From 65c2a2c859f8117179d4a66f098e3e8a7f72f3fe Mon Sep 17 00:00:00 2001
From: Stephan Richter <s.richter@srsoftware.de>
Date: Tue, 21 May 2024 01:48:02 +0200
Subject: [PATCH] started to implement HttpServlet

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>
---
 config/formatting.xml                         |  4 +-
 de.srsoftware.oidc.api/User.java              |  4 ++
 .../java/de/srsoftware/oidc/api/User.java     |  5 +++
 de.srsoftware.oidc.light/build.gradle         |  4 ++
 .../main/java/de/srsoftware/LightOICD.java    | 34 ++++++++++++++++-
 .../main/java/de/srsoftware/Templates.java    | 38 +++++++++++++++++++
 .../src/main/resources/templates/index.st     |  5 +++
 7 files changed, 90 insertions(+), 4 deletions(-)
 create mode 100644 de.srsoftware.oidc.api/User.java
 create mode 100644 de.srsoftware.oidc.api/src/main/java/de/srsoftware/oidc/api/User.java
 create mode 100644 de.srsoftware.oidc.light/src/main/java/de/srsoftware/Templates.java
 create mode 100644 de.srsoftware.oidc.light/src/main/resources/templates/index.st

diff --git a/config/formatting.xml b/config/formatting.xml
index 036621c..cdffb90 100644
--- a/config/formatting.xml
+++ b/config/formatting.xml
@@ -311,13 +311,13 @@
         <setting id="org.eclipse.jdt.core.formatter.join_wrapped_lines" value="true"/>
         <setting id="org.eclipse.jdt.core.formatter.keep_else_statement_on_same_line" value="false"/>
         <setting id="org.eclipse.jdt.core.formatter.keep_empty_array_initializer_on_one_line" value="false"/>
-        <setting id="org.eclipse.jdt.core.formatter.keep_imple_if_on_one_line" value="false"/>
+        <setting id="org.eclipse.jdt.core.formatter.keep_imple_if_on_one_line" value="true"/>
         <setting id="org.eclipse.jdt.core.formatter.keep_then_statement_on_same_line" value="false"/>
         <setting id="org.eclipse.jdt.core.formatter.lineSplit" value="999"/>
         <setting id="org.eclipse.jdt.core.formatter.never_indent_block_comments_on_first_column" value="false"/>
         <setting id="org.eclipse.jdt.core.formatter.never_indent_line_comments_on_first_column" value="false"/>
         <setting id="org.eclipse.jdt.core.formatter.number_of_blank_lines_at_beginning_of_method_body" value="0"/>
-        <setting id="org.eclipse.jdt.core.formatter.number_of_empty_lines_to_preserve" value="3"/>
+        <setting id="org.eclipse.jdt.core.formatter.number_of_empty_lines_to_preserve" value="1"/>
         <setting id="org.eclipse.jdt.core.formatter.put_empty_statement_on_new_line" value="false"/>
         <setting id="org.eclipse.jdt.core.formatter.tabulation.char" value="tab"/>
         <setting id="org.eclipse.jdt.core.formatter.tabulation.size" value="1"/>
diff --git a/de.srsoftware.oidc.api/User.java b/de.srsoftware.oidc.api/User.java
new file mode 100644
index 0000000..a567297
--- /dev/null
+++ b/de.srsoftware.oidc.api/User.java
@@ -0,0 +1,4 @@
+package de.srsoftware.oidc.api;
+
+public class User {
+}
diff --git a/de.srsoftware.oidc.api/src/main/java/de/srsoftware/oidc/api/User.java b/de.srsoftware.oidc.api/src/main/java/de/srsoftware/oidc/api/User.java
new file mode 100644
index 0000000..d188b46
--- /dev/null
+++ b/de.srsoftware.oidc.api/src/main/java/de/srsoftware/oidc/api/User.java
@@ -0,0 +1,5 @@
+/* © SRSoftware 2024 */
+package de.srsoftware.oidc.api;
+
+public class User {
+}
diff --git a/de.srsoftware.oidc.light/build.gradle b/de.srsoftware.oidc.light/build.gradle
index 5356f91..87d2639 100644
--- a/de.srsoftware.oidc.light/build.gradle
+++ b/de.srsoftware.oidc.light/build.gradle
@@ -16,6 +16,9 @@ dependencies {
     implementation 'org.slf4j:slf4j-api:2.0.13'
     testImplementation platform('org.junit:junit-bom:5.10.0')
     testImplementation 'org.junit.jupiter:junit-jupiter'
+    implementation 'ch.qos.logback:logback-classic:1.5.6'
+    implementation project(':de.srsoftware.oidc.api')
+    implementation('org.antlr:ST4:4.3.3')
 }
 
 test {
@@ -24,6 +27,7 @@ test {
 
 war {
     archiveFileName = 'oidc.war'
+    webAppDirName = 'src/main/resources'
 }
 
 
diff --git a/de.srsoftware.oidc.light/src/main/java/de/srsoftware/LightOICD.java b/de.srsoftware.oidc.light/src/main/java/de/srsoftware/LightOICD.java
index a930fba..d558ca1 100644
--- a/de.srsoftware.oidc.light/src/main/java/de/srsoftware/LightOICD.java
+++ b/de.srsoftware.oidc.light/src/main/java/de/srsoftware/LightOICD.java
@@ -1,9 +1,11 @@
 /* © SRSoftware 2024 */
 package de.srsoftware;
 
+import de.srsoftware.oidc.api.User;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.util.Arrays;
+import java.util.List;
 import javax.servlet.ServletException;
 import javax.servlet.annotation.WebServlet;
 import javax.servlet.http.HttpServlet;
@@ -11,24 +13,52 @@ import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.stringtemplate.v4.ST;
 
 @WebServlet(urlPatterns = "/")
 public class LightOICD extends HttpServlet {
-
 	private static final Logger LOG = LoggerFactory.getLogger(LightOICD.class);
+	private static final Templates templates;
+	static {
+		try {
+			templates = Templates.singleton();
+		} catch (IOException e) {
+			throw new RuntimeException(e);
+		}
+	}
 
 	@Override
 	public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
 		var path = Arrays.stream(req.getRequestURI().split("/")).skip(1).toList();
+		User user = null;
+		if (path.isEmpty()) {
+			landingPage(req, resp, user);
+			return;
+		}
+		switch (path.remove(0)) {
+			default:
+				helloWorld(req, resp, path);
+		}
+	}
+
+	private void helloWorld(HttpServletRequest req, HttpServletResponse resp, List<String> path) throws IOException {
+		LOG.debug("helloWorld(…), path = {}", path);
 		resp.setContentType("text/html");
 		PrintWriter out = resp.getWriter();
 		out.println("<html><head><title>Hello World Servlet</title></head>");
 		out.println("<body>");
 		out.println("<h1>Hello Guys!</h1>");
 		out.println("<ul>");
-		path.forEach(part -> out.println("<li>"+part+"</li>"));
+		path.forEach(part -> out.println("<li>" + part + "</li>"));
 		out.println("</ul>");
 		out.println("</body></html>");
 		out.close();
 	}
+
+	private void landingPage(HttpServletRequest req, HttpServletResponse resp, User user) throws IOException {
+		LOG.debug("landingPage(…)");
+		ST st = templates.getInstanceOf("index");
+		resp.setContentType("text/html");
+		resp.getWriter().println(st.render());
+	}
 }
diff --git a/de.srsoftware.oidc.light/src/main/java/de/srsoftware/Templates.java b/de.srsoftware.oidc.light/src/main/java/de/srsoftware/Templates.java
new file mode 100644
index 0000000..856eed6
--- /dev/null
+++ b/de.srsoftware.oidc.light/src/main/java/de/srsoftware/Templates.java
@@ -0,0 +1,38 @@
+/* © SRSoftware 2024 */
+package de.srsoftware;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.Optional;
+import org.stringtemplate.v4.*;
+
+public class Templates extends STRawGroupDir {
+	private static Templates singleton = null;
+
+	Templates() {
+		super(templateDir(), '«', '»');
+	}
+
+	private static String templateDir() {
+		return templateDir(new File(System.getProperty("user.dir"))).get().getAbsolutePath();
+	}
+
+	private static Optional<File> templateDir(File dir) {
+		if (dir.isDirectory()) {
+			var children = dir.listFiles();
+			for (File child : children) {
+				if (child.isDirectory()) {
+					if (child.getName().equals("templates")) return Optional.of(child);
+					var inner = templateDir(child);
+					if (inner.isPresent()) return inner;
+				}
+			}
+		}
+		return Optional.empty();
+	}
+
+	public static Templates singleton() throws IOException {
+		if (singleton == null) singleton = new Templates();
+		return singleton;
+	}
+}
diff --git a/de.srsoftware.oidc.light/src/main/resources/templates/index.st b/de.srsoftware.oidc.light/src/main/resources/templates/index.st
new file mode 100644
index 0000000..6e600a8
--- /dev/null
+++ b/de.srsoftware.oidc.light/src/main/resources/templates/index.st
@@ -0,0 +1,5 @@
+<html>
+<body>
+Dies ist die Index-Seite
+</body>
+</html>
\ No newline at end of file