How can I get a Javascript variable value in Java?

Question

In my current project I have to read a JavaScript file from the web and extract an object from it. The variable can vary from time to time, so I have to read it instead of h

Answer 1

There are many libraries in Java to parse the JSON. There is a list on JSON.org

Read the file with Java

import org.json.JSONObject;

URL url = new URL("http://example.com/foo.js");
InputStream urlInputStream = url.openStream();
JSONObject json = new JSONObject(urlInputStream.toString());  

Answer 2

Finally code it myself.

//remove comments
private String removeComment(String html){
    String commentA = "/*";
    String commentB = "*/";
    int indexA, indexB;
    indexA = html.indexOf(commentA);
    indexB = html.indexOf(commentB);
    while(indexA != -1 && indexB != -1 ){
        html = html.substring(0, indexA) + html.substring(indexB + commentB.length());
        indexA = html.indexOf(commentA);
        indexB = html.indexOf(commentB);
    }
    return html;
}

    //find variable with name varName
private String findVar(String varName, String html, char lBrace, char rBrace){
    String tmp = html.substring(html.indexOf(varName));
    tmp = tmp.substring(tmp.indexOf(lBrace));

    int braceCount = 0;
    int index = 0;
    while(true){
        if(tmp.charAt(index) == lBrace){
            braceCount ++;
        }else if(tmp.charAt(index) == rBrace){
            braceCount --;
        }
        index ++;
        if(braceCount == 0){
            break;
        }
    }
    return tmp.substring(0, index);
}