#27 Avoiding dependency to Guava

javac-plugin/pom.xml

@@ -45,10 +45,6 @@
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>
         </dependency>
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-        </dependency>
 
         <dependency>
             <groupId>junit</groupId>

javac-plugin/src/main/java/org/moditect/deptective/internal/graph/GraphUtils.java

@@ -15,42 +15,41 @@
  */
 package org.moditect.deptective.internal.graph;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.stream.Collectors;
 
 import org.moditect.deptective.internal.graph.impl.DependencyStructureMatrix;
 import org.moditect.deptective.internal.graph.impl.FastFasSorter;
 import org.moditect.deptective.internal.graph.impl.Tarjan;
 
 /**
- * 
+ *
  * @author Gerd Wütherich ([email protected])
  */
 public class GraphUtils {
 
     /**
      * A directed graph is called strongly connected if there is a path in each direction between each pair of vertices
      * of the graph. A strongly connected component (SCC) of a directed graph is a maximal strongly connected subgraph.
-     * 
+     *
      * @param nodes the collection of nodes (the directed graph)
      * @return a list of strongly connected components (SCCs). Note that the result also contains components that
      *         contain just a single node. If you want to detect 'real' cycle (size > 1) please use {@link GraphUtils#detectCycles(Collection)}.
      */
     public static List<List<Node>> detectStronglyConnectedComponents(Collection<Node> nodes) {
-        return new Tarjan<Node>().detectStronglyConnectedComponents(checkNotNull(nodes));
+        return new Tarjan<Node>().detectStronglyConnectedComponents(Objects.requireNonNull(nodes));
     }
 
     /**
-     * Returns all strongly connected subgraphs (size > 1) of the specified graph. 
-     * 
-     * @param nodes 
+     * Returns all strongly connected subgraphs (size > 1) of the specified graph.
+     *
+     * @param nodes
      * @return a list of strongly connected components (SCCs) with a size > 1.
      */
     public static List<List<Node>> detectCycles(Collection<Node> nodes) {
@@ -59,8 +58,8 @@ public static List<List<Node>> detectCycles(Collection<Node> nodes) {
     }
 
     /**
-     * Creates a dependency structure matrix (DSM) for the given graph nodes. 
-     * 
+     * Creates a dependency structure matrix (DSM) for the given graph nodes.
+     *
      * @param nodes the collection of nodes
      * @return
      */
@@ -70,21 +69,21 @@ public static IDependencyStructureMatrix createDependencyStructureMatrix(
     }
 
     /**
-     * An adjacency matrix is a square matrix used to represent a finite graph. The elements of the matrix 
+     * An adjacency matrix is a square matrix used to represent a finite graph. The elements of the matrix
      * indicate whether pairs of vertices are connected (adjacent) or not in the graph.
-     * 
+     *
      * @param nodes the collection of nodes
      * @return the adjacency matrix for the given list of nodes
      */
     public static int[][] computeAdjacencyMatrix(List<Node> nodes) {
-        checkNotNull(nodes);
-        return computeAdjacencyMatrix((Node[]) nodes.toArray(new Node[nodes.size()]));
+        Objects.requireNonNull(nodes);
+        return computeAdjacencyMatrix(nodes.toArray(new Node[nodes.size()]));
     }
 
     /**
-     * An adjacency matrix is a square matrix used to represent a finite graph. The elements of the matrix 
+     * An adjacency matrix is a square matrix used to represent a finite graph. The elements of the matrix
      * indicate whether pairs of vertices are connected (adjacent) or not in the graph.
-     * 
+     *
      * @param nodes the array of nodes
      * @return the adjacency matrix for the given list of nodes
      */
@@ -100,26 +99,26 @@ public static int[][] computeAdjacencyMatrix(Node... nodes) {
     }
 
     /**
-     * An adjacency list is a collection of (unordered) lists used to represent a finite graph. Each list 
-     * describes the set of neighbors of a node. 
-     * 
+     * An adjacency list is a collection of (unordered) lists used to represent a finite graph. Each list
+     * describes the set of neighbors of a node.
+     *
      * @param nodes the array of nodes
      * @return the adjacency list for the given list of nodes
      */
     public static int[][] computeAdjacencyList(Collection<Node> nodes) {
-        checkNotNull(nodes);
-        return computeAdjacencyList((Node[]) nodes.toArray(new Node[nodes.size()]));
+        Objects.requireNonNull(nodes);
+        return computeAdjacencyList(nodes.toArray(new Node[nodes.size()]));
     }
 
     /**
-     * An adjacency list is a collection of (unordered) lists used to represent a finite graph. Each list 
-     * describes the set of neighbors of a node. 
-     * 
+     * An adjacency list is a collection of (unordered) lists used to represent a finite graph. Each list
+     * describes the set of neighbors of a node.
+     *
      * @param nodes the array of nodes
      * @return the adjacency list for the given list of nodes
      */
     public static int[][] computeAdjacencyList(Node... nodes) {
-       
+
         int[][] matrix;
 
         // prepare
@@ -149,7 +148,7 @@ public static int[][] computeAdjacencyList(Node... nodes) {
 
     /**
      * Creates a FastFAS based {@link INodeSorter}.
-     * 
+     *
      * @return a FastFAS based {@link INodeSorter}.
      */
     public static INodeSorter createFasNodeSorter() {

javac-plugin/src/main/java/org/moditect/deptective/internal/graph/Node.java

@@ -15,27 +15,23 @@
  */
 package org.moditect.deptective.internal.graph;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 import java.util.stream.Collectors;
 
-import org.moditect.deptective.internal.graph.Dependency;
-import org.moditect.deptective.internal.graph.Node;
-
 /**
  * @author Gerd Wütherich ([email protected])
  */
 public class Node {
 
     private Map<Node, Dependency> outgoingDependencies;
-    private String id;
+    private final String id;
 
     public Node(String id) {
-        this.id = checkNotNull(id);
+        this.id = Objects.requireNonNull(id);
     }
 
     public String getId() {
@@ -44,15 +40,15 @@ public String getId() {
 
     public Dependency getOutgoingDependencyTo(Node node) {
 
-        if (!hasOutgoingDependencies() || !outgoingDependencies.containsKey(checkNotNull(node))) {
+        if (!hasOutgoingDependencies() || !outgoingDependencies.containsKey(Objects.requireNonNull(node))) {
             return null;
         }
 
         return outgoingDependencies.get(node);
     }
 
     public Set<Dependency> getOutgoingDependenciesTo(Collection<Node> nodes) {
-        return checkNotNull(nodes).stream().map(node -> getOutgoingDependencyTo(node)).filter(dep -> dep != null)
+        return Objects.requireNonNull(nodes).stream().map(node -> getOutgoingDependencyTo(node)).filter(dep -> dep != null)
                 .collect(Collectors.toSet());
     }
 
@@ -61,7 +57,7 @@ public boolean hasOutgoingDependencies() {
     }
 
     public void addOutgoingDependency(Dependency dependency) {
-        checkNotNull(dependency);
+        Objects.requireNonNull(dependency);
         outgoingDependencies().put(dependency.getTo(), dependency);
     }
 
@@ -95,7 +91,7 @@ else if (!id.equals(other.id))
             return false;
         return true;
     }
-    
+
     private Map<Node, Dependency> outgoingDependencies() {
         if (outgoingDependencies == null) {
             outgoingDependencies = new HashMap<>();

javac-plugin/src/main/java/org/moditect/deptective/internal/graph/impl/DependencyStructureMatrix.java

@@ -15,12 +15,11 @@
  */
 package org.moditect.deptective.internal.graph.impl;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
 import java.util.stream.Collectors;
 
 import org.moditect.deptective.internal.graph.Dependency;
@@ -91,8 +90,7 @@ public List<List<Node>> getCycles() {
     }
 
     private void initialize(Collection<Node> unorderedArtifacts) {
-
-        checkNotNull(unorderedArtifacts);
+        Objects.requireNonNull(unorderedArtifacts);
 
         upwardDependencies = new ArrayList<>();
 
@@ -123,7 +121,7 @@ private void initialize(Collection<Node> unorderedArtifacts) {
         }
         Collections.reverse(orderedArtifacts);
         nodes = orderedArtifacts;
-        
+
         //
         cycles = c.stream().filter(nodeList -> nodeList.size() > 1).collect(Collectors.toList());
     }

javac-plugin/src/main/java/org/moditect/deptective/internal/graph/impl/FastFAS.java

@@ -15,18 +15,17 @@
  */
 package org.moditect.deptective.internal.graph.impl;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Objects;
 import java.util.Set;
 
 /**
  * <p>
  * http://dl.acm.org/citation.cfm?id=595057
  * </p>
- * 
+ *
  * @author Gerd W&uuml;therich ([email protected])
  */
 public class FastFAS {
@@ -50,18 +49,18 @@ public class FastFAS {
      * <p>
      * Creates a new instance of type {@link FastFAS}.
      * </p>
-     * 
+     *
      * @param adjacencyMatrix the adjacency matrix
      */
     public FastFAS(int[][] adjacencyMatrix) {
-        this.adjacencyMatrix = checkNotNull(adjacencyMatrix);
+        this.adjacencyMatrix = Objects.requireNonNull(adjacencyMatrix);
     }
 
     /**
      * <p>
      * Returns the ordered sequence.
      * </p>
-     * 
+     *
      * @return the ordered sequence.
      */
     public int[] getOrderedSequence() {
@@ -101,9 +100,7 @@ public List<Integer[]> getSkippedEdge() {
     }
 
     public static int[] reverse(int[] sequence) {
-
-        //
-        checkNotNull(sequence);
+        Objects.requireNonNull(sequence);
 
         //
         int[] result = new int[sequence.length];
@@ -119,7 +116,7 @@ public static int[] reverse(int[] sequence) {
      * <p>
      * Tries to find and remove a sink.
      * </p>
-     * 
+     *
      * @return <code>true</code> if a sink was found and removed.
      */
     private boolean findSink() {
@@ -157,7 +154,7 @@ private boolean findSink() {
      * <p>
      * Tries to find and remove a source.
      * </p>
-     * 
+     *
      * @return <code>true</code> if a source was found and removed.
      */
     private boolean findSource() {
@@ -194,7 +191,7 @@ private boolean findSource() {
     /**
      * <p>
      * </p>
-     * 
+     *
      * @return
      */
     private boolean findVertexToRemove() {
@@ -229,7 +226,7 @@ private boolean findVertexToRemove() {
     /**
      * <p>
      * </p>
-     * 
+     *
      * @param vertex
      * @return
      */
@@ -253,7 +250,7 @@ private int getDelta(int vertex) {
      * <p>
      * Helper method. Concatenates the given lists and returns them as one array.
      * </p>
-     * 
+     *
      * @param s1 the list s1
      * @param s2 the list s2
      * @return the result array.

javac-plugin/src/main/java/org/moditect/deptective/internal/graph/impl/Tarjan.java

@@ -15,35 +15,34 @@
  */
 package org.moditect.deptective.internal.graph.impl;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import java.util.Objects;
 
 import org.moditect.deptective.internal.graph.GraphUtils;
 import org.moditect.deptective.internal.graph.Node;
 
 public class Tarjan<T extends Node> {
 
     private int _index = 0;
-    private ArrayList<Integer> _stack = new ArrayList<Integer>();
-    private List<List<T>> _stronglyConnectedComponents = new ArrayList<List<T>>();
+    private final ArrayList<Integer> _stack = new ArrayList<Integer>();
+    private final List<List<T>> _stronglyConnectedComponents = new ArrayList<List<T>>();
     int[] _vlowlink;
     int[] _vindex;
 
     private Node[] _artifacts;
 
     public List<List<T>> detectStronglyConnectedComponents(Collection<? extends T> artifacts) {
-        checkNotNull(artifacts);
+        Objects.requireNonNull(artifacts);
 
         _artifacts = artifacts.toArray(new Node[0]);
         int[][] adjacencyList = GraphUtils.computeAdjacencyList(_artifacts);
         return executeTarjan(adjacencyList);
     }
 
     private List<List<T>> executeTarjan(int[][] graph) {
-        checkNotNull(graph);
+        Objects.requireNonNull(graph);
 
         _stronglyConnectedComponents.clear();
         _index = 0;
@@ -66,8 +65,8 @@ private List<List<T>> executeTarjan(int[][] graph) {
 
     @SuppressWarnings("unchecked")
     private void tarjan(int v, int[][] graph) {
-        checkNotNull(v);
-        checkNotNull(graph);
+        Objects.requireNonNull(v);
+        Objects.requireNonNull(graph);
 
         _vindex[v] = _index;
         _vlowlink[v] = _index;

pom.xml

@@ -66,11 +66,6 @@
                 <artifactId>jackson-databind</artifactId>
                 <version>2.9.8</version>
             </dependency>
-            <dependency>
-                <groupId>com.google.guava</groupId>
-                <artifactId>guava</artifactId>
-                <version>27.0.1-jre</version>
-            </dependency>
         </dependencies>
     </dependencyManagement>