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--- osgi_web_application [2014/03/18 21:39]
+++ osgi_web_application [2021/04/05 11:23] (current)
@@ Line 1: / Line 1: @@
+====== OSGi Web Application ======
+OSGi has support for web applications included for a long time in form of Java Servlet support.
+===== Maven =====
+The maven-bundle-plugin does most of the work for getting the manifest right.
+<sxh xml>
+<dependencies>
+		<dependency>
+			<groupId>javax.servlet</groupId>
+			<artifactId>javax.servlet-api</artifactId>
+			<version>3.0.1</version>
+			<scope>provided</scope>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.felix</groupId>
+				<artifactId>maven-bundle-plugin</artifactId>
+				<version>2.3.5</version>
+				<executions>
+					<execution>
+						<id>bundle-manifest</id>
+						<phase>process-classes</phase>
+						<goals>
+							<goal>manifest</goal>
+						</goals>
+					</execution>
+				</executions>
+				<configuration>
+					<supportedProjectTypes>
+						<supportedProjectType>jar</supportedProjectType>
+						<supportedProjectType>bundle</supportedProjectType>
+						<supportedProjectType>war</supportedProjectType>
+					</supportedProjectTypes>
+					<instructions>
+						<Embed-Directory>WEB-INF/lib</Embed-Directory>
+						<Embed-Dependency>*;scope=compile</Embed-Dependency>
+						<Embed-Transitive>true</Embed-Transitive>
+					</instructions>
+				</configuration>
+			</plugin>
+			<plugin>
+				<!-- Need to use this plugin to build war files -->
+				<artifactId>maven-war-plugin</artifactId>
+				<groupId>org.apache.maven.plugins</groupId>
+				<version>2.4</version>
+				<configuration>
+					<!-- We don't always have a web.xml -->
+					<failOnMissingWebXml>false</failOnMissingWebXml>
+					<archive>
+						<manifestFile>${project.build.outputDirectory}/META-INF/MANIFEST.MF</manifestFile>
+					</archive>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+</sxh>
+The project specific manifest entries are extracted into an extra properties file:
+<sxh title:osgi.properties>
+Bundle-ClassPath: .,WEB-INF/classes
+Web-ContextPath: /application_url_part
+</sxh>
+It is important to add the root of the WAR file to the bundle classpath.
+===== Servlet =====
+An extremely simple Servlet:
+<sxh java>
+import java.io.IOException;
+import java.io.PrintWriter;
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+@WebServlet(displayName="RPG Next Gen OSGi Simple Servlet" , value="/*")
+public class SimpleServlet extends HttpServlet {
+	@Override
+	protected void doGet(HttpServletRequest request, HttpServletResponse response)
+			throws ServletException, IOException {
+		PrintWriter writer = response.getWriter();
+		writer.println("Enter the matrix ...");
+	}
+}
+</sxh>
+No ''web.xml'' file is needed for this simple setup.
+===== Apache Karaf =====
+For this example to work in Apache Karaf only the ''war'' feature is needed.
+  feature:install war
+{{tag>osgi devel java}}