随着 Servlet 3.0, http://docs.oracle.com/javaee/6/api/javax/servlet/annotation/WebServlet.html
我们可以定义一个带有 WebServlet 注解的类:
package com.example;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
@WebServlet({"/hello"})
public class HelloServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) {
response.getWriter().println("hello world");
}
}
并定义一个不映射 servlet 的 web.xml 文件:
<?xml version="1.0" encoding="UTF-8"?>
<web-app
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0">
</web-app>
因此,对 http://test.com/hello 的请求将正确打印“hello world”。
这是可行的,因为 Servlet 3.0 会扫描所有类以查找 WebServlet 注释。
有没有办法将此扫描限制在给定包内的类(例如,com.example.*)?
最佳答案
这取决于您的 Web 容器。例如,在 Tomcat 中,您可以在 catalina.properties 中使用以下设置(我从 catalina.properties 中复制了注释):
# List of JAR files that should not be scanned using the JarScanner
# functionality. This is typically used to scan JARs for configuration
# information. JARs that do not contain such information may be excluded from
# the scan to speed up the scanning process. This is the default list. JARs on
# this list are excluded from all scans. Scan specific lists (to exclude JARs
# from individual scans) follow this. The list must be a comma separated list of
# JAR file names.
# The JARs listed below include:
# - Tomcat Bootstrap JARs
# - Tomcat API JARs
# - Catalina JARs
# - Jasper JARs
# - Tomcat JARs
# - Common non-Tomcat JARs
tomcat.util.scan.DefaultJarScanner.jarsToSkip=\
bootstrap.jar,commons-daemon.jar,tomcat-juli.jar,\
annotations-api.jar,el-api.jar,jsp-api.jar,servlet-api.jar
# Additional JARs (over and above the default JARs listed above) to skip when
# scanning for Servlet 3.0 pluggability features. These features include web
# fragments, annotations, SCIs and classes that match @HandlesTypes. The list
# must be a comma separated list of JAR file names.
org.apache.catalina.startup.ContextConfig.jarsToSkip=
# Additional JARs (over and above the default JARs listed above) to skip when
# scanning for TLDs. The list must be a comma separated list of JAR file names.
org.apache.catalina.startup.TldConfig.jarsToSkip=
关于servlet-3.0 - Servlet 3.0,将 WebServlet 注释的扫描限制为给定的包,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/12047050/