Erro no web.xml

[MarKteus 1]

Olá

 

Estou tendo um problema que é o seguinte se meu web.xml contiver somente as linhas abaixo:

<?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" id="WebApp_ID" version="3.0">

<display-name>MyCrud</display-name>

<welcome-file-list>

<welcome-file>index.jsp</welcome-file>

</welcome-file-list>

Porém se acrescento mais linhas a aplicação não rodar mais

<?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" id="WebApp_ID" version="3.0">

<display-name>MyCrud</display-name>

<welcome-file-list>

<welcome-file>index.jsp</welcome-file>

</welcome-file-list>

<resource-ref>

<description>My DataSource</description>

<res-ref-name>jdbc/meucrud</res-ref-name>

<res-type>javax.sql.DataSource</res-type>

<res-auth>Container</res-auth>

</resource-ref>

<filter>

<filter-name>ConnectionFilter</filter-name>

<filter-class>com.meucrud.dao.utils.ConnectionFilter</filter-class>

</filter>

<filter-mapping>

<filter-name>ConnectionFilter</filter-name>

<url-pattern>/*</url-pattern>

</filter-mapping>

</web-app>

Alguém sabe o motivo ?