add json config parsing

.gitignore

@@ -15,5 +15,7 @@ buildNumber.properties
 .project
 # JDT-specific (Eclipse Java Development Tools)
 .classpath
-# Log files
+# retracker runtime files
 log/
+config.json
+retracker.pid

.settings/org.eclipse.core.resources.prefs

@@ -1,4 +1,5 @@
 eclipse.preferences.version=1
 encoding//src/main/java=UTF-8
+encoding//src/main/resources=UTF-8
 encoding//src/test/java=UTF-8
 encoding/<project>=UTF-8

notes.txt

@@ -12,7 +12,9 @@ on successful peer list retrieval - local tracker cache updated. If not, peers f
 On re-announce to destination trackers, proxied peer's real IP must be injected into announce request and
 other parameters should remain same as in original request.
 
-
+Whether retracker exposes its cache as tracker or not, the local tracker data shall be present all time.
+When there is need to expose local tracker a tracker endpoint should be declare in config. Tracker endpoint
+is HTTP or UDP server responsing to BitTorrent announces just like if it was any other regular torrent tracker.
 
 
 Maven exec with args:

pom.xml

@@ -60,6 +60,16 @@
     	<artifactId>logback-classic</artifactId>
     	<version>1.5.11</version>
     </dependency>
+    <dependency>
+    	<groupId>com.fasterxml.jackson.core</groupId>
+    	<artifactId>jackson-core</artifactId>
+    	<version>2.18.0</version>
+    </dependency>
+    <dependency>
+    	<groupId>com.fasterxml.jackson.core</groupId>
+    	<artifactId>jackson-databind</artifactId>
+    	<version>2.18.0</version>
+    </dependency>
   </dependencies>
 
   <build>

src/main/java/com/mykola2312/retracker/App.java

@@ -1,6 +1,7 @@
 package com.mykola2312.retracker;
 
 import java.io.File;
+import java.io.IOException;
 import java.nio.file.Path;
 
 import org.apache.commons.cli.CommandLine;
@@ -11,6 +12,8 @@ import org.apache.commons.cli.ParseException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.mykola2312.retracker.config.Config;
+
 import ch.qos.logback.classic.Level;
 import ch.qos.logback.classic.LoggerContext;
 import ch.qos.logback.classic.encoder.PatternLayoutEncoder;
@@ -21,9 +24,11 @@ public class App {
 	private static final Logger log = LoggerFactory.getLogger(App.class);
 	
 	public static void main(String[] args) {
+		final Option logDirOpt = new Option("l", "log", true, "log dir path");
+		final Option configFileOpt = new Option("c", "config", true, "config.json path");
 		final Options options = new Options()
-				.addOption("l", "log", true, "log dir path");
+				.addOption(configFileOpt)
-		final Option logDirOpt = options.getOption("log");
+				.addOption(logDirOpt);
 		
 		CommandLine cli = null;
 		try {
@@ -33,6 +38,21 @@ public class App {
 			System.exit(1);
 		}
 		
+		String configFilePath = cli.getOptionValue(configFileOpt);
+		if (configFilePath == null) {
+			System.err.println("config.json path not specified. exiting");
+			System.exit(1);
+		}
+		
+		// load config
+		Config config = null;
+		try {
+			config = Config.loadConfig(configFilePath);
+		} catch (IOException e) {
+			System.err.printf("failed to read %s: %s\n", configFilePath, e.toString());
+			System.exit(1);
+		}
+		
 		String logDirPath = cli.getOptionValue(logDirOpt);
 		if (logDirPath != null) {
 			// setup file logging

src/main/java/com/mykola2312/retracker/config/Config.java

@@ -0,0 +1,14 @@
+package com.mykola2312.retracker.config;
+
+import java.io.File;
+import java.io.IOException;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+public class Config {
+	public static Config loadConfig(String configPath) throws IOException {
+		return new ObjectMapper()
+				.readerFor(Config.class)
+					.readValue(new File(configPath));
+	}
+}