Allow the -javaagent argument on Java 8, even though it does nothing

PaperMC · Dec 19, 2020 · 2d4c7b3 · 2d4c7b3
1 parent e344bca
commit 2d4c7b3
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Showing 6 changed files with 12 additions and 5 deletions.
diff --git a/assembly/pom.xml b/assembly/pom.xml
@@ -6,7 +6,7 @@
 
     <groupId>io.papermc</groupId>
     <artifactId>paperclip-assembly</artifactId>
-    <version>1.3-SNAPSHOT</version>
+    <version>1.4.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <properties>

diff --git a/java8/pom.xml b/java8/pom.xml
@@ -6,7 +6,7 @@
 
     <groupId>io.papermc</groupId>
     <artifactId>paperclip-java8</artifactId>
-    <version>1.3-SNAPSHOT</version>
+    <version>1.4.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <properties>

diff --git a/java8/src/main/java/io/papermc/paperclip/Agent.java b/java8/src/main/java/io/papermc/paperclip/Agent.java
@@ -9,6 +9,7 @@
 
 package io.papermc.paperclip;
 
+import java.lang.instrument.Instrumentation;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.net.MalformedURLException;
@@ -18,6 +19,10 @@
 
 public final class Agent {
 
+    public static void premain(final String agentArgs, final Instrumentation inst) {
+        // noop - if this is called on Java 8 we just ignore it
+    }
+
     static void addToClassPath(final Path paperJar) {
         final ClassLoader loader = ClassLoader.getSystemClassLoader();
         if (!(loader instanceof URLClassLoader)) {

diff --git a/java9/pom.xml b/java9/pom.xml
@@ -6,7 +6,7 @@
 
     <groupId>io.papermc</groupId>
     <artifactId>paperclip-java9</artifactId>
-    <version>1.3-SNAPSHOT</version>
+    <version>1.4.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <properties>

diff --git a/java9/src/main/java/io/papermc/paperclip/Agent.java b/java9/src/main/java/io/papermc/paperclip/Agent.java
@@ -29,7 +29,9 @@ public static void agentmain(final String agentArgs, final Instrumentation inst)
     @SuppressWarnings("unused") // This class replaces the Agent class in the java8 module when run on Java9+
     static void addToClassPath(final Path paperJar) {
         if (inst == null) {
-            System.err.println("Unable to retrieve Instrumentation API to add Paper jar to ClassPath");
+            System.err.println("Unable to retrieve Instrumentation API to add Paper jar to classpath. If you're " +
+                "running paperclip without -jar then you also need to include the -javaagent:<paperclip_jar> JVM " +
+                "command line option.");
             System.exit(1);
             return;
         }

diff --git a/pom.xml b/pom.xml
@@ -6,7 +6,7 @@
 
     <groupId>io.papermc</groupId>
     <artifactId>paperclip</artifactId>
-    <version>1.4-SNAPSHOT</version>
+    <version>1.4.1-SNAPSHOT</version>
     <packaging>pom</packaging>
 
     <name>Paperclip</name>