org.apache.camel.support.ReloadStrategySupport Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of camel-core Show documentation
Show all versions of camel-core Show documentation
The Core Camel Java DSL based router
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.camel.support;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.apache.camel.CamelContext;
import org.apache.camel.api.management.ManagedAttribute;
import org.apache.camel.api.management.ManagedOperation;
import org.apache.camel.model.ModelHelper;
import org.apache.camel.model.RouteDefinition;
import org.apache.camel.model.RoutesDefinition;
import org.apache.camel.spi.ReloadStrategy;
import org.apache.camel.util.CollectionStringBuffer;
import org.apache.camel.util.LRUCacheFactory;
import org.apache.camel.util.ObjectHelper;
import org.apache.camel.util.StringHelper;
import org.apache.camel.util.XmlLineNumberParser;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Base class for implementing custom {@link ReloadStrategy} SPI plugins.
*/
public abstract class ReloadStrategySupport extends ServiceSupport implements ReloadStrategy {
protected final Logger log = LoggerFactory.getLogger(getClass());
protected Map cache;
private CamelContext camelContext;
private int succeeded;
private int failed;
@Override
public CamelContext getCamelContext() {
return camelContext;
}
@Override
public void setCamelContext(CamelContext camelContext) {
this.camelContext = camelContext;
}
@Override
public void onReloadXml(CamelContext camelContext, String name, InputStream resource) {
log.debug("Reloading routes from XML resource: {}", name);
Document dom;
String xml;
try {
xml = camelContext.getTypeConverter().mandatoryConvertTo(String.class, resource);
// the JAXB model expects the spring namespace (even for blueprint)
dom = XmlLineNumberParser.parseXml(new ByteArrayInputStream(xml.getBytes()), null, "camelContext,routeContext,routes", "http://camel.apache.org/schema/spring");
} catch (Exception e) {
failed++;
log.warn("Cannot load the resource {} as XML", name);
return;
}
ResourceState state = ObjectHelper.cast(ResourceState.class, cache.get(name));
if (state == null) {
state = new ResourceState(name, dom, xml);
cache.put(name, state);
}
String oldXml = state.getXml();
List changed = StringHelper.changedLines(oldXml, xml);
// find all which are the routes
NodeList list = dom.getElementsByTagName("route");
// collect which routes are updated/skipped
List routes = new ArrayList<>();
if (list != null && list.getLength() > 0) {
for (int i = 0; i < list.getLength(); i++) {
Node node = list.item(i);
// what line number are this within
String lineNumber = (String) node.getUserData(XmlLineNumberParser.LINE_NUMBER);
String lineNumberEnd = (String) node.getUserData(XmlLineNumberParser.LINE_NUMBER_END);
if (lineNumber != null && lineNumberEnd != null && !changed.isEmpty()) {
int start = Integer.valueOf(lineNumber);
int end = Integer.valueOf(lineNumberEnd);
boolean within = withinChanged(start, end, changed);
if (within) {
log.debug("Updating route in lines: {}-{}", start, end);
} else {
log.debug("No changes to route in lines: {}-{}", start, end);
continue;
}
}
try {
// load from XML -> JAXB model and store as routes to be updated
RoutesDefinition loaded = ModelHelper.loadRoutesDefinition(camelContext, node);
if (!loaded.getRoutes().isEmpty()) {
routes.addAll(loaded.getRoutes());
}
} catch (Exception e) {
failed++;
throw ObjectHelper.wrapRuntimeCamelException(e);
}
}
}
if (!routes.isEmpty()) {
try {
boolean unassignedRouteIds = false;
CollectionStringBuffer csb = new CollectionStringBuffer(",");
// collect route ids and force assign ids if not in use
for (RouteDefinition route : routes) {
unassignedRouteIds |= !route.hasCustomIdAssigned();
String id = route.idOrCreate(camelContext.getNodeIdFactory());
csb.append(id);
}
log.debug("Reloading routes: [{}] from XML resource: {}", csb, name);
if (unassignedRouteIds) {
log.warn("Routes with no id's detected. Its recommended to assign id's to your routes so Camel can reload the routes correctly.");
}
// update the routes (add will remove and shutdown first)
camelContext.addRouteDefinitions(routes);
log.info("Reloaded routes: [{}] from XML resource: {}", csb, name);
} catch (Exception e) {
failed++;
throw ObjectHelper.wrapRuntimeCamelException(e);
}
}
// update cache
state = new ResourceState(name, dom, xml);
cache.put(name, state);
succeeded++;
}
private boolean withinChanged(int start, int end, List changed) {
for (int change : changed) {
log.trace("Changed line: {} within {}-{}", change, start, end);
if (change >= start && change <= end) {
return true;
}
}
return false;
}
@ManagedAttribute(description = "Number of reloads succeeded")
public int getReloadCounter() {
return succeeded;
}
@ManagedAttribute(description = "Number of reloads failed")
public int getFailedCounter() {
return failed;
}
public void setSucceeded(int succeeded) {
this.succeeded = succeeded;
}
public void setFailed(int failed) {
this.failed = failed;
}
@ManagedOperation(description = "Reset counters")
public void resetCounters() {
succeeded = 0;
failed = 0;
}
@Override
@SuppressWarnings("unchecked")
protected void doStart() throws Exception {
// noop
cache = LRUCacheFactory.newLRUCache(100);
}
@Override
protected void doStop() throws Exception {
cache.clear();
}
/**
* To keep state of last reloaded resource
*/
private static final class ResourceState {
private final String name;
private final Document dom;
private final String xml;
ResourceState(String name, Document dom, String xml) {
this.name = name;
this.dom = dom;
this.xml = xml;
}
public String getName() {
return name;
}
public Document getDom() {
return dom;
}
public String getXml() {
return xml;
}
}
}