package com.et.mvc;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import com.et.mvc.filter.Filter;
import com.et.mvc.filter.FilterUtils;
import com.et.mvc.renderer.StringViewRenderer;
import com.et.mvc.renderer.VoidViewRenderer;
import com.et.mvc.util.Json;
/**
* 分发器类
* @author stworthy
*/
public class Dispatcher {
private static Log log = LogFactory.getLog("etmvc");
private static String controllerBasePackage;
private static String viewBasePath;
private static List<String> controllerPaths;
public static String getControllerBasePackage() {
return controllerBasePackage;
}
public static void setControllerBasePackage(String aControllerBasePackage) {
controllerBasePackage = aControllerBasePackage;
}
public static String getViewBasePath() {
return viewBasePath;
}
public static void setViewBasePath(String aViewBasePath) {
viewBasePath = aViewBasePath;
}
public static List<String> getControllerPaths() {
return controllerPaths;
}
public static void setControllerPaths(List<String> aControllerPaths) {
controllerPaths = aControllerPaths;
}
/**
* 反序执行AroundFilters的after方法，所有的过滤器都不执行到，但只要有一个返回false，则函数返回false，否则返回true
*/
private boolean afterInvokeAroundFilters(Controller controller,
List<Filter> arounds) throws Exception {
boolean result = true;
Exception exception = null;
for (int i = arounds.size() - 1; i >= 0; i--) {
Filter filter = arounds.get(i);
try {
boolean ret = filter.afterInvoke(controller);
if (!ret) {
result = false;
}
} catch (Exception ex) {
if (exception == null) {
exception = ex;
}
}
}
if (exception != null) {
throw exception;
}
return result;
}
public void service(Controller controller) throws Exception {
long t1 = System.currentTimeMillis();
if (log.isDebugEnabled()){
String logInfo = "Processing " + controller.request.getRequestURL()
+ " (for " + controller.request.getRemoteAddr() + ")"
+ " [" + controller.request.getMethod() + "]\n"
+ " Session ID: " + controller.session.getId() + "\n"
+ " controller: " + controller.controllerName + "\n"
+ " action:" + controller.actionName + "\n"
+ " Parameters: " + Json.toJson(Json.castMap(controller.request.getParameterMap()));
log.debug(logInfo);
}
// Before和Around过滤器
List<Filter> arounds = new ArrayList<Filter>(); // 已执行的Around过滤器
List<Filter> chains = FilterUtils.getFilterChain(controller);
boolean chainBroken = false;
try {
for (int i = 0; i < chains.size(); i++) {
Filter filter = chains.get(i);
if (filter.canInvoke(controller.getActionName())) {
boolean ret = filter.beforeInvoke(controller);
if (ret == true && filter.getAroundFilter() != null) {
arounds.add(filter);
}
if (!ret) {
chainBroken = true;
break;
}
}
}
} catch (Exception ex) {
try {
afterInvokeAroundFilters(controller, arounds);
} catch (Exception ex2) {
}
throw ex;
}
if (chainBroken == true) { // 过滤器链执行中断
afterInvokeAroundFilters(controller, arounds);
return;
}
// 执行控制器方法
Object actionResult = null;
try {
actionResult = controller.invoke();
} catch (Exception ex) {
controller.exception = ex;
}
// Around过滤器after方法，反序执行
if (afterInvokeAroundFilters(controller, arounds) == false) {
return; // 不继续执行后续代码
}
if (controller.exception != null) {
throw controller.exception;
}
// After过滤器，顺序执行
for (int i = 0; i < chains.size(); i++) {
Filter filter = chains.get(i);
if (filter.canInvoke(controller.getActionName())
&& filter.getAfterFilter() != null) {
boolean ret = filter.afterInvoke(controller);
if (!ret) {
return;
}
}
}
// 渲染视图
ViewContext viewContext = new ViewContext();
viewContext.setRequest(controller.getRequest());
viewContext.setResponse(controller.getResponse());
viewContext.setServletContext(controller.getServletContext());
viewContext.setViewBasePath(viewBasePath);
viewContext.setControllerPath(controller.getControllerPath());
viewContext.setActionName(controller.getActionName());
renderView(controller.getActionReturnType(), actionResult, viewContext);
long t2 = System.currentTimeMillis();
if (log.isDebugEnabled()){
String logInfo = "Completed in " + ((t2-t1)/1000.0) + "s "
+ "[" + controller.request.getRequestURL() + "]\n";
log.debug(logInfo);
}
}
protected void renderView(Class<?> viewClass, Object viewObject,
ViewContext viewContext) throws Exception {
if (viewClass.getName().equals("void")) {
VoidViewRenderer renderer = new VoidViewRenderer();
renderer.render((Void) viewObject, viewContext);
} else if (viewClass.getName().equals("java.lang.String")) {
StringViewRenderer renderer = new StringViewRenderer();
renderer.render((String) viewObject, viewContext);
} else if (viewObject instanceof View) {
ViewRendererClass vrc = viewObject.getClass().getAnnotation(ViewRendererClass.class);
Class<?> clasz = ((View)viewObject).getRendererClass();
if (clasz == null && vrc != null) {
clasz = vrc.value();
}
if (clasz != null) {
Object viewRenderer = clasz.newInstance();
Method method = clasz.getMethod("render", Object.class, ViewContext.class);
method.invoke(viewRenderer, viewObject, viewContext);
}
// if (vrc != null) {
// Class<?> clasz = vrc.value();
// Object viewRenderer = clasz.newInstance();
// Method method = clasz.getMethod("render", Object.class,
// ViewContext.class);
// method.invoke(viewRenderer, viewObject, viewContext);
// }
}
}
}