I'm currently trying to compile a class at runtime but for some reason it's only working on one system. Both systems use the exact same code and have the same java version installed, but on one system my .java file compiles to a .class and on the other system I'm getting exceptions because some classes which are, or should be, in the classpath can't be found.
The code I use to compile it is this:
private static File compile(File file) {
try {
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
List<String> optionList = new ArrayList<>();
File jar = getJar(RuntimeCompiler.class);
File pluginDirectory = new File(jar.getAbsolutePath().substring(0, jar.getAbsolutePath().length() - jar.getName().length()));
String classes = buildClassPath(getJar(Bukkit.class).getAbsolutePath(), pluginDirectory.getAbsolutePath() + "/*");
optionList.addAll(Arrays.asList("-classpath",classes));
boolean success;
try (StandardJavaFileManager fileManager = compiler.getStandardFileManager( null, null, null )) {
Iterable<? extends JavaFileObject> units;
units = fileManager.getJavaFileObjectsFromFiles(Arrays.asList(file));
JavaCompiler.CompilationTask task = compiler.getTask(null, fileManager, null, optionList, null, units);
success = task.call();
}
if(success) {
return new File(file.getAbsolutePath().substring(0, file.getAbsolutePath().length() - 5) + ".class");
}
else {
return null;
}
} catch (IOException ex) {
Logger.getLogger(RuntimeCompiler.class.getName()).log(Level.SEVERE, null, ex);
return null;
}
}
private static String buildClassPath(String... paths) {
StringBuilder sb = new StringBuilder();
for (String path : paths) {
if (path.endsWith("*")) {
path = path.substring(0, path.length() - 1);
File pathFile = new File(path);
for (File file : pathFile.listFiles()) {
if (file.isFile() && file.getName().endsWith(".jar")) {
sb.append(path);
sb.append(file.getName());
sb.append(System.getProperty("path.separator"));
}
}
} else {
sb.append(path);
sb.append(System.getProperty("path.separator"));
}
}
String s = sb.toString();
s = s.substring(0,s.length() - 1);
return s;
}
classpath (optionList.toString()) with Core-1.0-SNAPSHOT.jar containing the necessary files.
[-classpath, /usr/local/gpx/users/user/127.0.0.1:25702/spigot.jar:25702/plugins/Core-1.0-SNAPSHOT.jar]
Stacktrace
/usr/local/gpx/users/user/127.0.0.1:25702/plugins/debug/DebugClass.java:1: error: package net.nowcraft.core does not exist
[14:04:10] [Server thread/WARN]: import net.nowcraft.core.core;
[14:04:10] [Server thread/WARN]: ^
[14:04:10] [Server thread/WARN]: /usr/local/gpx/users/user/127.0.0.1:25702/plugins/debug/DebugClass.java:2: error: package net.nowcraft.core.RuntimeCompiler does not exist
[14:04:10] [Server thread/WARN]: import net.nowcraft.core.RuntimeCompiler.Debugger
[14:04:10] [Server thread/WARN]:
[14:04:10] [Server thread/WARN]: /usr/local/gpx/users/user/127.0.0.1:25702/plugins/debug/DebugClass.java:7: error: method does not override or implement a method from a supertype
[14:04:10] [Server thread/WARN]: @Override
[14:04:10] [Server thread/WARN]: ^
[14:04:10] [Server thread/WARN]: 3 errors
[14:04:10] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'rd' in plugin NowCraftCore v1.0
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spigot.jar:git-Spigot-330d66b-fe41b01]
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) ~[spigot.jar:git-Spigot-330d66b-fe41b01]
at org.bukkit.craftbukkit.v1_8_R1.CraftServer.dispatchCommand(CraftServer.java:642) ~[spigot.jar:git-Spigot-330d66b-fe41b01]
at net.minecraft.server.v1_8_R1.PlayerConnection.handleCommand(PlayerConnection.java:1115) [spigot.jar:git-Spigot-330d66b-fe41b01]
at net.minecraft.server.v1_8_R1.PlayerConnection.a(PlayerConnection.java:950) [spigot.jar:git-Spigot-330d66b-fe41b01]
at net.minecraft.server.v1_8_R1.PacketPlayInChat.a(PacketPlayInChat.java:26) [spigot.jar:git-Spigot-330d66b-fe41b01]
at net.minecraft.server.v1_8_R1.PacketPlayInChat.a(PacketPlayInChat.java:53) [spigot.jar:git-Spigot-330d66b-fe41b01]
at net.minecraft.server.v1_8_R1.PacketHandleTask.run(SourceFile:13) [spigot.jar:git-Spigot-330d66b-fe41b01]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_25]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_25]
at net.minecraft.server.v1_8_R1.MinecraftServer.z(MinecraftServer.java:683) [spigot.jar:git-Spigot-330d66b-fe41b01]
at net.minecraft.server.v1_8_R1.DedicatedServer.z(DedicatedServer.java:316) [spigot.jar:git-Spigot-330d66b-fe41b01]
at net.minecraft.server.v1_8_R1.MinecraftServer.y(MinecraftServer.java:623) [spigot.jar:git-Spigot-330d66b-fe41b01]
at net.minecraft.server.v1_8_R1.MinecraftServer.run(MinecraftServer.java:526) [spigot.jar:git-Spigot-330d66b-fe41b01]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_25]
Caused by: java.lang.NullPointerException
at net.nowcraft.core.RuntimeCompiler.RuntimeCompiler.load(RuntimeCompiler.java:127) ~[?:?]
at net.nowcraft.core.RuntimeCompiler.RuntimeCompiler.loadHastebin(RuntimeCompiler.java:88) ~[?:?]
at net.nowcraft.core.RuntimeCompiler.RuntimeCompiler.debugFromHastebin(RuntimeCompiler.java:170) ~[?:?]
at net.nowcraft.core.commands.RuntimeDebug.onCommand(RuntimeDebug.java:35) ~[?:?]
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[spigot.jar:git-Spigot-330d66b-fe41b01]
... 14 more
EDIT: I also tested it in a different directory, didn't work. When I use the code on my local windows laptop it does work though.
EDIT 2: It seems to be a problem with CentOS since it's not working on a 2nd CentOS system either.
Stacktrace helped immensely, and the surrounding context as well.
The issue here is linux. So the directory you're trying to hit:
/usr/local/gpx/users/user/127.0.0.1:25702/plugins/debug/DebugClass.java
is LITERALLY looking for a directory NAMED 127.0.0.1:25702 (though the : will have to be escaped because most shells use : as a syntax character.
Your network address is going to map to a specific directory. You're going to have to create a network share (Not familiar with CentOS but its usually pretty simple) to eliminate the network reference to a location that physically exists. If you can cd to it from the command line, then your java runtime should be able to actually reference it.
Here is a reference for mounting remote filesystems on CentOS. Yes, I know 127.0.0.1:25702 is technically "localhost" but neither the command shell nor the java runtime is going to know how to resolve a network address in the way you want to do it here. It works on Windows because Windows APIs are more forgiving.