Introduction of Java 8, dependency to guava resolved (issue #40)

pom.xml

@@ -60,16 +60,30 @@
             <artifactId>annotations</artifactId>
         </dependency>
 
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-        </dependency>
-
         <!-- for testing -->
         <dependency>
             <groupId>org.testng</groupId>
             <artifactId>testng</artifactId>
             <scope>test</scope>
         </dependency>
     </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+            <!-- //TODO the Jacoco version of the parent project isn't compatible with Java 8 -->
+            <plugin>
+                <groupId>org.jacoco</groupId>
+                <artifactId>jacoco-maven-plugin</artifactId>
+                <version>0.7.5.201505241946</version>
+            </plugin>
+        </plugins>
+    </build>
 </project>

src/main/java/io/airlift/airline/Accessor.java

@@ -1,22 +1,21 @@
 package io.airlift.airline;
 
-import com.google.common.base.Function;
-import com.google.common.base.Joiner;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.Iterables;
+import io.airlift.airline.util.ArgumentChecker;
+import io.airlift.airline.util.CollectionUtils;
 
 import java.lang.reflect.Field;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
 import java.lang.reflect.TypeVariable;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.SortedSet;
 import java.util.TreeSet;
+import java.util.stream.Collectors;
 
 public class Accessor
 {
@@ -27,23 +26,17 @@ public class Accessor
 
     public Accessor(Field... path)
     {
-        this(ImmutableList.copyOf(path));
+        this(Arrays.asList(path));
     }
 
     public Accessor(Iterable<Field> path)
     {
-        Preconditions.checkNotNull(path, "path is null");
-        Preconditions.checkArgument(!Iterables.isEmpty(path), "path is empty");
-
-        this.path = ImmutableList.copyOf(path);
-        this.name = this.path.get(0).getDeclaringClass().getSimpleName() + "." + Joiner.on('.').join(Iterables.transform(this.path, new Function<Field, String>()
-        {
-            public String apply(Field field)
-            {
-                return field.getName();
-            }
-        }));
+        ArgumentChecker.checkNotNull(path, "path is null");
+        ArgumentChecker.checkCondition(path.iterator().hasNext(), "path is empty");
+
+        this.path = CollectionUtils.asList(path);
 
+        this.name = this.path.get(0).getDeclaringClass().getSimpleName() + '.' + this.path.stream().map(Field::getName).collect(Collectors.joining("."));
 
         Field field = this.path.get(this.path.size() - 1);
         multiValued = Collection.class.isAssignableFrom(field.getType());
@@ -91,7 +84,7 @@ public Object getValue(Object instance)
 
     public void addValues(Object commandInstance, Iterable<?> values)
     {
-        if (Iterables.isEmpty(values)) {
+        if (!values.iterator().hasNext()) {
             return;
         }
 
@@ -100,13 +93,19 @@ public void addValues(Object commandInstance, Iterable<?> values)
 
         Field field = path.get(path.size() - 1);
         field.setAccessible(true);
+
+        final List<?> valueList = CollectionUtils.asList(values);
         if (Collection.class.isAssignableFrom(field.getType())) {
             Collection<Object> collection = getOrCreateCollectionField(name, instance, field);
-            Iterables.addAll(collection, values);
+            collection.addAll(valueList);
         }
         else {
             try {
-                field.set(instance, Iterables.getLast(values));
+                if(valueList.isEmpty()) {
+                    field.set(instance, null);
+                } else {
+                    field.set(instance, valueList.get(valueList.size() - 1));
+                }
             }
             catch (Exception e) {
                 throw new ParseException(e, "Error setting %s for argument %s", field.getName(), name);

src/main/java/io/airlift/airline/Cli.java

@@ -18,30 +18,29 @@
 
 package io.airlift.airline;
 
-import com.google.common.base.Function;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
-import com.google.common.collect.Iterables;
 import io.airlift.airline.model.ArgumentsMetadata;
 import io.airlift.airline.model.CommandGroupMetadata;
 import io.airlift.airline.model.CommandMetadata;
 import io.airlift.airline.model.GlobalMetadata;
 import io.airlift.airline.model.MetadataLoader;
 import io.airlift.airline.model.OptionMetadata;
+import io.airlift.airline.util.ArgumentChecker;
+import io.airlift.airline.util.CollectionUtils;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.stream.Collectors;
 
-import static com.google.common.collect.Lists.newArrayList;
-import static com.google.common.collect.Maps.newHashMap;
 import static io.airlift.airline.ParserUtil.createInstance;
 
 public class Cli<C>
 {
     public static <T> CliBuilder<T> builder(String name)
     {
-        Preconditions.checkNotNull(name, "name is null");
+        ArgumentChecker.checkNotNull(name, "name is null");
         return new CliBuilder<T>(name);
     }
 
@@ -66,8 +65,8 @@ private Cli(String name,
             Iterable<Class<? extends C>> defaultGroupCommands,
             Iterable<GroupBuilder<C>> groups)
     {
-        Preconditions.checkNotNull(name, "name is null");
-        Preconditions.checkNotNull(typeConverter, "typeConverter is null");
+        ArgumentChecker.checkNotNull(name, "name is null");
+        ArgumentChecker.checkNotNull(typeConverter, "typeConverter is null");
 
         CommandMetadata defaultCommandMetadata = null;
         if (defaultCommand != null) {
@@ -76,13 +75,9 @@ private Cli(String name,
 
         List<CommandMetadata> defaultCommandGroup = MetadataLoader.loadCommands(defaultGroupCommands);
 
-        List<CommandGroupMetadata> commandGroups = ImmutableList.copyOf(Iterables.transform(groups, new Function<GroupBuilder<C>, CommandGroupMetadata>()
-        {
-            public CommandGroupMetadata apply(GroupBuilder<C> group)
-            {
-                return MetadataLoader.loadCommandGroup(group.name, group.description, MetadataLoader.loadCommand(group.defaultCommand), MetadataLoader.loadCommands(group.commands));
-            }
-        }));
+        List<CommandGroupMetadata> commandGroups = CollectionUtils.asList(groups).stream()
+                .map(group -> MetadataLoader.loadCommandGroup(group.name, group.description, MetadataLoader.loadCommand(group.defaultCommand), MetadataLoader.loadCommands(group.commands)))
+                .collect(Collectors.toList());
 
         this.metadata = MetadataLoader.loadGlobal(name, description, defaultCommandMetadata, defaultCommandGroup, commandGroups);
     }
@@ -94,12 +89,12 @@ public GlobalMetadata getMetadata()
 
     public C parse(String... args)
     {
-        return parse(ImmutableList.copyOf(args));
+        return parse(Arrays.asList(args));
     }
 
     public C parse(Iterable<String> args)
     {
-        Preconditions.checkNotNull(args, "args is null");
+        ArgumentChecker.checkNotNull(args, "args is null");
 
         Parser parser = new Parser();
         ParseState state = parser.parse(metadata, args);
@@ -123,7 +118,7 @@ public C parse(Iterable<String> args)
                 command.getArguments(),
                 state.getParsedArguments(),
                 command.getMetadataInjections(),
-                ImmutableMap.<Class<?>, Object>of(GlobalMetadata.class, metadata));
+                CollectionUtils.<Class<?>, Object>asMap(GlobalMetadata.class, metadata));
     }
 
     private void validate(ParseState state)
@@ -170,38 +165,24 @@ public static class CliBuilder<C>
         protected TypeConverter typeConverter = new TypeConverter();
         protected String optionSeparators;
         private Class<? extends C> defaultCommand;
-        private final List<Class<? extends C>> defaultCommandGroupCommands = newArrayList();
-        protected final Map<String, GroupBuilder<C>> groups = newHashMap();
+        private final List<Class<? extends C>> defaultCommandGroupCommands = new ArrayList<>();
+        protected final Map<String, GroupBuilder<C>> groups = new HashMap<>();
 
         public CliBuilder(String name)
         {
-            Preconditions.checkNotNull(name, "name is null");
-            Preconditions.checkArgument(!name.isEmpty(), "name is empty");
+            ArgumentChecker.checkNotNull(name, "name is null");
+            ArgumentChecker.checkCondition(!name.isEmpty(), "name is empty");
             this.name = name;
         }
 
         public CliBuilder<C> withDescription(String description)
         {
-            Preconditions.checkNotNull(description, "description is null");
-            Preconditions.checkArgument(!description.isEmpty(), "description is empty");
+            ArgumentChecker.checkNotNull(description, "description is null");
+            ArgumentChecker.checkCondition(!description.isEmpty(), "description is empty");
             this.description = description;
             return this;
         }
 
-//        public CliBuilder<C> withTypeConverter(TypeConverter typeConverter)
-//        {
-//            Preconditions.checkNotNull(typeConverter, "typeConverter is null");
-//            this.typeConverter = typeConverter;
-//            return this;
-//        }
-
-//        public CliBuilder<C> withOptionSeparators(String optionsSeparator)
-//        {
-//            Preconditions.checkNotNull(optionsSeparator, "optionsSeparator is null");
-//            this.optionSeparators = optionsSeparator;
-//            return this;
-//        }
-
         public CliBuilder<C> withDefaultCommand(Class<? extends C> defaultCommand)
         {
             this.defaultCommand = defaultCommand;
@@ -217,20 +198,20 @@ public CliBuilder<C> withCommand(Class<? extends C> command)
         public CliBuilder<C> withCommands(Class<? extends C> command, Class<? extends C>... moreCommands)
         {
             this.defaultCommandGroupCommands.add(command);
-            this.defaultCommandGroupCommands.addAll(ImmutableList.copyOf(moreCommands));
+            this.defaultCommandGroupCommands.addAll(Arrays.asList(moreCommands));
             return this;
         }
 
         public CliBuilder<C> withCommands(Iterable<Class<? extends C>> commands)
         {
-            this.defaultCommandGroupCommands.addAll(ImmutableList.copyOf(commands));
+            this.defaultCommandGroupCommands.addAll(CollectionUtils.asList(commands));
             return this;
         }
 
         public GroupBuilder<C> withGroup(String name)
         {
-            Preconditions.checkNotNull(name, "name is null");
-            Preconditions.checkArgument(!name.isEmpty(), "name is empty");
+            ArgumentChecker.checkNotNull(name, "name is null");
+            ArgumentChecker.checkCondition(!name.isEmpty(), "name is empty");
 
             if (groups.containsKey(name)) {
                 return groups.get(name);
@@ -253,48 +234,48 @@ public static class GroupBuilder<C>
         private String description = null;
         private Class<? extends C> defaultCommand = null;
 
-        private final List<Class<? extends C>> commands = newArrayList();
+        private final List<Class<? extends C>> commands = new ArrayList<>();
 
         private GroupBuilder(String name)
         {
-            Preconditions.checkNotNull(name, "name is null");
+            ArgumentChecker.checkNotNull(name, "name is null");
             this.name = name;
         }
 
         public GroupBuilder<C> withDescription(String description)
         {
-            Preconditions.checkNotNull(description, "description is null");
-            Preconditions.checkArgument(!description.isEmpty(), "description is empty");
-            Preconditions.checkState(this.description == null, "description is already set");
+            ArgumentChecker.checkNotNull(description, "description is null");
+            ArgumentChecker.checkCondition(!description.isEmpty(), "description is empty");
+            ArgumentChecker.checkCondition(this.description == null, "description is already set");
             this.description = description;
             return this;
         }
 
         public GroupBuilder<C> withDefaultCommand(Class<? extends C> defaultCommand)
         {
-            Preconditions.checkNotNull(defaultCommand, "defaultCommand is null");
-            Preconditions.checkState(this.defaultCommand == null, "defaultCommand is already set");
+            ArgumentChecker.checkNotNull(defaultCommand, "defaultCommand is null");
+            ArgumentChecker.checkCondition(this.defaultCommand == null, "defaultCommand is already set");
             this.defaultCommand = defaultCommand;
             return this;
         }
 
         public GroupBuilder<C> withCommand(Class<? extends C> command)
         {
-            Preconditions.checkNotNull(command, "command is null");
+            ArgumentChecker.checkNotNull(command, "command is null");
             commands.add(command);
             return this;
         }
 
         public GroupBuilder<C> withCommands(Class<? extends C> command, Class<? extends C>... moreCommands)
         {
             this.commands.add(command);
-            this.commands.addAll(ImmutableList.copyOf(moreCommands));
+            this.commands.addAll(Arrays.asList(moreCommands));
             return this;
         }
 
         public GroupBuilder<C> withCommands(Iterable<Class<? extends C>> commands)
         {
-            this.commands.addAll(ImmutableList.copyOf(commands));
+            this.commands.addAll(CollectionUtils.asList(commands));
             return this;
         }
     }

src/main/java/io/airlift/airline/CommandGroupUsage.java

@@ -1,17 +1,17 @@
 package io.airlift.airline;
 
-import com.google.common.base.Preconditions;
 import io.airlift.airline.model.CommandGroupMetadata;
 import io.airlift.airline.model.CommandMetadata;
 import io.airlift.airline.model.GlobalMetadata;
 import io.airlift.airline.model.OptionMetadata;
+import io.airlift.airline.util.ArgumentChecker;
 
 import javax.annotation.Nullable;
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
 
-import static com.google.common.collect.Lists.newArrayList;
 import static io.airlift.airline.UsageHelper.DEFAULT_COMMAND_COMPARATOR;
 import static io.airlift.airline.UsageHelper.DEFAULT_OPTION_COMPARATOR;
 
@@ -39,7 +39,7 @@ public CommandGroupUsage(int columnSize, boolean hideGlobalOptions)
 
     public CommandGroupUsage(int columnSize, boolean hideGlobalOptions, @Nullable Comparator<? super OptionMetadata> optionComparator)
     {
-        Preconditions.checkArgument(columnSize > 0, "columnSize must be greater than 0");
+        ArgumentChecker.checkCondition(columnSize > 0, "columnSize must be greater than 0");
         this.columnSize = columnSize;
         this.hideGlobalOptions = hideGlobalOptions;
         this.optionComparator = optionComparator;
@@ -84,7 +84,7 @@ public void usage(@Nullable GlobalMetadata global, CommandGroupMetadata group, U
         out.append("SYNOPSIS").newline();
         UsagePrinter synopsis = out.newIndentedPrinter(8).newPrinterWithHangingIndent(8);
 
-        List<CommandMetadata> commands = newArrayList(group.getCommands());
+        List<CommandMetadata> commands = new ArrayList<>(group.getCommands());
         Collections.sort(commands, commandComparator);
 
         if (group.getDefaultCommand() != null) {
@@ -114,7 +114,7 @@ public void usage(@Nullable GlobalMetadata global, CommandGroupMetadata group, U
         //
         // OPTIONS
         //
-        List<OptionMetadata> options = newArrayList();
+        List<OptionMetadata> options = new ArrayList<>();
         options.addAll(group.getOptions());
         if (global != null && !hideGlobalOptions) {
             options.addAll(global.getOptions());