palfish 2017-06-09 05:46 采纳率: 100%
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URLClassLoader加载本地类文件为什么总是报ClassNotFound?求大神解惑

public class ServletProcessor1 {

public void process(Request request, Response response) {
        String uri            = request.getUri();
        String servletName    = uri.substring(uri.lastIndexOf("/") + 1);
        URLClassLoader loader = null;

        try {
            // create a URLClassLoader
            URLStreamHandler streamHandler = null;

            URL[] urls        = new URL[1];
            File classPath    = new File(HttpServer1.WEB_ROOT);
            String repository = (new URL("file", null, 
                classPath.getCanonicalPath() + File.separator)).toString() ;
            urls[0]           = new URL(null, repository, streamHandler);
            loader            = new URLClassLoader(urls);
            System.out.println(loader.findResource(servletName));
        }
        catch (IOException e) {
            System.out.println(e.toString() );
        }

        Class<?> myClass = null;

        try {
            myClass = loader.loadClass(servletName);
        }
        catch (ClassNotFoundException e) {
            System.out.println(e.toString());
        }
        Servlet servlet = null;
        try {
            servlet = (Servlet) myClass.newInstance();
            servlet.service((ServletRequest) request, (ServletResponse) response);
        }
        catch (Exception e) {
            System.out.println(e.toString());
        }
        catch (Throwable e) {
            System.out.println(e.toString());
        }
}

}

java.lang.ClassNotFoundException: PrimitiveServlet
java.lang.NullPointerException

Exception in thread "main" java.lang.NullPointerException
at ex02.pyrmont.HttpServer1.await(HttpServer1.java:50)
at ex02.pyrmont.HttpServer1.main(HttpServer1.java:22)

  • 写回答

3条回答 默认 最新

  • lihongbiao0610 2017-06-09 06:02
    关注

    servletName应该是包名+类名。如com.test.PrimitiveServlet

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论
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