org.springframework.web.context.support.HttpRequestHandlerServlet Maven / Gradle / Ivy
/*
* Copyright 2002-2017 the original author or authors.
*
* 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
*
* https://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.springframework.web.context.support;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.context.i18n.LocaleContextHolder;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
import org.springframework.web.HttpRequestHandler;
import org.springframework.web.HttpRequestMethodNotSupportedException;
import org.springframework.web.context.WebApplicationContext;
/**
* Simple HttpServlet that delegates to an {@link HttpRequestHandler} bean defined
* in Spring's root web application context. The target bean name must match the
* HttpRequestHandlerServlet servlet-name as defined in {@code web.xml}.
*
* This can for example be used to expose a single Spring remote exporter,
* such as {@link org.springframework.remoting.httpinvoker.HttpInvokerServiceExporter}
* or {@link org.springframework.remoting.caucho.HessianServiceExporter},
* per HttpRequestHandlerServlet definition. This is a minimal alternative
* to defining remote exporters as beans in a DispatcherServlet context
* (with advanced mapping and interception facilities being available there).
*
* @author Juergen Hoeller
* @since 2.0
* @see org.springframework.web.HttpRequestHandler
* @see org.springframework.web.servlet.DispatcherServlet
*/
@SuppressWarnings("serial")
public class HttpRequestHandlerServlet extends HttpServlet {
@Nullable
private HttpRequestHandler target;
@Override
public void init() throws ServletException {
WebApplicationContext wac = WebApplicationContextUtils.getRequiredWebApplicationContext(getServletContext());
this.target = wac.getBean(getServletName(), HttpRequestHandler.class);
}
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
Assert.state(this.target != null, "No HttpRequestHandler available");
LocaleContextHolder.setLocale(request.getLocale());
try {
this.target.handleRequest(request, response);
}
catch (HttpRequestMethodNotSupportedException ex) {
String[] supportedMethods = ex.getSupportedMethods();
if (supportedMethods != null) {
response.setHeader("Allow", StringUtils.arrayToDelimitedString(supportedMethods, ", "));
}
response.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED, ex.getMessage());
}
finally {
LocaleContextHolder.resetLocaleContext();
}
}
}