The struts²-arianna-plugin is a simple but quite flexible plugin to render and manage a simple breadcrumb navigational bar. It keep track of the executed action (storing them into session) to allow rendering of the breadcrumb.

• A @BreadCrumb annotation to mark actions or methods that needs to be tracked
• A simple breadcrumb tag to iterate over stored crumbs
• Configurable breadcrumb behaviour

• Struts 2.1.2+
• Java 1.5+

The plugin make use of Java5 annotation to select which action should be tracked, so you need java 5;

Just download the plugin and put the jar into your web application's /WEB-INF/lib directory.

The breadcrumb functionality is provided by an interceptor which needs to be added to your action's interceptor stack.

<interceptor name="breadCrumbs" class="xyz.timedrain.arianna.plugin.BreadCrumbInterceptor">
  <param name="trail.maxCrumbs">6</param>
  <param name="trail.rewindMode">AUTO</param>							
  <param name="trail.comparator">xyz.timedrain.arianna.plugin.NameComparator</param>
</interceptor>

You can configure the interceptor with the maximum number of crumbs to track, how it should handle duplicated crumbs (rewind parameter) and the default comparator to use. Once the breadCrumbs interceptor is part of your interceptor's stack, just annotate with @BreadCrumb the actions and/or methods that you need to track.

To render the bread crumbs in your page you can use the breadcrumbs tag

<%@ taglib prefix="bc" uri="/struts-arianna-tags" %>
  ...
<bc:breadcrumbs var='c' status='s'>
  <s:url id='url' action="%{action}" namespace="%{namespace}" method="%{method}" />
  <s:a href='%{url}'><s:property value='name'/></s:a>
</bc:breadcrumbs>
  ...

For a complete description of parameters see parameters

@BreadCrumb("My Action")
public class MyAction {

  public String execute() {
    // action's code
    ...
  }
  

when struts executes MyAction a crumb with name "My Action" will be added to the application's breadcrumb.

You can also annotate single methods of a class as in the following example:

public class ActionClass {

  public String notTrackedMethod() {
    // action's code
    ...
  }

  @BreadCrumb("Action A")
  public String aMethodA() {
    // action's code
    ...
  }
	
  @BreadCrumb("Action B")
  public String aMethodB() {
    // action's code
    ...
  }

when the actions mapped to aMethod1 or aMethod2 are called a crumb with name "Action A" or "Action B" (respectively) will be added to the breadcrumb.

public class ActionClass {

  public String getCrumbName() {
    return "Hello";
  }

  @BreadCrumb("%{crumbName}")
  public String aMethodA() {
    // action's code
    ...
  }

when using the %{ ... } syntax the plugin will evaluate the OGNL expression against the action's value stack to get the crumb name, in this case, a crumb with name Hello will be added to the application's breadcrumb.

some configuration parameters can be overwritten on a per action basis. So for the following action a RequestComparator will always be used, without regard the actual plugin configuration is.

@BreadCrumb(value="My Crumb", comparator=RequestComparator)
public class ActionClass {

  public String execute() {
    // your code
  }

the same is true for the rewind mode

@BreadCrumb(value="My Crumb", rewind=NEVER)
public class MyAction {

  public String execute() {
    // your code
  }