/**
* 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.soybeanMilk.web.servlet;
import java.io.FileNotFoundException;
import java.io.IOException;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.soybeanMilk.SbmUtils;
import org.soybeanMilk.core.ExecutableNotFoundException;
import org.soybeanMilk.core.ExecuteException;
import org.soybeanMilk.core.exe.support.DefaultResolverObjectFactory;
import org.soybeanMilk.core.exe.support.ResolverObjectFactory;
import org.soybeanMilk.web.DefaultWebExecutor;
import org.soybeanMilk.web.WebConstants;
import org.soybeanMilk.web.WebExecutor;
import org.soybeanMilk.web.WebObjectSource;
import org.soybeanMilk.web.config.WebConfiguration;
import org.soybeanMilk.web.config.parser.WebConfigurationParser;
import org.soybeanMilk.web.exe.th.AbstractTargetHandler;
import org.soybeanMilk.web.os.DefaultWebObjectSource;
/**
* 框架整合servlet，它可以将WEB请求转给{@linkplain WebExecutor Web执行器}。
* @author earthangry@gmail.com
* @date 2010-12-28
*/
public class DispatchServlet extends HttpServlet
{
private static final long serialVersionUID = -1647302324862162094L;
private static Log log=LogFactory.getLog(DispatchServlet.class);
/**Web执行器*/
private WebExecutor webExecutor;
/**WEB对象源工厂*/
private WebObjectSourceFactory webObjectSourceFactory;
/**编码*/
private String encoding;
/**WEB执行器存储关键字*/
private String appExecutorKey;
public DispatchServlet()
{
super();
}
public WebExecutor getWebExecutor()
{
return webExecutor;
}
public void setWebExecutor(WebExecutor webExecutor)
{
this.webExecutor = webExecutor;
}
public WebObjectSourceFactory getWebObjectSourceFactory() {
return webObjectSourceFactory;
}
public void setWebObjectSourceFactory(
WebObjectSourceFactory webObjectSourceFactory) {
this.webObjectSourceFactory = webObjectSourceFactory;
}
public String getEncoding() {
return encoding;
}
public void setEncoding(String encoding) {
this.encoding = encoding;
}
public String getAppExecutorKey() {
return appExecutorKey;
}
public void setAppExecutorKey(String appExecutorKey) {
this.appExecutorKey = appExecutorKey;
}
//@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException
{
doProcess(req,resp);
}
//@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException
{
doProcess(req,resp);
}
//@Override
public void destroy()
{
String aek=getAppExecutorKey();
if(aek != null)
getServletContext().removeAttribute(aek);
setWebExecutor(null);
super.destroy();
}
//@Override
public void init() throws ServletException
{
if(log.isInfoEnabled())
log.info("start initializing SoybeanMilk web context");
super.init();
String ec=getInitEncoding();
WebObjectSourceFactory wsf=getInitWebObjectSourceFactory();
String appExecutorKey=getInitAppExecutorKey();
WebExecutor webExecutor=getInitWebExecutor();
//设置编码
if(ec==null || ec.length()==0)
ec=WebConstants.DEFAULT_ENCODING;
setEncoding(ec);
//创建Web对象源工厂
if(wsf == null)
{
wsf=new WebObjectSourceFactory()
{
//@Override
public WebObjectSource create(HttpServletRequest request, HttpServletResponse response, ServletContext application)
{
return new DefaultWebObjectSource(request, response, application);
}
};
}
setWebObjectSourceFactory(wsf);
//创建执行器
setWebExecutor(webExecutor);
if(log.isInfoEnabled())
{
int totalExecutables= getWebExecutor().getWebConfiguration().getExecutables() == null ? 0 : getWebExecutor().getWebConfiguration().getExecutables().size();
log.info(totalExecutables+" executables has been initialized");
}
//执行器存储关键字
setAppExecutorKey(appExecutorKey);
String aek=getAppExecutorKey();
if(aek!=null && aek.length()==0)
setAppExecutorKey(null);
if(aek != null)
getServletContext().setAttribute(aek, getWebExecutor());
if(log.isInfoEnabled())
log.info("finish initializing SoybeanMilk web context");
}
/**
* 处理WEB请求。
* @param request
* @param response
* @throws ServletException
* @throws IOException
*/
protected void doProcess(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
{
if(request.getCharacterEncoding() == null)
request.setCharacterEncoding(getEncoding());
String exeName=getRequestExecutableName(request, response);
if(log.isDebugEnabled())
log.debug("processing request "+SbmUtils.toString(exeName));
WebObjectSource webObjSource=getWebObjectSourceFactory().create(request, response, getServletContext());
try
{
getWebExecutor().execute(exeName, webObjSource);
}
catch(ExecutableNotFoundException e)
{
handleExecutableNotFound(exeName, webObjSource);
}
catch(ExecuteException e)
{
handleExecuteException(e, exeName, webObjSource);
}
}
/**
* 取得用于处理请求的可执行对象名。
* @param request
* @param response
* @return
* @throws ServletException
* @throws IOException
*/
protected String getRequestExecutableName(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
{
String result=null;
String pathInfo=null;
String servletPath=null;
//include请求
pathInfo=(String)request.getAttribute(AbstractTargetHandler.INCLUDE_PATH_INFO_ATTRIBUTE);
servletPath=(String)request.getAttribute(AbstractTargetHandler.INCLUDE_SERVLET_PATH_ATTRIBUTE);
if(pathInfo==null && servletPath==null)
{
pathInfo=request.getPathInfo();
servletPath=request.getServletPath();
}
if(servletPath == null)
servletPath="";
int period=servletPath.lastIndexOf(".");
if(period>=0 && period>servletPath.lastIndexOf("/"))
result=servletPath;
else
{
if(pathInfo != null)
result=servletPath+pathInfo;
else
result=servletPath;
}
return result;
}
/**
* 没有找到能够处理请求的可执行对象。
* @param requestExeName
* @param objSource
* @throws ServletException
* @throws IOException
*/
protected void handleExecutableNotFound(String requestExeName, WebObjectSource objSource)
throws ServletException, IOException
{
//servlet规范规定这里要抛出FileNotFoundException异常
if(AbstractTargetHandler.isJspIncludeRequest(objSource.getRequest()))
throw new FileNotFoundException(requestExeName);
objSource.getResponse().sendError(HttpServletResponse.SC_NOT_FOUND, requestExeName);
}
/**
* 处理执行异常。
* @param e
* @param requestExeName
* @param webObjSource
* @throws ServletException
* @throws IOException
* @date 2011-1-12
*/
protected void handleExecuteException(ExecuteException e, String requestExeName, WebObjectSource webObjSource)
throws ServletException, IOException
{
throw new ServletException(e);
}
/**
* 取得初始化编码。
*/
protected String getInitEncoding() throws ServletException
{
return getInitParameter(WebConstants.ServletInitParams.ENCODING);
}
/**
* 取得执行器在应用中的存储关键字。
*/
protected String getInitAppExecutorKey() throws ServletException
{
return getInitParameter(WebConstants.ServletInitParams.APPLICATION_EXECUTOR_KEY);
}
/**
* 取得初始化{@linkplain WebExecutor Web执行器}对象。
*/
protected WebExecutor getInitWebExecutor() throws ServletException
{
DefaultWebExecutor we=null;
DefaultResolverObjectFactory rf=new DefaultResolverObjectFactory();
rf.setExternalResolverObjectFactory(getInitExternalResolverObjectFactory());
WebConfiguration webConfiguration=new WebConfiguration();
webConfiguration.setResolverObjectFactory(rf);
String configFileName=getInitParameter(WebConstants.ServletInitParams.SOYBEAN_MILK_CONFIG);
WebConfigurationParser parser=new WebConfigurationParser(webConfiguration,getServletContext());
parser.parse(configFileName);
we=new DefaultWebExecutor(webConfiguration);
return we;
}
/**
* 取得初始化{@linkplain WebObjectSourceFactory WEB对象源工厂}。
*/
protected WebObjectSourceFactory getInitWebObjectSourceFactory() throws ServletException
{
WebObjectSourceFactory wsf=null;
String clazz=getInitParameter(WebConstants.ServletInitParams.WEB_OBJECT_SOURCE_FACTORY_CLASS);
if(clazz!=null && clazz.length()!=0)
{
try
{
wsf=(WebObjectSourceFactory)SbmUtils.narrowToClass(SbmUtils.nameToType(clazz)).newInstance();
}
catch(Exception e)
{
throw new ServletException(e);
}
}
return wsf;
}
/**
* 取得初始化调用目标对象工厂，它将被整合到框架中。
* @return
*/
protected ResolverObjectFactory getInitExternalResolverObjectFactory() throws ServletException
{
String erfKey=getInitParameter(WebConstants.ServletInitParams.EXTERNAL_RESOLVER_OBJECT_FACTORY);
ResolverObjectFactory erf=null;
if(erfKey!=null && erfKey.length()!=0)
{
erf=(ResolverObjectFactory)getServletContext().getAttribute(erfKey);
if(erf == null)
log.warn("no external ResolverObjectFactory found in "+SbmUtils.toString(WebConstants.Scope.APPLICATION)+" scope with key "+SbmUtils.toString(erfKey));
else
if(log.isDebugEnabled())
log.debug("found external ResolverObjectFactory "+SbmUtils.toString(erf.getClass())+" in "+SbmUtils.toString(WebConstants.Scope.APPLICATION)+" scope");
}
return erf;
}
//@Override
public String getInitParameter(String name)
{
String re=null;
try
{
re=super.getInitParameter(name);
}
catch(Exception e)
{
re=null;
}
if(log.isInfoEnabled())
log.info("got init parameter "+SbmUtils.toString(name)+" value :"+SbmUtils.toString(re));
return re;
}
}