java調用js,js中調用java__js

 

 

1)使用指令碼語言的優勢

Rapid turnaround, encouraging experimentation.

Changing the behavior of a running program.

Enabling customization by program users.

 

2)

The site http://scripting.dev.java.net provides engines for a wide range of scripting languages.

 For example, to add support for Groovy, the class path should contain groovy/lib/* 

 (from http://groovy.codehaus.org) and groovy-engine.jar (from http://scripting.dev.java.net).

 

3)

javax.script.ScriptEngineManager

javax.script.ScriptEngineFactory

javax.script.ScriptEngine

javax.script.Invocable 

javax.script.CompiledScript

 

ScriptEngine engine = manager.getEngineByName("JavaScript");

 

Object result = engine.eval(scriptString);

Object result = engine.eval(reader);

engine.put(k, 1728);

Object result = engine.eval("k + 1");

 

4)重新導向Input和Output

StringWriter writer = new StringWriter();

engine.getContext().setWriter(new PrintWriter(writer, true));

 

5)Calling Scripting Functions and Methods

 

To call a function, call the invokeFunction method with the function name, followed by the function parameters:

 

if (engine implements Invocable)

   ((Invocable) engine).invokeFunction("aFunction", param1, param2);

 

 

If the scripting language is object oriented, you call can a method like this:

 

Code View:

((Invocable) engine).invokeMethod(implicitParam, "aMethod", explicitParam1, explicitParam2);

 

 

 

6)Compiling a Script

Reader reader = new FileReader("myscript.js");

CompiledScript script = null;

if (engine implements Compilable)

   CompiledScript script = ((Compilable) engine).compile(reader);

 

if (script != null)

   script.eval();

else

   engine.eval(reader);

7)

在 http://www.mozilla.org/rhino/ 下載rhino：

把js.jar加入系統CLASSPATH中

可以以互動模式調用js解譯器：

java org.mozilla.javascript.tools.shell.Main

java org.mozilla.javascript.tools.debugger.Main

 

8)相互調用

HelloWorld hello = new HelloWorld();

engine.put("script_hello", hello);

engine.eval("script_hello.sayHello()");

 

String script = "function say(first,second){ print(first +' '+ second+'//n'); }";

engine.eval(script);

Invocable inv = (Invocable) engine;

inv.invokeFunction("say", "Hello", "Tony");

script = "function max(first,second) "

+ "{ return (first > second) ?first:second;}";

engine.eval(script);

  //js與java介面的調用

Object obj = inv.invokeFunction("max", "1", "0");