当实现或继承一个方法并且覆盖它本身的方法时,如果覆盖的是init()方法,记得初始化,否则会出现空指针异常!!!
例子:
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public abstract class MyGenericServlet implements Servlet, ServletConfig { private ServletConfig servletConfig; @Override public void init(ServletConfig servletConfig) throws ServletException { // TODO Auto-generated method stub this.servletConfig = servletConfig; } ...... } - - - public class LoginServlet extends MyGenericServlet { public void init() throws ServletException { System.out.println("初始化"); init(); // 记得初始化 } }
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