Whitespace trimming in Struts2 using filter

Source link: https://app.box.com/s/j7sji6xhn1sc26rayosi

• Create a filter for trimming
• Add the filter to web.xml

1. Create filter for trimming

When you use the struts2 filter org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter  use should create a Request wrapper extend StrutsRequestWrapper

The full WhitespaceFilter class:

 package com.vmtram.struts2.filters;  
 import java.io.IOException;  
 import java.util.HashMap;  
 import java.util.Iterator;  
 import java.util.Map;  
 import javax.servlet.Filter;  
 import javax.servlet.FilterChain;  
 import javax.servlet.FilterConfig;  
 import javax.servlet.ServletException;  
 import javax.servlet.ServletRequest;  
 import javax.servlet.ServletResponse;  
 import javax.servlet.http.HttpServletRequest;  
 import org.apache.struts2.dispatcher.StrutsRequestWrapper;  
 public class WhitespaceFilter implements Filter {  
      public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException,  
                ServletException {  
           HttpServletRequest request = (HttpServletRequest) req;  
           chain.doFilter(new RequestWrapper(request), res);  
      }  
      @Override  
      public void destroy() {  
      }  
      @Override  
      public void init(FilterConfig arg0) throws ServletException {  
      }  
      class RequestWrapper extends StrutsRequestWrapper {  
           public RequestWrapper(HttpServletRequest request) {  
                super(request);  
           }  
           @Override  
           public Map<String, String[]> getParameterMap() {  
                Map<String, String[]> paramMapIn = super.getParameterMap();  
                Map<String, String[]> paramMapOut = new HashMap<String, String[]>();  
                Iterator<String> keys = paramMapIn.keySet().iterator();  
                while (keys.hasNext()) {  
                     String key = keys.next();  
                     String[] values = paramMapIn.get(key);  
                     if (values.length == 1) {  
                          String value = values[0].trim();  
                          paramMapOut.put(key, new String[] { value });  
                     } else {  
                          paramMapOut.put(key, values);  
                     }  
                }  
                return paramMapOut;  
           }  
      }  
 }  

Because the implement doFilter of StrutsPrepareAndExecuteFilter  will make a wrapRequest for input ServletRequest.

 ...  
         prepare.setEncodingAndLocale(request, response);  
         prepare.createActionContext(request, response);  
         prepare.assignDispatcherToThread();  
         request = prepare.wrapRequest(request);  
         ActionMapping mapping = prepare.findActionMapping(request, response, true);  
 ...  

Have a checking in the implememt of wrapRequest

  if (request instanceof StrutsRequestWrapper) {  
       return request;  
     }  

If RequestWrapper of user extends HttpServletRequestWrapper it cannot invoke to user getParameterMap() method to trim() the  parameters.

2. Add filter to web.xml

     <filter>  
           <filter-name>whitespaceFilter</filter-name>  
           <filter-class>com.vmtram.struts2.filters.WhitespaceFilter</filter-class>  
      </filter>  
      <filter-mapping>  
           <filter-name>whitespaceFilter</filter-name>  
           <url-pattern>/*</url-pattern>  
      </filter-mapping>  

The results:

Relate: 

Create Struts2 project with eclipse and maven

Support UTF-8 in java web

Support UTF-8 in Struts2 using filter

This charset filter can apply for many Java web like JSF, Struts, Struts2, JSP ...

Source link: https://app.box.com/s/s8ldu549lt3jt1ppvxs7

• Create a charset filter
• Add filter to web.xml
• Enable encoding UTF-8 in view

1. Create a filter to support UTF-8:

 package com.vmtram.struts2.filters;  
 import java.io.IOException;  
 import javax.servlet.Filter;  
 import javax.servlet.FilterChain;  
 import javax.servlet.FilterConfig;  
 import javax.servlet.ServletException;  
 import javax.servlet.ServletRequest;  
 import javax.servlet.ServletResponse;  
 public class CharsetFilter implements Filter {  
      @Override  
      public void destroy() {  
      }  
      @Override  
      public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException,  
                ServletException {  
           req.setCharacterEncoding("UTF-8");  
           res.setContentType("text/html; charset=UTF-8");  
           chain.doFilter(req, res);  
      }  
      @Override  
      public void init(FilterConfig arg0) throws ServletException {  
      }  
 }

2. Add filter to web.xml

      <filter>  
           <filter-name>charsetFilter</filter-name>  
           <filter-class>com.vmtram.struts2.filters.CharsetFilter</filter-class>  
      </filter>  
      <filter-mapping>  
           <filter-name>charsetFilter</filter-name>  
           <url-pattern>/*</url-pattern>  
      </filter-mapping>  

3. Enable encoding UTF-8 in view. 

Such as in JSP file.

 <%@ page language="java" contentType="text/html; charset=UTF-8"  
      pageEncoding="ISO-8859-1"%>  

The results:

Related:

• Create Struts2 project with eclipse and maven
• Whitespace trimming in Struts2

Create Struts2 project with eclipse and maven

Source link: https://app.box.com/s/q47fwfkiam0j98nuuncl

• Create a Struts2 project with eclipse
• Convert to maven project
• First HelloStruts2 example

1. Create a Dynamic Web Project with eclipse Kepler:

Eclipse -> new project -> select Dynamic Web Project -> enter Project name (HelloStruts2) -> select Next -> select Generate web.xml and click finish.

Add struts.xml to folder /WEB-INF/classes. Create folder /classes if it does not existed.

 <?xml version="1.0" encoding="UTF-8"?>  
 <!DOCTYPE struts PUBLIC  
   "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"  
   "http://struts.apache.org/dtds/struts-2.0.dtd">  
 <struts>  
      <constant name="struts.devMode" value="true" />  
 </struts>  

Add the filter StrutsPrepareAndExecuteFilter to web.xml as the below:

 <?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>HelloStruts2</display-name>  
  <display-name>Struts2 with eclipse and maven</display-name>  
      <welcome-file-list>  
           <welcome-file>pages/index.jsp</welcome-file>  
      </welcome-file-list>  
      <filter>  
           <filter-name>struts2</filter-name>  
           <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>  
      </filter>  
      <filter-mapping>  
           <filter-name>struts2</filter-name>  
           <url-pattern>/*</url-pattern>  
      </filter-mapping>  
 </web-app>  

2. Convert to maven project:

Right click on project -> Configure -> Convert to Maven Project.

Add dependency for struts2 in pom.xml:

 <dependency>   
         <groupId>org.apache.struts</groupId>   
         <artifactId>struts2-core</artifactId>   
         <version>2.3.16.3</version>   
    </dependency>   

3. First HelloStruts2 example

Create HelloAction.java

 package com.vmtram.struts2.action;  
 public class HelloAction {  
      private static final String SUCCESS = "SUCCESS";  
      private String username;  
      public String doAction() {  
           return SUCCESS;  
      }  
      // Getter & Setter  
      public String getUsername() {  
           return username;  
      }  
      public void setUsername(String username) {  
           this.username = username;  
      }  
 }  

Mapping the action in struts.xml

 <?xml version="1.0" encoding="UTF-8"?>  
 <!DOCTYPE struts PUBLIC  
   "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"  
   "http://struts.apache.org/dtds/struts-2.0.dtd">  
 <struts>  
      <constant name="struts.devMode" value="true" />  
      <package name="helloWorld" extends="struts-default">  
           <action name="hello" class="com.vmtram.struts2.action.HelloAction"  
                method="doAction">  
                <result name="SUCCESS">/pages/hello-view.jsp</result>  
           </action>  
      </package>  
 </struts>  

Create a view index.jsp to input data

 <%@ page language="java" contentType="text/html; charset=UTF-8"  
      pageEncoding="ISO-8859-1"%>  
 <%@ taglib prefix="s" uri="/struts-tags"%>  
 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">  
 <html>  
 <head>  
 <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">  
 <title>Index</title>  
 </head>  
 <body>  
      <s:form action="hello">  
           <s:textfield name="username" label="Enter your name" />  
           <s:submit value="SUBMIT" />  
      </s:form>  
 </body>  
 </html>  

Create a view hello-view.jsp to show data

 <%@ page language="java" contentType="text/html; charset=UTF-8"  
      pageEncoding="UTF-8"%>  
 <%@ taglib prefix="s" uri="/struts-tags"%>  
 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">  
 <html>  
 <head>  
 <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">  
 <title>Hello view</title>  
 </head>  
 <body>  
      Hello  
      <s:property value="username" />  
 </body>  
 </html>  

The project structure:

The result:

Related:

• Support UTF-8 in java web
• Whitespace trimming in Struts2