BAEL-9 #3 (#1207)

* BAEL-9 #3

* pom.xml fix

pom.xml

@@ -109,6 +109,7 @@
         <module>spring-autowire</module>
         <module>spring-batch</module>
         <module>spring-boot</module>
+        <module>spring-boot-servlet</module>
         <module>spring-cloud-data-flow</module>
         <module>spring-cloud</module>
         <module>spring-core</module>

spring-boot-servlet/.gitignore

@@ -0,0 +1,4 @@
+/target/
+.settings/
+.classpath
+.project

spring-boot-servlet/README.md

@@ -0,0 +1,2 @@
+###Relevant Articles:
+- [How to Register a Servlet in a Java Web Application](http://www.baeldung.com/how-to-register-a-servlet-in-a-java-web-application/)

spring-boot-servlet/pom.xml

@@ -0,0 +1,55 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.baeldung</groupId>
+    <artifactId>spring-boot-servlet</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <packaging>war</packaging>
+    <name>spring-boot-servlet</name>
+
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-dependencies</artifactId>
+        <version>1.5.1.RELEASE</version>
+    </parent>
+
+    <dependencies>
+        <!-- Spring Boot Dependencies -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-tomcat</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <!-- Embedded EmbeddedTomcatExample Dependencies -->
+        <dependency>
+            <groupId>org.apache.tomcat.embed</groupId>
+            <artifactId>tomcat-embed-core</artifactId>
+            <version>${tomcat.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.tomcat.embed</groupId>
+            <artifactId>tomcat-embed-jasper</artifactId>
+            <version>${tomcat.version}</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <java.version>1.8</java.version>
+        <tomcat.version>8.5.11</tomcat.version>
+    </properties>
+
+</project>

spring-boot-servlet/src/main/java/META-INF/MANIFEST.MF

@@ -0,0 +1,2 @@
+Manifest-Version: 1.0
+Main-Class: com.baeldung.ApplicationMain

spring-boot-servlet/src/main/java/com/baeldung/ApplicationMain.java

@@ -0,0 +1,19 @@
+package com.baeldung;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.web.support.SpringBootServletInitializer;
+
+@SpringBootApplication
+public class ApplicationMain extends SpringBootServletInitializer {
+
+    public static void main(String[] args) {
+        SpringApplication.run(ApplicationMain.class, args);
+    }
+
+    @Override
+    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
+        return application.sources(ApplicationMain.class);
+    }
+}

spring-boot-servlet/src/main/java/com/baeldung/configuration/WebAppInitializer.java

@@ -0,0 +1,32 @@
+package com.baeldung.configuration;
+
+import org.springframework.web.WebApplicationInitializer;
+import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
+import org.springframework.web.context.support.XmlWebApplicationContext;
+import org.springframework.web.servlet.DispatcherServlet;
+import javax.servlet.ServletContext;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRegistration;
+
+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 servletOne = container.addServlet("SpringProgrammaticDispatcherServlet", new DispatcherServlet(ctx));
+        servletOne.setLoadOnStartup(1);
+        servletOne.addMapping("/");
+
+        XmlWebApplicationContext xctx = new XmlWebApplicationContext();
+        xctx.setConfigLocation("/WEB-INF/context.xml");
+        xctx.setServletContext(container);
+
+        ServletRegistration.Dynamic servletTwo = container.addServlet("SpringProgrammaticXMLDispatcherServlet", new DispatcherServlet(xctx));
+        servletTwo.setLoadOnStartup(1);
+        servletTwo.addMapping("/");
+    }
+
+}

spring-boot-servlet/src/main/java/com/baeldung/configuration/WebMvcConfigure.java

@@ -0,0 +1,40 @@
+package com.baeldung.configuration;
+
+import org.springframework.boot.web.support.ErrorPageFilter;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.ViewResolver;
+import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
+import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
+import org.springframework.web.servlet.resource.PathResourceResolver;
+import org.springframework.web.servlet.view.InternalResourceViewResolver;
+
+@Configuration
+public class WebMvcConfigure extends WebMvcConfigurerAdapter {
+
+    @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());
+    }
+
+    @Bean
+    public ErrorPageFilter errorPageFilter() {
+        return new ErrorPageFilter();
+    }
+}
+

spring-boot-servlet/src/main/java/com/baeldung/props/Constants.java

@@ -0,0 +1,20 @@
+package com.baeldung.props;
+
+import org.springframework.beans.factory.annotation.Autowired;
+
+import java.util.Properties;
+
+public final class Constants {
+
+    @Autowired
+    PropertySourcesLoader psl;
+
+    public static final String breakLine = System.getProperty("line.separator");
+    private static final PropertyLoader pl = new PropertyLoader();
+    private static final Properties mainProps = pl.getProperties("custom.properties");
+    public static final String DISPATCHER_SERVLET_NAME = mainProps.getProperty("dispatcher.servlet.name");
+    public static final String DISPATCHER_SERVLET_MAPPING = mainProps.getProperty("dispatcher.servlet.mapping");
+    private final String EXAMPLE_SERVLET_NAME = psl.getProperty("example.servlet.name");
+    private final String EXAMPLE_SERVLET_MAPPING = psl.getProperty("example.servlet.mapping");
+
+}

spring-boot-servlet/src/main/java/com/baeldung/props/PropertyLoader.java

@@ -0,0 +1,27 @@
+package com.baeldung.props;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Properties;
+
+public class PropertyLoader {
+    private static final Logger log = LoggerFactory.getLogger(PropertyLoader.class);
+
+    public Properties getProperties(String file) {
+        Properties prop = new Properties();
+        InputStream input = null;
+        try {
+            input = getClass().getResourceAsStream(file);
+            prop.load(input);
+            if (input != null) {
+                input.close();
+            }
+        } catch (IOException ex) {
+            log.error("IOException: " + ex);
+        }
+        return prop;
+    }
+}

spring-boot-servlet/src/main/java/com/baeldung/props/PropertySourcesLoader.java

@@ -0,0 +1,23 @@
+package com.baeldung.props;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.PropertySource;
+import org.springframework.core.env.ConfigurableEnvironment;
+
+@Configuration
+@ComponentScan(basePackages = { "com.baeldung.*" })
+@PropertySource("classpath:custom.properties") public class PropertySourcesLoader {
+
+    private static final Logger log = LoggerFactory.getLogger(PropertySourcesLoader.class);
+
+    @Autowired
+    ConfigurableEnvironment env;
+
+    public String getProperty(String key) {
+        return env.getProperty(key);
+    }
+}

spring-boot-servlet/src/main/java/com/baeldung/servlets/GenericCustomServlet.java

@@ -0,0 +1,18 @@
+package com.baeldung.servlets;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import java.io.PrintWriter;
+
+public class GenericCustomServlet extends HttpServlet {
+
+    @Override
+    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        response.setContentType("text/html");
+        PrintWriter out = response.getWriter();
+        out.println("<p>Hello World</p>");
+    }
+}

spring-boot-servlet/src/main/java/com/baeldung/servlets/javaee/AnnotationServlet.java

@@ -0,0 +1,20 @@
+package com.baeldung.servlets.javaee;
+
+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(name = "AnnotationServlet",
+    description = "Example Servlet Using Annotations",
+    urlPatterns = { "/annotationservlet" })
+public class AnnotationServlet extends HttpServlet {
+    private static final long serialVersionUID = 1L;
+
+    @Override
+    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        request.getRequestDispatcher("/annotationservlet.jsp").forward(request, response);
+    }
+}

spring-boot-servlet/src/main/java/com/baeldung/servlets/javaee/EEWebXmlServlet.java

@@ -0,0 +1,20 @@
+package com.baeldung.servlets.javaee;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import java.io.PrintWriter;
+
+public class EEWebXmlServlet extends HttpServlet {
+
+    private static final long serialVersionUID = 1L;
+
+    @Override
+    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        response.setContentType("text/html");
+        PrintWriter out = response.getWriter();
+        out.println("<p>Hello World</p>");
+    }
+}

spring-boot-servlet/src/main/java/com/baeldung/servlets/springboot/SpringRegistrationBeanServlet.java

@@ -0,0 +1,19 @@
+package com.baeldung.servlets.springboot;
+
+import com.baeldung.servlets.GenericCustomServlet;
+import org.springframework.boot.web.servlet.ServletRegistrationBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class SpringRegistrationBeanServlet {
+
+    @Bean
+    public ServletRegistrationBean genericCustomServlet() {
+        ServletRegistrationBean bean = new ServletRegistrationBean(new GenericCustomServlet(), "/springregistrationbeanservlet/*");
+        bean.setLoadOnStartup(1);
+        return bean;
+    }
+}
+
+

spring-boot-servlet/src/main/java/com/baeldung/servlets/springboot/embedded/EmbeddedTomcatExample.java

@@ -0,0 +1,16 @@
+package com.baeldung.servlets.springboot.embedded;
+
+import org.springframework.boot.context.embedded.EmbeddedServletContainerFactory;
+import org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class EmbeddedTomcatExample {
+
+    @Bean
+    public EmbeddedServletContainerFactory servletContainer() {
+        TomcatEmbeddedServletContainerFactory tomcat = new TomcatEmbeddedServletContainerFactory();
+        return tomcat;
+    }
+}

spring-boot-servlet/src/main/resources/application.properties

@@ -0,0 +1,10 @@
+#Server Configuration
+#server.port=8080
+#server.context-path=/javabootdata
+#Resource Handling
+#spring.resources.static-locations=classpath:/WEB-INF/resources
+#spring.mvc.view.prefix=/WEB-INF/
+#spring.mvc.view.suffix=.jsp
+#spring.resources.cache-period=3600
+servlet.name=dispatcherExample
+servlet.mapping=/dispatcherExampleURL

spring-boot-servlet/src/main/resources/custom.properties

@@ -0,0 +1,4 @@
+dispatcher.servlet.name=dispatcherExample
+dispatcher.servlet.mapping=/dispatcherExampleURL
+example.servlet.name=dispatcherExample
+example.servlet.mapping=/dispatcherExampleURL

spring-boot-servlet/src/main/webapp/WEB-INF/context.xml

@@ -0,0 +1,12 @@
+<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:context="http://www.springframework.org/schema/context"
+       xmlns="http://www.springframework.org/schema/beans"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans
+                           http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
+                           http://www.springframework.org/schema/context
+                           http://www.springframework.org/schema/context/spring-context-4.3.xsd">
+
+    <context:component-scan base-package="com.baeldung"/>
+
+    <bean class="com.baeldung.configuration.WebAppInitializer"/>
+</beans>

spring-boot-servlet/src/main/webapp/WEB-INF/dispatcher.xml

@@ -0,0 +1,16 @@
+<beans xmlns:context="http://www.springframework.org/schema/context"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns="http://www.springframework.org/schema/beans"
+       xsi:schemaLocation="
+   http://www.springframework.org/schema/beans
+   http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
+   http://www.springframework.org/schema/context
+   http://www.springframework.org/schema/context/spring-context-3.0.xsd">
+
+    <context:component-scan base-package="com.baeldung"/>
+
+    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
+        <property name="prefix" value="/WEB-INF/jsp/"/>
+        <property name="suffix" value=".jsp"/>
+    </bean>
+</beans>