml</configLocation>
+                    <suppressionsLocation>checkstyle-suppressions.xml</suppressionsLocation>
+                    <violationSeverity>warning</violationSeverity>
+                </configuration>
+                <dependencies>
+                    <dependency>
+                        <groupId>com.puppycrawl.tools</groupId>
+                        <artifactId>checkstyle</artifactId>
+                        <version>10.3</version>
+                    </dependency>
+                </dependencies>
+                <executions>
+                    <execution>
+                        <id>test</id>
+                        <phase>test</phase>
+                        <goals>
+                            <goal>check</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-gpg-plugin</artifactId>
@@ -78,8 +106,8 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.10.1</version>
                 <configuration>
-                    <source>8</source>
-                    <target>8</target>
+                    <source>11</source>
+                    <target>11</target>
                 </configuration>
             </plugin>
             <plugin>
@@ -97,7 +125,7 @@
                 <configuration>
                     <format>xml</format>
                     <maxmem>256m</maxmem>
-                    <check />
+                    <check/>
                 </configuration>
             </plugin>
             <plugin>
@@ -141,7 +169,7 @@
                     <plugin>
                         <artifactId>maven-compiler-plugin</artifactId>
                         <configuration>
-                            <release>8</release>
+                            <release>11</release>
                         </configuration>
                     </plugin>
                 </plugins>

src/main/java/com/maxmind/db/BufferHolder.java

@@ -1,5 +1,6 @@
 package com.maxmind.db;
 
+import com.maxmind.db.Reader.FileMode;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.IOException;
@@ -9,23 +10,21 @@
 import java.nio.channels.FileChannel;
 import java.nio.channels.FileChannel.MapMode;
 
-import com.maxmind.db.Reader.FileMode;
-
 final class BufferHolder {
     // DO NOT PASS OUTSIDE THIS CLASS. Doing so will remove thread safety.
     private final ByteBuffer buffer;
 
     BufferHolder(File database, FileMode mode) throws IOException {
         try (
-                final RandomAccessFile file = new RandomAccessFile(database, "r");
-                final FileChannel channel = file.getChannel()
+            final RandomAccessFile file = new RandomAccessFile(database, "r");
+            final FileChannel channel = file.getChannel()
         ) {
             if (mode == FileMode.MEMORY) {
                 final ByteBuffer buf = ByteBuffer.wrap(new byte[(int) channel.size()]);
                 if (channel.read(buf) != buf.capacity()) {
                     throw new IOException("Unable to read "
-                            + database.getName()
-                            + " into memory. Unexpected end of stream.");
+                        + database.getName()
+                        + " into memory. Unexpected end of stream.");
                 }
                 this.buffer = buf.asReadOnlyBuffer();
             } else {
@@ -61,19 +60,21 @@ final class BufferHolder {
     ByteBuffer get() {
         // The Java API docs for buffer state:
         //
-        //     Buffers are not safe for use by multiple concurrent threads. If a buffer is to be used by more than
-        //     one thread then access to the buffer should be controlled by appropriate synchronization.
+        //     Buffers are not safe for use by multiple concurrent threads. If a buffer is to be
+        //     used by more than one thread then access to the buffer should be controlled by
+        //     appropriate synchronization.
         //
-        // As such, you may think that this should be synchronized. This used to be the case, but we had several
-        // complaints about the synchronization causing contention, e.g.:
+        // As such, you may think that this should be synchronized. This used to be the case, but
+        // we had several complaints about the synchronization causing contention, e.g.:
         //
         // * https://github.com/maxmind/MaxMind-DB-Reader-java/issues/65
         // * https://github.com/maxmind/MaxMind-DB-Reader-java/pull/69
         //
-        // Given that we are not modifying the original ByteBuffer in any way and all currently known and most
-        // reasonably imaginable implementations of duplicate() only do read operations on the original buffer object,
-        // the risk of not synchronizing this call seems relatively low and worth taking for the performance benefit
-        // when lookups are being done from many threads.
+        // Given that we are not modifying the original ByteBuffer in any way and all currently
+        // known and most reasonably imaginable implementations of duplicate() only do read
+        // operations on the original buffer object, the risk of not synchronizing this call seems
+        // relatively low and worth taking for the performance benefit when lookups are being done
+        // from many threads.
         return this.buffer.duplicate();
     }
 }

src/main/java/com/maxmind/db/CachedConstructor.java

@@ -10,10 +10,10 @@ final class CachedConstructor<T> {
     private final Map<String, Integer> parameterIndexes;
 
     CachedConstructor(
-            Constructor<T> constructor,
-            Class<?>[] parameterTypes,
-            java.lang.reflect.Type[] parameterGenericTypes,
-            Map<String, Integer> parameterIndexes
+        Constructor<T> constructor,
+        Class<?>[] parameterTypes,
+        java.lang.reflect.Type[] parameterGenericTypes,
+        Map<String, Integer> parameterIndexes
     ) {
         this.constructor = constructor;
         this.parameterTypes = parameterTypes;

src/main/java/com/maxmind/db/DecodedValue.java

@@ -1,7 +1,7 @@
 package com.maxmind.db;
 
 public final class DecodedValue {
-     final Object value;
+    final Object value;
 
     DecodedValue(Object value) {
         this.value = value;