J2SE 8的脚本

た入场券 2023-06-03 05:58 89阅读 0赞

# **1. 引擎工厂的属性**    #

<table> 
 <tbody> 
  <tr> 
   <th>引擎</th> 
   <th>名字</th> 
   <th>MIME类型</th> 
   <th>文件扩展</th> 
  </tr> 
 </tbody> 
 <tbody> 
  <tr> 
   <td>Nashorn</td> 
   <td>nashorn,Nashorn<br>js,JS<br>JavaScript,javascript<br>ECMAScript,mcmascript</td> 
   <td>application/javascript<br>application/ecmascript<br>text/javascript<br>text/ecmascript</td> 
   <td>js</td> 
  </tr> 
  <tr> 
   <td>Groovy</td> 
   <td>groovy</td> 
   <td>&nbsp;</td> 
   <td>groovy</td> 
  </tr> 
  <tr> 
   <td>Renjin</td> 
   <td>Renjin</td> 
   <td>text/x-R</td> 
   <td>R,r,S,s</td> 
  </tr> 
  <tr> 
   <td>SISC Scheme</td> 
   <td>sisc</td> 
   <td>&nbsp;</td> 
   <td>scheme,sisc</td> 
  </tr> 
 </tbody> 
</table>

# **2. 获取manager**    #

ScriptEngineManager manager = new ScriptEngineManager();
    		System.out.println("Available factories: ");

# **3. 查看线程安全** #

for (ScriptEngineFactory factory : manager.getEngineFactories()){
        System.out.println(factory.getEngineName());
        
        //null:不安全
        //MULTITHREADED:安全
        //...
        System.out.println("线程安全:"+factory.getParameter("THREADING"));
    }

# **4. 获取js引擎**    #

final ScriptEngine engine = manager.getEngineByName("nashorn");
    		if (engine == null) {
    			System.err.println("No engine for nashorn");
    			System.exit(1);
    		}

# **5. 调用脚本** #

engine.eval("n=88");
    		Object evalResult = engine.eval("n+2");
    		System.out.println(evalResult);
    		
    		engine.put("x", 99);
    		evalResult = engine.eval("x+2");
    		System.out.println(evalResult);

# **6. 重定向输出** #

Writer orinalWriter = engine.getContext().getWriter();
    		engine.getContext().setWriter(new PrintWriter("E:\\js.txt"));
    		engine.eval("print('hello')");
    		engine.getContext().setWriter(orinalWriter);
    		
    		//只有脚本引擎的输出被改变
    		System.out.println("hello");

# **7. 调用函数** #

engine.eval("function greet(how ,whom) {return how+','+whom}");
    		evalResult = ((Invocable)engine).invokeFunction("greet", "hello","world");
    		System.out.println(evalResult);

# **8. 调用方法** #

engine.eval("function Greeter(how){this.how=how}");
    		engine.eval("Greeter.prototype.welcome= function(whom) {return this.how+','+whom}");
    		Object yo = engine.eval("new Greeter('Yo')");
    		evalResult = ((Invocable)engine).invokeMethod(yo, "welcome","world");
    		System.out.println(evalResult);

# **9.调用接口** #

package shell;
    
    public interface Greeter {
    	String welcome(String whom);
    }

//定义function
    		engine.eval("function welcome(whom) {return 'welcome hello,'+whom}");
    		
    		Greeter greeter = ((Invocable)engine).getInterface(Greeter.class);
    		evalResult = greeter.welcome("world");
    		System.out.println(evalResult);

# **10. 编译脚本** #

if(engine instanceof Compilable){
    			CompiledScript compiledScript = ((Compilable)engine).compile("print('hello  xxx')");
    			compiledScript.eval();
    		}

转载于:https://www.cnblogs.com/xiang--liu/p/9710366.html