[FAB-4366] Java SDK release process document

Release process document explains how to publish java jar
to nexus/maven. All the steps included here applicable to
manual release.

Change-Id: I3dd7d71464dfb52d5b3fe45e5848b0a0b640c00f
Signed-off-by: rameshbabu <rameshbabu.thoomu@gmail.com>

docs/java_sdk_release.md

@@ -0,0 +1,148 @@
+# Java SDK Release Process Document:
+
+Below are the steps explains how to publish Hyperledger Fabric sdk-java jar file to OSSRH
+(Open Source Software Repository Hosting) and then to Maven central.
+Sonatype OSSRH uses Sonatype Nexus Repository Manager to provide repository hosting service for
+Open source projects like Hyperledger Fabric.
+
+OSSRH uses the Maven repository format and allow you to
+
+1) deploy development version (snapshots)
+2) stage release binaries
+3) promote release and sync them to Maven central repository
+
+Before you deploy developement version or stable release, you have to follow below steps
+to continue further
+
+1) Create JIRA account (https://issues.sonatype.org/secure/Signup!default.jspa)
+2) Create a new Project
+See this example for reference
+https://issues.sonatype.org/browse/OSSRH-30331
+
+Make sure your requested project is created and JIRA ticket is marked a Resolved.
+
+Add below lines in **pom.xml**
+
+```
+<distributionManagement>
+        <snapshotRepository>
+            <id>ossrh</id>
+            <url>https://oss.sonatype.org/content/repositories/snapshots</url>
+        </snapshotRepository>
+</distributionManagement>
+```
+
+```
+<configuration>
+            <serverId>ossrh</serverId>
+            <nexusUrl>https://oss.sonatype.org/</nexusUrl>
+            <autoReleaseAfterClose>false</autoReleaseAfterClose>
+</configuration>
+```
+
+Add below lines in **settings.xml**
+
+```
+<settings>
+    <servers>
+        <server>
+            <id>ossrh</id>
+            <username>${env.OSSRH_USER_TOKEN}</username>
+            <password>${env.OSSRH_PWD_TOKEN}</password>
+        </server>
+     </servers>
+   <profiles>
+        <profile>
+            <id>ossrh</id>
+            <activation>
+                <activeByDefault>true</activeByDefault>
+            </activation>
+            <properties>
+                <gpg.keyname>${env.GPG_KEY}</gpg.keyname>
+                <gpg.passphrase>${env.GPG_PWD}</gpg.passphrase>
+            </properties>
+        </profile>
+    </profiles>
+</settings>
+```
+Please make sure **settings.xml** is copied in maven home path.
+Verify **settings.xml** in `cd ~/.m2/`. Follow below steps to publish java jar artifacts to
+nexus/maven repository using Maven approach.
+
+### Step 1: Export Environment Variables
+
+Make sure values are passed to the environment variables placed in settings.xml file
+
+```
+export OSSRH_USER_TOKEN=ossrh ID
+export OSSRH_PWD_TOKEN=ossrh pwd
+```
+### Step 2: Generate gpg keys.
+
+Follow below link to generate gpg keys http://central.sonatype.org/pages/working-with-pgp-signatures.html
+
+Follow below steps to generate gpg keys:
+
+- Execute below command to generate gpg key to sign artifacts
+
+      `gpg --gen-key` Stick to the defaulut values like
+     - Key type should be RSA & RSA (default)
+     - Key Size should be 2048 (default)
+     - Key valid for 0 (defaulut)
+     - Confirm above section - (y)
+     - Provide Real Name (ossrh userid)
+     - Provide email address (associated to the ossrh userid)
+     - Provide comment ( Any of your choice)
+     - Confirm the selection (Type O for Okay)
+     - Enter Passphrase (remember this) and re-enter Passphrase
+
+After provide the correct information above, it generates gpg keys.
+If the process taking time to generate gpg key, perform some other actions like accessing keyboard,
+mouse and accessing disk usage to fasten the process.
+
+- List out generated gpg keys
+      `gpg2 --list-keys`
+ex:
+```
+/home/juven/.gnupg/pubring.gpg
+------------------------------
+pub   1024D/E8EBD57A 2017-06-17
+uid                  Juven Xu (Juven Xu works at Sonatype) <juven@sonatype.com>
+sub   2048g/D704745C 2017-06-17
+```
+
+- Distribute public key
+
+Run below command to distribute public key
+
+`gpg2 --keyserver hkp://pool.sks-keyservers.net --send-keys E8EBD57A`
+
+```
+export GPG_KEY=<gpg public key> (E8EBD57A)
+export GPG_PWD=<passphrase>
+```
+### Step 3: Deploy Artifact
+
+Execute below command from fabric-sdk-java directory to build and publish java jar artifact to
+maven repository
+
+```
+mvn clean install deploy -P release -s settings.xml -DskipITs=false -Dmaven.test.failure.ignore=false
+```
+
+Once the command is successfully execute, you will see fabric-sdk-java artifacts in maven central
+repository https://mvnrepository.com/artifact/org.hyperledger.fabric-sdk-java/fabric-sdk-java
+and snapshot java artifacts in nexus repository
+https://oss.sonatype.org/content/repositories/snapshots/org/hyperledger/fabric-sdk-java/fabric-sdk-java/
+
+### Step 4: Perform Release to Maven
+
+Promote release build from sonatype nexus the artifact is successfully pushed to
+https://oss.sonatype.org/#stagingProfiles. Wait for sometime to syncup this release in maven central
+repository. If everything goes fine, published artifact should be available in maven central repository.
+
+https://mvnrepository.com/artifact/org.hyperledger.fabric-sdk-java/fabric-sdk-java
+
+# Test Java SDK jar file using sample APP
+
+[TODO]