我试图使用反射来加载类的实例.当我尝试这样做时,我得到了一个没有这种方法的例外.我检查并检查并重新检查.那个构造函数显然确实存在.有没有人有任何想法？我之前已成功使用过这个代码基本相同的另一个项目,所以我不确定我搞砸了.来源可以在这里找到：
private void loadCommands() {
try {
for (Class<?> clazz : ReflectionsReplacement.getSubtypesOf(BaseCommand.class,"us.zsugano.itemsave.commands",plugin.getClass().getClassLoader(),BaseCommand.class)) {
BaseCommand baseCommand = null;
try {
baseCommand = (BaseCommand) clazz.getConstructor(ItemSave.class).newInstance(plugin);
if(Listener.class.isAssignableFrom(clazz)) {
plugin.getServer().getPluginManager().registerEvents((Listener) baseCommand,plugin);
}
} catch (Exception e) {
plugin.PluginPM.sendMessage(Level.SEVERE,"Issues encountered when trying to load commands.");
e.printStackTrace();
}
commands.add(baseCommand);
}
} catch (Exception e) {
plugin.PluginPM.sendMessage(Level.SEVERE,"Exception caught while loading commands.");
e.printStackTrace();
}
for (BaseCommand command : commands) {
plugin.getCommand(command.getName().toLowerCase()).setExecutor(this);
}
}
public abstract class BaseCommand {
public ItemSave plugin;
public BaseCommand(ItemSave plugin) {
this.plugin = plugin;
}
完整来源：https://github.com/zachoooo/ItemSave
这是堆栈跟踪：
19:43:10 [SEVERE] [ItemSave] Issues encountered when trying to load commands. 19:43:10 [SEVERE] java.lang.NoSuchMethodException: us.zsugano.itemsave.commands. StoreCommand.<init>(us.zsugano.itemsave.ItemSave) 19:43:10 [SEVERE] at java.lang.Class.getConstructor0(Unknown Source) 19:43:10 [SEVERE] at java.lang.Class.getConstructor(Unknown Source) 19:43:10 [SEVERE] at us.zsugano.itemsave.commands.CommandManager.loadComma nds(CommandManager.java:32) 19:43:10 [SEVERE] at us.zsugano.itemsave.commands.CommandManager.<init>(Co mmandManager.java:23) 19:43:10 [SEVERE] at us.zsugano.itemsave.ItemSave.onEnable(ItemSave.java:1 9) 19:43:10 [SEVERE] at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlug in.java:217) 19:43:10 [SEVERE] at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin( JavaPluginLoader.java:457) 19:43:10 [SEVERE] at org.bukkit.plugin.SimplePluginManager.enablePlugin(Si mplePluginManager.java:381) 19:43:10 [SEVERE] at org.bukkit.craftbukkit.v1_6_R2.CraftServer.loadPlugin (CraftServer.java:282) 19:43:10 [SEVERE] at org.bukkit.craftbukkit.v1_6_R2.CraftServer.enablePlug ins(CraftServer.java:264) 19:43:10 [SEVERE] at net.minecraft.server.v1_6_R2.MinecraftServer.l(Minecr aftServer.java:313) 19:43:10 [SEVERE] at net.minecraft.server.v1_6_R2.MinecraftServer.f(Minecr aftServer.java:290) 19:43:10 [SEVERE] at net.minecraft.server.v1_6_R2.MinecraftServer.a(Minecr aftServer.java:250) 19:43:10 [SEVERE] at net.minecraft.server.v1_6_R2.DedicatedServer.init(Ded icatedServer.java:151) 19:43:10 [SEVERE] at net.minecraft.server.v1_6_R2.MinecraftServer.run(Mine craftServer.java:391) 19:43:10 [SEVERE] at net.minecraft.server.v1_6_R2.ThreadServerApplication. run(SourceFile:582)
解决方法
在StoreCommand.java中,我看到这个包私有构造函数：
StoreCommand(ItemSave plugin) {
super(plugin);
}
来自getConstructor的API文档(强调我的)：
Returns a Constructor object that reflects the specified public
constructor of the class represented by this Class object.
要么将构造函数设为public,要么使用getDeclaredConstructor()并设置setAccesible(true)
