BAEL-1267: programmatically create, configure and run a tomcat server

libraries/pom.xml

@@ -705,6 +705,38 @@
             <classifier>test</classifier>
             <scope>test</scope>
         </dependency>
+
+        <!-- tomcat -->
+        <dependency>
+            <groupId>org.apache.tomcat</groupId>
+            <artifactId>tomcat-catalina</artifactId>
+            <version>${tomcat.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.tomcat.embed</groupId>
+            <artifactId>tomcat-embed-core</artifactId>
+            <version>${tomcat.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.tomcat.embed</groupId>
+            <artifactId>tomcat-embed-jasper</artifactId>
+            <version>${tomcat.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.tomcat</groupId>
+            <artifactId>tomcat-jasper</artifactId>
+            <version>${tomcat.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.tomcat</groupId>
+            <artifactId>tomcat-jasper-el</artifactId>
+            <version>${tomcat.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.tomcat</groupId>
+            <artifactId>tomcat-jsp-api</artifactId>
+            <version>${tomcat.version}</version>
+        </dependency>
     </dependencies>
     <repositories>
         <repository>
@@ -786,5 +818,6 @@
         <google-sheets.version>v4-rev493-1.21.0</google-sheets.version>
         <kafka.version>1.0.0</kafka.version>
         <docker.version>3.0.14</docker.version>
+        <tomcat.version>8.5.24</tomcat.version>
     </properties>
 </project>

libraries/src/main/java/com/baeldung/tomcat/MyFilter.java

@@ -0,0 +1,31 @@
+package com.baeldung.tomcat;
+
+import javax.servlet.*;
+import javax.servlet.annotation.WebFilter;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+/**
+ * Created by adi on 1/14/18.
+ */
+@WebFilter(urlPatterns = "/my-servlet/*")
+public class MyFilter implements Filter {
+
+    @Override
+    public void init(FilterConfig filterConfig) {
+
+    }
+
+    @Override
+    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
+        System.out.println("Filtering stuff...");
+        HttpServletResponse httpResponse = (HttpServletResponse) response;
+        httpResponse.addHeader("myHeader", "myHeaderValue");
+        chain.doFilter(request, httpResponse);
+    }
+
+    @Override
+    public void destroy() {
+
+    }
+}

libraries/src/main/java/com/baeldung/tomcat/MyServlet.java

@@ -0,0 +1,25 @@
+package com.baeldung.tomcat;
+
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+/**
+ * Created by adi on 1/10/18.
+ */
+@WebServlet(
+  name = "com.baeldung.tomcat.programmatic.MyServlet",
+  urlPatterns = {"/my-servlet"}
+)
+public class MyServlet extends HttpServlet {
+
+    @Override
+    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
+        resp.setStatus(HttpServletResponse.SC_OK);
+        resp.getWriter().write("test");
+        resp.getWriter().flush();
+        resp.getWriter().close();
+    }
+}

libraries/src/main/java/com/baeldung/tomcat/ProgrammaticTomcat.java

@@ -0,0 +1,63 @@
+package com.baeldung.tomcat;
+
+import org.apache.catalina.Context;
+import org.apache.catalina.LifecycleException;
+import org.apache.catalina.startup.Tomcat;
+import org.apache.tomcat.util.descriptor.web.FilterDef;
+import org.apache.tomcat.util.descriptor.web.FilterMap;
+
+import java.io.File;
+
+/**
+ * Created by adi on 1/10/18.
+ */
+public class ProgrammaticTomcat {
+
+    private Tomcat tomcat = null;
+
+    //uncomment for live test
+    //    public static void main(String[] args) throws LifecycleException, ServletException, URISyntaxException, IOException {
+    //        startTomcat();
+    //    }
+
+    public void startTomcat() throws LifecycleException {
+        tomcat = new Tomcat();
+        tomcat.setPort(8080);
+        tomcat.setHostname("localhost");
+        String appBase = ".";
+        tomcat
+          .getHost()
+          .setAppBase(appBase);
+
+        File docBase = new File(System.getProperty("java.io.tmpdir"));
+        Context context = tomcat.addContext("", docBase.getAbsolutePath());
+
+        //add a servlet
+        Class servletClass = MyServlet.class;
+        Tomcat.addServlet(context, servletClass.getSimpleName(), servletClass.getName());
+        context.addServletMappingDecoded("/my-servlet/*", servletClass.getSimpleName());
+
+        //add a filter and filterMapping
+        Class filterClass = MyFilter.class;
+        FilterDef myFilterDef = new FilterDef();
+        myFilterDef.setFilterClass(filterClass.getName());
+        myFilterDef.setFilterName(filterClass.getSimpleName());
+        context.addFilterDef(myFilterDef);
+
+        FilterMap myFilterMap = new FilterMap();
+        myFilterMap.setFilterName(filterClass.getSimpleName());
+        myFilterMap.addURLPattern("/my-servlet/*");
+        context.addFilterMap(myFilterMap);
+
+        tomcat.start();
+        //uncomment for live test
+        //        tomcat
+        //          .getServer()
+        //          .await();
+    }
+
+    public void stopTomcat() throws LifecycleException {
+        tomcat.stop();
+        tomcat.destroy();
+    }
+}

libraries/src/test/java/com/baeldung/tomcat/ProgrammaticTomcatTest.java

@@ -0,0 +1,62 @@
+package com.baeldung.tomcat;
+
+import org.apache.http.HttpEntity;
+import org.apache.http.HttpResponse;
+import org.apache.http.HttpStatus;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClientBuilder;
+import org.apache.http.util.EntityUtils;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.BlockJUnit4ClassRunner;
+
+
+import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+/**
+ * Created by adi on 1/14/18.
+ */
+@RunWith(BlockJUnit4ClassRunner.class)
+public class ProgrammaticTomcatTest {
+
+    private ProgrammaticTomcat tomcat = new ProgrammaticTomcat();
+
+    @Before
+    public void setUp() throws Exception {
+        tomcat.startTomcat();
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        tomcat.stopTomcat();
+    }
+
+    @Test
+    public void givenTomcatStarted_whenAccessServlet_responseIsTestAndResponseHeaderIsSet() throws Exception {
+        CloseableHttpClient httpClient = HttpClientBuilder
+          .create()
+          .build();
+        HttpGet getServlet = new HttpGet("http://localhost:8080/my-servlet");
+
+        HttpResponse response = httpClient.execute(getServlet);
+        assertEquals(HttpStatus.SC_OK, response
+          .getStatusLine()
+          .getStatusCode());
+
+        String myHeaderValue = response
+          .getFirstHeader("myHeader")
+          .getValue();
+        assertEquals("myHeaderValue", myHeaderValue);
+
+        HttpEntity responseEntity = response.getEntity();
+        assertNotNull(responseEntity);
+
+        String responseString = EntityUtils.toString(responseEntity, "UTF-8");
+        assertEquals("test", responseString);
+    }
+
+}