Java tutorial
/* * Created on Oct 17, 2005 * * Copyright (c) 2005, the JUNG Project and the Regents of the University * of California * All rights reserved. * * This software is open-source under the BSD license; see either * "license.txt" or * http://jung.sourceforge.net/license.txt for a description. */ package graph; import java.io.Serializable; import java.util.Collection; import java.util.Collections; import java.util.HashMap; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Set; import org.apache.commons.collections15.Factory; import edu.uci.ics.jung.graph.AbstractSparseGraph; import edu.uci.ics.jung.graph.DirectedGraph; import edu.uci.ics.jung.graph.util.EdgeType; import edu.uci.ics.jung.graph.util.Pair; @SuppressWarnings("serial") public class DependencyDirectedSparceMultiGraph<V, E> extends AbstractSparseGraph<V, E> implements DirectedGraph<V, E>, Serializable { public static <V, E> Factory<DirectedGraph<V, E>> getFactory() { return new Factory<DirectedGraph<V, E>>() { public DirectedGraph<V, E> create() { return new DependencyDirectedSparceMultiGraph<V, E>(); } }; } /** * * @author biggie * * @param <V> */ class Edge<V> { private Attributes _attr; private Pair<V> _edge; // Constructors protected Edge(V fromVertex_, V toVertex_) { _edge = new Pair<V>(fromVertex_, toVertex_); } protected Edge(V fromVertex_, V toVertex_, Attributes attr_) { _edge = new Pair<V>(fromVertex_, toVertex_); _attr = attr_; } protected Edge(Pair<V> edge_, Attributes attr_) { _edge = edge_; _attr = attr_; } protected Pair<V> getNodes() { return _edge; } protected Attributes getAttributes() { return _attr; } public boolean equals(Object o) { boolean compare = false; if (o instanceof Edge) { Edge<V> edgeToCompare = (Edge<V>) o; if (!equals(edgeToCompare)) { compare = _edge.equals(edgeToCompare.getNodes()); } } return compare; } } protected Map<V, Pair<Set<E>>> vertices; // Map of vertices to Pair of adjacency sets {incoming, outgoing} protected Map<E, Edge<V>> edges; // Map of edges to incident vertex pairs public DependencyDirectedSparceMultiGraph() { vertices = new HashMap<V, Pair<Set<E>>>(); edges = new HashMap<E, Edge<V>>(); } public Collection<E> getEdges() { return Collections.unmodifiableCollection(edges.keySet()); } public Collection<V> getVertices() { return Collections.unmodifiableCollection(vertices.keySet()); } public boolean containsVertex(V vertex) { return vertices.keySet().contains(vertex); } public boolean containsEdge(E edge) { return edges.keySet().contains(edge); } protected Collection<E> getIncoming_internal(V vertex) { return vertices.get(vertex).getFirst(); } protected Collection<E> getOutgoing_internal(V vertex) { return vertices.get(vertex).getSecond(); } public boolean addVertex(V vertex) { if (vertex == null) { throw new IllegalArgumentException("vertex may not be null"); } if (!vertices.containsKey(vertex)) { vertices.put(vertex, new Pair<Set<E>>(new HashSet<E>(), new HashSet<E>())); return true; } else { return false; } } public boolean removeVertex(V vertex) { if (!containsVertex(vertex)) return false; // copy to avoid concurrent modification in removeEdge Set<E> incident = new HashSet<E>(getIncoming_internal(vertex)); incident.addAll(getOutgoing_internal(vertex)); for (E edge : incident) removeEdge(edge); vertices.remove(vertex); return true; } public boolean removeEdge(E edge) { if (!containsEdge(edge)) return false; Pair<V> endpoints = this.getEndpoints(edge); V source = endpoints.getFirst(); V dest = endpoints.getSecond(); // remove edge from incident vertices' adjacency sets getOutgoing_internal(source).remove(edge); getIncoming_internal(dest).remove(edge); edges.remove(edge); return true; } public Collection<E> getInEdges(V vertex) { return Collections.unmodifiableCollection(getIncoming_internal(vertex)); } public Collection<E> getOutEdges(V vertex) { return Collections.unmodifiableCollection(getOutgoing_internal(vertex)); } public Collection<V> getPredecessors(V vertex) { Set<V> preds = new HashSet<V>(); for (E edge : getIncoming_internal(vertex)) preds.add(this.getSource(edge)); return Collections.unmodifiableCollection(preds); } public Collection<V> getSuccessors(V vertex) { Set<V> succs = new HashSet<V>(); for (E edge : getOutgoing_internal(vertex)) succs.add(this.getDest(edge)); return Collections.unmodifiableCollection(succs); } public Collection<V> getNeighbors(V vertex) { Collection<V> neighbors = new HashSet<V>(); for (E edge : getIncoming_internal(vertex)) neighbors.add(this.getSource(edge)); for (E edge : getOutgoing_internal(vertex)) neighbors.add(this.getDest(edge)); return Collections.unmodifiableCollection(neighbors); } public Collection<E> getIncidentEdges(V vertex) { Collection<E> incident = new HashSet<E>(); incident.addAll(getIncoming_internal(vertex)); incident.addAll(getOutgoing_internal(vertex)); return incident; } public E findEdge(V v1, V v2) { for (E edge : getOutgoing_internal(v1)) if (this.getDest(edge).equals(v2)) return edge; return null; } @Override public boolean addEdge(E edge, Pair<? extends V> endpoints) { return addEdge(edge, endpoints, EdgeType.DIRECTED, null); } @Override public boolean addEdge(E edge, Pair<? extends V> endpoints, EdgeType edgeType) { return addEdge(edge, endpoints, EdgeType.DIRECTED, null); } public boolean addEdge(E edge, V source, V dest, Attributes attr_) { return addEdge(edge, source, dest, EdgeType.DIRECTED, attr_); } public boolean addEdge(E edge, V source, V dest) { return addEdge(edge, source, dest, EdgeType.DIRECTED); } /** * Adds <code>edge</code> to the graph. Also adds * <code>source</code> and <code>dest</code> to the graph if they * are not already present. Returns <code>false</code> if * the specified edge (with the specified source and destination) are already * in the graph. */ public boolean addEdge(E edge, V source, V dest, EdgeType edgeType) { return addEdge(edge, new Pair<V>(source, dest), edgeType, null); } public boolean addEdge(E edge, V source, V dest, EdgeType edgeType, Attributes attr) { return addEdge(edge, new Pair<V>(source, dest), edgeType, attr); } public boolean addEdge(E edge, Pair<? extends V> endpoints, EdgeType edgeType, Attributes attr) { if (edgeType != EdgeType.DIRECTED) throw new IllegalArgumentException("This graph does not accept edges of type " + edgeType); return addEdge(edge, endpoints, attr); } public boolean addEdge(E edge, Pair<? extends V> endpoints, Attributes attr) { Pair<V> new_endpoints = getValidatedEndpoints(edge, endpoints); if (new_endpoints == null) return false; edges.put(edge, new Edge<V>(new_endpoints, attr)); V source = new_endpoints.getFirst(); V dest = new_endpoints.getSecond(); if (!vertices.containsKey(source)) this.addVertex(source); if (!vertices.containsKey(dest)) this.addVertex(dest); getIncoming_internal(dest).add(edge); getOutgoing_internal(source).add(edge); return true; } public V getSource(E edge) { return this.getEndpoints(edge).getFirst(); } public V getDest(E edge) { return this.getEndpoints(edge).getSecond(); } public boolean isSource(V vertex, E edge) { return vertex.equals(this.getEndpoints(edge).getFirst()); } public boolean isDest(V vertex, E edge) { return vertex.equals(this.getEndpoints(edge).getSecond()); } public Pair<V> getEndpoints(E edge) { return edges.get(edge).getNodes(); } public Attributes getEdgeAttributes(E edge) { return edges.get(edge).getAttributes(); } public EdgeType getEdgeType(E edge) { if (containsEdge(edge)) return EdgeType.DIRECTED; else return null; } public Collection<E> getEdges(EdgeType edgeType) { if (edgeType == EdgeType.DIRECTED) return getEdges(); else return null; } public int getEdgeCount() { return edges.size(); } public int getVertexCount() { return vertices.size(); } }