增加项目说明

2019-01-08 17:02:55 +08:00
parent f1594c6de7
commit 48039923fe
61 changed files with 3345 additions and 100 deletions
--- a/spring-boot/spring-boot-servlet/README.md
+++ b/spring-boot/spring-boot-servlet/README.md
@ -0,0 +1,230 @@
+# spring boot 整合 servlet 
+
+## 一、说明
+
+#### 1.1 项目结构说明
+
+1. 项目提供与servlet整合的两种方式，一种是servlet3.0 原生的注解方式，一种是采用spring 注册的方式；
+2. servlet、过滤器、监听器分别位于servlet、filter、listen 下，其中以Annotation命名结尾的代表是servlet注解方式实现，采用spring注册方式则在ServletConfig中进行注册；
+3. 为了说明外置容器对servlet注解的自动发现机制，项目采用外置容器构建，关于spring boot 整合外置容器的详细说明可以参考[spring-boot-tomcat](https://github.com/heibaiying/spring-samples-for-all/tree/master/spring-boot/spring-boot-tomcat)
+
+![spring-boot-servlet](D:\spring-samples-for-all\pictures\spring-boot-servlet.png)
+
+#### 1.2 项目依赖
+
+```xml
+<dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+            <!--排除依赖 使用外部tomcat容器启动-->
+            <exclusions>
+                <exclusion>
+                    <groupId>org.springframework.boot</groupId>
+                    <artifactId>spring-boot-starter-tomcat</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+        <dependency>
+            <!--使用外置容器时候SpringBootServletInitializer 依赖此包 -->
+            <groupId>javax.servlet</groupId>
+            <artifactId>servlet-api</artifactId>
+            <version>2.5</version>
+            <scope>provided</scope>
+        </dependency>
+        <!--servlet api 注解依赖包-->
+        <dependency>
+            <groupId>javax.servlet</groupId>
+            <artifactId>javax.servlet-api</artifactId>
+        </dependency>
+    </dependencies>
+```
+
+## 二、采用spring 注册方式整合 servlet
+
+#### 2.1 新建过滤器、监听器和servlet
+
+```java
+/**
+ * @author : heibaiying
+ * @description : 自定义过滤器
+ */
+
+public class CustomFilter implements Filter {
+
+    @Override
+    public void init(FilterConfig filterConfig) throws ServletException {
+
+    }
+
+    @Override
+    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
+        request.setAttribute("filterParam","我是filter传递的参数");
+        chain.doFilter(request,response);
+        response.getWriter().append(" CustomFilter ");
+    }
+
+    @Override
+    public void destroy() {
+
+    }
+}
+```
+
+```java
+/**
+ * @author : heibaiying
+ * @description : 自定义监听器
+ */
+public class CustomListen implements ServletContextListener {
+
+    //Web应用程序初始化过程正在启动的通知
+    @Override
+    public void contextInitialized(ServletContextEvent sce) {
+        System.out.println("容器初始化启动");
+    }
+
+
+
+    /* 通知servlet上下文即将关闭
+     * 这个地方如果我们使用的是spring boot 内置的容器 是监听不到销毁过程，所以我们使用了外置 tomcat 容器
+     */
+    @Override
+    public void contextDestroyed(ServletContextEvent sce) {
+        System.out.println("容器即将销毁");
+    }
+}
+```
+
+```java
+/**
+ * @author : heibaiying
+ * @description : 自定义servlet
+ */
+public class CustomServlet extends HttpServlet {
+
+    @Override
+    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        System.out.println("doGet 执行：" + req.getAttribute("filterParam"));
+        resp.getWriter().append("CustomServlet");
+    }
+
+    @Override
+    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        doGet(req, resp);
+    }
+}
+```
+
+#### 2.2 注册过滤器、监听器和servlet
+
+```java
+/**
+ * @author : heibaiying
+ */
+@Configuration
+public class ServletConfig {
+
+    @Bean
+    public ServletRegistrationBean registrationBean() {
+        return new ServletRegistrationBean<HttpServlet>(new CustomServlet(), "/servlet");
+    }
+
+    @Bean
+    public FilterRegistrationBean filterRegistrationBean() {
+        FilterRegistrationBean bean = new FilterRegistrationBean<Filter>();
+        bean.setFilter(new CustomFilter());
+        bean.addUrlPatterns("/servlet");
+        return bean;
+    }
+
+    @Bean
+    public ServletListenerRegistrationBean listenerRegistrationBean() {
+        return new ServletListenerRegistrationBean<ServletContextListener>(new CustomListen());
+    }
+
+}
+```
+
+## 三、采用注解方式整合 servlet
+
+#### 3.1 新建过滤器、监听器和servlet,分别使用@WebFilter、@WebListener、@WebServlet注解标注
+
+```java
+/**
+ * @author : heibaiying
+ * @description : 自定义过滤器
+ */
+
+@WebFilter(urlPatterns = "/servletAnn")
+public class CustomFilterAnnotation implements Filter {
+
+    @Override
+    public void init(FilterConfig filterConfig) throws ServletException {
+
+    }
+
+    @Override
+    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
+        chain.doFilter(request,response);
+        response.getWriter().append(" CustomFilter Annotation");
+    }
+
+    @Override
+    public void destroy() {
+
+    }
+}
+```
+
+```java
+/**
+ * @author : heibaiying
+ * @description :自定义监听器
+ */
+@WebListener
+public class CustomListenAnnotation implements ServletContextListener {
+
+    //Web应用程序初始化过程正在启动的通知
+    @Override
+    public void contextInitialized(ServletContextEvent sce) {
+        System.out.println("容器初始化启动 Annotation");
+    }
+
+
+
+    /* 通知servlet上下文即将关闭
+     * 这个地方如果我们使用的是spring boot 内置的容器 是监听不到销毁过程，所以我们使用了外置 tomcat 容器
+     */
+    @Override
+    public void contextDestroyed(ServletContextEvent sce) {
+        System.out.println("容器即将销毁 Annotation");
+    }
+}
+```
+
+```java
+
+/**
+ * @author : heibaiying
+ * @description : 自定义servlet
+ */
+@WebServlet(urlPatterns = "/servletAnn")
+public class CustomServletAnnotation extends HttpServlet {
+
+    @Override
+    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        resp.getWriter().append("CustomServlet Annotation");
+    }
+
+    @Override
+    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        doGet(req, resp);
+    }
+}
+```
+
+#### 3.2 使注解生效
+
+1. 如果是内置容器，需要在启动类上添加@ServletComponentScan("com.heibaiying.springbootservlet") ，指定扫描的包目录；
+2. 如果是外置容器，不需要进行任何配置，依靠容器内建的discovery机制自动发现，需要说明的是这里的容器必须支持servlet3.0（tomcat从7.0版本开始支持Servlet3.0）。