org.apache.camel.processor.RestBindingAdvice Maven / Gradle / Ivy
/*
* 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.processor;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import org.apache.camel.AsyncProcessor;
import org.apache.camel.CamelContext;
import org.apache.camel.CamelContextAware;
import org.apache.camel.CamelExchangeException;
import org.apache.camel.Exchange;
import org.apache.camel.Message;
import org.apache.camel.spi.CamelInternalProcessorAdvice;
import org.apache.camel.spi.DataFormat;
import org.apache.camel.spi.DataType;
import org.apache.camel.spi.DataTypeAware;
import org.apache.camel.spi.RestConfiguration;
import org.apache.camel.support.ExchangeHelper;
import org.apache.camel.support.MessageHelper;
import org.apache.camel.support.processor.MarshalProcessor;
import org.apache.camel.support.processor.UnmarshalProcessor;
import org.apache.camel.util.ObjectHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A {@link CamelInternalProcessorAdvice} that binds the REST DSL incoming
* and outgoing messages from sources of json or xml to Java Objects.
*
* The binding uses {@link org.apache.camel.spi.DataFormat} for the actual work to transform
* from xml/json to Java Objects and reverse again.
*
* The rest producer side is implemented in {@link org.apache.camel.component.rest.RestProducerBindingProcessor}
*
* @see CamelInternalProcessor
*/
public class RestBindingAdvice implements CamelInternalProcessorAdvice> {
private static final Logger LOG = LoggerFactory.getLogger(RestBindingAdvice.class);
private static final String STATE_KEY_DO_MARSHAL = "doMarshal";
private static final String STATE_KEY_ACCEPT = "accept";
private static final String STATE_JSON = "json";
private static final String STATE_XML = "xml";
private final AsyncProcessor jsonUnmarshal;
private final AsyncProcessor xmlUnmarshal;
private final AsyncProcessor jsonMarshal;
private final AsyncProcessor xmlMarshal;
private final String consumes;
private final String produces;
private final String bindingMode;
private final boolean skipBindingOnErrorCode;
private final boolean clientRequestValidation;
private final boolean enableCORS;
private final Map corsHeaders;
private final Map queryDefaultValues;
private final boolean requiredBody;
private final Set requiredQueryParameters;
private final Set requiredHeaders;
public RestBindingAdvice(CamelContext camelContext, DataFormat jsonDataFormat, DataFormat xmlDataFormat,
DataFormat outJsonDataFormat, DataFormat outXmlDataFormat,
String consumes, String produces, String bindingMode,
boolean skipBindingOnErrorCode, boolean clientRequestValidation, boolean enableCORS,
Map corsHeaders,
Map queryDefaultValues,
boolean requiredBody, Set requiredQueryParameters, Set requiredHeaders) throws Exception {
if (jsonDataFormat != null) {
this.jsonUnmarshal = new UnmarshalProcessor(jsonDataFormat);
} else {
this.jsonUnmarshal = null;
}
if (outJsonDataFormat != null) {
this.jsonMarshal = new MarshalProcessor(outJsonDataFormat);
} else if (jsonDataFormat != null) {
this.jsonMarshal = new MarshalProcessor(jsonDataFormat);
} else {
this.jsonMarshal = null;
}
if (xmlDataFormat != null) {
this.xmlUnmarshal = new UnmarshalProcessor(xmlDataFormat);
} else {
this.xmlUnmarshal = null;
}
if (outXmlDataFormat != null) {
this.xmlMarshal = new MarshalProcessor(outXmlDataFormat);
} else if (xmlDataFormat != null) {
this.xmlMarshal = new MarshalProcessor(xmlDataFormat);
} else {
this.xmlMarshal = null;
}
if (jsonMarshal != null) {
camelContext.addService(jsonMarshal, true);
}
if (jsonUnmarshal != null) {
camelContext.addService(jsonUnmarshal, true);
}
if (xmlMarshal instanceof CamelContextAware) {
camelContext.addService(xmlMarshal, true);
}
if (xmlUnmarshal instanceof CamelContextAware) {
camelContext.addService(xmlUnmarshal, true);
}
this.consumes = consumes;
this.produces = produces;
this.bindingMode = bindingMode;
this.skipBindingOnErrorCode = skipBindingOnErrorCode;
this.clientRequestValidation = clientRequestValidation;
this.enableCORS = enableCORS;
this.corsHeaders = corsHeaders;
this.queryDefaultValues = queryDefaultValues;
this.requiredBody = requiredBody;
this.requiredQueryParameters = requiredQueryParameters;
this.requiredHeaders = requiredHeaders;
}
@Override
public Map before(Exchange exchange) throws Exception {
Map state = new HashMap<>();
if (isOptionsMethod(exchange, state)) {
return state;
}
unmarshal(exchange, state);
return state;
}
@Override
public void after(Exchange exchange, Map state) throws Exception {
if (enableCORS) {
setCORSHeaders(exchange, state);
}
if (state.get(STATE_KEY_DO_MARSHAL) != null) {
marshal(exchange, state);
}
}
private boolean isOptionsMethod(Exchange exchange, Map state) {
String method = exchange.getIn().getHeader(Exchange.HTTP_METHOD, String.class);
if ("OPTIONS".equalsIgnoreCase(method)) {
// for OPTIONS methods then we should not route at all as its part of CORS
exchange.setRouteStop(true);
return true;
}
return false;
}
private void unmarshal(Exchange exchange, Map state) throws Exception {
boolean isXml = false;
boolean isJson = false;
String contentType = ExchangeHelper.getContentType(exchange);
if (contentType != null) {
isXml = contentType.toLowerCase(Locale.ENGLISH).contains("xml");
isJson = contentType.toLowerCase(Locale.ENGLISH).contains("json");
}
// if content type could not tell us if it was json or xml, then fallback to if the binding was configured with
// that information in the consumes
if (!isXml && !isJson) {
isXml = consumes != null && consumes.toLowerCase(Locale.ENGLISH).contains("xml");
isJson = consumes != null && consumes.toLowerCase(Locale.ENGLISH).contains("json");
}
// set data type if in use
if (exchange.getContext().isUseDataType()) {
if (exchange.getIn() instanceof DataTypeAware && (isJson || isXml)) {
((DataTypeAware) exchange.getIn()).setDataType(new DataType(isJson ? "json" : "xml"));
}
}
// only allow xml/json if the binding mode allows that
isXml &= bindingMode.equals("auto") || bindingMode.contains("xml");
isJson &= bindingMode.equals("auto") || bindingMode.contains("json");
// if we do not yet know if its xml or json, then use the binding mode to know the mode
if (!isJson && !isXml) {
isXml = bindingMode.equals("auto") || bindingMode.contains("xml");
isJson = bindingMode.equals("auto") || bindingMode.contains("json");
}
String accept = exchange.getMessage().getHeader("Accept", String.class);
state.put(STATE_KEY_ACCEPT, accept);
// perform client request validation
if (clientRequestValidation) {
// check if the content-type is accepted according to consumes
if (!isValidOrAcceptedContentType(consumes, contentType)) {
LOG.trace("Consuming content type does not match contentType header {}. Stopping routing.", contentType);
// the content-type is not something we can process so its a HTTP_ERROR 415
exchange.getMessage().setHeader(Exchange.HTTP_RESPONSE_CODE, 415);
// set empty response body as http error code indicate the problem
exchange.getMessage().setBody(null);
// stop routing and return
exchange.setRouteStop(true);
return;
}
// check if what is produces is accepted by the client
if (!isValidOrAcceptedContentType(produces, accept)) {
LOG.trace("Produced content type does not match accept header {}. Stopping routing.", contentType);
// the response type is not accepted by the client so its a HTTP_ERROR 406
exchange.getMessage().setHeader(Exchange.HTTP_RESPONSE_CODE, 406);
// set empty response body as http error code indicate the problem
exchange.getMessage().setBody(null);
// stop routing and return
exchange.setRouteStop(true);
return;
}
}
String body = null;
if (exchange.getIn().getBody() != null) {
// okay we have a binding mode, so need to check for empty body as that can cause the marshaller to fail
// as they assume a non-empty body
if (isXml || isJson) {
// we have binding enabled, so we need to know if there body is empty or not
// so force reading the body as a String which we can work with
body = MessageHelper.extractBodyAsString(exchange.getIn());
if (body != null) {
if (exchange.getIn() instanceof DataTypeAware) {
((DataTypeAware)exchange.getIn()).setBody(body, new DataType(isJson ? "json" : "xml"));
} else {
exchange.getIn().setBody(body);
}
if (isXml && isJson) {
// we have still not determined between xml or json, so check the body if its xml based or not
isXml = body.startsWith("<");
isJson = !isXml;
}
}
}
}
// add missing default values which are mapped as headers
if (queryDefaultValues != null) {
for (Map.Entry entry : queryDefaultValues.entrySet()) {
if (exchange.getIn().getHeader(entry.getKey()) == null) {
exchange.getIn().setHeader(entry.getKey(), entry.getValue());
}
}
}
// check for required
if (clientRequestValidation) {
if (requiredBody) {
// the body is required so we need to know if we have a body or not
// so force reading the body as a String which we can work with
if (body == null) {
body = MessageHelper.extractBodyAsString(exchange.getIn());
if (body != null) {
exchange.getIn().setBody(body);
}
}
if (body == null) {
// this is a bad request, the client did not include a message body
exchange.getMessage().setHeader(Exchange.HTTP_RESPONSE_CODE, 400);
exchange.getMessage().setBody("The request body is missing.");
// stop routing and return
exchange.setRouteStop(true);
return;
}
}
if (requiredQueryParameters != null && !exchange.getIn().getHeaders().keySet().containsAll(requiredQueryParameters)) {
// this is a bad request, the client did not include some of the required query parameters
exchange.getMessage().setHeader(Exchange.HTTP_RESPONSE_CODE, 400);
exchange.getMessage().setBody("Some of the required query parameters are missing.");
// stop routing and return
exchange.setRouteStop(true);
return;
}
if (requiredHeaders != null && !exchange.getIn().getHeaders().keySet().containsAll(requiredHeaders)) {
// this is a bad request, the client did not include some of the required http headers
exchange.getMessage().setHeader(Exchange.HTTP_RESPONSE_CODE, 400);
exchange.getMessage().setBody("Some of the required HTTP headers are missing.");
// stop routing and return
exchange.setRouteStop(true);
return;
}
}
// favor json over xml
if (isJson && jsonUnmarshal != null) {
// add reverse operation
state.put(STATE_KEY_DO_MARSHAL, STATE_JSON);
if (ObjectHelper.isNotEmpty(body)) {
jsonUnmarshal.process(exchange);
ExchangeHelper.prepareOutToIn(exchange);
}
return;
} else if (isXml && xmlUnmarshal != null) {
// add reverse operation
state.put(STATE_KEY_DO_MARSHAL, STATE_XML);
if (ObjectHelper.isNotEmpty(body)) {
xmlUnmarshal.process(exchange);
ExchangeHelper.prepareOutToIn(exchange);
}
return;
}
// we could not bind
if ("off".equals(bindingMode) || bindingMode.equals("auto")) {
// okay for auto we do not mind if we could not bind
state.put(STATE_KEY_DO_MARSHAL, STATE_JSON);
} else {
if (bindingMode.contains("xml")) {
exchange.setException(new CamelExchangeException("Cannot bind to xml as message body is not xml compatible", exchange));
} else {
exchange.setException(new CamelExchangeException("Cannot bind to json as message body is not json compatible", exchange));
}
}
}
private void marshal(Exchange exchange, Map state) {
// only marshal if there was no exception
if (exchange.getException() != null) {
return;
}
if (skipBindingOnErrorCode) {
Integer code = exchange.getMessage().getHeader(Exchange.HTTP_RESPONSE_CODE, Integer.class);
// if there is a custom http error code then skip binding
if (code != null && code >= 300) {
return;
}
}
boolean isXml = false;
boolean isJson = false;
// accept takes precedence
String accept = (String)state.get(STATE_KEY_ACCEPT);
if (accept != null) {
isXml = accept.toLowerCase(Locale.ENGLISH).contains("xml");
isJson = accept.toLowerCase(Locale.ENGLISH).contains("json");
}
// fallback to content type if still undecided
if (!isXml && !isJson) {
String contentType = ExchangeHelper.getContentType(exchange);
if (contentType != null) {
isXml = contentType.toLowerCase(Locale.ENGLISH).contains("xml");
isJson = contentType.toLowerCase(Locale.ENGLISH).contains("json");
}
}
// if content type could not tell us if it was json or xml, then fallback to if the binding was configured with
// that information in the consumes
if (!isXml && !isJson) {
isXml = produces != null && produces.toLowerCase(Locale.ENGLISH).contains("xml");
isJson = produces != null && produces.toLowerCase(Locale.ENGLISH).contains("json");
}
// only allow xml/json if the binding mode allows that (when off we still want to know if its xml or json)
if (bindingMode != null) {
isXml &= bindingMode.equals("off") || bindingMode.equals("auto") || bindingMode.contains("xml");
isJson &= bindingMode.equals("off") || bindingMode.equals("auto") || bindingMode.contains("json");
// if we do not yet know if its xml or json, then use the binding mode to know the mode
if (!isJson && !isXml) {
isXml = bindingMode.equals("auto") || bindingMode.contains("xml");
isJson = bindingMode.equals("auto") || bindingMode.contains("json");
}
}
// in case we have not yet been able to determine if xml or json, then use the same as in the unmarshaller
if (isXml && isJson) {
isXml = state.get(STATE_KEY_DO_MARSHAL).equals(STATE_XML);
isJson = !isXml;
}
// need to prepare exchange first
ExchangeHelper.prepareOutToIn(exchange);
// ensure there is a content type header (even if binding is off)
ensureHeaderContentType(produces, isXml, isJson, exchange);
if (bindingMode == null || "off".equals(bindingMode)) {
// binding is off, so no message body binding
return;
}
// is there any marshaller at all
if (jsonMarshal == null && xmlMarshal == null) {
return;
}
// is the body empty
if (exchange.getMessage().getBody() == null) {
return;
}
String contentType = exchange.getIn().getHeader(Exchange.CONTENT_TYPE, String.class);
// need to lower-case so the contains check below can match if using upper case
contentType = contentType.toLowerCase(Locale.US);
try {
// favor json over xml
if (isJson && jsonMarshal != null) {
// only marshal if its json content type
if (contentType.contains("json")) {
jsonMarshal.process(exchange);
setOutputDataType(exchange, new DataType("json"));
}
} else if (isXml && xmlMarshal != null) {
// only marshal if its xml content type
if (contentType.contains("xml")) {
xmlMarshal.process(exchange);
setOutputDataType(exchange, new DataType("xml"));
}
} else {
// we could not bind
if (bindingMode.equals("auto")) {
// okay for auto we do not mind if we could not bind
} else {
if (bindingMode.contains("xml")) {
exchange.setException(new CamelExchangeException("Cannot bind to xml as message body is not xml compatible", exchange));
} else {
exchange.setException(new CamelExchangeException("Cannot bind to json as message body is not json compatible", exchange));
}
}
}
} catch (Throwable e) {
exchange.setException(e);
}
}
private void setOutputDataType(Exchange exchange, DataType type) {
Message target = exchange.getMessage();
if (target instanceof DataTypeAware) {
((DataTypeAware)target).setDataType(type);
}
}
private void ensureHeaderContentType(String contentType, boolean isXml, boolean isJson, Exchange exchange) {
// favor given content type
if (contentType != null) {
String type = ExchangeHelper.getContentType(exchange);
if (type == null) {
exchange.getIn().setHeader(Exchange.CONTENT_TYPE, contentType);
}
}
// favor json over xml
if (isJson) {
// make sure there is a content-type with json
String type = ExchangeHelper.getContentType(exchange);
if (type == null) {
exchange.getIn().setHeader(Exchange.CONTENT_TYPE, "application/json");
}
} else if (isXml) {
// make sure there is a content-type with xml
String type = ExchangeHelper.getContentType(exchange);
if (type == null) {
exchange.getIn().setHeader(Exchange.CONTENT_TYPE, "application/xml");
}
}
}
private void setCORSHeaders(Exchange exchange, Map state) {
// add the CORS headers after routing, but before the consumer writes the response
Message msg = exchange.getMessage();
// use default value if none has been configured
String allowOrigin = corsHeaders != null ? corsHeaders.get("Access-Control-Allow-Origin") : null;
if (allowOrigin == null) {
allowOrigin = RestConfiguration.CORS_ACCESS_CONTROL_ALLOW_ORIGIN;
}
String allowMethods = corsHeaders != null ? corsHeaders.get("Access-Control-Allow-Methods") : null;
if (allowMethods == null) {
allowMethods = RestConfiguration.CORS_ACCESS_CONTROL_ALLOW_METHODS;
}
String allowHeaders = corsHeaders != null ? corsHeaders.get("Access-Control-Allow-Headers") : null;
if (allowHeaders == null) {
allowHeaders = RestConfiguration.CORS_ACCESS_CONTROL_ALLOW_HEADERS;
}
String maxAge = corsHeaders != null ? corsHeaders.get("Access-Control-Max-Age") : null;
if (maxAge == null) {
maxAge = RestConfiguration.CORS_ACCESS_CONTROL_MAX_AGE;
}
String allowCredentials = corsHeaders != null ? corsHeaders.get("Access-Control-Allow-Credentials") : null;
// Restrict the origin if credentials are allowed.
// https://www.w3.org/TR/cors/ - section 6.1, point 3
String origin = exchange.getIn().getHeader("Origin", String.class);
if ("true".equalsIgnoreCase(allowCredentials) && "*".equals(allowOrigin) && origin != null) {
allowOrigin = origin;
}
msg.setHeader("Access-Control-Allow-Origin", allowOrigin);
msg.setHeader("Access-Control-Allow-Methods", allowMethods);
msg.setHeader("Access-Control-Allow-Headers", allowHeaders);
msg.setHeader("Access-Control-Max-Age", maxAge);
if (allowCredentials != null) {
msg.setHeader("Access-Control-Allow-Credentials", allowCredentials);
}
}
private static boolean isValidOrAcceptedContentType(String valid, String target) {
if (valid == null || target == null) {
return true;
}
// Any MIME type
// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Accept#Directives
if ("*/*".equals(target)) {
return true;
}
boolean isXml = valid.toLowerCase(Locale.ENGLISH).contains("xml");
boolean isJson = valid.toLowerCase(Locale.ENGLISH).contains("json");
String type = target.toLowerCase(Locale.ENGLISH);
if (isXml && !type.contains("xml")) {
return false;
}
if (isJson && !type.contains("json")) {
return false;
}
return true;
}
}
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