在java中执行javascript - 打开一个URL并获取链接

问题描述

  import javax.script.ScriptEngine; 
 import javax.script.ScriptEngineManager; 
 import java.io.FileReader; 
 
 public class Main {
 
 public static void main（String [] args）{
 
 ScriptEngineManager manager = new ScriptEngineManager（）; 
 ScriptEngine engine = manager.getEngineByName（js）; 
尝试{
 FileReader reader = new FileReader（C：/yourfile.js）; 
 engine.put（urlfromjava，http://www.something.com/?asvb）; 
 engine.eval（reader）; 
 reader.close（）; 
} catch（Exception e）{
 e.printStackTrace（）; 
} 
} 
} 
  

现在，yourfile。 js包含此行

 函数urlget（url）
 {
 print（URL：+ url ）; 
 var loc = window.open（url）; 
 var link = document.getElementsByTagName（'a'）[61]。href; 
 return（\\\
Link is：\\\
+ link）; 
 
} 
 var x = urlget（urlfromjava）; 
 print（x）; 
  

我收到错误

 javax.script.ScriptException：sun.org.mozilla.javascript.internal.EcmaError：ReferenceError：windowis not defined
  

如何打开一个URL并从java中获取链接？

解决方案

根据：

由于您没有执行你的脚本在浏览器中，窗口对象没有被定义。

您可以使用URL / URLConnecion类读取URL并将其提供给ScriptEngine。 。

import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import java.io.FileReader;

public class Main {

    public static void main(String[] args) {

        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("js");
        try {
            FileReader reader = new FileReader("C:/yourfile.js");
            engine.put("urlfromjava", "http://www.something.com/?asvb");
            engine.eval(reader);
            reader.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Right now, the yourfile.js contains this line

function urlget(url)
{
    print("URL:"+url);
    var loc = window.open(url);
    var link = document.getElementsByTagName('a')["61"].href;
    return ("\nLink is: \n"+link);

}
var x = urlget(urlfromjava);
print(x);

I get the error

"javax.script.ScriptException: sun.org.mozilla.javascript.internal.EcmaError: ReferenceError: "window" is not defined"

How to open a URL and get the links of it from java?

解决方案

According to the documentation:

Since you are not executing your script in a browser, the window object is not defined.

You can read the URL using the URL/URLConnecion classes and feed it to the ScriptEngine. There is a tutorial here.

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