Java腳本教程 - Java全局腳本

每個Nashorn引擎使用多個腳本全局變量

import javax.script.ScriptContext;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.SimpleScriptContext;

public class Main {
  public static void main(String[] args) throws Exception {
    ScriptEngineManager manager = new ScriptEngineManager();
    ScriptEngine engine = manager.getEngineByName("JavaScript");

    engine.eval("var msg = "Hello globals"");
    engine.eval("print(this.msg);");
    ScriptContext ctx = new SimpleScriptContext();
    engine.eval("print(this.msg);", ctx);
  }
}

上面的代碼生成以下結(jié)果。

例子

以下代碼顯示了如何通過復(fù)制引擎的默認上下文的引擎范圍綁定來共享腳本。

import static javax.script.ScriptContext.ENGINE_SCOPE;

import javax.script.Bindings;
import javax.script.ScriptContext;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.SimpleScriptContext;

public class Main {
  public static void main(String[] args) throws Exception {
    ScriptEngineManager manager = new ScriptEngineManager();
    ScriptEngine engine = manager.getEngineByName("JavaScript");
    engine.eval("var msg = "Hello globals"");
    engine.eval("print(this.msg);");
    ScriptContext ctx = new SimpleScriptContext();
    ScriptContext defaultCtx = engine.getContext();
    Bindings engineBindings = defaultCtx.getBindings(ENGINE_SCOPE);
    ctx.setBindings(engineBindings, ENGINE_SCOPE);
    engine.eval("print(this.msg);", ctx);
  }
}

上面的代碼生成以下結(jié)果。