第一、doFilter - 沿着 Handler 链，每个 handler 调用 handle 方法进行处理，然后交给下一个 handler。
容器初始化时访问 web.xml 配置的 JFinalFilter.doFilter。
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
// 获取 request、response，设置编码
HttpServletRequest request = (HttpServletRequest)req;
HttpServletResponse response = (HttpServletResponse)res;
request.setCharacterEncoding(encoding);
// 初始化的时候可以看出 contextPathLength 为 0 或者为 项目名称的长度
// 比如 target = webapp/xx/yy/zz，则截取后的 target = /xx/yy/zz
String target = request.getRequestURI();
if (contextPathLength != 0)
target = target.substring(contextPathLength);
// 在调用了 ActionHandler的 handle 方法之后，isHandled[0] 才会被置为 true。
boolean[] isHandled = {false};
try {
// 重头戏，handler 链首到链尾 ActionHandler 依次进行处理
handler.handle(target, request, response, isHandled);
}
catch (Exception e) {
if (log.isErrorEnabled()) {
String qs = request.getQueryString();
log.error(qs == null ? target : target + "?" + qs, e);
}
}
// 若最后 isHandled[0] = false，会执行下一个 Filter。
if (isHandled[0] == false)
chain.doFilter(request, response);
}
JFinal 初始化过程中可以 add JFinal 库中的Handler 或自定义的 Handler。
例如：ContextPathHandler，JFinal 自身扩展的 Handler。
访问项目时就会走过 handler 方法设置 contextPath。这样在前端就可以通过 ${CONTEXT_PATH} 得到项目根路径。
public class ContextPathHandler extends Handler {
private String contextPathName;
public ContextPathHandler() {
contextPathName = "CONTEXT_PATH";
}
public ContextPathHandler(String contextPathName) {
if (StrKit.isBlank(contextPathName))
throw new IllegalArgumentException("contextPathName can not be blank.");
this.contextPathName = contextPathName;
}
public void handle(String target, HttpServletRequest request, HttpServletResponse response, boolean[] isHandled) {
request.setAttribute(contextPathName, request.getContextPath());
System.out.println("哈哈哈");
next.handle(target, request, response, isHandled);
}
}
FakeStaticHandler，也是 JFinal 自身扩展的 Handler。new FakeStaticHandler 时可定义后缀，访问路径 target 必须是以这个后缀结尾才可以进行下去。
public class FakeStaticHandler extends Handler {
private String viewPostfix;
public FakeStaticHandler() {
viewPostfix = ".html";
}
public FakeStaticHandler(String viewPostfix) {
if (StrKit.isBlank(viewPostfix))
throw new IllegalArgumentException("viewPostfix can not be blank.");
this.viewPostfix = viewPostfix;
}
public void handle(String target, HttpServletRequest request, HttpServletResponse response, boolean[] isHandled) {
if ("/".equals(target)) {
next.handle(target, request, response, isHandled);
return;
}
if (target.indexOf(‘.‘) == -1) {
HandlerKit.renderError404(request, response, isHandled);
return ;
}
int index = target.lastIndexOf(viewPostfix);
if (index != -1)
target = target.substring(0, index);
next.handle(target, request, response, isHandled);
}
}
第二、访问交给 Handler 链尾 ActionHandler，调用 handle 方法进行处理：根据访问路径 target 得到 Action，由 Action 得到 Controller。接着 invoke 调用 Controller 的方法处理（此方法可根据 Action 获得）。
public final void handle(String target, HttpServletRequest request, HttpServletResponse response, boolean[] isHandled) {
if (target.indexOf(‘.‘) != -1) {
return ;
}
isHandled[0] = true;
String[] urlPara = {null};
// actionMapping 根据 target 得到对应的 action
Action action = actionMapping.getAction(target, urlPara);
if (action == null) {
if (log.isWarnEnabled()) {
String qs = request.getQueryString();
log.warn("404 Action Not Found: " + (qs == null ? target : target + "?" + qs));
}
renderFactory.getErrorRender(404).setContext(request, response).render();
return ;
}
try {
// 由 action 得到对应的 Controller
Controller controller = action.getControllerClass().newInstance();
// Controller 初始化
controller.init(request, response, urlPara[0]);
if (devMode) {
if (ActionReporter.isReportAfterInvocation(request)) {
new Invocation(action, controller).invoke();
ActionReporter.report(controller, action);
} else {
ActionReporter.report(controller, action);
new Invocation(action, controller).invoke();
}
}
else {
// 调用 Controller 相应的处理方法
new Invocation(action, controller).invoke();
}
// 获取对应的 Render，如果是一个 ActionRender，就再交给 handler 处理；如果 Render == null会按照默认Render处理；
Render render = controller.getRender();
if (render instanceof ActionRender) {
String actionUrl = ((ActionRender)render).getActionUrl();
if (target.equals(actionUrl))
throw new RuntimeException("The forward action url is the same as before.");
else
handle(actionUrl, request, response, isHandled);
return ;
}
if (render == null)
render = renderFactory.getDefaultRender(action.getViewPath() + action.getMethodName());
// 调用 Render 实现类讲数据写入页面
render.setContext(request, response, action.getViewPath()).render();
}
catch (RenderException e) {
if (log.isErrorEnabled()) {
String qs = request.getQueryString();
log.error(qs == null ? target : target + "?" + qs, e);
}
}
catch (ActionException e) {
int errorCode = e.getErrorCode();
if (errorCode == 404 && log.isWarnEnabled()) {
String qs = request.getQueryString();
log.warn("404 Not Found: " + (qs == null ? target : target + "?" + qs));
}
else if (errorCode == 401 && log.isWarnEnabled()) {
String qs = request.getQueryString();
log.warn("401 Unauthorized: " + (qs == null ? target : target + "?" + qs));
}
else if (errorCode == 403 && log.isWarnEnabled()) {
String qs = request.getQueryString();
log.warn("403 Forbidden: " + (qs == null ? target : target + "?" + qs));
}
else if (log.isErrorEnabled()) {
String qs = request.getQueryString();
log.error(qs == null ? target : target + "?" + qs, e);
}
e.getErrorRender().setContext(request, response, action.getViewPath()).render();
}
catch (Throwable t) {
if (log.isErrorEnabled()) {
String qs = request.getQueryString();
log.error(qs == null ? target : target + "?" + qs, t);
}
renderFactory.getErrorRender(500).setContext(request, response, action.getViewPath()).render();
}
}
new Invocation(action, controller).invoke();
public void invoke() {
if (index < inters.length) {
inters[index++].intercept(this); // 调用拦截器的 intercept 方法，前后加一些东西
}
else if (index++ == inters.length) { // index++ ensure invoke action only one time
try {
// Invoke the action
if (action != null) {
returnValue = action.getMethod().invoke(target, args); // 调用该方法并且得到返回值
}
// else 不会运行到
else {
// if (!Modifier.isAbstract(method.getModifiers()))
// returnValue = methodProxy.invokeSuper(target, args);
if (useInjectTarget)
returnValue = methodProxy.invoke(target, args);
else
returnValue = methodProxy.invokeSuper(target, args);
}
}
catch (InvocationTargetException e) {
Throwable t = e.getTargetException();
throw t instanceof RuntimeException ? (RuntimeException)t : new RuntimeException(e);
}
catch (RuntimeException e) {
throw e;
}
catch (Throwable t) {
throw new RuntimeException(t);
}
}
}
第三、接着上面 ActionHandler.handle 继续，Controller 的方法处理过程中创建了 render 对象，调用此方法后获取此实例进行页面展现。
在 Controller 方法处理的最后，往往要调用 render 方法来实例化 render 变量。例如，我自定义的一个 IndexController，在最后一步调用 render("next.html")。
public class IndexController extends Controller {
public void index() {
// ...
render("next.html");
}
}
用到父类 Controller 的 render 方法，通过 renderFactory.getRender 得到 render 实例。
public abstract class Controller {
// ...
// render below ---
private static final RenderFactory renderFactory = RenderFactory.me();
/**
* Hold Render object when invoke renderXxx(...)
*/
private Render render;
public Render getRender() {
return render;
}
/**
* Render with any Render which extends Render
*/
public void render(Render render) {
this.render = render;
}
/**
* Render with view use default type Render configured in JFinalConfig
*/
public void render(String view) {
render = renderFactory.getRender(view);
}
/**
* Render with jsp view
*/
public void renderJsp(String view) {
render = renderFactory.getJspRender(view);
}
/**
* Render with freemarker view
*/
public void renderFreeMarker(String view) {
render = renderFactory.getFreeMarkerRender(view);
}
/**
* Render with velocity view
*/
public void renderVelocity(String view) {
render = renderFactory.getVelocityRender(view);
}
/**
* Render with json
* <p>
* Example:<br>
* renderJson("message", "Save successful");<br>
* renderJson("users", users);<br>
*/
public void renderJson(String key, Object value) {
render = renderFactory.getJsonRender(key, value);
}
/**
* Render with json
*/
public void renderJson() {
render = renderFactory.getJsonRender();
}
/**
* Render with attributes set by setAttr(...) before.
* <p>
* Example: renderJson(new String[]{"blogList", "user"});
*/
public void renderJson(String[] attrs) {
render = renderFactory.getJsonRender(attrs);
}
/**
* Render with json text.
* <p>
* Example: renderJson("{\"message\":\"Please input password!\"}");
*/
public void renderJson(String jsonText) {
render = renderFactory.getJsonRender(jsonText);
}
/**
* Render json with object.
* <p>
* Example: renderJson(new User().set("name", "JFinal").set("age", 18));
*/
public void renderJson(Object object) {
render = object instanceof JsonRender ? (JsonRender)object : renderFactory.getJsonRender(object);
}
/**
* Render with text. The contentType is: "text/plain".
*/
public void renderText(String text) {
render = renderFactory.getTextRender(text);
}
/**
* Render with text and content type.
* <p>
* Example: renderText("<user id=‘5888‘>James</user>", "application/xml");
*/
public void renderText(String text, String contentType) {
render = renderFactory.getTextRender(text, contentType);
}
/**
* Render with text and ContentType.
* <p>
* Example: renderText("<html>Hello James</html>", ContentType.HTML);
*/
public void renderText(String text, ContentType contentType) {
render = renderFactory.getTextRender(text, contentType);
}
/**
* Forward to an action
*/
public void forwardAction(String actionUrl) {
render = new ActionRender(actionUrl);
}
/**
* Render with file
*/
public void renderFile(String fileName) {
render = renderFactory.getFileRender(fileName);
}
/**
* Render with file
*/
public void renderFile(File file) {
render = renderFactory.getFileRender(file);
}
/**
* Redirect to url
*/
public void redirect(String url) {
render = renderFactory.getRedirectRender(url);
}
/**
* Redirect to url
*/
public void redirect(String url, boolean withQueryString) {
render = renderFactory.getRedirectRender(url, withQueryString);
}
/**
* Render with view and status use default type Render configured in JFinalConfig
*/
public void render(String view, int status) {
render = renderFactory.getRender(view);
response.setStatus(status);
}
/**
* Render with url and 301 status
*/
public void redirect301(String url) {
render = renderFactory.getRedirect301Render(url);
}
/**
* Render with url and 301 status
*/
public void redirect301(String url, boolean withQueryString) {
render = renderFactory.getRedirect301Render(url, withQueryString);
}
/**
* Render with view and errorCode status
*/
public void renderError(int errorCode, String view) {
throw new ActionException(errorCode, renderFactory.getErrorRender(errorCode, view));
}
/**
* Render with render and errorCode status
*/
public void renderError(int errorCode, Render render) {
throw new ActionException(errorCode, render);
}
/**
* Render with view and errorCode status configured in JFinalConfig
*/
public void renderError(int errorCode) {
throw new ActionException(errorCode, renderFactory.getErrorRender(errorCode));
}
/**
* Render nothing, no response to browser
*/
public void renderNull() {
render = renderFactory.getNullRender();
}
/**
* Render with javascript text. The contentType is: "text/javascript".
*/
public void renderJavascript(String javascriptText) {
render = renderFactory.getJavascriptRender(javascriptText);
}
/**
* Render with html text. The contentType is: "text/html".
*/
public void renderHtml(String htmlText) {
render = renderFactory.getHtmlRender(htmlText);
}
/**
* Render with xml view using freemarker.
*/
public void renderXml(String view) {
render = renderFactory.getXmlRender(view);
}
public void renderCaptcha() {
render = renderFactory.getCaptchaRender();
}
}
根据 Controller 可以看出还能使用 renderJosn、renderText 等多种方法，这里一笔带过。
就先写到这里吧~~
时间： 2024-10-14 05:17:13