史上最全web.xml配置文件元素详解

一、web.xml配置文件常用元素及其意义预览

 1 <web-app>
 2 
 3      
 4      <display-name>display-name>
 5 
 6      
 7      <description>description>
 8 
 9      
10      <context-param>context-param>
11 
12      
13      <filter>filter>
14 
15      
16      <filter-mapping>filter-mapping>
17 
18      
20      <listener>listener>
21 
22      
24      <servlet>servlet>
25 
26      
29      <servlet-mapping>servlet-mapping>
30 
31      
33      <session-config>session-config>
34 
35      
36      <mime-mapping>mime-mapping>
37 
38      
39      <welcome-file-list>welcome-file-list>
40 
41      
42      <error-page>error-page>
43 
44      
46      <taglib>taglib>
47 
48      
49      <resource-env-ref>resource-env-ref>
50 
51      
52      <resource-ref>resource-ref>
53 
54      
55      <security-constraint>security-constraint>
56 
57      
58      <login-config>login-config>
59 
60      
62      <security-role>security-role>
63 
64      
65      <env-entry>env-entry>
66 
67      
68      <ejb-ref>ejb-ref>
69 
70      
71      <ejb-local-ref>ejb-local-ref>
72 
73  web-app> 

二、各个配置元素详解

1.Web应用图标：指出IDE和GUI工具用来表示Web应用的大图标和小图标

1 <icon>  
2      <small-icon>/images/app_small.gifsmall-icon>  
3      <large-icon>/images/app_large.giflarge-icon>  
4  icon>

 

2.Web 应用名称：提供GUI工具可能会用来标记这个特定的Web应用的一个名称

<display-name>Tomcat Exampledisplay-name>

 

3.Web 应用描述：给出于此相关的说明性文本

<desciption>Tomcat Example servlets and JSP pages.desciption>

 

4.上下文参数：声明应用范围内的初始化参数

1 <context-param>
2      <param-name>参数名para-name>
3      <param-value>参数值param-value>
4      <description>参数描述description>
5  context-param>

在servlet里面可以通过 getServletContext().getInitParameter(“context/param”)得到

 

5.过滤器配置：将一个名字与一个实现javaxs.servlet.Filter接口的类相关联

 1 <filter>
 2      <filter-name>setCharacterEncodingfilter-name>
 3      <filter-class>com.myTest.setCharacterEncodingFilterfilter-class>
 4      <init-param>
 5          <param-name>encodingparam-name>
 6          <param-value>GB2312param-value>
 7      init-param>
 8  filter>
 9  <filter-mapping>
10      <filter-name>setCharacterEncodingfilter-name>
11      <url-pattern>/*url-pattern>
12  filter-mapping>

 

6.监听器配置

1 <listener>
2      <listerner-class>org.springframework.web.context.ContextLoaderListenerlistener-class>
3  listener>

 

7.Servlet配置

 1 <servlet>
 2    <servlet-name>servlet名称servlet-name>
 3    <servlet-class>servlet类全路径servlet-class>
 4    <init-param>
 5        <param-name>参数名param-name>
 6        <param-value>参数值param-value>
 7    init-param>
 8    <run-as>
 9        <description>Security role for anonymous accessdescription>
10        <role-name>tomcatrole-name>
11    run-as>
12 　 <load-on-startup>指定当Web应用启动时，装载Servlet的次序load-on-startup>
13 servlet>
14 <servlet-mapping>
15   <servlet-name>servlet名称servlet-name>
16   <url-pattern>映射路径url-pattern>
17 servlet-mapping>

 

8.会话超时配置（单位为分钟）

1 <session-config>
2      <session-timeout>120session-timeout>
3  session-config>

 

9.MIME类型配置

1 <mime-mapping>
2      <extension>htmextension>
3      <mime-type>text/htmlmime-type>
4  mime-mapping>

 

10.指定欢迎文件页配置

1  <welcome-file-list>
2      <welcome-file>index.jspwelcome-file>
3      <welcome-file>index.htmlwelcome-file>
4      <welcome-file>index.htmwelcome-file>
5  welcome-file-list>

 

11.配置错误页面

　　(1).通过错误码来配置error-page

1 
2 <error-page>
3       <error-code>404error-code>
4       <location>/NotFound.jsplocation>
5  error-page>

　　(2).通过异常的类型配置error-page

1 
2 <error-page>
3       <exception-type>java.lang.NullExceptionexception-type>
4       <location>/error.jsplocation>
5 error-page>

 

12.TLD配置

1 <taglib>
2      <taglib-uri>http://jakarta.apache.org/tomcat/debug-taglibtaglib-uri>
3      <taglib-location>/WEB-INF/jsp/debug-taglib.tldtaglib-location>
4  taglib>

如果开发工具一直在报错,应该把 放到 中

1 <jsp-config>
2      <taglib>
3          <taglib-uri>http://jakarta.apache.org/tomcat/debug-taglibtaglib-uri>
4          <taglib-location>/WEB-INF/pager-taglib.tldtaglib-location>
5      taglib>
6  jsp-config>

 

13.资源管理对象配置

1 <resource-env-ref>
2      <resource-env-ref-name>jms/StockQueueresource-env-ref-name>
3  resource-env-ref>

 

14.资源工厂配置

1 <resource-ref>
2      <res-ref-name>mail/Sessionres-ref-name>
3      <res-type>javax.mail.Sessionres-type>
4      <res-auth>Containerres-auth>
5 resource-ref>

　　配置数据库连接池就可在此配置

1  <resource-ref>
2      <description>JNDI JDBC DataSource of shopdescription>
3      <res-ref-name>jdbc/sample_dbres-ref-name>
4      <res-type>javax.sql.DataSourceres-type>
5      <res-auth>Containerres-auth>
6  resource-ref>

 

15.安全限制配置

 1 <security-constraint>
 2      <display-name>Example Security Constraintdisplay-name>
 3      <web-resource-collection>
 4          <web-resource-name>Protected Areaweb-resource-name>
 5          <url-pattern>/jsp/security/protected/*url-pattern>
 6          <http-method>DELETEhttp-method>
 7          <http-method>GEThttp-method>
 8          <http-method>POSThttp-method>
 9          <http-method>PUThttp-method>
10      web-resource-collection>
11      <auth-constraint>
12          <role-name>tomcatrole-name>
13          <role-name>role1role-name>
14      auth-constraint>
15 security-constraint>

 

16.登陆验证配置

1  <login-config>
2      <auth-method>FORMauth-method>
3      <realm-name>Example-Based Authentiation Arearealm-name>
4      <form-login-config>
5          <form-login-page>/jsp/security/protected/login.jspform-login-page>
6          <form-error-page>/jsp/security/protected/error.jspform-error-page>
7      form-login-config>
8  login-config>

 

17.安全角色：security-role元素给出安全角色的一个列表，这些角色将出现在servlet元素内的security-role-ref元素的role-name子元素中。
分别地声明角色可使高级IDE处理安全信息更为容易。

1 <security-role>
2      <role-name>tomcatrole-name>
3  security-role>

 

18.Web环境参数：env-entry元素声明Web应用的环境项

1 <env-entry>
2      <env-entry-name>minExemptionsenv-entry-name>
3      <env-entry-value>1env-entry-value>
4      <env-entry-type>java.lang.Integerenv-entry-type>
5 env-entry>

 

19.EJB 声明

1 <ejb-ref>
2      <description>Example EJB referencedecription>
3      <ejb-ref-name>ejb/Accountejb-ref-name>
4      <ejb-ref-type>Entityejb-ref-type>
5      <home>com.mycompany.mypackage.AccountHomehome>
6      <remote>com.mycompany.mypackage.Accountremote>
7  ejb-ref>

 

20.本地EJB声明

1  <ejb-local-ref>
2      <description>Example Loacal EJB referencedecription>
3      <ejb-ref-name>ejb/ProcessOrderejb-ref-name>
4      <ejb-ref-type>Sessionejb-ref-type>
5      <local-home>com.mycompany.mypackage.ProcessOrderHomelocal-home>
6      <local>com.mycompany.mypackage.ProcessOrderlocal>
7  ejb-local-ref>

 

三、总结

　　以上就是常用的web.xml中元素的配置以及作用了，欢迎提出异议和不适当的地方共同学习。