From d19e0587fa69876617ce47b9723e79280dc9fac3 Mon Sep 17 00:00:00 2001
From: Nick Dimiduk <ndimiduk@apache.org>
Date: Mon, 3 May 2021 12:28:15 -0700
Subject: [PATCH] HBASE-25841 Add basic jshell support

Signed-off-by: Bharath Vissapragada <bharathv@apache.org>
Signed-off-by: Pankaj Kumar <pankajkumar@apache.org>
Signed-off-by: Duo Zhang <zhangduo@apache.org>
---
 bin/hbase                                | 25 ++++++++++++++++++++++--
 bin/hbase_startup.jsh                    | 20 +++++++++++++++++++
 conf/hbase-env.sh                        |  3 +++
 src/main/asciidoc/_chapters/ops_mgt.adoc |  1 +
 4 files changed, 47 insertions(+), 2 deletions(-)
 create mode 100644 bin/hbase_startup.jsh

diff --git a/bin/hbase b/bin/hbase
index 59c48712b67..16516083375 100755
--- a/bin/hbase
+++ b/bin/hbase
@@ -54,6 +54,9 @@
 #   HBASE_SHELL_OPTS Extra options passed to the hbase shell.
 #                    Empty by default.
 #
+#   HBASE_JSHELL_ARGS Additional arguments passed to the jshell.
+#                     Defaults to `--startup DEFAULT --startup PRINTING --startup hbase_startup.jsh`
+#
 bin=`dirname "$0"`
 bin=`cd "$bin">/dev/null; pwd`
 
@@ -87,6 +90,7 @@ show_usage() {
     echo "  thrift2          Run the HBase Thrift2 server"
     echo "  clean            Run the HBase clean up script"
   fi
+  echo "  jshell           Run a jshell with HBase on the classpath"
   echo "  classpath        Dump hbase CLASSPATH"
   echo "  mapredcp         Dump CLASSPATH entries required by mapreduce"
   echo "  pe               Run PerformanceEvaluation"
@@ -506,6 +510,9 @@ if [[ $jruby_needed ]]; then
   fi
 fi
 
+# set default values for HBASE_JSHELL_ARGS
+read -r -a JSHELL_ARGS <<< "${HBASE_JSHELL_ARGS:-"--startup DEFAULT --startup PRINTING --startup ${HBASE_HOME}/bin/hbase_startup.jsh"}"
+
 # figure out which class to run
 if [ "$COMMAND" = "shell" ] ; then
 	#find the hbase ruby sources
@@ -525,6 +532,14 @@ if [ "$COMMAND" = "shell" ] ; then
     CLASS="org.jruby.Main -X+O ${JRUBY_OPTS} ${HBASE_HOME}/hbase-shell/src/main/ruby/jar-bootstrap.rb"
   fi
   HBASE_OPTS="$HBASE_OPTS $HBASE_SHELL_OPTS"
+elif [ "$COMMAND" = 'jshell' ] ; then
+  java_version="$(read_java_version)"
+  major_version_number="$(parse_java_major_version "${java_version}")"
+  if [ "${major_version_number}" -lt 9 ] ; then
+    echo "JShell is available only with JDK9 and lated. Detected JDK version is ${java_version}".
+    exit 1
+  fi
+  CLASS='jdk.internal.jshell.tool.JShellToolProvider'
 elif [ "$COMMAND" = "hbck" ] ; then
   # Look for the -j /path/to/HBCK2.jar parameter. Else pass through to hbck.
   case "${1}" in
@@ -778,9 +793,15 @@ if [ "${DEBUG}" = "true" ]; then
   HBASE_OPTS="${HBASE_OPTS} -Xdiag"
 fi
 
+# resolve the command arguments
+read -r -a CMD_ARGS <<< "$@"
+if [ "${#JSHELL_ARGS[@]}" -gt 0 ] ; then
+  CMD_ARGS=("${JSHELL_ARGS[@]}" "${CMD_ARGS[@]}")
+fi
+
 if [ "${HBASE_NOEXEC}" != "" ]; then
-  "$JAVA" -Dproc_$COMMAND -XX:OnOutOfMemoryError="kill -9 %p" $HEAP_SETTINGS $HBASE_OPTS $CLASS "$@"
+  "$JAVA" -Dproc_$COMMAND -XX:OnOutOfMemoryError="kill -9 %p" $HEAP_SETTINGS $HBASE_OPTS $CLASS "${CMD_ARGS[@]}"
 else
   export JVM_PID="$$"
-  exec "$JAVA" -Dproc_$COMMAND -XX:OnOutOfMemoryError="kill -9 %p" $HEAP_SETTINGS $HBASE_OPTS $CLASS "$@"
+  exec "$JAVA" -Dproc_$COMMAND -XX:OnOutOfMemoryError="kill -9 %p" $HEAP_SETTINGS $HBASE_OPTS $CLASS "${CMD_ARGS[@]}"
 fi
diff --git a/bin/hbase_startup.jsh b/bin/hbase_startup.jsh
new file mode 100644
index 00000000000..0f5dd9c25bb
--- /dev/null
+++ b/bin/hbase_startup.jsh
@@ -0,0 +1,20 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.
+ */
+
+import org.apache.hadoop.hbase.*;
+import org.apache.hadoop.hbase.client.*;
diff --git a/conf/hbase-env.sh b/conf/hbase-env.sh
index f99373e653a..6cc16d8db49 100644
--- a/conf/hbase-env.sh
+++ b/conf/hbase-env.sh
@@ -141,3 +141,6 @@
 # Override text processing tools for use by these launch scripts.
 # export GREP="${GREP-grep}"
 # export SED="${SED-sed}"
+
+# Additional argments passed to jshell invocation
+# export HBASE_JSHELL_ARGS="--startup DEFAULT --startup PRINTING --startup hbase_startup.jsh"
diff --git a/src/main/asciidoc/_chapters/ops_mgt.adoc b/src/main/asciidoc/_chapters/ops_mgt.adoc
index d62e2345ab6..6458112e1c1 100644
--- a/src/main/asciidoc/_chapters/ops_mgt.adoc
+++ b/src/main/asciidoc/_chapters/ops_mgt.adoc
@@ -64,6 +64,7 @@ Some commands take arguments. Pass no args or -h for usage.
   thrift          Run the HBase Thrift server
   thrift2         Run the HBase Thrift2 server
   clean           Run the HBase clean up script
+  jshell          Run a jshell with HBase on the classpath
   classpath       Dump hbase CLASSPATH
   mapredcp        Dump CLASSPATH entries required by mapreduce
   pe              Run PerformanceEvaluation