From 445fee41b3925c4bd8272068e432263ec06d378c Mon Sep 17 00:00:00 2001 From: Joel Juarez Date: Sun, 30 Dec 2018 23:38:13 +0100 Subject: [PATCH] java web application without web.xml - servlets 3.0 --- javax-servlets-3/.gitignore | 6 +++ javax-servlets-3/Dockerfile | 2 + javax-servlets-3/README.md | 9 ++++ javax-servlets-3/pom.xml | 51 +++++++++++++++++++ .../servlets3/spring/AppInitializer.java | 27 ++++++++++ .../servlets3/spring/config/AppConfig.java | 11 ++++ .../controllers/UppercaseController.java | 17 +++++++ .../web/filters/EmptyParamFilter.java | 44 ++++++++++++++++ .../servlets3/web/listeners/AppListener.java | 21 ++++++++ .../web/listeners/RequestListener.java | 24 +++++++++ .../web/servlets/CounterServlet.java | 27 ++++++++++ .../web/servlets/UppercaseServlet.java | 26 ++++++++++ 12 files changed, 265 insertions(+) create mode 100644 javax-servlets-3/.gitignore create mode 100644 javax-servlets-3/Dockerfile create mode 100644 javax-servlets-3/README.md create mode 100644 javax-servlets-3/pom.xml create mode 100644 javax-servlets-3/src/main/java/com/baeldung/servlets3/spring/AppInitializer.java create mode 100644 javax-servlets-3/src/main/java/com/baeldung/servlets3/spring/config/AppConfig.java create mode 100644 javax-servlets-3/src/main/java/com/baeldung/servlets3/spring/controllers/UppercaseController.java create mode 100644 javax-servlets-3/src/main/java/com/baeldung/servlets3/web/filters/EmptyParamFilter.java create mode 100644 javax-servlets-3/src/main/java/com/baeldung/servlets3/web/listeners/AppListener.java create mode 100644 javax-servlets-3/src/main/java/com/baeldung/servlets3/web/listeners/RequestListener.java create mode 100644 javax-servlets-3/src/main/java/com/baeldung/servlets3/web/servlets/CounterServlet.java create mode 100644 javax-servlets-3/src/main/java/com/baeldung/servlets3/web/servlets/UppercaseServlet.java diff --git a/javax-servlets-3/.gitignore b/javax-servlets-3/.gitignore new file mode 100644 index 0000000000..dfbd063287 --- /dev/null +++ b/javax-servlets-3/.gitignore @@ -0,0 +1,6 @@ +# Created by .ignore support plugin (hsz.mobi) +.idea +classes +target +*.iml +out \ No newline at end of file diff --git a/javax-servlets-3/Dockerfile b/javax-servlets-3/Dockerfile new file mode 100644 index 0000000000..97cc1897dd --- /dev/null +++ b/javax-servlets-3/Dockerfile @@ -0,0 +1,2 @@ +FROM tomcat +ADD ./target/javax-servlets-3-1.0-SNAPSHOT.war /usr/local/tomcat/webapps/ \ No newline at end of file diff --git a/javax-servlets-3/README.md b/javax-servlets-3/README.md new file mode 100644 index 0000000000..ff310b5928 --- /dev/null +++ b/javax-servlets-3/README.md @@ -0,0 +1,9 @@ +## Build with maven: +mvn package + +## Run with Tomcat on Docker container: +docker build --tag my-tomcat . +docker run -it --rm -p 8080:8080 my-tomcat + +### Relevant Articles: +- [Java Web Application Without Web.xml] diff --git a/javax-servlets-3/pom.xml b/javax-servlets-3/pom.xml new file mode 100644 index 0000000000..2b4fc37fc4 --- /dev/null +++ b/javax-servlets-3/pom.xml @@ -0,0 +1,51 @@ + + + 4.0.0 + javax-servlets-3 + 1.0-SNAPSHOT + javax-servlets-3 + war + + + com.baeldung + parent-modules + 1.0.0-SNAPSHOT + + + + + + javax.servlet + javax.servlet-api + ${javax.servlet-api.version} + + + org.springframework + spring-webmvc + ${spring.version} + + + + 4.0.1 + 5.1.3.RELEASE + + + + + org.apache.maven.plugins + maven-war-plugin + 3.1.0 + + + default-war + prepare-package + + false + + + + + + + diff --git a/javax-servlets-3/src/main/java/com/baeldung/servlets3/spring/AppInitializer.java b/javax-servlets-3/src/main/java/com/baeldung/servlets3/spring/AppInitializer.java new file mode 100644 index 0000000000..837d439cf4 --- /dev/null +++ b/javax-servlets-3/src/main/java/com/baeldung/servlets3/spring/AppInitializer.java @@ -0,0 +1,27 @@ +package com.baeldung.servlets3.spring; + +import com.baeldung.servlets3.spring.config.AppConfig; +import org.springframework.web.WebApplicationInitializer; +import org.springframework.web.context.ContextLoaderListener; +import org.springframework.web.context.support.AnnotationConfigWebApplicationContext; +import org.springframework.web.servlet.DispatcherServlet; + +import javax.servlet.ServletContext; +import javax.servlet.ServletException; +import javax.servlet.ServletRegistration; + +public class AppInitializer implements WebApplicationInitializer { + @Override + public void onStartup(ServletContext servletContext) throws ServletException { + AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext(); + context.register(AppConfig.class); + + servletContext.addListener(new ContextLoaderListener(context)); + + ServletRegistration.Dynamic dispatcher = servletContext.addServlet("spring-dispatcher", + new DispatcherServlet(context)); + + dispatcher.setLoadOnStartup(1); + dispatcher.addMapping("/spring/*"); + } +} diff --git a/javax-servlets-3/src/main/java/com/baeldung/servlets3/spring/config/AppConfig.java b/javax-servlets-3/src/main/java/com/baeldung/servlets3/spring/config/AppConfig.java new file mode 100644 index 0000000000..0088bad770 --- /dev/null +++ b/javax-servlets-3/src/main/java/com/baeldung/servlets3/spring/config/AppConfig.java @@ -0,0 +1,11 @@ +package com.baeldung.servlets3.spring.config; + +import org.springframework.context.annotation.ComponentScan; +import org.springframework.context.annotation.Configuration; +import org.springframework.web.servlet.config.annotation.EnableWebMvc; + +@Configuration +@EnableWebMvc +@ComponentScan("com.baeldung.servlets3.spring") +public class AppConfig { +} diff --git a/javax-servlets-3/src/main/java/com/baeldung/servlets3/spring/controllers/UppercaseController.java b/javax-servlets-3/src/main/java/com/baeldung/servlets3/spring/controllers/UppercaseController.java new file mode 100644 index 0000000000..74585e6b5e --- /dev/null +++ b/javax-servlets-3/src/main/java/com/baeldung/servlets3/spring/controllers/UppercaseController.java @@ -0,0 +1,17 @@ +package com.baeldung.servlets3.spring.controllers; + +import org.springframework.web.bind.annotation.GetMapping; +import org.springframework.web.bind.annotation.RequestMapping; +import org.springframework.web.bind.annotation.RequestParam; +import org.springframework.web.bind.annotation.RestController; + +@RestController +@RequestMapping("/uppercase") +public class UppercaseController { + + @GetMapping(produces = "text/html") + public String getUppercase(@RequestParam(required = false)String param) { + String response = param != null ? param.toUpperCase() : "Missing param"; + return "From Spring: " + response; + } +} diff --git a/javax-servlets-3/src/main/java/com/baeldung/servlets3/web/filters/EmptyParamFilter.java b/javax-servlets-3/src/main/java/com/baeldung/servlets3/web/filters/EmptyParamFilter.java new file mode 100644 index 0000000000..2c9f603d2c --- /dev/null +++ b/javax-servlets-3/src/main/java/com/baeldung/servlets3/web/filters/EmptyParamFilter.java @@ -0,0 +1,44 @@ +package com.baeldung.servlets3.web.filters; + +import javax.servlet.Filter; +import javax.servlet.FilterChain; +import javax.servlet.FilterConfig; +import javax.servlet.ServletException; +import javax.servlet.ServletRequest; +import javax.servlet.ServletResponse; +import javax.servlet.annotation.WebFilter; +import java.io.IOException; +import java.io.PrintWriter; + +@WebFilter(servletNames = { "uppercaseServlet" }, filterName = "emptyParamFilter") +public class EmptyParamFilter implements Filter { + + @Override + public void init(FilterConfig filterConfig) throws ServletException { + } + + @Override + public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, + FilterChain filterChain) throws IOException, ServletException { + String inputString = servletRequest.getParameter("input"); + + if (inputString == null || inputString.isEmpty()) { + response(servletResponse); + } else { + filterChain.doFilter(servletRequest, servletResponse); + } + } + + private void response(ServletResponse response) throws IOException { + response.setContentType("text/html"); + + PrintWriter out = response.getWriter(); + + out.println("Missing input parameter"); + } + + @Override + public void destroy() { + } + +} diff --git a/javax-servlets-3/src/main/java/com/baeldung/servlets3/web/listeners/AppListener.java b/javax-servlets-3/src/main/java/com/baeldung/servlets3/web/listeners/AppListener.java new file mode 100644 index 0000000000..d61af65c31 --- /dev/null +++ b/javax-servlets-3/src/main/java/com/baeldung/servlets3/web/listeners/AppListener.java @@ -0,0 +1,21 @@ +package com.baeldung.servlets3.web.listeners; + +import javax.servlet.ServletContext; +import javax.servlet.ServletContextEvent; +import javax.servlet.ServletContextListener; +import javax.servlet.annotation.WebListener; + +@WebListener +public class AppListener implements ServletContextListener { + + @Override + public void contextInitialized(ServletContextEvent event) { + ServletContext context = event.getServletContext(); + context.setAttribute("counter", 0); + } + + @Override + public void contextDestroyed(ServletContextEvent event) { + + } +} diff --git a/javax-servlets-3/src/main/java/com/baeldung/servlets3/web/listeners/RequestListener.java b/javax-servlets-3/src/main/java/com/baeldung/servlets3/web/listeners/RequestListener.java new file mode 100644 index 0000000000..aeebf482fb --- /dev/null +++ b/javax-servlets-3/src/main/java/com/baeldung/servlets3/web/listeners/RequestListener.java @@ -0,0 +1,24 @@ +package com.baeldung.servlets3.web.listeners; + +import javax.servlet.ServletContext; +import javax.servlet.ServletRequestEvent; +import javax.servlet.ServletRequestListener; +import javax.servlet.annotation.WebListener; +import javax.servlet.http.HttpServletRequest; + +@WebListener +public class RequestListener implements ServletRequestListener { + + @Override + public void requestInitialized(ServletRequestEvent event) { + } + + @Override + public void requestDestroyed(ServletRequestEvent event) { + HttpServletRequest request = (HttpServletRequest)event.getServletRequest(); + if (!request.getServletPath().equals("/counter")) { + ServletContext context = event.getServletContext(); + context.setAttribute("counter", (int)context.getAttribute("counter") + 1); + } + } +} diff --git a/javax-servlets-3/src/main/java/com/baeldung/servlets3/web/servlets/CounterServlet.java b/javax-servlets-3/src/main/java/com/baeldung/servlets3/web/servlets/CounterServlet.java new file mode 100644 index 0000000000..4bb92bbf77 --- /dev/null +++ b/javax-servlets-3/src/main/java/com/baeldung/servlets3/web/servlets/CounterServlet.java @@ -0,0 +1,27 @@ +package com.baeldung.servlets3.web.servlets; + +import javax.servlet.annotation.WebServlet; +import javax.servlet.http.HttpServlet; +import javax.servlet.http.HttpServletRequest; +import javax.servlet.http.HttpServletResponse; +import java.io.IOException; +import java.io.PrintWriter; + +@WebServlet(urlPatterns = "/counter", name = "counterServlet") +public class CounterServlet extends HttpServlet { + + public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException { + doGet(request, response); + } + + public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException { + response.setContentType("text/html"); + + PrintWriter out = response.getWriter(); + + int count = (int)request.getServletContext().getAttribute("counter"); + + out.println("Request counter: " + count); + } + +} diff --git a/javax-servlets-3/src/main/java/com/baeldung/servlets3/web/servlets/UppercaseServlet.java b/javax-servlets-3/src/main/java/com/baeldung/servlets3/web/servlets/UppercaseServlet.java new file mode 100644 index 0000000000..9b948cd994 --- /dev/null +++ b/javax-servlets-3/src/main/java/com/baeldung/servlets3/web/servlets/UppercaseServlet.java @@ -0,0 +1,26 @@ +package com.baeldung.servlets3.web.servlets; + +import javax.servlet.annotation.WebServlet; +import javax.servlet.http.HttpServlet; +import javax.servlet.http.HttpServletRequest; +import javax.servlet.http.HttpServletResponse; +import java.io.IOException; +import java.io.PrintWriter; + +@WebServlet(urlPatterns = "/uppercase", name = "uppercaseServlet") +public class UppercaseServlet extends HttpServlet { + + public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException { + doGet(request, response); + } + + public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException { + String inputString = request.getParameter("input").toUpperCase(); + + response.setContentType("text/html"); + + PrintWriter out = response.getWriter(); + + out.println(inputString); + } +}