package org.douyu.mvc;
import java.util.Map;
import java.util.HashMap;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import douyu.mvc.Context;
import douyu.mvc.ControllerException;
import douyu.mvc.ViewException;
import douyu.mvc.ViewManager;
import douyu.mvc.ViewManagerProvider;
import org.douyu.core.Config;
/**
*
* 执行控制器的Action时，会为这个控制器生成一个Context，这个Context用来管理一次请求过程中用到的相关上下文信息。
*
* 此类不是线程安全的，存活期与HttpServletRequest相同。
*
* @author ZHH
*
*/
public abstract class AbstractContext implements Context {
private Config config;
private String controllerClassName;
//编译器在编译带有@Controller的类时，会为它自动生成一个AbstractContext的子类，
//这4个字段会在自动生成的子类中直接访问，所以用protected.
//如果修改了这4个字段的名称要记得修改com.sun.tools.javac.processing.ControllerProcessor类
protected ServletContext servletContext;
protected HttpServletRequest request;
protected HttpServletResponse response;
protected String actionName;
private Map<String, Object> viewArgs = new HashMap<String, Object>();
public void init(Config config, String controllerClassName, ServletContext servletContext, HttpServletRequest request,
HttpServletResponse response) {
this.config = config;
this.controllerClassName = controllerClassName;
this.servletContext = servletContext;
this.request = request;
this.response = response;
}
public void free() {
config = null;
controllerClassName = null;
servletContext = null;
request = null;
response = null;
actionName = null;
viewArgs.clear();
viewArgs = null;
}
protected void checkHttpMethods(String... methods) {
String method = request.getMethod();
for (String m : methods) {
if (m.equals(method)) {
return;
}
}
throw new ControllerException("501 Not Implemented method: " + method);
}
// ========================================================
// 实现douyu.mvc.ControllerManager
// ========================================================
@Override
public ServletContext getServletContext() {
return servletContext;
}
@Override
public HttpServletRequest getHttpServletRequest() {
return request;
}
@Override
public HttpServletResponse getHttpServletResponse() {
return response;
}
@Override
public String getControllerClassName() {
return controllerClassName;
}
@Override
public String getActionName() {
return actionName;
}
@Override
public String getApplicationBase() {
if (config.srcDir == null)
return config.classesDir;
if (config.classesDir == null)
return config.srcDir;
if (config.isDevMode)
return config.srcDir;
else
return config.classesDir;
}
@Override
public void executeAction(String actionName) throws ControllerException {
this.actionName = actionName;
try {
executeAction();
} catch (Exception e) {
throw new ControllerException("failed to execute action: " + actionName, e);
}
}
protected abstract void executeAction() throws Exception;
// ========================================================
// 实现douyu.mvc.ViewManager
// ========================================================
@Override
public void put(String key, Object value) {
viewArgs.put(key, value);
}
@Override
public void out() {
ViewManagerProvider def = config.getDefaultViewManagerProvider();
if (def != null) {
try {
outView(def, null);
return;
} catch (Exception e) {
}
}
for (ViewManagerProvider vmp : config.getViewManagerProviders()) {
if (vmp != def) {
try {
outView(vmp, null);
return;
} catch (Exception e) {
}
}
}
throw new ViewException("No ViewManager for 'ViewManager.out()', controller='" + controllerClassName + "', attion='"
+ actionName + "'.");
}
private void outView(ViewManagerProvider vmp, String viewFileName) {
ViewManager vm = vmp.getViewManager(this);
if (vm == null)
throw new ViewException("No ViewManager for view file: " + viewFileName);
for (Map.Entry<String, Object> e : viewArgs.entrySet()) {
vm.put(e.getKey(), e.getValue());
}
if (viewFileName == null)
vm.out();
else
vm.out(viewFileName);
}
@Override
public void out(String viewFileName) {
String extension = null;
int dotPos = viewFileName.lastIndexOf('.');
if (dotPos >= 0) {
extension = viewFileName.substring(dotPos + 1).trim();
}
ViewManagerProvider vmp;
if (extension == null) {
vmp = config.getDefaultViewManagerProvider();
} else {
vmp = config.getViewManagerProvider(extension);
}
if (vmp == null) {
throw new ViewException("No ViewManagerProvider for view file: " + viewFileName);
}
outView(vmp, viewFileName);
}
}