获取构造函数时的Java NoSuchMethodException
我试图使用reflection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，所以我不知道我搞砸了。 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.(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.(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)
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）：
返回一个Constructor对象，该对象反映此Class对象所表示的类的指定公共构造函数。
要么将构造函数设为public，要么使用getDeclaredConstructor()并设置setAccesible(true)