got rid of stringtemplates in favor of lightweight solution

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

de.srsoftware.oidc.light/build.gradle

@@ -13,12 +13,11 @@ repositories {
 dependencies {
     compileOnly 'javax.servlet:javax.servlet-api:4.0.1'
     implementation 'ch.qos.logback:logback-core:1.5.6'
+    implementation 'ch.qos.logback:logback-classic:1.5.6'
     implementation 'org.slf4j:slf4j-api:2.0.13'
+    implementation project(':de.srsoftware.oidc.api')
     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 {

de.srsoftware.oidc.light/src/main/java/de/srsoftware/LightOICD.java

@@ -6,6 +6,7 @@ import java.io.IOException;
 import java.io.PrintWriter;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Map;
 import javax.servlet.ServletException;
 import javax.servlet.annotation.WebServlet;
 import javax.servlet.http.HttpServlet;
@@ -13,7 +14,6 @@ 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 {
@@ -57,8 +57,8 @@ public class LightOICD extends HttpServlet {
 
 	private void landingPage(HttpServletRequest req, HttpServletResponse resp, User user) throws IOException {
 		LOG.debug("landingPage(…)");
-		ST st = templates.getInstanceOf("index");
+		var index = templates.get("index.html", Map.of("user","Darling"));
 		resp.setContentType("text/html");
-		resp.getWriter().println(st.render());
+		resp.getWriter().println(index.get());
 	}
 }

de.srsoftware.oidc.light/src/main/java/de/srsoftware/Templates.java

@@ -2,28 +2,33 @@
 package de.srsoftware;
 
 import java.io.File;
+import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Map;
 import java.util.Optional;
-import org.stringtemplate.v4.*;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
-public class Templates extends STRawGroupDir {
+public class Templates {
 	private static Templates singleton = null;
+	private static Logger LOG = LoggerFactory.getLogger(Templates.class);
+	private Path dir = searchTemplates();
 
-	Templates() {
-		super(templateDir(), '«', '»');
+	public Templates() throws FileNotFoundException {}
+
+	private static Path searchTemplates() throws FileNotFoundException {
+		return searchTemplates(new File(System.getProperty("user.dir"))).map(File::toPath).orElseThrow(() -> new FileNotFoundException("Missing template directory"));
 	}
 
-	private static String templateDir() {
-		return templateDir(new File(System.getProperty("user.dir"))).get().getAbsolutePath();
-	}
-
-	private static Optional<File> templateDir(File dir) {
+	private static Optional<File> searchTemplates(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);
+					var inner = searchTemplates(child);
 					if (inner.isPresent()) return inner;
 				}
 			}
@@ -35,4 +40,21 @@ public class Templates extends STRawGroupDir {
 		if (singleton == null) singleton = new Templates();
 		return singleton;
 	}
+
+	public Optional<String> get(String path, Map<String, String> replacements) {
+		var file = dir.resolve(path);
+		try {
+			return Optional.of(Files.readString(file)).map(s -> replaceKeys(s,replacements));
+			// TODO: replacements
+		} catch (IOException e) {
+			LOG.warn("Failed to read {}", path, e);
+			return Optional.empty();
+		}
+
+	}
+
+	private String replaceKeys(String text, Map<String, String> replacements) {
+		for (Map.Entry<String, String> replacement : replacements.entrySet()) text = text.replace("{"+replacement.getKey()+"}",replacement.getValue());
+		return text;
+	}
 }

de.srsoftware.oidc.light/src/main/resources/templates/index.html

@@ -0,0 +1,5 @@
+<html>
+<body>
+Hallo {user}, dies ist die Index-Seite!
+</body>
+</html>

de.srsoftware.oidc.light/src/main/resources/templates/index.st

@@ -1,5 +0,0 @@
-<html>
-<body>
-Dies ist die Index-Seite
-</body>
-</html>