Javaでサーブレットを登録する方法

    index.html
    index.htm
    index.jsp


    Example
    com.example.Example


    Example
    /Example

@WebServlet(
  name = "AnnotationExample",
  description = "Example Servlet Using Annotations",
  urlPatterns = {"/AnnotationExample"}
)
public class Example extends HttpServlet {

    @Override
    protected void doGet(
      HttpServletRequest request,
      HttpServletResponse response) throws ServletException, IOException {

        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.println("
Hello World!
");
    }
}

public class WebAppInitializer implements WebApplicationInitializer {

    public void onStartup(ServletContext container) throws ServletException {
        AnnotationConfigWebApplicationContext ctx
          = new AnnotationConfigWebApplicationContext();
        ctx.register(WebMvcConfigure.class);
        ctx.setServletContext(container);

        ServletRegistration.Dynamic servlet = container.addServlet(
          "dispatcherExample", new DispatcherServlet(ctx));
        servlet.setLoadOnStartup(1);
        servlet.addMapping("/");
     }
}

@Configuration
public class WebMvcConfigure implements WebMvcConfigurer {

    @Bean
    public ViewResolver getViewResolver() {
        InternalResourceViewResolver resolver
          = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/");
        resolver.setSuffix(".jsp");
        return resolver;
    }

    @Override
    public void configureDefaultServletHandling(
      DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/resources/**")
          .addResourceLocations("/resources/").setCachePeriod(3600)
          .resourceChain(true).addResolver(new PathResourceResolver());
    }
}

    dispatcher
    org.springframework.web.servlet.DispatcherServlet
    
        contextConfigLocation
        /WEB-INF/spring/dispatcher.xml
    
    1



    dispatcher
    /

public void onStartup(ServletContext container) throws ServletException {
   XmlWebApplicationContext xctx = new XmlWebApplicationContext();
   xctx.setConfigLocation('classpath:/context.xml');
   xctx.setServletContext(container);

   ServletRegistration.Dynamic servlet = container.addServlet(
     "dispatcher", new DispatcherServlet(ctx));
   servlet.setLoadOnStartup(1);
   servlet.addMapping("/");
}

@Bean
public ServletRegistrationBean exampleServletBean() {
    ServletRegistrationBean bean = new ServletRegistrationBean(
      new CustomServlet(), "/exampleServlet/*");
    bean.setLoadOnStartup(1);
    return bean;
}

public class CustomServlet extends HttpServlet{
    ...
}

servlet.name=dispatcherExample
servlet.mapping=/dispatcherExampleURL

System.setProperty("custom.config.location", "classpath:custom.properties");

System.getProperty("custom.config.location");

servlet.name=dispatcherExample
servlet.mapping=/dispatcherExampleURL

public Properties getProperties(String file) throws IOException {
  Properties prop = new Properties();
  InputStream input = null;
  input = getClass().getResourceAsStream(file);
  prop.load(input);
  if (input != null) {
      input.close();
  }
  return prop;
}

private static final PropertyLoader pl = new PropertyLoader();
private static final Properties springProps
  = pl.getProperties("custom_spring.properties");

public static final String SERVLET_NAME
  = springProps.getProperty("servlet.name");
public static final String SERVLET_MAPPING
  = springProps.getProperty("servlet.mapping");

ServletRegistration.Dynamic servlet = container.addServlet(
  SERVLET_NAME, new DispatcherServlet(ctx));
servlet.setLoadOnStartup(1);
servlet.addMapping(SERVLET_MAPPING);

@Configuration
@PropertySource("classpath:/com/yourapp/custom.properties")
public class ExampleCustomConfig {
    @Autowired
    ConfigurableEnvironment env;

    public String getProperty(String key) {
        return env.getProperty(key);
    }
}

ConfigurableEnvironment env = new StandardEnvironment();
MutablePropertySources props = env.getPropertySources();
Map map = new HashMap(); map.put("key", "value");
props.addFirst(new MapPropertySource("Map", map));

server.jsp-servlet.class-name=org.apache.jasper.servlet.JspServlet
server.jsp-servlet.registered=true
server.port=8080
server.servlet-path=/

YamlPropertySourceLoader sourceLoader = new YamlPropertySourceLoader();
PropertySource yamlProps = sourceLoader.load("yamlProps", resource, null);

@Bean
public ConfigurableServletWebServerFactory servletContainer() {
    TomcatServletWebServerFactory tomcatContainerFactory
      = new TomcatServletWebServerFactory();
    return tomcatContainerFactory;
}

tomcatContainerFactory.setPort(9000);
tomcatContainerFactory.setContextPath("/springboottomcatexample");

Tomcat tomcat = new Tomcat();
tomcat.setPort(port);
tomcat.setContextPath("/springboottomcatexample");
tomcat.start();