关于"ServletWebServerApplicationContext创建Web容器Tomcat示例",以下是完整攻略:
ServletWebServerApplicationContext创建Web容器Tomcat示例
什么是ServletWebServerApplicationContext
ServletWebServerApplicationContext是Spring Framework中Web模块的ApplicationContext实现,它的作用是在Spring应用程序中启动和管理Web服务器和Servlet容器。
创建Web容器Tomcat的示例
下面我们以Spring Boot应用程序为例创建Web容器Tomcat的示例。
步骤1:在pom.xml中添加Tomcat依赖
在pom.xml文件中添加Tomcat的依赖:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-core</artifactId>
<version>9.0.30</version>
</dependency>
步骤2:编写Spring Boot应用程序
在Spring Boot应用程序的启动类中,添加如下代码启动Web容器Tomcat:
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ImportResource;
import java.io.IOException;
@SpringBootApplication
@ImportResource(locations = { "classpath:spring.xml" }) // 加载外部xml配置文件
public class Application {
@Bean
public TomcatServletWebServerFactory tomcatFactory() {
return new TomcatServletWebServerFactory() {
@Override
protected void postProcessContext(org.apache.catalina.Context context) {
((org.apache.catalina.core.StandardContext) context).setReloadable(false);
}
};
}
public static void main(String[] args) throws IOException {
ConfigurableApplicationContext context = SpringApplication.run(Application.class, args);
int port = context.getEnvironment().getProperty("server.port", Integer.class, 8080);
System.out.println("Tomcat容器启动成功,端口号为:" + port);
System.in.read();
context.close();
}
}
在上述代码中,我们定义了一个bean,它继承了TomcatServletWebServerFactory类,并且重写了postProcessContext()方法,用来配置context不可重载。最后在main()方法中,我们获取了Tomcat容器的端口号,并打印输出。
示例1:自定义Servlet
添加一个自定义的Servlet类,代码如下:
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
@WebServlet(urlPatterns = "/myServlet")
public class MyServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
resp.getWriter().print("Hello, MyServlet!");
}
}
在Application类中加入一个@ServletComponentScan注解,该注解会扫描和注册所有@WebServlet、@WebListener和@Filter注解的类。
import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebFilter;
import javax.servlet.annotation.WebListener;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
@ServletComponentScan
@SpringBootApplication
@ImportResource(locations = { "classpath:spring.xml" }) // 加载外部xml配置文件
public class Application {
// 省略代码...
}
示例2:自定义Filter
添加一个自定义的Filter类,代码如下:
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;
@WebFilter(urlPatterns = "/myServlet")
public class MyFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
System.out.println("MyFilter init...");
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
System.out.println("MyFilter doFilter...");
filterChain.doFilter(servletRequest, servletResponse);
}
@Override
public void destroy() {
System.out.println("MyFilter destroy...");
}
}
步骤3:运行应用程序
现在,我们可以运行Spring Boot应用程序,并在浏览器中访问 http://localhost:8080/myServlet 了。在运行过程中,我们可以看到Console中打印了"MyFilter init..."、"MyFilter doFilter..."、"Hello, MyServlet!"、"MyFilter doFilter..."、"MyFilter destroy..."这些信息。
以上是"ServletWebServerApplicationContext创建Web容器Tomcat示例"的攻略,希望对你有所帮助!
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