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Thread: Exception in thread "main" java.lang.NullPointerException

  1. #1
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    Default Exception in thread "main" java.lang.NullPointerException

    So ive been working on this RPG for awhile now but i keep getting this cursed error
    DEBUG 11:02:35,740 [main] org.game.orpg.server.ServerConfig - Loaded
    INFO  11:02:35,741 [main] org.game.orpg.server.Server - Starting server
    INFO  11:02:35,779 [main] org.game.orpg.common.maps.BackgroundMapper - 84 background tiles loaded.
    Exception in thread "main" java.lang.NullPointerException
    ERROR 11:02:35,781 [main] org.game.orpg.common.maps.ArchetypeManager2 - Archetypes file not found, raising exception
    	at org.game.orpg.common.util.StreamUtil.readLine(StreamUtil.java:13)
    	at org.game.orpg.common.maps.ArchetypeManager2.loadFromFile(ArchetypeManager2.java:120)
    	at org.game.orpg.common.maps.ArchetypeManager2.<init>(ArchetypeManager2.java:49)
    	at org.game.orpg.common.maps.ArchetypeManager2.getInstance(ArchetypeManager2.java:43)
    	at org.game.orpg.server.Server.run(Server.java:32)
    	at org.game.orpg.server.ServerMain.main(ServerMain.java:21)

    These are all the files mentioned in the error

    package org.game.orpg.common.maps;
     
    import java.io.BufferedReader;
    import java.io.FileNotFoundException;
    import java.io.FileReader;
    import java.io.IOException;
    import java.util.Collections;
    import java.util.HashMap;
    import java.util.LinkedList;
    import java.util.List;
    import java.util.Map;
     
    import org.apache.log4j.Logger;
    import org.game.orpg.common.util.PathConfig;
    import org.game.orpg.common.util.StreamUtil;
     
    /**
     * Simple, non-XML archetype manager.
     * 
     * Archetypes are basically key/value pairs of strings. They also have single inheritance.
     * 
     * TODO: cache full archetypes
     */
    public class ArchetypeManager2 {
    	private static ArchetypeManager2 instance = null;
     
    	private static Logger logger = Logger.getLogger(ArchetypeManager2.class);
     
    	private static final String INHERITS = "inherits";
     
    	/**
    	 * archetype_name -> {key -> value}
    	 */
    	private Map<String,Map<String,String>> archetypes = Collections.synchronizedMap(new HashMap<String,Map<String,String>>());
     
    	/**
    	 * List of archetype names, in the order they were loaded from file.
    	 */
    	private List<String> archetypeList = Collections.synchronizedList(new LinkedList<String>());
     
    	public static ArchetypeManager2 getInstance() {
    		if (instance == null) {
    			instance = new ArchetypeManager2();
    		}
    		return instance;
    	}
     
    	public ArchetypeManager2() {
    		loadFromFile();
    	}
     
    	public synchronized Map<String,String> getArchetype(String name) {
    		return archetypes.get(name);
    	}
     
    	public synchronized String getArchetypeFace(String name) {
    		Map<String,String> props = getFullArchetype(name);
    		if (props != null && props.containsKey("face")) {
    			return props.get("face");
    		}
    		return null;
    	}
     
    	public List<String> getArchetypeList() {
    		return archetypeList;
    	}
     
    	/**
    	 * Get archetype with inheritance.
    	 */
    	public synchronized Map<String,String> getFullArchetype(String name) {
    		Map<String,String> baseArch = getArchetype(name);
    		if (baseArch == null) {
    			return null;
    		}
     
    		Map<String,String> result = new HashMap<String,String>(baseArch);
     
    		// now the inheritance part
    		String parentName = name;
    		String inherits = result.get(INHERITS);
    		while (inherits != null) {
    			Map<String,String> parent = getArchetype(inherits);
    			if (parent == null) {
    				logger.warn("Archetype '" + inherits + "' inherited by '" + parentName + "' is not defined, ignored");
    				break;
    			}
     
    			// Copy all non-existing keys from parent
    			for (Map.Entry<String,String> pair : parent.entrySet()) {
    				if (!result.containsKey(pair.getKey())) {
    					result.put(pair.getKey(), pair.getValue());
    				}
    			}
     
    			parentName = inherits;
    			inherits = parent.get(INHERITS);
    		}
    		result.remove(INHERITS);
     
    		return result;
    	}
     
    	public synchronized void loadFromFile() {
    		archetypeList.clear();
    		archetypes.clear();
     
    		String filename = PathConfig.getXmlDir() + "archetypes.txt";
     
    		BufferedReader in = null;
    		try {
    			in = new BufferedReader(new FileReader(filename));
    		} catch (FileNotFoundException e) {
    			logger.error("Archetypes file not found, raising exception");
    		}
     
    		String in_arch = null;
    		Map<String,String> archMap = null;
    		try {
    			for (String line = StreamUtil.readLine(in); line != null; line = StreamUtil.readLine(in)) {
    				String[] parts = line.split(" +", 2);
    				String key = parts[0];
    				String value = null;
    				if (parts.length > 1) {
    					value = parts[1];
    				}
     
    				if (in_arch != null) {
    					if (line.startsWith("</")) {
    						logger.trace("Added archetype '" + in_arch + "' with " + archMap.size() + " properties");
    						archetypes.put(in_arch, archMap);
    						archetypeList.add(in_arch);
    						in_arch = null;
    						archMap = null;
    					}
    					else {
    						archMap.put(key, value);
    					}
    				}
    				else {
    					if ("archetype".equals(key)) {
    						in_arch = value;
    						archMap = new HashMap<String,String>();
    					}
    					else {
    						logger.error("Unhandled line: " + line);
    					}
    				}
    			}
    		} catch (IOException e1) {
    			logger.error("loadFromFile() failed", e1);
    		}
     
    		try {
    			in.close();
    		} catch (IOException e) {
    			logger.error("loadFromFile() close failed", e);
    		}
     
    		logger.debug(archetypes.size() + " archetypes loaded");
    	}
     
    	public int size() {
    		return archetypeList.size();
    	}
     
    	public void reload() {
    		loadFromFile();
    	}
    }
    package org.game.orpg.common.util;
     
    import java.io.BufferedReader;
    import java.io.IOException;
     
    public class StreamUtil {
    	/**
    	 * Read a line from specially formatted file/stream. Empty/comment lines are skipped
    	 * and other lines trimmed.
    	 */
    	public static String readLine(BufferedReader in) throws IOException {
    		while (true) {
    			String line = in.readLine();
    			if (line == null) {
    				return line;
    			}
    			line = StringUtil.trimLeft(line);
    			if (line.length() != 0 && !line.startsWith("#")) {
    				return line;
    			}
    		}
    	}
    }
    package org.game.orpg.server;
     
    import java.net.ServerSocket;
    import java.net.Socket;
     
    import org.apache.log4j.Logger;
    import org.game.orpg.common.maps.ArchetypeManager2;
    import org.game.orpg.common.maps.BackgroundMapper;
     
    /**
     * The game server. Listens to connections from clients, and creates or loads necessary parts
     * of world to accommodate them. 
     */
    public class Server implements Runnable {
    	private static Logger logger = Logger.getLogger(Server.class);
     
    	private int port = ServerConfig.getInstance().getPropertyAsInt("server.port");
    	private ServerSocket socket;
     
    	private long bytesIn = 0;
    	private long bytesOut = 0;
     
    	public Server() {
    	}
     
        @Override
    	public void run() {
    		logger.info("Starting server");
     
    		BackgroundMapper.getInstance();
    		PlayerManager.getInstance();
    		ArchetypeManager2.getInstance();
     
    		logger.info("Initialization done");
     
    		// Start listening for incoming connections
    		try {
    			socket = new ServerSocket(port);
    		}
    		catch (Exception e) {
    			logger.error("Listen failed: " + e.getMessage());
    			return;
    		}
     
    		WorldThread.getInstance().start();
     
    		logger.info("Listening on port " + socket.getLocalPort());
     
    		// Create a ClientThread for each
    		while (!socket.isClosed()) {
    			Socket client = null;
    			try {
    				client = socket.accept();
    				logger.info("New connection from " + client.getRemoteSocketAddress());
    				Thread ct = new Thread(new ClientThread(client, this));
    				ct.setName("ClientThread");
    				ct.start();
    			}
    			catch (Exception e) {
    				logger.error("Accept failed", e);
    			}
    		}
    	}
     
    	public int getPort() {
    		return port;
    	}
     
    	public void setPort(int port) {
    		this.port = port;
    	}
     
    	public synchronized void incrementBytesTransferred(long in, long out) {
    		bytesIn += in;
    		bytesOut += out;
    	}
     
    	public long getBytesIn() {
    		return bytesIn;
    	}
     
    	public long getBytesOut() {
    		return bytesOut;
    	}
    }
    package org.game.orpg.server;
     
    public class ServerMain {
     
    	public static void main(String[] args) {
    		System.setProperty("log4j.configuration", "log4j-server.properties");
     
    		Server server = new Server();
     
    		for (int i = 0; i < args.length; i++) {
    			if ("--help".equals(args[i]) || "-h".equals(args[i])) {
    				System.out.println("Options:\n-p <port>\tListen on <port>\n\n");
    				System.exit(1);
    			}
    			else if ("--port".equals(args[i]) || "-p".equals(args[i])) {
    				server.setPort(Integer.parseInt(args[i+1]));
    				i++;
    			}
    		}
     
    		server.run();
    	}
     
    }

    If its any help I am pretty sure the error is in ArchetypeManager2


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: Exception in thread "main" java.lang.NullPointerException

    loadFromFile(ArchetypeManager2.java:120)
    What code is at line 120? It looks like it is making a call to StreamUtil.readLine
    Do all the variables used on that line have the right values?

    Also add a call to the printStackTrace method in the catch blocks so you get the FULL error message.

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