javascript - How to call methods in js in java?-PHP Chinese Network Q&A

How to call methods in js in java

// js 代码 STRING_UTIL = {}; STRING_UTIL.isNotEmpty = function (str){ return "" != str; }

// java 代码 Reader scriptReaderB = new InputStreamReader( new FileInputStream( new File("F:\tech-study\js-comm\release\bundle.js")),"utf-8"); engine.eval(scriptReaderB); // engine.eval(scriptReaderA); if (engine instanceof Invocable) { // 调用JS方法 Invocable invocable = (Invocable)engine; Object result = invocable.invokeFunction("STRING_UTIL.isNotEmpty", new Object[]{"hahaha"}); System.out.println(result.toString()); } // 调用异常 java.lang.NoSuchMethodException: no such method: STRING_UTIL.isNotEmpty at com.sun.script.javascript.RhinoScriptEngine.invoke(RhinoScriptEngine.java:286) at com.sun.script.javascript.RhinoScriptEngine.invokeFunction(RhinoScriptEngine.java:258) at AAAAAAA.main(AAAAAAA.java:29) // 如果在添加一个全局函数 function isNotEmpty (str){ return STRING_UTIL.isNotEmpty(str); }

Change the calling method to

Object result = invocable.invokeFunction("isNotEmpty", new Object[]{"hahaha"});

This is a successful operation

ScriptEngineManager manager = new ScriptEngineManager(); ScriptEngine javaScript = manager.getEngineByName("JavaScript"); InputStream stream = JS.class.getResourceAsStream("/js/test.js"); BufferedReader reader = new BufferedReader(new InputStreamReader(stream)); javaScript.eval(reader); invocable = (Invocable) javaScript; invocable.invokeFunction("method");

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为情所困2017-07-05 10:28:55 3 floor

After your own implementation, you can use two methods to achieve it:

Use engine.eval
Object result = engine.eval("STRING_UTIL.isNotEmpty('" + str + "')"); to call.
Use the invokeMethod method to implement
First get the object

Object thiz = engine.get("STRING_UTIL");
Next, call the method according to the object
Object result = invocable.invokeMethod(thiz, "isNotEmpty", new Object[]{"hahaha"});

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Peter_Zhu2017-07-05 10:28:55 2 floor

invokeFunction method description The first parameter is the method name, the following parameters are all method parameters, and the return value is object.