How to Quickstart graphhopper with my own graph - The Basics
graphhopper, java
Solution
If you don't want to use OSM as data source you have to options:
- Using the low level API via copy and pasting the code under GraphHopper.route. No need to reuse the GraphHopper class. But this is probably harder.
- Do `MyGraphHopper extends GraphHopper` and overload the necessary methods. Be sure you set the graph before the 'postProcessing' method is called. Which e.g. creates the shortcuts and builds the locationIndex.
BTW: in master GraphHopper.setGraph is public?
Problem
After two hard days getting through the unit tests and snippets of graphhopper on GitHub and the JavaDocs, thinking that I might be able to put all together in a very basic java app, I have to come to the conclusion, that I am not able :( All I want to do is: - Build a graph - Init graphhopper and configure it correctly - Load the graph - Route on it Thats my code so far: ``` package javaapplication1; import com.graphhopper.*; import com.graphhopper.routing.util.EncodingManager; import com.graphhopper.storage.GraphBuilder; import com.graphhopper.storage.GraphStorage; public class JavaApplication1 { protected static String location = "./tmp/graphstorage"; protected static String defaultGraph = "./tmp/graphstorage/default"; private static final EncodingManager encodingManager = new EncodingManager("CAR"); public static GraphStorage createGraph() { GraphStorage graph = new GraphBuilder(encodingManager).setLocation(location).create(); graph.setNode(0, 42, 10); graph.setNode(1, 42.1, 10.1); graph.setNode(2, 42.1, 10.2); graph.setNode(3, 42, 10.4); graph.setNode(4, 41.9, 10.2); graph.edge(0, 1, 10, true); graph.edge(1, 2, 10, false); graph.edge(2, 3, 10, true); graph.edge(0, 4, 40, true); graph.edge(4, 3, 40, true); return graph; } public static void main(String[] args) { double fromLat = 42; double fromLon = 10.4; double toLat = 42; double toLon = 10; GraphStorage gs = createGraph(); GraphHopperAPI instance = new GraphHopper() .setEncodingManager(encodingManager) .setGraphHopperLocation(location) .disableCHShortcuts(); GraphHopper hopper = (GraphHopper) instance; //hopper.setGraph(createGraph()); // protected because only for testing? hopper.load(location); GHResponse ph = hopper.route(new GHRequest(fromLat, fromLon, toLat, toLon)); if(ph.isFound()) { System.out.println(ph.getDistance()); System.out.println(ph.getPoints().getSize()); } else { System.out.println("No Route found!"); } } } ``` Java says: "Exception in thread "main" java.lang.IllegalStateException: Call load or importOrLoad before routing". But I am calling .load() on hopper, which unfortunately returns 'false', but I am not able to figure out why. My goal for this thread is to provide a very basic working code example of the GH Components and how to wire them up to solve the use case "Route on a graph, not loaded from OSM".