valuestack

We are using Struts 2 validators @FieldExpressionValidator and @ExpressionValidator . These validators check on OGNL expression. There are lots of cases where we deal with Strings in these expressions. expression="(captcha=='' && captcha== null || ....) We find it is very useful if we can use StringUtils ( isEmpty ,trimToEmpty,... ) here. As we set the struts.ognl.allowStaticMethodAccess to false, for security issues, we tried to solve it by adding this getter to action public StringUtils getStringUtils(){ return new StringUtils(); } and then stringUtils.isEmpty(captcha) in the expression. But

I want list of items to be displayed along with each having a blank textfield to fill amount on my JSP page and once I fill the required items amount, I will submit. I have ExampleAction class as below, where I have populate() method which I fire first so that items are filled. I fire URL : http://localhost:8084/WebExample/populate.action. Same ExampleAction has execute mtd which I call on SUBMIT button action from JSP page. But my problem is in execute method, I am unable to get the objects in list i.e. exList. Is this because an instance of the action class is associated with just one

I have to send object of Bean class back to JSP from my action class. I am instantiating the Bean class in my action class and and setting some values in my Action class. ElasticitiesVariable elasticitiesVariable = new ElasticitiesVariable(); elasticitiesVariable.setAuto_Auto_cost_peak("-0.047"); elasticitiesVariable.setAuto_Ride_cost_peak("0.000"); elasticitiesVariable.setAuto_Van_cost_peak("0.000"); elasticitiesVariable.setAuto_Transit_cost_peak("0.050"); elasticitiesVariable.setAuto_Bike_cost_peak("0.000"); and in my JSP I am declaring the bean class as well. <s:bean name="org.apache.struts

I am new to Struts 2. I am studying it from the book Struts2 In Action. I am having difficulty in understanding some concepts in OGNL which are as follows- We know that params interceptor moves the data from the request parameters to the action object in ValueStack . Now while reading, I came upon a line that says- "The tricky part of the job is mapping the name of the parameter to an actual property on the ValueStack . This is where OGNL comes in. The params interceptor interprets the request parameter name as an OGNL expression to locate the correct destination property on the ValueStack".

I am trying to understand the path data takes within Struts2, how is data placed on the ValueStack? How can I find out which object is currently present in the ValueStack? What other data can I access from different scopes application, session, request, page? How to decide the scopes my variables should have? Dave Newton That's a lot of questions. The value stack is just a data structure, sort of a combination of a map and stack. Named objects (accessed via the # tag in OGNL) are in the map (like the request scope, say), objects to search through for properties/methods are on the stack. The <s

一、ValueStack 1 .ValueStack是一个接口，在struts2中使用OGNL（Object-Graph Navigation Language）表达式实际上是使用 实现了ValueStack接口的类OgnlValueStack.它是ValueStack的默认实现类. 2 .ValueStack贯穿整个action的生命周期，每一个action实例都拥有一个ValueStack对象，其中保存了当前action对象和其他相关对象. 3 .struts2把ValueStack对象保存在名为：struts.valueStack的request域中.即ValueStack作用域为request.当action创建的时候，ValueStack就创建了，action被销毁的时候，ValueStack就销毁了 4 .ValueStack中的数据分两部分存放：root（栈结构，CompoundRoot）和context（map形式,OgnlContext） （1） * 其中的root对象是CompoundRoot，CompoundRoot继承了ArrayList，提供了额外的方法：push(),和pop()方法， 用来对root对象中所包含的数据进行存取.正是由于这两个方法，CompoundRoot变成了一个栈结构. * struts2中，一个请求在最终到达Action的方法之前