我开发一个Android游戏在Java中使用了Lua脚本。要执行这些脚本,我使用LuaJ与Java的的ScriptEngine类。例如...
I'm developing an Android game in Java which uses Lua scripts. To execute these scripts, I'm using LuaJ with Java's ScriptEngine class. For example...
ScriptEngineManager sem = new ScriptEngineManager();
scriptEngine = sem.getEngineByExtension(".lua");
script = ((Compilable)scriptEngine).compile("some lua here");
不过,这显然是不支持的Android(事做与Android没有一个完全成熟的JVM,我读的地方)。有没有一种方法,我可以在Android上使用Lua脚本?也许有一个LuaJ选择呢?或许有编译和执行直接使用LuaJ Lua脚本的方式(虽然我看不出)。
However, this is apparently not supported on Android (something to do with android not having a full blown JVM, I read somewhere). Is there a way I can use Lua scripts on Android? Maybe there's a LuaJ alternative? Perhaps there is a way of compiling and executing Lua scripts using LuaJ directly (though I can't see how).
仅供参考,我看到这个错误,当我尝试运行在Android这个code:
FYI, I see this error when I try to run this code on Android:
05-06 16:12:32.870: E/dalvikvm(17509): Could not find class 'javax.script.ScriptEngineManager', referenced from method unearth.levels.LevelReader.<init>
05-06 16:12:32.870: W/dalvikvm(17509): VFY: unable to resolve new-instance 787 (Ljavax/script/ScriptEngineManager;) in Lunearth/levels/LevelReader;
05-06 16:12:32.870: D/dalvikvm(17509): VFY: replacing opcode 0x22 at 0x0018
05-06 16:12:32.875: E/dalvikvm(17509): Could not find class 'javax.script.Compilable', referenced from method unearth.levels.LevelReader.parseScript
05-06 16:12:32.875: W/dalvikvm(17509): VFY: unable to resolve check-cast 782 (Ljavax/script/Compilable;) in Lunearth/levels/LevelReader;
05-06 16:12:32.875: D/dalvikvm(17509): VFY: replacing opcode 0x1f at 0x0047
05-06 16:12:32.875: W/dalvikvm(17509): VFY: unable to resolve exception class 788 (Ljavax/script/ScriptException;)
05-06 16:12:32.875: W/dalvikvm(17509): VFY: unable to find exception handler at addr 0x51
05-06 16:12:32.875: W/dalvikvm(17509): VFY: rejected Lunearth/levels/LevelReader;.parseScript (Lorg/w3c/dom/Element;Lunearth/levels/Level;)V
05-06 16:12:32.875: W/dalvikvm(17509): VFY: rejecting opcode 0x0d at 0x0051
05-06 16:12:32.875: W/dalvikvm(17509): VFY: rejected Lunearth/levels/LevelReader;.parseScript (Lorg/w3c/dom/Element;Lunearth/levels/Level;)V
05-06 16:12:32.875: W/dalvikvm(17509): Verifier rejected class Lunearth/levels/LevelReader;
05-06 16:12:32.890: W/dalvikvm(17509): threadid=11: thread exiting with uncaught exception (group=0x40c331f8)
05-06 16:12:32.895: E/AndroidRuntime(17509): FATAL EXCEPTION: GLThread 1062
05-06 16:12:32.895: E/AndroidRuntime(17509): java.lang.VerifyError: unearth/levels/LevelReader
05-06 16:12:32.895: E/AndroidRuntime(17509): at unearth.Game.startGame(Game.java:201)
05-06 16:12:32.895: E/AndroidRuntime(17509): at unearth.Game.update(Game.java:713)
05-06 16:12:32.895: E/AndroidRuntime(17509): at unearth.screens.LoadScreen.update(LoadScreen.java:56)
05-06 16:12:32.895: E/AndroidRuntime(17509): at unearth.UnearthListener.render(UnearthListener.java:71)
05-06 16:12:32.895: E/AndroidRuntime(17509): at com.badlogic.gdx.backends.android.AndroidGraphics.onDrawFrame(AndroidGraphics.java:423)
05-06 16:12:32.895: E/AndroidRuntime(17509): at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1462)
05-06 16:12:32.895: E/AndroidRuntime(17509): at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1216)
05-06 16:12:58.600: D/dalvikvm(17509): GC_CONCURRENT freed 334K, 3% free 16196K/16647K, paused 2ms+6ms
也许这个项目有一些有用的code? http://$c$c.google.com/p/android-scripting/
我发现使用LuaJ在Android的一种方式! : - )
I found a way of using LuaJ on Android! :-)
关键是使用LuaJ API直接通过的javax.script
反对。这是一个有点棘手弄清楚,因为没有教程,所以这里有一个前后,这样其他人没有经历过LuaJ源$ C $ c和JavaDoc的采摘。我真的希望这可以帮助别人,因为它驱使我疯狂!
The key is to use the LuaJ API directly as opposed to through javax.script
. It's a little tricky to figure out as there's no tutorials, so here's a before and after so that others don't have to go through picking through the LuaJ source code and JavaDoc. I really hope this helps someone as it drove me bonkers!
注意:的secretgame是我的比赛没有实际的名称; - )
Note: "secretgame" isn't the actual name of my game ;-)
之后:
package secretgame.scripting;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import org.luaj.vm2.LuaClosure;
import org.luaj.vm2.LuaTable;
import org.luaj.vm2.LuaValue;
import org.luaj.vm2.Prototype;
import org.luaj.vm2.compiler.LuaC;
import org.luaj.vm2.lib.jse.CoerceJavaToLua;
import org.luaj.vm2.lib.jse.JsePlatform;
import secretgame.SecretGameException;
import secretgame.events.EventArgs;
import secretgame.levels.Level;
public class DirectLuaj implements Lua
{
private final Level level;
private final ScriptTools scriptTools;
private final ScriptEvents scriptEvents;
private int nextId = 0;
private ArrayList<LuaClosure> scripts = new ArrayList<LuaClosure>();
public DirectLuaj(Level level, ScriptTools scriptTools,
ScriptEvents scriptEvents)
{
this.level = level;
this.scriptTools = scriptTools;
this.scriptEvents = scriptEvents;
}
@Override
public int add(String scriptText) throws SecretGameException
{
try {
InputStream input = new ByteArrayInputStream(scriptText.getBytes());
Prototype p = LuaC.compile(input, "script");
LuaValue g = JsePlatform.standardGlobals();
LuaClosure c = new LuaClosure(p, g);
scripts.add(c);
}
catch (IOException e) {
throw new SecretGameException("compile failed", e);
}
return nextId++;
}
@Override
public void run(int id, EventArgs args) throws SecretGameException
{
LuaClosure script = scripts.get(id);
LuaTable bindings = new LuaTable();
bindings.set("java", toLua(scriptTools));
bindings.set("level", toLua(level));
bindings.set("args", toLua(args));
bindings.set("events", toLua(scriptEvents));
script.setfenv(bindings);
script.call();
}
private LuaValue toLua(Object javaValue) {
return javaValue == null? LuaValue.NIL:
javaValue instanceof LuaValue? (LuaValue) javaValue:
CoerceJavaToLua.coerce(javaValue);
}
}
之前:
package secretgame.scripting;
import java.util.ArrayList;
import javax.script.Bindings;
import javax.script.Compilable;
import javax.script.CompiledScript;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
import secretgame.SecretGameException;
import secretgame.events.EventArgs;
import secretgame.levels.Level;
// sadly this won't work on Android because there's no such thing
// as javax.script in Dalvik ... dumb Android java :|
public class JavaxScriptingLua implements Lua
{
private ScriptEngine scriptEngine;
private final Level level;
private final ScriptTools scriptTools;
private final ScriptEvents scriptEvents;
private int nextId = 0;
private ArrayList<CompiledScript> scripts = new ArrayList<CompiledScript>();
public JavaxScriptingLua(Level level, ScriptTools scriptTools, ScriptEvents scriptEvents)
{
this.level = level;
this.scriptTools = scriptTools;
this.scriptEvents = scriptEvents;
ScriptEngineManager sem = new ScriptEngineManager();
scriptEngine = sem.getEngineByExtension(".lua");
}
public int add(String scriptText) throws SecretGameException
{
try {
CompiledScript script = ((Compilable)scriptEngine).compile(scriptText);
scripts.add(script);
}
catch (ScriptException e) {
throw new SecretGameException("could not compile lua.", e);
}
return nextId++;
}
public void run(int id, EventArgs args) throws SecretGameException
{
Bindings bindings = scriptEngine.createBindings();
bindings.put("java", scriptTools);
bindings.put("level", level);
bindings.put("args", args);
bindings.put("events", scriptEvents);
try {
scripts.get(id).eval(bindings);
}
catch (ScriptException e) {
throw new SecretGameException("could not run script.", e);
}
}
}