/*
* JBoss, Home of Professional Open Source
* Copyright 2010, Red Hat Middleware LLC, and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* 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 org.jboss.seam.servlet.http;
import java.lang.reflect.Constructor;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.Enumeration;
import javax.enterprise.inject.Produces;
import javax.enterprise.inject.spi.InjectionPoint;
import javax.inject.Inject;
import javax.servlet.http.HttpServletRequest;
import org.jboss.seam.servlet.ServletExtension;
import org.jboss.seam.solder.reflection.PrimitiveTypes;
/**
* A producer for a String bean qualified @{@link HeaderParam}.
*
* <p>
* Provides a producer method that retrieves the value of the specified HTTP header from
* {@link HttpServletRequest#getHeader(String)} and makes it available as a dependent-scoped bean of type String qualified
* @HeaderParam. The name of the HTTP header to lookup is either the value of the @HeaderParam annotation or, if the
* annotation value is empty, the name of the injection point (e.g., the field name).
* </p>
* <p>
* If the HTTP header is not present, and the injection point is annotated with @DefaultValue, the value of the
* @DefaultValue annotation is returned instead. If @DefaultValue is not present, <code>null</code> is returned.
* </p>
*
* @author <a href="http://community.jboss.org/people/dan.j.allen">Dan Allen</a>
*
* @see HeaderParam
* @see DefaultValue
*/
public class HeaderParamProducer {
@Inject
private HttpServletRequest request;
@Produces
@TypedParamValue
// FIXME find better place to cache the valueOf methods
protected Object getTypedParamValue(InjectionPoint ip, ServletExtension ext) {
String v = getHeaderValue(getHeaderName(ip), ip);
Class<?> t = PrimitiveTypes.box(resolveExpectedType(ip));
if (t.equals(String.class)) {
return v;
}
try {
Member converter = ext.getConverterMember(t);
return converter instanceof Constructor ? ((Constructor<?>) converter).newInstance(v) : ((Method) converter)
.invoke(null, v);
}
// TODO should at least debug we couldn't convert the value
catch (Exception e) {
}
return null;
}
private String getHeaderName(InjectionPoint ip) {
String headerName = ip.getAnnotated().getAnnotation(HeaderParam.class).value();
if ("".equals(headerName)) {
headerName = ip.getMember().getName();
}
return headerName;
}
private String getHeaderValue(String headerName, InjectionPoint ip) {
return isHeaderInRequest(headerName) ? request.getHeader(headerName) : getDefaultValue(ip);
}
private boolean isHeaderInRequest(String headerName) {
for (Enumeration<String> names = request.getHeaderNames(); names.hasMoreElements();) {
if (names.nextElement().equals(headerName)) {
return true;
}
}
return false;
}
private String getDefaultValue(InjectionPoint ip) {
DefaultValue defaultValueAnnotation = ip.getAnnotated().getAnnotation(DefaultValue.class);
return defaultValueAnnotation == null ? null : defaultValueAnnotation.value();
}
private Class<?> resolveExpectedType(final InjectionPoint ip) {
Type t = ip.getType();
if (t instanceof ParameterizedType && ((ParameterizedType) t).getActualTypeArguments().length == 1) {
return (Class<?>) ((ParameterizedType) t).getActualTypeArguments()[0];
} else if (t instanceof Class) {
return (Class<?>) t;
} else {
return Object.class;
}
}
}