org.apache.struts2.components
类 Set

java.lang.Object
  org.apache.struts2.components.Component
      org.apache.struts2.components.ContextBean
          org.apache.struts2.components.Set

public class Set
extends ContextBean

The set tag assigns a value to a variable in a specified scope. It is useful when you wish to assign a variable to a complex expression and then simply reference that variable each time rather than the complex expression. This is useful in both cases: when the complex expression takes time (performance improvement) or is hard to read (code readability improvement).

If the tag is used with body content, the evaluation of the value parameter is omitted. Instead, the String to which the body evaluates is set as value for the scoped variable.

The scopes available are as follows :-

• application - the value will be set in application scope according to servlet spec. using the name as its key
• session - the value will be set in session scope according to servlet spec. using the name as key
• request - the value will be set in request scope according to servlet spec. using the name as key
• page - the value will be set in page scope according to servlet sepc. using the name as key
• action - the value will be set in the request scope and Struts' action context using the name as key

NOTE:

If no scope is specified, it will default to action scope.

Parameters

• name* (String): The name of the new variable that is assigned the value of value
• value (Object): The value that is assigned to the variable named name
• scope (String): The scope in which to assign the variable. Can be application, session, request, page, or action. By default it is action.

Examples

 
 <s:set var="personName" value="person.name"/>
 Hello, <s:property value="#personName"/>

 <s:set var="janesName">Jane Doe</s:set>
 <s:property value="#janesName"/>
 
 

字段摘要

从类 org.apache.struts2.components.Component 继承的字段

COMPONENT_STACK

构造方法摘要

Set(com.opensymphony.xwork2.util.ValueStack stack)

方法摘要

boolean	end(Writer writer, String body) Callback for the end tag of this component.
void	setName(String name)
void	setScope(String scope)
void	setValue(String value)
void	setVar(String var)
boolean	usesBody() Overwrite to set if body should be used.

从类 org.apache.struts2.components.ContextBean 继承的方法

setId

从类 org.apache.struts2.components.Component 继承的方法

addAllParameters, addParameter, altSyntax, copyParams, getComponentStack, getParameters, getStack, setActionMapper, setThrowExceptionsOnELFailure, setUrlHelper, start

从类 java.lang.Object 继承的方法

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造方法详细信息

Set

public Set(com.opensymphony.xwork2.util.ValueStack stack)

方法详细信息

end

public boolean end(Writer writer,
                   String body)

从类 Component 复制的描述

Callback for the end tag of this component. Should the body be evaluated again?

NOTE: will pop component stack.

覆盖：

类 Component 中的 end

参数：

writer - the output writer.

body - the rendered body.

返回：

true if the body should be evaluated again

setVar

public void setVar(String var)

覆盖：

类 ContextBean 中的 setVar

setName

public void setName(String name)

setScope

public void setScope(String scope)

setValue

public void setValue(String value)

usesBody

public boolean usesBody()

从类 Component 复制的描述

Overwrite to set if body should be used.

覆盖：

类 Component 中的 usesBody

返回：

always false for this component.