Java tutorial
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However, if you add GPL Version 2 code * and therefore, elected the GPL Version 2 license, then the option applies * only if the new code is made subject to such option by the copyright * holder. */ package org.nuxeo.ecm.platform.ui.web.application; import java.util.Map; import java.util.concurrent.atomic.AtomicInteger; import java.io.IOException; import javax.faces.FacesException; import javax.faces.context.FacesContext; import javax.faces.context.ExternalContext; import javax.faces.context.ResponseWriter; import javax.faces.component.UIViewRoot; import com.sun.faces.util.TypedCollections; import com.sun.faces.util.LRUMap; import com.sun.faces.util.Util; import com.sun.faces.util.RequestStateManager; import static com.sun.faces.config.WebConfiguration.BooleanWebContextInitParameter.AutoCompleteOffOnViewState; import static com.sun.faces.config.WebConfiguration.BooleanWebContextInitParameter.EnableViewStateIdRendering; import javax.faces.render.ResponseStateManager; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.jboss.seam.contexts.Contexts; import org.jboss.seam.core.Conversation; import com.sun.faces.renderkit.ServerSideStateHelper; /** * @since 6.0 */ public class NuxeoServerSideStateHelper extends ServerSideStateHelper { private static final Log log = LogFactory.getLog(NuxeoServerSideStateHelper.class); public static final int DEFAULT_NUMBER_OF_CONVERSATIONS_IN_SESSION = 4; public static final String NUMBER_OF_CONVERSATIONS_IN_SESSION = "nuxeo.jsf.numberOfConversationsInSession"; protected static final String NO_LONGRUNNING_CONVERSATION_ID = "NOLRC"; protected static Integer numbersOfConversationsInSession = null; /** * The top level attribute name for storing the state structures within the session. */ public static final String CONVERSATION_VIEW_MAP = NuxeoServerSideStateHelper.class.getName() + ".ConversationViewMap"; protected static int getNbOfConversationsInSession(FacesContext context) { if (numbersOfConversationsInSession == null) { ExternalContext externalContext = context.getExternalContext(); String value = externalContext.getInitParameter(NUMBER_OF_CONVERSATIONS_IN_SESSION); if (null == value) { numbersOfConversationsInSession = DEFAULT_NUMBER_OF_CONVERSATIONS_IN_SESSION; } else { try { numbersOfConversationsInSession = Integer.parseInt(value); } catch (NumberFormatException e) { throw new FacesException( "Context parameter " + NUMBER_OF_CONVERSATIONS_IN_SESSION + " must have integer value"); } } } return numbersOfConversationsInSession; } @Override public void writeState(FacesContext ctx, Object state, StringBuilder stateCapture) throws IOException { Util.notNull("context", ctx); String id; if (!ctx.getViewRoot().isTransient()) { Util.notNull("state", state); Object[] stateToWrite = (Object[]) state; ExternalContext externalContext = ctx.getExternalContext(); Object sessionObj = externalContext.getSession(true); Map<String, Object> sessionMap = externalContext.getSessionMap(); // noinspection SynchronizationOnLocalVariableOrMethodParameter synchronized (sessionObj) { String conversationId = NO_LONGRUNNING_CONVERSATION_ID; if (Contexts.isConversationContextActive() && Conversation.instance().isLongRunning()) { conversationId = Conversation.instance().getId(); } Map<String, Map> conversationMap = TypedCollections .dynamicallyCastMap((Map) sessionMap.get(CONVERSATION_VIEW_MAP), String.class, Map.class); if (conversationMap == null) { conversationMap = new LRUMap<String, Map>(getNbOfConversationsInSession(ctx)); sessionMap.put(CONVERSATION_VIEW_MAP, conversationMap); } Map<String, Map> logicalMap = TypedCollections .dynamicallyCastMap(conversationMap.get(conversationId), String.class, Map.class); if (logicalMap == null) { if (conversationMap.size() == getNbOfConversationsInSession(ctx)) { if (log.isDebugEnabled()) { log.warn("Too many conversations, dumping the least recently used conversation (" + conversationMap.keySet().iterator().next() + ")"); } } logicalMap = new LRUMap<String, Map>(numberOfLogicalViews); conversationMap.put(conversationId, logicalMap); } Object structure = stateToWrite[0]; Object savedState = handleSaveState(stateToWrite[1]); String idInLogicalMap = (String) RequestStateManager.get(ctx, RequestStateManager.LOGICAL_VIEW_MAP); if (idInLogicalMap == null) { idInLogicalMap = ((generateUniqueStateIds) ? createRandomId() : createIncrementalRequestId(ctx)); } String idInActualMap = null; if (ctx.getPartialViewContext().isPartialRequest()) { // If partial request, do not change actual view Id, because // page not actually changed. // Otherwise partial requests will soon overflow cache with // values that would be never used. idInActualMap = (String) RequestStateManager.get(ctx, RequestStateManager.ACTUAL_VIEW_MAP); } if (null == idInActualMap) { idInActualMap = ((generateUniqueStateIds) ? createRandomId() : createIncrementalRequestId(ctx)); } Map<String, Object[]> actualMap = TypedCollections .dynamicallyCastMap(logicalMap.get(idInLogicalMap), String.class, Object[].class); if (actualMap == null) { actualMap = new LRUMap<String, Object[]>(numberOfViews); logicalMap.put(idInLogicalMap, actualMap); } id = idInLogicalMap + ':' + idInActualMap; Object[] stateArray = actualMap.get(idInActualMap); // reuse the array if possible if (stateArray != null) { stateArray[0] = structure; stateArray[1] = savedState; } else { actualMap.put(idInActualMap, new Object[] { structure, savedState }); } conversationMap.put(conversationId, logicalMap); // always call put/setAttribute as we may be in a clustered // environment. sessionMap.put(CONVERSATION_VIEW_MAP, conversationMap); } } else { id = "stateless"; } if (stateCapture != null) { stateCapture.append(id); } else { ResponseWriter writer = ctx.getResponseWriter(); writer.startElement("input", null); writer.writeAttribute("type", "hidden", null); writer.writeAttribute("name", ResponseStateManager.VIEW_STATE_PARAM, null); if (webConfig.isOptionEnabled(EnableViewStateIdRendering)) { String viewStateId = Util.getViewStateId(ctx); writer.writeAttribute("id", viewStateId, null); } writer.writeAttribute("value", id, null); if (webConfig.isOptionEnabled(AutoCompleteOffOnViewState)) { writer.writeAttribute("autocomplete", "off", null); } writer.endElement("input"); writeClientWindowField(ctx, writer); writeRenderKitIdField(ctx, writer); } } @Override public Object getState(FacesContext ctx, String viewId) { String compoundId = getStateParamValue(ctx); if (compoundId == null) { return null; } if ("stateless".equals(compoundId)) { return "stateless"; } int sep = compoundId.indexOf(':'); assert (sep != -1); assert (sep < compoundId.length()); String idInLogicalMap = compoundId.substring(0, sep); String idInActualMap = compoundId.substring(sep + 1); ExternalContext externalCtx = ctx.getExternalContext(); Object sessionObj = externalCtx.getSession(false); // stop evaluating if the session is not available if (sessionObj == null) { if (log.isTraceEnabled()) { log.trace(String.format( "Unable to restore server side state for view ID %s as no session is available", viewId)); } return null; } // noinspection SynchronizationOnLocalVariableOrMethodParameter synchronized (sessionObj) { Map<String, Map> conversationMap = (Map) externalCtx.getSessionMap().get(CONVERSATION_VIEW_MAP); if (conversationMap == null) { return null; } Map logicalMap = null; for (Map lm : conversationMap.values()) { if (lm.get(idInLogicalMap) != null) { logicalMap = lm; break; } } if (logicalMap != null) { Map actualMap = (Map) logicalMap.get(idInLogicalMap); if (actualMap != null) { RequestStateManager.set(ctx, RequestStateManager.LOGICAL_VIEW_MAP, idInLogicalMap); Object[] state = (Object[]) actualMap.get(idInActualMap); Object[] restoredState = new Object[2]; restoredState[0] = state[0]; restoredState[1] = state[1]; if (state != null) { RequestStateManager.set(ctx, RequestStateManager.ACTUAL_VIEW_MAP, idInActualMap); if (state.length == 2 && state[1] != null) { restoredState[1] = handleRestoreState(state[1]); } } return restoredState; } } } return null; } /** * @param ctx the <code>FacesContext</code> for the current request * @return a unique ID for building the keys used to store views within a session */ private String createIncrementalRequestId(FacesContext ctx) { Map<String, Object> sm = ctx.getExternalContext().getSessionMap(); AtomicInteger idgen = (AtomicInteger) sm.get(STATEMANAGED_SERIAL_ID_KEY); if (idgen == null) { idgen = new AtomicInteger(1); } // always call put/setAttribute as we may be in a clustered environment. sm.put(STATEMANAGED_SERIAL_ID_KEY, idgen); return (UIViewRoot.UNIQUE_ID_PREFIX + idgen.getAndIncrement()); } private String createRandomId() { return Long.valueOf(random.nextLong()).toString(); } }