Check source code using ErrorProne static analyzer (#1872)

* Added support for ErrorProne
---------

Author: Asapin

.mvn/jvm.config

@@ -0,0 +1,10 @@
+--add-exports jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.main=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.model=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.processing=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED
+--add-opens jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED
+--add-opens jdk.compiler/com.sun.tools.javac.comp=ALL-UNNAMED

client/src/main/java/org/asynchttpclient/util/AuthenticatorUtils.java

@@ -21,6 +21,7 @@
 import org.asynchttpclient.uri.Uri;
 
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.Base64;
 import java.util.List;
 
@@ -95,7 +96,7 @@ private static String computeDigestAuthentication(Realm realm) {
         builder.setLength(builder.length() - 2); // remove tailing ", "
 
         // FIXME isn't there a more efficient way?
-        return new String(StringUtils.charSequence2Bytes(builder, ISO_8859_1));
+        return new String(StringUtils.charSequence2Bytes(builder, ISO_8859_1), StandardCharsets.UTF_8);
     }
 
     private static void append(StringBuilder builder, String name, String value, boolean quoted) {

pom.xml

@@ -211,6 +211,31 @@
                 <configuration>
                     <source>11</source>
                     <target>11</target>
+                    <encoding>UTF-8</encoding>
+                    <compilerArgs>
+                        <arg>-XDcompilePolicy=simple</arg>
+                        <arg>-Xplugin:ErrorProne
+                            -Xep:JavaTimeDefaultTimeZone:ERROR
+                            -Xep:JavaUtilDate:ERROR
+                            -Xep:DateChecker:ERROR
+                            -Xep:DateFormatConstant:ERROR
+                            -Xep:EmptyBlockTag:ERROR
+                            -Xep:VariableNameSameAsType:ERROR
+                            -Xep:DoubleCheckedLocking:ERROR
+                            -Xep:DefaultCharset:ERROR
+                            -Xep:NullablePrimitive:ERROR
+                            -Xep:NullOptional:ERROR
+                            -XepExcludedPaths:.*/src/test/java/.*
+                        </arg>
+                    </compilerArgs>
+                    <annotationProcessorPaths>
+                        <path>
+                            <groupId>com.google.errorprone</groupId>
+                            <artifactId>error_prone_core</artifactId>
+                            <version>2.18.0</version>
+                        </path>
+                        <!-- Other annotation processors go here -->
+                    </annotationProcessorPaths>
                 </configuration>
             </plugin>