从java代码调用外部javascript函数

通过使用Java脚本API，我能够在Java中执行JavaScript。但是，有人能解释一下，为了能够调用C:/Scripts/Jsfunctions.js中的函数，我需要向这段代码添加什么吗

import javax.script.*;

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

    // JavaScript code in a String
    String script1 = "function hello(name) {print ('Hello, ' + name);}";
    String script2 = "function getValue(a,b) { if (a===\"Number\") return 1; 
                     else return b;}";
    // evaluate script
    engine.eval(script1);
    engine.eval(script2);

    Invocable inv = (Invocable) engine;

    inv.invokeFunction("hello", "Scripting!!");  //This one works.      
 }
}

var display = function(name) {
print("Hello, I am a Javascript display function",name);
return "display function return"
}

用于读取脚本

ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName("JavaScript");
// read script file
engine.eval(Files.newBufferedReader(Paths.get("C:/Scripts/Jsfunctions.js"), StandardCharsets.UTF_8));

Invocable inv = (Invocable) engine;
// call function from script file
inv.invokeFunction("yourFunction", "param");

---

假设您的jsfunctions.js文件有一个函数“display”，该文件存储在C:/Scripts/jsfunctions.js中

import javax.script.*;

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

    // JavaScript code in a String
    String script1 = "function hello(name) {print ('Hello, ' + name);}";
    String script2 = "function getValue(a,b) { if (a===\"Number\") return 1; 
                     else return b;}";
    // evaluate script
    engine.eval(script1);
    engine.eval(script2);

    Invocable inv = (Invocable) engine;

    inv.invokeFunction("hello", "Scripting!!");  //This one works.      
 }
}

var display = function(name) {
print("Hello, I am a Javascript display function",name);
return "display function return"
}

jsfunctions.js

import javax.script.*;

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

    // JavaScript code in a String
    String script1 = "function hello(name) {print ('Hello, ' + name);}";
    String script2 = "function getValue(a,b) { if (a===\"Number\") return 1; 
                     else return b;}";
    // evaluate script
    engine.eval(script1);
    engine.eval(script2);

    Invocable inv = (Invocable) engine;

    inv.invokeFunction("hello", "Scripting!!");  //This one works.      
 }
}

var display = function(name) {
print("Hello, I am a Javascript display function",name);
return "display function return"
}

现在，在java代码中，我建议您使用Java8Nashorn。 在java类中

import java.io.FileNotFoundException;
import java.io.FileReader;

import javax.script.Invocable;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;

class Test {
public void runDisplay() {
ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn");
try {
  engine.eval(new FileReader("C:/Scripts/Jsfunctions.js"));
  Invocable invocable = (Invocable) engine;
  Object result;
  result = invocable.invokeFunction("display", helloWorld);
  System.out.println(result);
  System.out.println(result.getClass());
  } catch (FileNotFoundException | NoSuchMethodException | ScriptException e) {
    e.printStackTrace();
    }
  }
}

---

注意：获取javascript文件的绝对路径，并在FileReader（）中替换，然后运行java代码。应该有用。

是的，很有用，谢谢。我们如何在提供的javascript中使用窗口，因为通过java代码将没有用于此的浏览器。您指的是哪个窗口或浏览器？解决方案是什么？如果在加载相对路径时遇到困难，请使用下面的代码<代码>URL文件URL=getClass（）.getResource（“js/WebWorker.js”）；eval（Files.newbuffereder（path.get（fileUrl.toURI（）），StandardCharsets.UTF_8））您好，我有疑问，我已经尝试调用了依赖于moment.js库的函数。所以我也添加了库脚本，比如

engine.eval（Files.newbufferederader（path.get（“/Volumes/Bala/Eclipse-Mars/Workspace/ClientWebAccessFullHistory/war/js/library/Moment.js”）、StandardCharsets.UTF_8）；eval（Files.newbufferederader（path.get（“/Volumes/Bala/Eclipse-Mars/Workspace/ClientWebAccessFullHistory/war/js/newLayout/FullHistory/FullHistory.js”）、StandardCharsets.UTF_8）但它在全局范围内不可用。感谢您提供此代码段，它可能会提供一些有限的即时帮助。A通过展示为什么这是一个很好的解决问题的方法，并将使它对未来有其他类似问题的读者更有用。请在您的回答中添加一些解释，包括您所做的假设。仅供参考……对于那些由于Oracle Java许可证变更或其他原因而迁移到OpenJDK的人，Nashorn在OpenJDK中不受欢迎。