From 36f5fd2156fe0c443e0f7aaff5a17da83826d872 Mon Sep 17 00:00:00 2001
From: Haoqiong Bian <bianhaoqiong@gmail.com>
Date: Fri, 3 Jan 2025 23:42:02 +0800
Subject: [PATCH] [Issue #819] revise jdk version check for reflect constructor
 (#821)

---
 .../common/physical/natives/DirectIoLib.java       | 14 +++++++-------
 pixels-daemon/pom.xml                              |  5 +++--
 .../pixels/daemon/scaling/policy/AIASPolicy.java   |  8 ++++----
 pom.xml                                            |  1 +
 4 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/pixels-common/src/main/java/io/pixelsdb/pixels/common/physical/natives/DirectIoLib.java b/pixels-common/src/main/java/io/pixelsdb/pixels/common/physical/natives/DirectIoLib.java
index 8994eda8a..1f7b98cf0 100644
--- a/pixels-common/src/main/java/io/pixelsdb/pixels/common/physical/natives/DirectIoLib.java
+++ b/pixels-common/src/main/java/io/pixelsdb/pixels/common/physical/natives/DirectIoLib.java
@@ -86,25 +86,25 @@ public class DirectIoLib
             {
                 if (JavaVersion <= 11)
                 {
-                    // this is from sun.nio.ch.Util.initDBBRConstructor
+                    // This is from sun.nio.ch.Util.initDBBRConstructor.
                     Class<?> cl = Class.forName("java.nio.DirectByteBufferR");
                     directByteBufferRConstructor = cl.getDeclaredConstructor(
                             int.class, long.class, FileDescriptor.class, Runnable.class);
                 }
-                else if (JavaVersion <= 17)
+                else if (JavaVersion < 21)
                 {
-                    /* the creator of DirectByteBufferR is changed after java 11 and is not compatible with java 8.
+                    /* The creator of DirectByteBufferR is changed after java 11 and is not compatible with java 8.
                      * Therefore, we use DirectByteBuffer to create direct read only buffer.
                      */
                     Class<?> cl = Class.forName("java.nio.DirectByteBuffer");
-                    directByteBufferRConstructor = cl.getDeclaredConstructor(
-                            long.class, int.class);
+                    directByteBufferRConstructor = cl.getDeclaredConstructor(long.class, int.class);
                 }
                 else
                 {
+                    /* the creator of DirectByteBuffer is changed in java 21+.
+                     */
                     Class<?> cl = Class.forName("java.nio.DirectByteBuffer");
-                    directByteBufferRConstructor = cl.getDeclaredConstructor(
-                            long.class, long.class);
+                    directByteBufferRConstructor = cl.getDeclaredConstructor(long.class, long.class);
                 }
                 directByteBufferRConstructor.setAccessible(true);
 
diff --git a/pixels-daemon/pom.xml b/pixels-daemon/pom.xml
index cb7debf07..71d4a0afb 100644
--- a/pixels-daemon/pom.xml
+++ b/pixels-daemon/pom.xml
@@ -197,9 +197,10 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
+                <version>${maven.plugin.compile.version}</version>
                 <configuration>
-                    <source>11</source>
-                    <target>11</target>
+                    <source>8</source>
+                    <target>8</target>
                 </configuration>
             </plugin>
         </plugins>
diff --git a/pixels-daemon/src/main/java/io/pixelsdb/pixels/daemon/scaling/policy/AIASPolicy.java b/pixels-daemon/src/main/java/io/pixelsdb/pixels/daemon/scaling/policy/AIASPolicy.java
index 4c3180a89..c0b15fd2b 100644
--- a/pixels-daemon/src/main/java/io/pixelsdb/pixels/daemon/scaling/policy/AIASPolicy.java
+++ b/pixels-daemon/src/main/java/io/pixelsdb/pixels/daemon/scaling/policy/AIASPolicy.java
@@ -19,9 +19,6 @@
  */
 package io.pixelsdb.pixels.daemon.scaling.policy;
 
-import java.io.IOException;
-import java.io.InputStreamReader;
-
 import io.grpc.ManagedChannel;
 import io.grpc.ManagedChannelBuilder;
 import io.pixelsdb.pixels.common.utils.ConfigFactory;
@@ -31,6 +28,8 @@
 import org.apache.logging.log4j.Logger;
 
 import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
 import java.util.Arrays;
 
 public class AIASPolicy extends Policy
@@ -49,7 +48,8 @@ private void scaling(double[] cpuTimes, double[] memUsages)
         log.info("INFO: expend to "+ WorkerNum1 + " or " + WorkerNum2);
     }
 
-    public boolean transDump(long timestamp){
+    public boolean transDump(long timestamp)
+    {
         String host = ConfigFactory.Instance().getProperty("trans.server.host");
         int port = Integer.parseInt(ConfigFactory.Instance().getProperty("trans.server.port"));
         ManagedChannel channel = ManagedChannelBuilder.forAddress(host,port)
diff --git a/pom.xml b/pom.xml
index 9b9462d1c..c604a6bbc 100644
--- a/pom.xml
+++ b/pom.xml
@@ -68,6 +68,7 @@
         <maven.compiler.target>8</maven.compiler.target>
         <maven.compiler.useIncrementalCompilation>true</maven.compiler.useIncrementalCompilation>
         <maven.plugin.source.version>3.1.0</maven.plugin.source.version>
+        <maven.plugin.compile.version>3.8.1</maven.plugin.compile.version>
         <maven.plugin.shade.version>3.2.2</maven.plugin.shade.version>
         <maven.plugin.assembly.version>3.5.0</maven.plugin.assembly.version>
         <maven.plugin.deploy.version>3.1.0</maven.plugin.deploy.version>