一、CAS 基本原理 (3,4,5,9.2,9.3是主要步骤)
第一次访问:
1. 浏览器 发起访问WebAPP 请求: http://www.web.com/app
2. 客户端 AuthenticationFilter Filter 发现Session中无 Assertion,且URL中无 ticket 变量。生成 service url 变量,并重定向到: https://www.cas-server.com/cas/login?service=http://www.web.com/app
3. CAS server 生成 Login ticket, service 对象,并展示 login 页面,默认提供 username / password 给用户验证。
4. CAS server 端,用户输入 username / password 验证,若通过则生成TGT,存入服务器段(默认为 Map 类型的 cache),同时将TGT id 作为 content创建 cookie 并发送到浏览器。
5. CAS server 端通过TGT 生成service ticket. 重定向到 http://www.web.com/app?ticket=ST-xxx
6. 客户端 访问 http://www.web.com/app?ticket=ST-xxx
7. 客户端 AuthenticationFilter Filter 发现URL中有 ticket, 跳过 AuthenticationFilter过滤器,到达 Cas20ProxyReceivingTicketValidationFilter过滤器。
8. 客户端 生成验证 service url: http://www.web.com/app
9. 客户端 Cas20ProxyReceivingTicketValidationFilter 过滤器,使用6处的ticket 与8处的 service 作为参数验证。
9.1 客户端 生成验证 servlet: https://www.cas-server.com/cas/serviceValidate?ticket=ST-xxx&service=http://www.web.com/app
9.2 客户端 通过HttpClient访问 9.1 的 url
注:AbstractUrlBasedTicketValidator.java line 207,如果是用CAS ptotocol验证,则第二个参数 ticket无用。
得到如下形式的 response:
- 546 <cas:serviceResponse xmlns:cas='http://www.yale.edu/tp/cas'>
- 547 <cas:authenticationSuccess>
- 548 <cas:user>jack</cas:user>
- 549
- 550
- 551 </cas:authenticationSuccess>
- 552 </cas:serviceResponse>
546 <cas:serviceResponse xmlns:cas='http://www.yale.edu/tp/cas'> 547 <cas:authenticationSuccess> 548 <cas:user>jack</cas:user> 549 550 551 </cas:authenticationSuccess> 552 </cas:serviceResponse>
9.3 客户端 解析 response 字符串,生成 assertion (包含 username, validate info 等)
9.4 客户端 设置 assertion 为 request 的 _const_cas_assertion_ 属性。
9.5 客户端 如果设置了重定向属性,则重定向到 http://www.web.com/app -- 转步骤10
否则继续执行以后的 filter,通过servlet 访问 http://www.web.com/app 服务,结束CAS的验证。
用户已成功登录,非第一次访问:
10. 客户端 通过重定向访问 http://www.web.com/app
11. 客户端 AuthenticationFilter Filter 发现 session 中有Assertion, 结束本过滤器,转移到下一个过滤器 Cas20ProxyReceivingTicketValidationFilter.
12. 客户段 Cas20ProxyReceivingTicketValidationFilter 发现 本次访问的URL 无 ticket,结束本次过滤,转移到下一个过滤器,继续执行以后的 filter,通过servlet 访问 http://www.web.com/app 服务。
二 源码解析
1. 客户端 web.xml 片段:
- ...
- <filter>
- <filter-name>CAS Authentication Filter</filter-name>
- <filter-class>org.jasig.cas.client.authentication.AuthenticationFilter</filter-class>
- <init-param>
- <param-name>casServerLoginUrl</param-name>
- <param-value>https://www.colorcc.com:8443/cas/login</param-value>
- </init-param>
- <init-param>
- <param-name>serverName</param-name>
- <param-value>http://localhost:8080</param-value>
- </init-param>
- </filter>
- <filter>
- <filter-name>CAS Validation Filter</filter-name>
- <filter-class>org.jasig.cas.client.validation.Cas20ProxyReceivingTicketValidationFilter</filter-class>
- <init-param>
- <param-name>casServerUrlPrefix</param-name>
- <param-value>https://www.colorcc.com:8443/cas</param-value>
- </init-param>
- <init-param>
- <param-name>serverName</param-name>
- <param-value>http://localhost:8080</param-value>
- </init-param>
- <!-- <init-param>
- <param-name>redirectAfterValidation</param-name>
- <param-value>false</param-value>
- </init-param> -->
- </filter>
- <filter-mapping>
- <filter-name>CAS Authentication Filter</filter-name>
- <url-pattern>/*</url-pattern>
- </filter-mapping>
- <filter-mapping>
- <filter-name>CAS Validation Filter</filter-name>
- <url-pattern>/*</url-pattern>
- </filter-mapping>
- ...
... <filter> <filter-name>CAS Authentication Filter</filter-name> <filter-class>org.jasig.cas.client.authentication.AuthenticationFilter</filter-class> <init-param> <param-name>casServerLoginUrl</param-name> <param-value>https://www.colorcc.com:8443/cas/login</param-value> </init-param> <init-param> <param-name>serverName</param-name> <param-value>http://localhost:8080</param-value> </init-param> </filter> <filter> <filter-name>CAS Validation Filter</filter-name> <filter-class>org.jasig.cas.client.validation.Cas20ProxyReceivingTicketValidationFilter</filter-class> <init-param> <param-name>casServerUrlPrefix</param-name> <param-value>https://www.colorcc.com:8443/cas</param-value> </init-param> <init-param> <param-name>serverName</param-name> <param-value>http://localhost:8080</param-value> </init-param> <!-- <init-param> <param-name>redirectAfterValidation</param-name> <param-value>false</param-value> </init-param> --> </filter> <filter-mapping> <filter-name>CAS Authentication Filter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <filter-mapping> <filter-name>CAS Validation Filter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> ...
2. AuthenticationFilter 代码:
- public final void doFilter(final ServletRequest servletRequest, final ServletResponse servletResponse, final FilterChain filterChain) throws IOException, ServletException {
- final HttpServletRequest request = (HttpServletRequest) servletRequest;
- final HttpServletResponse response = (HttpServletResponse) servletResponse;
- final HttpSession session = request.getSession(false);
- final Assertion assertion = session != null ? (Assertion) session.getAttribute(CONST_CAS_ASSERTION) : null;
- // 如果 session 中有 assertion,则结束 authentication 过滤器,直接跳到下一个过滤器
- if (assertion != null) {
- filterChain.doFilter(request, response);
- return;
- }
- // 2.1 如果 session 中无 assertion, 则构造 service, 如 http://www.web.com/a1
- <STRONG> final String serviceUrl = constructServiceUrl(request, response);</STRONG>
- final String ticket = CommonUtils.safeGetParameter(request,getArtifactParameterName());
- final boolean wasGatewayed = this.gatewayStorage.hasGatewayedAlready(request, serviceUrl);
- // 如果 request 中有 ticke变量,则结束本过滤器,直接跳到下一个过滤器
- if (CommonUtils.isNotBlank(ticket) || wasGatewayed) {
- filterChain.doFilter(request, response);
- return;
- }
- final String modifiedServiceUrl;
- log.debug("no ticket and no assertion found");
- if (this.gateway) {
- log.debug("setting gateway attribute in session");
- modifiedServiceUrl = this.gatewayStorage.storeGatewayInformation(request, serviceUrl);
- } else {
- modifiedServiceUrl = serviceUrl;
- }
- if (log.isDebugEnabled()) {
- log.debug("Constructed service url: " + modifiedServiceUrl);
- }
- // 2.2 否则构造重定向 URL, 其中 casServerLoginUrl 为 web.xml 中 filter 配置,eg: https://www.cas-server.com/cas/login?service=http://www.web.com/a1
- final String urlToRedirectTo = CommonUtils.constructRedirectUrl(this.casServerLoginUrl, getServiceParameterName(), modifiedServiceUrl, this.renew, this.gateway);
- if (log.isDebugEnabled()) {
- log.debug("redirecting to \"" + urlToRedirectTo + "\"");
- }
- // 2.3 重定向到 CAS server
- response.sendRedirect(urlToRedirectTo);<EM>
- </EM>
- }
public final void doFilter(final ServletRequest servletRequest, final ServletResponse servletResponse, final FilterChain filterChain) throws IOException, ServletException { final HttpServletRequest request = (HttpServletRequest) servletRequest; final HttpServletResponse response = (HttpServletResponse) servletResponse; final HttpSession session = request.getSession(false); final Assertion assertion = session != null ? (Assertion) session.getAttribute(CONST_CAS_ASSERTION) : null; // 如果 session 中有 assertion,则结束 authentication 过滤器,直接跳到下一个过滤器 if (assertion != null) { filterChain.doFilter(request, response); return; } // 2.1 如果 session 中无 assertion, 则构造 service, 如 http://www.web.com/a1 final String serviceUrl = constructServiceUrl(request, response); final String ticket = CommonUtils.safeGetParameter(request,getArtifactParameterName()); final boolean wasGatewayed = this.gatewayStorage.hasGatewayedAlready(request, serviceUrl); // 如果 request 中有 ticke变量,则结束本过滤器,直接跳到下一个过滤器 if (CommonUtils.isNotBlank(ticket) || wasGatewayed) { filterChain.doFilter(request, response); return; } final String modifiedServiceUrl; log.debug("no ticket and no assertion found"); if (this.gateway) { log.debug("setting gateway attribute in session"); modifiedServiceUrl = this.gatewayStorage.storeGatewayInformation(request, serviceUrl); } else { modifiedServiceUrl = serviceUrl; } if (log.isDebugEnabled()) { log.debug("Constructed service url: " + modifiedServiceUrl); } // 2.2 否则构造重定向 URL, 其中 casServerLoginUrl 为 web.xml 中 filter 配置,eg: https://www.cas-server.com/cas/login?service=http://www.web.com/a1 final String urlToRedirectTo = CommonUtils.constructRedirectUrl(this.casServerLoginUrl, getServiceParameterName(), modifiedServiceUrl, this.renew, this.gateway); if (log.isDebugEnabled()) { log.debug("redirecting to \"" + urlToRedirectTo + "\""); } // 2.3 重定向到 CAS server response.sendRedirect(urlToRedirectTo); }
2.1 构造 service url: http://www.web.com/a1
- protected final String constructServiceUrl(final HttpServletRequest request, final HttpServletResponse response) {
- return CommonUtils.constructServiceUrl(request, response, this.service, this.serverName, this.artifactParameterName, this.encodeServiceUrl);
- }
protected final String constructServiceUrl(final HttpServletRequest request, final HttpServletResponse response) { return CommonUtils.constructServiceUrl(request, response, this.service, this.serverName, this.artifactParameterName, this.encodeServiceUrl); }
3. 重定向URL: https://www.cas-server.com/cas/login?service=http://www.web.com/a1, 其中 cas server的 web.xml:
- <servlet>
- <servlet-name>cas</servlet-name>
- <servlet-class>
- org.jasig.cas.web.init.SafeDispatcherServlet
- </servlet-class>
- <init-param>
- <param-name>publishContext</param-name>
- <param-value>false</param-value>
- </init-param>
- <load-on-startup>1</load-on-startup>
- </servlet>
- <servlet-mapping>
- <servlet-name>cas</servlet-name>
- <url-pattern>/login</url-pattern>
- </servlet-mapping>
<servlet> <servlet-name>cas</servlet-name> <servlet-class> org.jasig.cas.web.init.SafeDispatcherServlet </servlet-class> <init-param> <param-name>publishContext</param-name> <param-value>false</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>cas</servlet-name> <url-pattern>/login</url-pattern> </servlet-mapping>
3.1 SafeDispatcherServlet 使用 Spring DispatcherServlet 作为 delegate
- public final class SafeDispatcherServlet extends HttpServlet {
- // 定义 Spring DispatcherServlet 作为 delegate
- private DispatcherServlet delegate = new DispatcherServlet();
- // 使用 delegate 初始化 servlet
- public void init(final ServletConfig config) {
- try {
- this.delegate.init(config);
- } catch (final Throwable t) {
- ...
- // 使用 delegate 的 service 执行 web 操作
- public void service(final ServletRequest req, final ServletResponse resp)
- throws ServletException, IOException {
- if (this.initSuccess) {
- this.delegate.service(req, resp);
- } else {
- throw new ApplicationContextException(
- "Unable to initialize application context.");
- }
- }
public final class SafeDispatcherServlet extends HttpServlet { // 定义 Spring DispatcherServlet 作为 delegate private DispatcherServlet delegate = new DispatcherServlet(); // 使用 delegate 初始化 servlet public void init(final ServletConfig config) { try { this.delegate.init(config); } catch (final Throwable t) { ... // 使用 delegate 的 service 执行 web 操作 public void service(final ServletRequest req, final ServletResponse resp) throws ServletException, IOException { if (this.initSuccess) { this.delegate.service(req, resp); } else { throw new ApplicationContextException( "Unable to initialize application context."); } }
3.2 cas-servlet.xml 配置文件如下, 可以看到 login 对应的 webflow 为: login-webflow.xml
- <webflow:flow-registry id="flowRegistry" flow-builder-services="builder">
- <webflow:flow-location path="/WEB-INF/login-webflow.xml" id="login"/>
- </webflow:flow-registry>
<webflow:flow-registry id="flowRegistry" flow-builder-services="builder"> <webflow:flow-location path="/WEB-INF/login-webflow.xml" id="login"/> </webflow:flow-registry>
3.3 根据 login-webflow.xml 配置文件(结合 cas-servlet.xml):
- <on-start>
- <evaluate expression="initialFlowSetupAction" />
- </on-start>
- <bean id="initialFlowSetupAction" class="org.jasig.cas.web.flow.InitialFlowSetupAction"
- p:argumentExtractors-ref="argumentExtractors"
- p:warnCookieGenerator-ref="warnCookieGenerator"
- p:ticketGrantingTicketCookieGenerator-ref="ticketGrantingTicketCookieGenerator"/>
<on-start> <evaluate expression="initialFlowSetupAction" /> </on-start> <bean id="initialFlowSetupAction" class="org.jasig.cas.web.flow.InitialFlowSetupAction" p:argumentExtractors-ref="argumentExtractors" p:warnCookieGenerator-ref="warnCookieGenerator" p:ticketGrantingTicketCookieGenerator-ref="ticketGrantingTicketCookieGenerator"/>
3.4 InitialFlowSetupAction
- protected Event doExecute(final RequestContext context) throws Exception {
- final HttpServletRequest request = WebUtils.getHttpServletRequest(context);
- if (!this.pathPopulated) {
- final String contextPath = context.getExternalContext().getContextPath();
- final String cookiePath = StringUtils.hasText(contextPath) ? contextPath + "/" : "/";
- logger.info("Setting path for cookies to: "
- + cookiePath);
- this.warnCookieGenerator.setCookiePath(cookiePath);
- this.ticketGrantingTicketCookieGenerator.setCookiePath(cookiePath);
- this.pathPopulated = true;
- }
- // 给 FlowScope 的设置 ticketGrantingTicketId, warnCookieValue 参数
- context.getFlowScope().put(
- "ticketGrantingTicketId", this.ticketGrantingTicketCookieGenerator.retrieveCookieValue(request));
- context.getFlowScope().put("warnCookieValue",
- Boolean.valueOf(this.warnCookieGenerator.retrieveCookieValue(request)));
- // 3.4.1 抽取 service 参数
- final Service service = WebUtils.getService(this.argumentExtractors, context);
- if (service != null && logger.isDebugEnabled()) {
- logger.debug("Placing service in FlowScope: " + service.getId());
- }
- // 给 FlowScope 的设置 service 参数
- context.getFlowScope().put("service", service);
- return result("success");
- }
protected Event doExecute(final RequestContext context) throws Exception { final HttpServletRequest request = WebUtils.getHttpServletRequest(context); if (!this.pathPopulated) { final String contextPath = context.getExternalContext().getContextPath(); final String cookiePath = StringUtils.hasText(contextPath) ? contextPath + "/" : "/"; logger.info("Setting path for cookies to: " + cookiePath); this.warnCookieGenerator.setCookiePath(cookiePath); this.ticketGrantingTicketCookieGenerator.setCookiePath(cookiePath); this.pathPopulated = true; } // 给 FlowScope 的设置 ticketGrantingTicketId, warnCookieValue 参数 context.getFlowScope().put( "ticketGrantingTicketId", this.ticketGrantingTicketCookieGenerator.retrieveCookieValue(request)); context.getFlowScope().put("warnCookieValue", Boolean.valueOf(this.warnCookieGenerator.retrieveCookieValue(request))); // 3.4.1 抽取 service 参数 final Service service = WebUtils.getService(this.argumentExtractors, context); if (service != null && logger.isDebugEnabled()) { logger.debug("Placing service in FlowScope: " + service.getId()); } // 给 FlowScope 的设置 service 参数 context.getFlowScope().put("service", service); return result("success"); }
3.4.1 WebApplicationService.getService
- public static WebApplicationService getService(
- final List<ArgumentExtractor> argumentExtractors,
- final HttpServletRequest request) {
- for (final ArgumentExtractor argumentExtractor : argumentExtractors) {
- // 3.4.1.1 通过配置的 argumentExtractor 抽取 service
- final WebApplicationService service = argumentExtractor.extractService(request);
- if (service != null) {
- return service;
- }
- }
- return null;
- }
public static WebApplicationService getService( final List<ArgumentExtractor> argumentExtractors, final HttpServletRequest request) { for (final ArgumentExtractor argumentExtractor : argumentExtractors) { // 3.4.1.1 通过配置的 argumentExtractor 抽取 service final WebApplicationService service = argumentExtractor.extractService(request); if (service != null) { return service; } } return null; }
3.4.1.1 CasArgumentExtractor 代码
- public final class CasArgumentExtractor extends AbstractSingleSignOutEnabledArgumentExtractor {
- public final WebApplicationService extractServiceInternal(final HttpServletRequest request) {
- return SimpleWebApplicationServiceImpl.createServiceFrom(request, getHttpClientIfSingleSignOutEnabled());
- }
- }
- // SimpleWebApplicationServiceImpl
- private static final String CONST_PARAM_SERVICE = "service";
- private static final String CONST_PARAM_TARGET_SERVICE = "targetService";
- private static final String CONST_PARAM_TICKET = "ticket";
- private static final String CONST_PARAM_METHOD = "method";
- public static SimpleWebApplicationServiceImpl createServiceFrom(
- final HttpServletRequest request, final HttpClient httpClient) {
- final String targetService = request
- .getParameter(CONST_PARAM_TARGET_SERVICE);
- final String method = request.getParameter(CONST_PARAM_METHOD);
- final String serviceToUse = StringUtils.hasText(targetService)
- ? targetService : request.getParameter(CONST_PARAM_SERVICE);
- if (!StringUtils.hasText(serviceToUse)) {
- return null;
- }
- final String id = cleanupUrl(serviceToUse);
- final String artifactId = request.getParameter(CONST_PARAM_TICKET);
- return new SimpleWebApplicationServiceImpl(id, serviceToUse,
- artifactId, "POST".equals(method) ? ResponseType.POST
- : ResponseType.REDIRECT, httpClient);
- }
- private SimpleWebApplicationServiceImpl(final String id,
- final String originalUrl, final String artifactId,
- final ResponseType responseType, final HttpClient httpClient) {
- super(id, originalUrl, artifactId, httpClient);
- this.responseType = responseType;
- }
- protected AbstractWebApplicationService(final String id, final String originalUrl, final String artifactId, final HttpClient httpClient) {
- this.id = id;
- this.originalUrl = originalUrl;
- this.artifactId = artifactId;
- this.httpClient = httpClient;
- }
public final class CasArgumentExtractor extends AbstractSingleSignOutEnabledArgumentExtractor { public final WebApplicationService extractServiceInternal(final HttpServletRequest request) { return SimpleWebApplicationServiceImpl.createServiceFrom(request, getHttpClientIfSingleSignOutEnabled()); } } // SimpleWebApplicationServiceImpl private static final String CONST_PARAM_SERVICE = "service"; private static final String CONST_PARAM_TARGET_SERVICE = "targetService"; private static final String CONST_PARAM_TICKET = "ticket"; private static final String CONST_PARAM_METHOD = "method"; public static SimpleWebApplicationServiceImpl createServiceFrom( final HttpServletRequest request, final HttpClient httpClient) { final String targetService = request .getParameter(CONST_PARAM_TARGET_SERVICE); final String method = request.getParameter(CONST_PARAM_METHOD); final String serviceToUse = StringUtils.hasText(targetService) ? targetService : request.getParameter(CONST_PARAM_SERVICE); if (!StringUtils.hasText(serviceToUse)) { return null; } final String id = cleanupUrl(serviceToUse); final String artifactId = request.getParameter(CONST_PARAM_TICKET); return new SimpleWebApplicationServiceImpl(id, serviceToUse, artifactId, "POST".equals(method) ? ResponseType.POST : ResponseType.REDIRECT, httpClient); } private SimpleWebApplicationServiceImpl(final String id, final String originalUrl, final String artifactId, final ResponseType responseType, final HttpClient httpClient) { super(id, originalUrl, artifactId, httpClient); this.responseType = responseType; } protected AbstractWebApplicationService(final String id, final String originalUrl, final String artifactId, final HttpClient httpClient) { this.id = id; this.originalUrl = originalUrl; this.artifactId = artifactId; this.httpClient = httpClient; }
3. Cas20ProxyReceivingTicketValidationFilter 及 AbstractTicketValidationFilter代码:
- public final void doFilter(final ServletRequest servletRequest, final ServletResponse servletResponse, final FilterChain filterChain) throws IOException, ServletException {
- if (!preFilter(servletRequest, servletResponse, filterChain)) {
- return;
- }
- final HttpServletRequest request = (HttpServletRequest) servletRequest;
- final HttpServletResponse response = (HttpServletResponse) servletResponse;
- final String ticket = CommonUtils.safeGetParameter(request, getArtifactParameterName());
- // 如果 URL 中包含 ticket 参数,则执行 service 验证工作
- if (CommonUtils.isNotBlank(ticket)) {
- if (log.isDebugEnabled()) {
- log.debug("Attempting to validate ticket: " + ticket);
- }
- try {
- final Assertion assertion = this.ticketValidator.validate(ticket, constructServiceUrl(request, response));
- if (log.isDebugEnabled()) {
- log.debug("Successfully authenticated user: " + assertion.getPrincipal().getName());
- }
- request.setAttribute(CONST_CAS_ASSERTION, assertion);
- if (this.useSession) {
- request.getSession().setAttribute(CONST_CAS_ASSERTION, assertion);
- }
- onSuccessfulValidation(request, response, assertion);
- if (this.redirectAfterValidation) {
- log. debug("Redirecting after successful ticket validation.");
- response.sendRedirect(constructServiceUrl(request, response));
- return;
- }
- } catch (final TicketValidationException e) {
- response.setStatus(HttpServletResponse.SC_FORBIDDEN);
- log.warn(e, e);
- onFailedValidation(request, response);
- if (this.exceptionOnValidationFailure) {
- throw new ServletException(e);
- }
- return;
- }
- }
- // 如果不包含 ticket, 直接跳过CAS Filter验证,继续其他 filter 或 web app 操作
- filterChain.doFilter(request, response);
- }
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在本示例中,我们将重点讨论如何在Java环境下使用代理模式来实现代理逻辑,特别是在CAS(Central Authentication Service)认证框架中的应用。CAS是一种基于Web的单点登录(SSO)解决方案,广泛用于网络应用程序的...
Proxy源代码分析可以帮助我们深入了解网络通信的原理以及如何在Linux环境下实现客户端-服务器模型。以下是对Proxy源代码及其涉及的关键知识点的详细说明: 1. **套接字(socket)**:在Linux网络编程中,套接字是进程...
4. **代理票证(Proxy Ticket)**:在需要代表用户访问其他资源时,CAS服务器会生成的一种特殊的票证。 5. **Ticket Granting Ticket(TGT)**:用户首次登录时,CAS服务器生成的主票证,用于生成后续的服务票证。 ...
Proxy模式是软件设计模式中的一个关键元素,属于结构型模式的一种。在C++中,Proxy模式主要用于为其他对象提供一种代理以控制对这个对象的访问。这种模式的核心思想是通过创建一个代理对象来充当目标对象的中介,...
**源码分析** 在提供的压缩包中,包含以下几个关键文件和项目: 1. **DotNetCasClient.sln** 和 **DotNetCasClient.vs2010.sln**:这是解决方案文件,用于在Visual Studio中打开和管理项目。两个版本的解决方案...
MySQL数据库中间件:基于C语言开发,包含59个文件,包括22个C源文件...该项目是一个分布式MySQL数据库中间件,采用Proxy模式设计,基于核心业务对象切分,旨在提供高效的数据库查询和处理能力,适用于分布式系统环境。
在"DynamicProxy"目录下的源码中,可以看到如何使用这些类和接口创建并操作动态代理的例子。 3. 接口代理(JDK动态代理): 接口代理是基于Java的反射机制实现的动态代理,适用于目标对象实现了接口的情况。在...
标题中的“从房屋买卖看 java proxy 模式”暗示了我们将通过一个具体的场景来探讨 Java 中的代理(Proxy)模式。在软件设计中,代理模式是一种结构型设计模式,它为其他对象提供一种代理以控制对这个对象的访问。在...