java - 尝试设置 Jython 解释器时出错

Question

我想在插件中启动一个 Jython 解释器，然后在解释器中执行文件。

package com.jakob.jython;

import org.bukkit.plugin.java.JavaPlugin;
import org.python.core.PyObject;
import org.python.util.PythonInterpreter;

import java.io.IOException;
import java.io.InputStream;
import java.util.logging.Logger;

public class EmbeddedJython extends JavaPlugin {

    private static final Logger log = Logger.getLogger("Minecraft");
    private PythonInterpreter interpreter;
    private PyObject plugin;


    public void onEnable() {
        log.info("JythonTest enabled");
        this.interpreter = new PythonInterpreter();
        log.info("Jython interpreter fired up and cooking on gas");

        log.info("Loading Python Plugin");

        InputStream pythonScript = EmbeddedJython.class.getResourceAsStream("MyPlugin.py");
        this.interpreter.execfile(pythonScript, "MyPlugin.py");

        log.info("Getting plg method.");
        this.plugin = this.interpreter.get("plg");
        log.info("Plugin loaded");
        log.info(plugin.invoke("onEnable").toString());
    }

    public void onDisable() {
        log.info(plugin.invoke("onDisable").toString());
        log.info("Jython disabled");
    }

}

在其他测试中，我可以启动 Jython 解释器并运行我传递给它的字符串，但是当我使用上面的代码片段时，我最终得到一个看起来像这样的异常:

11:03:38 [SEVERE] Error occurred while enabling JythonTest v0.12 (Is it up to da
te?): null
java.io.IOException: Stream closed
        at java.io.BufferedInputStream.getInIfOpen(Unknown Source)
        at java.io.BufferedInputStream.fill(Unknown Source)
        at java.io.BufferedInputStream.read(Unknown Source)
        at org.python.core.ParserFacade.adjustForBOM(ParserFacade.java:371)
        at org.python.core.ParserFacade.prepBufReader(ParserFacade.java:298)
        at org.python.core.ParserFacade.prepBufReader(ParserFacade.java:288)
        at org.python.core.ParserFacade.parse(ParserFacade.java:183)
        at org.python.core.Py.compile_flags(Py.java:1717)
        at org.python.util.PythonInterpreter.execfile(PythonInterpreter.java:235
)
        at com.jakob.jython.EmbeddedJython.onEnable(EmbeddedJython.java:26)
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:125)
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader
.java:750)
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManage
r.java:253)
        at org.bukkit.craftbukkit.CraftServer.loadPlugin(CraftServer.java:132)
        at org.bukkit.craftbukkit.CraftServer.loadPlugins(CraftServer.java:110)
        at net.minecraft.server.MinecraftServer.e(MinecraftServer.java:218)
        at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:205)
        at net.minecraft.server.MinecraftServer.init(MinecraftServer.java:145)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:265)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:394)

java.io.IOException: java.io.IOException: Stream closed

        at org.python.core.PyException.fillInStackTrace(PyException.java:70)
        at java.lang.Throwable.<init>(Throwable.java:181)
        at java.lang.Exception.<init>(Unknown Source)
        at java.lang.RuntimeException.<init>(Unknown Source)
        at org.python.core.PyException.<init>(PyException.java:46)
        at org.python.core.PyException.<init>(PyException.java:43)
        at org.python.core.Py.JavaError(Py.java:481)
        at org.python.core.ParserFacade.fixParseError(ParserFacade.java:104)
        at org.python.core.ParserFacade.parse(ParserFacade.java:186)
        at org.python.core.Py.compile_flags(Py.java:1717)
        at org.python.util.PythonInterpreter.execfile(PythonInterpreter.java:235
)
        at com.jakob.jython.EmbeddedJython.onEnable(EmbeddedJython.java:26)
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:125)
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader
.java:750)
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManage
r.java:253)
        at org.bukkit.craftbukkit.CraftServer.loadPlugin(CraftServer.java:132)
        at org.bukkit.craftbukkit.CraftServer.loadPlugins(CraftServer.java:110)
        at net.minecraft.server.MinecraftServer.e(MinecraftServer.java:218)
        at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:205)
        at net.minecraft.server.MinecraftServer.init(MinecraftServer.java:145)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:265)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:394)
Caused by: java.io.IOException: Stream closed
        at java.io.BufferedInputStream.getInIfOpen(Unknown Source)
        at java.io.BufferedInputStream.fill(Unknown Source)
        at java.io.BufferedInputStream.read(Unknown Source)
        at org.python.core.ParserFacade.adjustForBOM(ParserFacade.java:371)
        at org.python.core.ParserFacade.prepBufReader(ParserFacade.java:298)
        at org.python.core.ParserFacade.prepBufReader(ParserFacade.java:288)
        at org.python.core.ParserFacade.parse(ParserFacade.java:183)
        ... 13 more

会不会是我用错了execfile？ 或者它是一个错误还是我在 InputStream 的工作方式中遗漏了什么？

Answer 1

您确定 EmbeddedJython.class.getResourceAsStream("MyPlugin.py"); 正在寻找资源吗？

如果找不到资源，getResourceAsStream 将返回一个 null，Jython 解释器可能会将其视为空(已关闭)流.

您的应用程序可能应该检查这一点，而不是假设 getResourceAsStream 已经成功。

---

If I private File pythonFile = new File('MyScirpt.py'); and then hand getResourceAsStream(pythonFile.getAbsolutePath());

那是行不通的。 getResourceAsStream 方法在类加载器的类路径上查找资源，并期望一个可以相对于类路径上的某个条目解析的路径。

你可能想这样做:

private File pythonFile = new File('MyScirpt.py');
InputStream is = new FileInputStream(pythonFile);

并将is传递给解释器。您还需要安排在解释器完成时流总是关闭......无论发生什么机制。