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Struts example source code file (PrefixBasedActionMapper.java)

This example Struts source code file (PrefixBasedActionMapper.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Struts tags/keywords

actionmapper, actionmapper, actionmapping, actionmapping, configurationmanager, defaultactionmapper, http, inject, object, object, parameters, prefixbasedactionmapper, request, response, servlet, string, string, using, util

The Struts PrefixBasedActionMapper.java source code

package org.apache.struts2.dispatcher.mapper;

import com.opensymphony.xwork2.config.ConfigurationManager;
import com.opensymphony.xwork2.inject.Container;
import com.opensymphony.xwork2.inject.Inject;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts2.StrutsConstants;

import javax.servlet.http.HttpServletRequest;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

/**
 * <!-- START SNIPPET: description -->
 * 
 * A prefix based action mapper that is capable of delegating to other {@link ActionMapper}s based on the request's prefix
 *
 * It is configured through struts.xml
 *
 * For example, with the following entries in struts.properties
 *
 * <pre>
 * <constant name="struts.mapper.class" value="org.apache.struts2.dispatcher.mapper.PrefixBasedActionMapper"/>
 * <constant name="struts.mapper.prefixMapping" value="/communities:pseudoRestful,/communityTags:pseudoRestful,/events:pseudoRestful,/mediaList:pseudoRestful,/users:pseudoRestful,/community:struts,/communityTag:struts,/event:struts,/media:struts,/user:struts,:struts"/>
 * </pre>
 * <p/>
 * When {@link PrefixBasedActionMapper#getMapping(HttpServletRequest, ConfigurationManager)} or
 * {@link PrefixBasedActionMapper#getUriFromActionMapping(ActionMapping)} is invoked,
 * {@link PrefixBasedActionMapper} will check each possible prefix (url prefix terminating just before a /) to find the most specific ActionMapper that returns a mapping when asked to map the request.  If none are found, null is returned for both
 * {@link PrefixBasedActionMapper#getMapping(HttpServletRequest, ConfigurationManager)} and
 * {@link PrefixBasedActionMapper#getUriFromActionMapping(ActionMapping)} methods.
 * <p/>
 *
 * <!-- END SNIPPET: description -->
 *
 * @see ActionMapper
 * @see ActionMapping
 *
 */
public class PrefixBasedActionMapper extends DefaultActionMapper implements ActionMapper {
  protected transient final Log log = LogFactory.getLog(getClass());
  protected Container container;
  protected Map<String,ActionMapper> actionMappers = new HashMap();

  @Inject
  public void setContainer(Container container) {
    this.container = container;
  }

  @Inject(StrutsConstants.PREFIX_BASED_MAPPER_CONFIGURATION)
  public void setPrefixBasedActionMappers(String list) {
    if (list != null) {
      String[] mappers = list.split(",");
      for (String mapper : mappers) {
        String[] thisMapper = mapper.split(":");
        if ((thisMapper != null) && (thisMapper.length == 2)) {
          String mapperPrefix = thisMapper[0].trim();
          String mapperName = thisMapper[1].trim();
          Object obj = container.getInstance(ActionMapper.class, mapperName);
          if (obj != null) {
            actionMappers.put(mapperPrefix, (ActionMapper) obj);
          } else if (log.isDebugEnabled()) {
            log.debug("invalid PrefixBasedActionMapper config entry: " + mapper);
          }
        }
      }
    }
  }


  @SuppressWarnings("unchecked")
  public ActionMapping getMapping(HttpServletRequest request, ConfigurationManager configManager) {
    String uri = getUri(request);
    for (int lastIndex = uri.lastIndexOf('/'); lastIndex > (-1); lastIndex = uri.lastIndexOf('/', lastIndex-1)) {
      ActionMapper actionMapper = actionMappers.get(uri.substring(0,lastIndex));
      if (actionMapper != null) {
        ActionMapping actionMapping = actionMapper.getMapping(request, configManager);
        if (log.isDebugEnabled()) {
          log.debug("Using ActionMapper "+actionMapper);
        }
        if (actionMapping != null) {
          if (log.isDebugEnabled()) {
            if (actionMapping.getParams() != null) {
              log.debug("ActionMapper found mapping. Parameters: "+actionMapping.getParams());
              for (Map.Entry<String,Object> mappingParameterEntry : ((Map)(actionMapping.getParams())).entrySet()) {
                Object paramValue = mappingParameterEntry.getValue();
                if (paramValue == null) {
                  log.debug(mappingParameterEntry.getKey()+" : null!");
                } else if (paramValue instanceof String[]) {
                  log.debug(mappingParameterEntry.getKey()+" : (String[]) "+Arrays.toString((String[])paramValue));
                } else if (paramValue instanceof String) {
                  log.debug(mappingParameterEntry.getKey()+" : (String) "+(String)paramValue);
                } else {
                  log.debug(mappingParameterEntry.getKey()+" : (Object) "+(paramValue.toString()));
                }
              }
            }
          }
          return actionMapping;
        } else if (log.isDebugEnabled()) {
          log.debug("ActionMapper "+actionMapper+" failed to return an ActionMapping");
        }
      }
    }
    if (log.isDebugEnabled()) {
      log.debug("no ActionMapper found");
    }
    return null;
  }

  public String getUriFromActionMapping(ActionMapping mapping) {
    String namespace = mapping.getNamespace();
    for (int lastIndex = namespace.length(); lastIndex > (-1); lastIndex = namespace.lastIndexOf('/', lastIndex-1)) {
      ActionMapper actionMapper = actionMappers.get(namespace.substring(0,lastIndex));
      if (actionMapper != null) {
        String uri = actionMapper.getUriFromActionMapping(mapping);
        if (log.isDebugEnabled()) {
          log.debug("Using ActionMapper "+actionMapper);
        }
        if (uri != null) {
          return uri;
        } else if (log.isDebugEnabled()) {
          log.debug("ActionMapper "+actionMapper+" failed to return an ActionMapping (null)");
        }
      }
    }
    if (log.isDebugEnabled()) {
      log.debug("ActionMapper failed to return a uri");
    }
    return null;
  }
}

Other Struts examples (source code examples)

Here is a short list of links related to this Struts PrefixBasedActionMapper.java source code file:

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