问题
I've a JSF 2.0 web application running in tomcat 7.0.29 and tried to use the Servlet 3.0 annotation but the servlet didn't work as i can't see the log written in its init() method.
i ve read many answers for the same problem but still not seccessful.
This how my files look:
The web.xml :
<?xml version="1.0" encoding="UTF-8"?>
<web-app metadata-complete="false"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0">
<display-name>GestionCongesFeki</display-name>
<welcome-file-list>
<welcome-file>index.xhtml</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>Faces Servlet</servlet-name>
<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>*.xhtml</url-pattern>
</servlet-mapping>
<!-- <servlet> -->
<!-- <servlet-name>AjaxRelaisServlet</servlet-name> -->
<!-- <servlet-class>utils.AjaxRelaisServlet</servlet-class> -->
<!-- <load-on-startup>2</load-on-startup> -->
<!-- </servlet> -->
<!-- <servlet-mapping> -->
<!-- <servlet-name>AjaxRelaisServlet</servlet-name> -->
<!-- <url-pattern>/AjaxRelaisServlet/*</url-pattern> -->
<!-- </servlet-mapping> -->
</web-app>
the pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>esprit.pfe2013</groupId>
<artifactId>GestionCongesFeki</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>GestionCongesFeki Maven Webapp</name>
<url>http://maven.apache.org</url>
<repositories>
<repository>
<id>central</id>
<name>Maven Repository Switchboard</name>
<layout>default</layout>
<url>http://repo1.maven.org/maven2</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
</repository>
<repository>
<id>prime-repo</id>
<name>Prime Repo</name>
<url>http://repository.primefaces.org</url>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>central</id>
<name>Maven Plugin Repository</name>
<url>http://repo1.maven.org/maven2</url>
<layout>default</layout>
<snapshots>
<enabled>false</enabled>
</snapshots>
<releases>
<updatePolicy>never</updatePolicy>
</releases>
</pluginRepository>
</pluginRepositories>
<!-- <repositories> -->
<!-- <repository> -->
<!-- <id>central</id> -->
<!-- <name>Central Repository</name> -->
<!-- <url>http://repo.maven.apache.org/maven2</url> -->
<!-- <layout>default</layout> -->
<!-- <snapshots> -->
<!-- <enabled>false</enabled> -->
<!-- </snapshots> -->
<!-- </repository> -->
<!-- </repositories> -->
<dependencies>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.0.1</version>
</dependency>
<!-- PrimeFaces -->
<dependency>
<groupId>org.primefaces</groupId>
<artifactId>primefaces</artifactId>
<version>3.4.1</version>
</dependency>
<!-- JSF 2 -->
<dependency>
<groupId>com.sun.faces</groupId>
<artifactId>jsf-api</artifactId>
<version>2.1.11</version>
</dependency>
<dependency>
<groupId>com.sun.faces</groupId>
<artifactId>jsf-impl</artifactId>
<version>2.1.11</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>taglibs</groupId>
<artifactId>standard</artifactId>
<version>1.1.2</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.13</version>
</dependency>
<dependency>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
<version>2.4.3</version>
</dependency>
</dependencies>
<build>
<finalName>GestionCongesFeki</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>1.6</source>
<target>1.6</target>
</configuration>
</plugin>
</plugins>
</build>
</project>
and the servlet :
package utils;
import java.io.IOException;
import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class AjaxRelaisServlet
*/
@WebServlet("/AjaxRelaisServlet")
public class AjaxRelaisServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public AjaxRelaisServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see Servlet#init(ServletConfig)
*/
public void init(ServletConfig config) throws ServletException {
System.out.println("This is AjaxRelaisServlet initialisaton !!!");
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
}
Actually the servlet was working fine when i was declaring it in the web.xml(the commented code) but not when i used the annotation. By the way , i would like to know if i can get rid of the web.xml when this problem will be resolved, but i don't know how the JSF servlet will be declared without it.
Thanks for help!
回答1:
Add the loadOnStartup=1 attribute to your @WebServlet annotation to cause the servlet to load on app startup. This attribute is analogous to the <load-on-startup/> element you'll find in the web.xml.
@WebServlet(name="AjaxRelaisServlet",loadOnStartup=1,urlPatterns={"/AjaxRelaisServlet"})
When you have a hammer, every problem looks like a nail.
On the issue of replacing the web.xml entirely, you should be aware that there are some things that the annotations based model currently cannot achieve. Filter ordering, for example, cannot be achieved with annotations only (AFAIK). Also, you should realise thata concrete configuration document is self-documenting. Maintainers of your system can take one look at the web.xml and figure out what's going on in your app, config wise. Contrast that with an annotations-only architecture. It'll be painstaking to figure out the wiring of all the pieces of the system.
来源：https://stackoverflow.com/questions/15691240/servlet-3-0-doesnt-load-on-application-startup