package com.firefly.mvc.web.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.util.Enumeration;
import java.util.Set;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.firefly.mvc.web.AnnotationWebContext;
import com.firefly.mvc.web.DispatcherController;
import com.firefly.mvc.web.WebContext;
import com.firefly.mvc.web.support.MvcMetaInfo;
import com.firefly.mvc.web.support.MethodParam;
import com.firefly.mvc.web.support.ParamMetaInfo;
import com.firefly.utils.VerifyUtils;
import com.firefly.utils.log.Log;
import com.firefly.utils.log.LogFactory;
/**
* 前端控制器
* @author alvinqiu
*
*/
public class HttpServletDispatcherController implements DispatcherController {
private static Log log = LogFactory.getInstance().getLog("firefly-system");
private WebContext webContext;
private HttpServletDispatcherController() {
}
private static class Holder {
private static HttpServletDispatcherController instance = new HttpServletDispatcherController();
}
public static HttpServletDispatcherController getInstance() {
return Holder.instance;
}
@Override
public void dispatcher(HttpServletRequest request,
HttpServletResponse response) {
String encoding = webContext.getEncoding();
try {
request.setCharacterEncoding(encoding);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
response.setCharacterEncoding(encoding);
String uri = request.getRequestURI();
String prePath = request.getContextPath() + request.getServletPath();
String invokeUri = uri.substring(prePath.length());
String key = request.getMethod() + "@" + invokeUri;
String beforeIntercept = "b#" + invokeUri;
String afterIntercept = "a#" + invokeUri;
Set<MvcMetaInfo> beforeSet = webContext.getBean(beforeIntercept);
Set<MvcMetaInfo> afterSet = webContext.getBean(afterIntercept);
log.debug("uri map [{}]", key);
MvcMetaInfo mvcMetaInfo = webContext.getBean(key);
if (mvcMetaInfo != null) {
Object ret = null;
Object beforeRet = null; // 前置拦截器的返回值
MvcMetaInfo lastBefore = null; // 最后得到的前置拦截器
Object afterRet = null; // 后置拦截器的返回值
MvcMetaInfo lastAfter = null; // 最后得到的后置拦截器
// 前置拦截栈调用
if (beforeSet != null) {
for (MvcMetaInfo before : beforeSet) {
Object[] beforeP = getParams(request, response, before);
beforeRet = before.invoke(beforeP);
if (beforeRet != null) {
lastBefore = before;
break;
}
}
}
if (beforeRet == null) {
// controller调用
Object[] p = getParams(request, response, mvcMetaInfo);
ret = mvcMetaInfo.invoke(p);
// 后置拦截栈调用
if (afterSet != null) {
for (MvcMetaInfo after : afterSet) {
Object[] afterP = getParams(request, response, after);
afterRet = after.invoke(afterP);
if (afterRet != null) {
lastAfter = after;
break;
}
}
}
}
// 视图渲染
try {
if (afterRet != null) {
lastAfter.getViewHandle().render(request, response,
afterRet);
} else if (beforeRet != null) {
lastBefore.getViewHandle().render(request, response,
beforeRet);
} else {
mvcMetaInfo.getViewHandle().render(request, response, ret);
}
} catch (ServletException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
} else {
scNotFound(request, response);
}
}
public HttpServletDispatcherController init(String initParam) {
webContext = new AnnotationWebContext(initParam);
return this;
}
/**
* controller方法参数注入
* @param request
* @param response
* @param mvcMetaInfo
* @return
*/
@SuppressWarnings("unchecked")
private Object[] getParams(HttpServletRequest request,
HttpServletResponse response, MvcMetaInfo mvcMetaInfo) {
byte[] methodParam = mvcMetaInfo.getMethodParam();
ParamMetaInfo[] paramMetaInfos = mvcMetaInfo.getParamMetaInfos();
Object[] p = new Object[methodParam.length];
for (int i = 0; i < p.length; i++) {
switch (methodParam[i]) {
case MethodParam.REQUEST:
p[i] = request;
break;
case MethodParam.RESPONSE:
p[i] = response;
break;
case MethodParam.HTTP_PARAM:
// 请求参数封装到javabean
Enumeration<String> enumeration = request.getParameterNames();
ParamMetaInfo paramMetaInfo = paramMetaInfos[i];
p[i] = paramMetaInfo.newParamInstance();
// 把http参数赋值给参数对象
while (enumeration.hasMoreElements()) {
String httpParamName = enumeration.nextElement();
String paramValue = request.getParameter(httpParamName);
paramMetaInfo.setParam(p[i], httpParamName, paramValue);
}
if (VerifyUtils.isNotEmpty(paramMetaInfo.getAttribute())) {
request.setAttribute(paramMetaInfo.getAttribute(), p[i]);
}
break;
}
}
return p;
}
private void scNotFound(HttpServletRequest request,
HttpServletResponse response) {
response.setStatus(HttpServletResponse.SC_NOT_FOUND);
response.setHeader("Content-Type", "text/html; charset="
+ webContext.getEncoding());
PrintWriter writer = null;
try {
writer = response.getWriter();
} catch (IOException e) {
e.printStackTrace();
}
writer.print("<html><body>");
writer.print("<h2>HTTP ERROR 404</h2>");
writer.print("<hr/><i><small>firefly mvc framework</small></i>");
writer.print("</body></html>");
writer.close();
}
}