使用时找不到Java类异常

Question

I am writing a web crawler using Jsoup, but I get a class not found exception when running the code after the class was properly imported. When I compiled a program that just imports the JSoup class without using it, it imports fine, but when I try to use the class I get an exception.

Exception in thread "main" java.lang.NoClassDefFoundError: org/jsoup/Jsoup
        at crawler.getLinksFromPage(crawler.java:14)
        at crawler.main(crawler.java:56)
Caused by: java.lang.ClassNotFoundException: org.jsoup.Jsoup
        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        ... 2 more

I imported all of the classes that get used and set the classpath to the jar file when I compiled it and it compiled without errors, but I keep getting thas exception when I run it.

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

Answer 1

java -cp .;youJsoup.jar com.your.main.faile.ClassName

最后，请确保在使用-classpath命令行选项之前，将您依赖的任何jar文件放入系统类加载器搜索路径中。