webwork中使用JSTL--理想的动力

webwork中使用JSTL

lhf_z 发表于 2005-6-8 11:56:00

参考：http://wiki.opensymphony.com/display/WW/Using+WebWork2+and+XWork1+with+JSP+2.0+and+JSTL+1.1

使用webwork，action返回页面后以下内容不放入request中：

                actionMessages
                locale
                webwork.valueStack
                errors
                webwork.request_uri
                model
                fieldErrors

使用webwork中的拦截机制，在action返回页面后将必要的内容放入request

Interceptor代码如下：

package interceptors;

import com.opensymphony.webwork.WebWorkStatics;
import com.opensymphony.xwork.Action;
import com.opensymphony.xwork.ActionInvocation;
import com.opensymphony.xwork.interceptor.AroundInterceptor;
import com.opensymphony.xwork.interceptor.PreResultListener;
import org.apache.commons.beanutils.PropertyUtils;
import javax.servlet.http.HttpServletRequest;
import java.beans.PropertyDescriptor;
import java.util.*;

/**
* Populates HTTP Request Attributes with all gettable properties of the current action.
*/
public class ActionPropertyExportInterceptor extends AroundInterceptor {
    protected void before(ActionInvocation invocation) throws Exception {
        invocation.addPreResultListener( new PropertyExporter() );
    }
    protected void after(ActionInvocation dispatcher, String result) throws Exception { }

    public static class PropertyExporter implements PreResultListener {
        private static final List   ignore = Arrays.asList(new String[] {"class", "texts"}); //skip getClass,...

        //Invoked after Action.execute() but before Result
        //Calls all getters of the action and insert the values into the request
        public void beforeResult(ActionInvocation invocation, String resultCode) {
            Map                 props   = extractGetterPropertyValues( invocation.getAction() );
            HttpServletRequest request = getRequest(invocation);
            for (Iterator it = props.entrySet().iterator(); it.hasNext();) {
                Map.Entry   e = (Map.Entry) it.next();
                request.setAttribute((String) e.getKey(), e.getValue());
            }
        }

        public Map extractGetterPropertyValues(Object bean) {
            PropertyDescriptor[] descr = PropertyUtils.getPropertyDescriptors(bean);
            Map                   props = new HashMap();
            for (int i = 0; i < descr.length; i++) {
                PropertyDescriptor d = descr[i];
                if (d.getReadMethod() == null) continue;
                if (ignore.contains(d.getName())) continue;

                try {
                    props.put(d.getName(), PropertyUtils.getProperty(bean, d.getName()));
                } catch (Exception e) { }
            }
            return props;
        }

        public HttpServletRequest getRequest(ActionInvocation invocation) {
            return (HttpServletRequest) invocation.getInvocationContext().get(WebWorkStatics.HTTP_REQUEST);
        }
    }
}