@WebServlet注释当中的相关内容

public @interface WebServlet {
    String name() default "";

    String[] value() default {};

    String[] urlPatterns() default {};

    int loadOnStartup() default -1;

    WebInitParam[] initParams() default {};

    boolean asyncSupported() default false;

    String smallIcon() default "";

    String largeIcon() default "";

    String description() default "";

    String displayName() default "";
}

url-partten：servlet访问路径

一个servlet可以定义多个访问路径

@WebServlet(urlPatterns = {"/demo", "/demo_", "/_demo"})

url-partten的定义规则

1、“/XXXXX”

@WebServlet(urlPatterns = {"/demo", "/demo_", "/_demo"})

2、“/XXXX/XXX”：多层路径，目录结构，*是通配符

@WebServlet(urlPatterns = {"/demo/cjd", "/user/*"})

3、*.do：do可以使任意的内容

@WebServlet(urlPatterns = {"*.do"})
@WebServlet(urlPatterns = {"*.cjd"})
@WebServlet(urlPatterns = {"*.all"})