Build jar with correct version string automatically (Fixes #280)

build.gradle

@@ -64,6 +64,15 @@ if (JavaVersion.current().isJava8Compatible()) {
   }
 }
 
+task writeSshjVersionProperties << {
+  project.file("${project.buildDir}/resources/main").mkdirs()
+  project.file("${project.buildDir}/resources/main/sshj.properties").withWriter { w ->
+    w.append("sshj.version=${version}")
+  }
+}
+
+jar.dependsOn writeSshjVersionProperties
+
 jar {
   manifest {
     instruction "Bundle-Description", "SSHv2 library for Java"

src/main/java/net/schmizz/sshj/DefaultConfig.java

@@ -38,10 +38,8 @@ import net.schmizz.sshj.userauth.keyprovider.PKCS8KeyFile;
 import net.schmizz.sshj.userauth.keyprovider.PuTTYKeyFile;
 import org.slf4j.Logger;
 
-import java.util.Arrays;
-import java.util.Iterator;
-import java.util.LinkedList;
-import java.util.List;
+import java.io.IOException;
+import java.util.*;
 
 /**
  * A {@link net.schmizz.sshj.Config} that is initialized as follows. Items marked with an asterisk are added to the config only if
@@ -68,13 +66,11 @@ import java.util.List;
 public class DefaultConfig
         extends ConfigImpl {
 
-    private static final String VERSION = "SSHJ_0_17_2";
-
     private Logger log;
 
     public DefaultConfig() {
         setLoggerFactory(LoggerFactory.DEFAULT);
-        setVersion(VERSION);
+        setVersion(readVersionFromProperties());
         final boolean bouncyCastleRegistered = SecurityUtils.isBouncyCastleRegistered();
         initKeyExchangeFactories(bouncyCastleRegistered);
         initRandomFactory(bouncyCastleRegistered);
@@ -86,6 +82,18 @@ public class DefaultConfig
         setKeepAliveProvider(KeepAliveProvider.HEARTBEAT);
     }
 
+    private String readVersionFromProperties() {
+        try {
+            Properties properties = new Properties();
+            properties.load(Thread.currentThread().getContextClassLoader().getResourceAsStream("sshj.properties"));
+            String property = properties.getProperty("sshj.version");
+            return "SSHJ_" + property.replace('-', '_'); // '-' is a disallowed character, see RFC-4253#section-4.2
+        } catch (IOException e) {
+            log.error("Could not read the sshj.properties file, returning an 'unknown' version as fallback.");
+            return "SSHJ_VERSION_UNKNOWN";
+        }
+    }
+
     @Override
     public void setLoggerFactory(LoggerFactory loggerFactory) {
 	super.setLoggerFactory(loggerFactory);

src/test/resources/sshj.properties

@@ -0,0 +1,17 @@
+#
+# Copyright (C)2009 - SSHJ Contributors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+sshj.version=0.18.0