Could not find or load main class on simple Java Soup app [duplicate]

问题

I do the compilation of this simple programm i found here

package com.stackoverflow.q2835505;

import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

public class Test {

public static void main(String[] args) throws Exception {
    String url = "https://stackoverflow.com/questions/2835505";
    Document document = Jsoup.connect(url).get();

    String question = document.select("#question .post-text").text();
    System.out.println("Question: " + question);

    Elements answerers = document.select("#answers .user-details a");
    for (Element answerer : answerers) {
        System.out.println("Answerer: " + answerer.text());
    }
}

}

with this command in terminal:

javac -cp ./jsoup-1.10.2.jar Test.java

but when i try to run it i take this:

Error:Could not find or load main class

and I can't find the solution, where is the problem? Thanks.

回答1:

You might be running into more than one issue here...

Javac. To be sure, compile your Java app like this:

javac -cp ./jsoup-1.10.2.jar -d . Test.java

the -d option ensures that the compiled class is placed in the corresponding package directory:

com/stackoverflow/q2835505/Test.class

and not on your current directory. Let's check the man page just to be sure (-d option):

Sets the destination directory for class files. The directory must already exist because javac does not create it. If a class is part of a package, then javac puts the class file in a subdirectory that reflects the package name and creates directories as needed.

If the -d option is not specified, then javac puts each class file in the same directory as the source file from which it was generated.

Java. Finally, run it using:

java -cp .:./jsoup-1.10.2.jar com.stackoverflow.q2835505.Test

this runs your app using your current directory (.) and jsoup-1.10.2.jar as your class path. The current directory is mandatory so java finds your Test.class as well as the JSoup jar.

See this nice answer for a lot more information on the java command syntax.

来源：https://stackoverflow.com/questions/44098381/could-not-find-or-load-main-class-on-simple-java-soup-app

标签

java

web-scraping

jsoup

classpath