io.syndesis.integration.runtime.util.JsonSimplePredicate Maven / Gradle / Ivy
/*
* Copyright (C) 2016 Red Hat, Inc.
*
* Licensed 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 io.syndesis.integration.runtime.util;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.datatype.jdk8.Jdk8Module;
import io.syndesis.common.util.IOStreams;
import org.apache.camel.CamelContext;
import org.apache.camel.Exchange;
import org.apache.camel.Message;
import org.apache.camel.Predicate;
import org.apache.camel.language.bean.RuntimeBeanExpressionException;
import org.apache.camel.spi.Language;
import org.apache.camel.spi.Registry;
import org.apache.camel.util.ExchangeHelper;
import org.apache.camel.util.ObjectHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Predicate which tries to convert a JSON message to a map first before
* applying
*/
public final class JsonSimplePredicate implements Predicate {
private static final Pattern SIMPLE_EXPRESSION = Pattern.compile("\\$\\{([^}]+)\\}");
private static final Logger LOG = LoggerFactory.getLogger(JsonSimplePredicate.class);
private static final ObjectMapper MAPPER = new ObjectMapper().registerModules(new Jdk8Module());
private final ObjectMapper mapper;
private final Predicate ognlPredicate;
private final Predicate predicate;
public JsonSimplePredicate(final String expression, final CamelContext context) {
final Language language = ObjectHelper.notNull(context.resolveLanguage("simple"), "simple language");
final String ognlExpression = convertSimpleToOGNLForMaps(expression);
predicate = language.createPredicate(expression);
ognlPredicate = language.createPredicate(ognlExpression);
final Registry registry = context.getRegistry();
final Set mappers = registry.findByType(ObjectMapper.class);
if (mappers.size() != 1) {
mapper = MAPPER;
} else {
mapper = mappers.iterator().next();
}
}
@Override
public boolean matches(final Exchange exchange) {
// Clone the exchange and set the JSON message converted to a Map /
// List as in message.
// The intention is that only this predicate acts on the converted
// value, but the original in-message still continues to carry the
// same format.
// The predicated is supposed to be read only with respect to the
// incoming message.
final Exchange exchangeForProcessing = ExchangeHelper.createCopy(exchange, true);
final Message payload = exchangeForProcessing.getIn();
if (payload.getBody() instanceof List) {
List jsonBeans = payload.getBody(List.class);
payload.setBody("[" + jsonBeans.stream().map(Object::toString).collect(Collectors.joining(",")) + "]");
}
try (InputStream stream = payload.getBody(InputStream.class)) {
if (stream == null) {
return predicate.matches(exchange);
}
ResetAfterCloseInputStream resetAfterCloseInputStream = new ResetAfterCloseInputStream(stream);
if (exchange.getIn().getBody() instanceof InputStream) {
exchange.getIn().setBody(resetAfterCloseInputStream);
}
// If it is a JSON document, suppose that this is a document which
// needs to be parsed as JSON, therefore we set a map instead of the
// string
final JsonNode json = mapper.readTree(resetAfterCloseInputStream);
if (json != null) {
if (json.isArray()) {
payload.setBody(mapper.convertValue(json, List.class));
try {
return ognlPredicate.matches(exchangeForProcessing);
} catch (RuntimeBeanExpressionException e) {
if (Optional.ofNullable(e.getCause())
.map(Object::getClass)
.map(IndexOutOfBoundsException.class::equals)
.orElse(false)) {
LOG.debug("Try to match array item out of bounds");
// we do not need to dump on the logs so log it at trace level.
LOG.trace("Try to match array item out of bounds ", e);
return false;
}
throw e;
}
} else if (json.isObject()) {
payload.setBody(mapper.convertValue(json, Map.class));
return ognlPredicate.matches(exchangeForProcessing);
}
}
} catch (final JsonParseException e) {
LOG.debug("Incoming message is not a json, try to match using simple language");
// in case the body is not convertible to a map, the json converter
// may throw an exception we do not need to dump on the logs so log
// it at trace level.
LOG.trace("Unable to parse incoming message body as JSON ", e);
} catch (final IOException e) {
LOG.warn("Unable to apply simple filter to the given payload");
LOG.debug("Unable to parse incoming message body as JSON needed for simple filtering", e);
}
// if above fails
return predicate.matches(exchange);
}
static String convertSimpleToOGNLForMaps(final String simple) {
final Matcher matcher = SIMPLE_EXPRESSION.matcher(simple);
final StringBuffer ognl = new StringBuffer(simple.length() + 5);
while (matcher.find()) {
final String expression = toOgnl(matcher);
matcher.appendReplacement(ognl, "\\$\\{" + expression + "\\}");
}
matcher.appendTail(ognl);
return ognl.toString();
}
static String toOgnl(final Matcher matcher) {
final String expression = matcher.group(1);
if (!(expression.startsWith("body.") || expression.startsWith("body[")) || isCollectionPath(expression)) {
return expression;
}
final StringBuilder ognl = new StringBuilder(expression.length() + 5);
final char[] chars = expression.toCharArray();
boolean start = true;
for (final char ch : chars) {
if (ch == '.' || ch == '[') {
if (!start) {
ognl.append(']');
}
start = false;
ognl.append('[');
} else if (ch == '$') {
ognl.append("\\$");
} else if (ch != ']') {
ognl.append(ch);
}
}
if (!start) {
ognl.append(']');
}
return ognl.toString();
}
private static boolean isCollectionPath(String expression) {
String[] collectionPaths = new String[] { "size()" };
return Stream.of(collectionPaths)
.map(path -> "body." + path)
.anyMatch(path -> path.equals(expression));
}
/**
* Input stream being able to reset on close in order to ensure exchange processing can consume stream content
* one more time.
*/
private static class ResetAfterCloseInputStream extends InputStream {
private final byte[] sourceBytes;
private ByteArrayInputStream delegate;
ResetAfterCloseInputStream(InputStream inputStream) throws IOException {
sourceBytes = IOStreams.readBytes(inputStream);
delegate = new ByteArrayInputStream(sourceBytes);
}
@Override
public void close() throws IOException {
delegate.close();
delegate = new ByteArrayInputStream(sourceBytes);
}
@Override
public int read() {
return delegate.read();
}
@Override
public int read(byte[] b) throws IOException {
return delegate.read(b);
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
return delegate.read(b, off, len);
}
}
}