changed the way anonymization works

Dockerfile

@@ -7,7 +7,8 @@ FROM mvn as builder
 
 WORKDIR /build
 ADD . .
-RUN mvn package
+ARG KC_HOSTNAME
+RUN mvn package -DKC_HOSTNAME=${KC_HOSTNAME}
 
 
 FROM eclipse-temurin:21-jdk-alpine

pom.xml

@@ -37,7 +37,24 @@
             <artifactId>postgresql</artifactId>
             <version>42.7.3</version>
         </dependency>
-
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-oauth2-resource-server</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-security</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <optional>true</optional>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.security</groupId>
+            <artifactId>spring-security-test</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>

src/main/java/de/anxietyprime/swajodel/JodelPost.java

@@ -1,14 +1,22 @@
 package de.anxietyprime.swajodel;
 
-import java.util.Date;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.Vector;
 
+import java.sql.*;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
 public class JodelPost {
     // id of the post
     public Long id;
+    // Parent id
+    public Optional<Long> parent = Optional.empty();
     // id of the author in db
-    private Long authorID;
+    private final Long authorID;
     // anonymized authorID
     public Long anonymousID;
     // title of the post
@@ -16,32 +24,27 @@ public class JodelPost {
     // content of the post
     public String content;
     // date of the post
-    public Date date;
+    public Timestamp date;
     // location if the post
     public Location location;
-    // list of all comments for the post
-    public Vector<JodelPost> comments = new Vector<>();
     // the own reaction (null = none, true = positive, false = negative)
     public Optional<Boolean> reaction;
     // all other reactions
-    public Reaction reactions;
+    public Reactions reactions;
+    // list of all comments for the post
+    public Vector<JodelPost> comments = new Vector<>();
 
     // anonymize function to recursively anonymize the posts
-    public void anonymize(Optional<Vector<Long>> idCache) {
-        // check if this is the first post in this process
-        if (idCache.isEmpty()) {
-            // create a new Vector as cache
-            idCache = Optional.of(new Vector());
-        }
+    public void anonymize(Vector<Long> idCache) {
 
         // get the anonymized id as index in cached authorIDs
-        int i = idCache.get().indexOf(this.authorID);
+        int i = idCache.indexOf(this.authorID);
         // if the index is -1 the authorID has not been cached jet
         if (i == -1) {
             // set the current anonymousID as length of the cache (== next index)
-            this.anonymousID = (long) idCache.get().size();
+            this.anonymousID = (long) idCache.size();
             // push the current authorID to to cache
-            idCache.get().add(this.authorID);
+            idCache.add(this.authorID);
         }
         // the authorID has been anonymized once before, so we can get it from cache
         else this.anonymousID = (long) i;
@@ -53,9 +56,10 @@ public class JodelPost {
     }
 
     // add a comment if it is really a comment
-    public boolean addComment(JodelPost post, long parent) {
+    public boolean addComment(JodelPost post) {
+        if (post.parent.isEmpty()) return true;
         // check if the post is a direct comment
-        if (parent == this.id) {
+        if (Objects.equals(post.parent.get(), this.id)) {
             // add the comment
             this.comments.add(post);
             // return success
@@ -64,14 +68,52 @@ public class JodelPost {
         // recursively repeat this for all comments
         for (JodelPost comment : this.comments) {
             // return success if the post is a comment on a child
-            if (comment.addComment(post, parent)) return true;
+            if (comment.addComment(post)) return true;
         }
         // return no success
         return false;
     }
 
-    // constructor with private authorID
-    public JodelPost(long authorID) {
-        this.authorID = authorID;
+    // constructor from
+    public JodelPost(ResultSet rs) throws SQLException {
+        // add all other information to the post
+        this.authorID = rs.getLong("author");
+        this.id = rs.getLong("id");
+        this.title = rs.getString("title");
+        this.content = rs.getString("content");
+        this.date = rs.getTimestamp("postdate");
+        this.location = new Location(rs.getFloat("longitude"), rs.getFloat("latitude"));
+        this.reaction = rs.getString("reaction") == null ? Optional.empty() : Optional.of(rs.getBoolean("reaction"));
+        this.reactions = new Reactions(rs.getLong("positive"), rs.getLong("negative"));
+        this.parent = Optional.of(rs.getLong("parent"));
+    }
+
+    // constructor from authorID for tests
+    public JodelPost(int authorID) {
+        this.authorID = (long) authorID;
+    }
+
+    @JsonCreator
+    public JodelPost(@JsonProperty("title") String title,
+		     @JsonProperty("content") String content,
+		     @JsonProperty("date") Timestamp date,
+		     @JsonProperty("location") Location location,
+             @JsonProperty("parent") Optional<Long> parent) {
+	this.authorID = User.getID(); // TODO: getter from Keycloak
+	this.title = title;
+	this.content = content;
+	this.date = date;
+	this.location = location;
+    this.parent = parent;
+    }
+
+    @JsonIgnore
+    public long getAuthorID() {
+        return authorID;
+    }
+
+    @JsonIgnore
+    public boolean isComment() {
+        return parent.filter(aLong -> !Objects.equals(id, aLong)).isPresent();
     }
 }

src/main/java/de/anxietyprime/swajodel/Location.java

@@ -1,10 +1,14 @@
 package de.anxietyprime.swajodel;
 
-public class Location {
-    public float longitude;
-    public float latitude;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
 
-    public Location(float longitude, float latitude) {
+public class Location {
+    public float latitude;
+    public float longitude;
+
+    @JsonCreator
+    public Location(@JsonProperty("longitude") float longitude, @JsonProperty("latitude") float latitude ) {
         this.longitude = longitude;
         this.latitude = latitude;
     }

src/main/java/de/anxietyprime/swajodel/Reaction.java

@@ -1,6 +0,0 @@
-package de.anxietyprime.swajodel;
-
-public class Reaction {
-    private long positive;
-    private long negative;
-}

src/main/java/de/anxietyprime/swajodel/Reactions.java

@@ -0,0 +1,11 @@
+package de.anxietyprime.swajodel;
+
+public class Reactions {
+    public long positive;
+    public long negative;
+
+    Reactions(long positive, long negative) {
+        this.positive = positive;
+        this.negative = negative;
+    }
+}

src/main/java/de/anxietyprime/swajodel/Routes.java

@@ -1,8 +1,8 @@
 package de.anxietyprime.swajodel;
 
-import org.springframework.web.bind.annotation.GetMapping;
-import org.springframework.web.bind.annotation.PathVariable;
-import org.springframework.web.bind.annotation.RestController;
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.*;
+import org.springframework.web.server.ResponseStatusException;
 
 import java.sql.*;
 
@@ -10,16 +10,20 @@ import java.util.Optional;
 import java.util.Vector;
 
 @RestController
+@CrossOrigin(origins = "*", allowedHeaders = "*", maxAge = 3600)
 public class Routes {
 
-    @GetMapping("/posts/{longitude}/{latitude}")
-    public Vector<JodelPost> getPosts(@PathVariable("longitude") float longitude, @PathVariable("latitude") float latitude) {
+    @GetMapping("/posts/{latitude}/{longitude}")
+    public Vector<JodelPost> getPostsByLocation(@PathVariable("longitude") float longitude, @PathVariable("latitude") float latitude) {
         // list of all posts (not comments) in range
         Vector<JodelPost> posts = new Vector<>();
 
+        // get UserID
+        Long userID = User.getID();
+
         // DB connection and statement
-        Connection c = null;
-        PreparedStatement stmt = null;
+        Connection c;
+        PreparedStatement stmt;
 
         // try to get data from db
         try {
@@ -34,40 +38,49 @@ public class Routes {
             c.setAutoCommit(false);
 
             // create a new statement
-            stmt = c.prepareStatement("WITH RECURSIVE targets AS (\n" +
-                    "  SELECT\n" +
-                    "    id,\n" +
-                    "    id AS parent,\n" +
-                    "    author,\n" +
-                    "    title,\n" +
-                    "    content,\n" +
-                    "    postdate,\n" +
-                    "    postlocation[0] AS longitude,\n" +
-                    "    postlocation[1] AS latitude\n" +
-                    "  FROM\n" +
-                    "    posts\n" +
-                    "  WHERE\n" +
-                    "    deleted IS NULL\n" +
-                    "    AND sqrt(power(postlocation[0] - (?), 2) + power(postlocation[1] - (?), 2)) <= 10\n" +
-                    "    AND id NOT IN (SELECT child FROM comments)\n" +
-                    "  UNION\n" +
-                    "  SELECT\n" +
-                    "    com.child,\n" +
-                    "    com.parent,\n" +
-                    "    com.author,\n" +
-                    "    com.title,\n" +
-                    "    com.content,\n" +
-                    "    com.postdate,\n" +
-                    "    com.postlocation[0],\n" +
-                    "    com.postlocation[1]\n" +
-                    "  FROM\n" +
-                    "      (SELECT * FROM comments inner join posts ON comments.child = posts.id) com\n" +
-                    "          inner join targets ON targets.id = com.parent\n" +
-                    ")\n" +
-                    "SELECT * FROM targets;");
+            stmt = c.prepareStatement("""
+                    WITH RECURSIVE targets AS (
+                      SELECT
+                        posts.id,
+                        posts.id AS parent,
+                        posts.author,
+                        posts.title,
+                        posts.content,
+                        posts.postdate,
+                        posts.postlocation[0] AS latitude,
+                        posts.postlocation[1] AS longitude,
+                        (SELECT count(*) FROM reactions WHERE reactions.post = posts.id AND reactions.positive = TRUE) AS positive,
+                        (SELECT count(*) FROM reactions WHERE reactions.post = posts.id AND reactions.positive = FALSE) AS negative
+                      FROM
+                        posts
+                      WHERE
+                        deleted IS NULL
+                        AND earth_distance(
+                                        ll_to_earth(posts.postlocation[0], posts.postlocation[1]),
+                                        ll_to_earth((?), (?))
+                                      ) <= 10000
+                        AND posts.id NOT IN (SELECT child FROM comments)
+                      UNION
+                      SELECT
+                        com.child,
+                        com.parent,
+                        com.author,
+                        com.title,
+                        com.content,
+                        com.postdate,
+                        com.postlocation[0],
+                        com.postlocation[1],
+                        (SELECT count(*) FROM reactions WHERE reactions.post = com.child AND reactions.positive = TRUE) AS positive,
+                        (SELECT count(*) FROM reactions WHERE reactions.post = com.child AND reactions.positive = FALSE) AS negative
+                      FROM
+                          (SELECT * FROM comments inner join posts ON comments.child = posts.id) com
+                              inner join targets ON targets.id = com.parent
+                    )
+                    SELECT * FROM targets LEFT JOIN (SELECT post, positive as reaction FROM reactions WHERE userid = (?)) ON post = id;""");
 
-            stmt.setObject(1, longitude);
-            stmt.setObject(2, latitude);
+            stmt.setObject(1, latitude);
+            stmt.setObject(2, longitude);
+            stmt.setObject(3, userID);
 
             // query recursively for posts inside a 10km radius
             ResultSet rs = stmt.executeQuery();
@@ -75,20 +88,11 @@ public class Routes {
             // for all the posts found
             while ( rs.next() ) {
                 // create a post from the author id
-                JodelPost post = new JodelPost(rs.getLong("author"));
-                // add all other information to the post
-                post.id = rs.getLong("id");
-                post.title = rs.getString("title");
-                post.content = rs.getString("content");
-                post.date = rs.getDate("postdate");
-                post.location = new Location(rs.getLong("longitude"), rs.getLong("latitude"));
-
-                // get the posts parent
-                long parent = rs.getLong("parent");
+                JodelPost post = new JodelPost(rs);
 
                 // check if the parent is the own id
                 // if it is, it is a post
-                if (parent == post.id) {
+                if (!post.isComment()) {
                     // add the post to the posts
                     posts.add(post);
                 }
@@ -97,7 +101,7 @@ public class Routes {
                     // iterate over all posts
                     for (JodelPost p : posts) {
                         // try to add the post to a parent
-                        p.addComment(post, parent);
+                        p.addComment(post);
                     }
                 }
             }
@@ -111,13 +115,304 @@ public class Routes {
         // else log the error
         catch ( Exception e ) {
             System.err.println( e.getClass().getName()+": "+ e.getMessage() );
+            throw new ResponseStatusException(HttpStatus.SERVICE_UNAVAILABLE, "Database is offline");
         }
 
         // calculate anonymous IDs for the posts
+        Vector<Long> anonymousIDs = new Vector<Long>();
+        anonymousIDs.add(userID);
         posts.forEach(post -> {
-            post.anonymize(Optional.empty());
+            post.anonymize(anonymousIDs);
         });
+
         // return the posts
         return posts;
     }
+
+    @GetMapping("/post/{id}")
+    public JodelPost getPostByID(@PathVariable("id") long id) {
+        // list of all posts (not comments) in range
+        Optional<JodelPost> root_post = Optional.empty();
+
+        // get UserID
+        Long userID = User.getID();
+
+        // DB connection and statement
+        Connection c;
+        PreparedStatement stmt;
+
+        // try to get data from db
+        try {
+            // check for the driver
+            Class.forName("org.postgresql.Driver");
+            // get the connection with credentials from env variables
+            c = DriverManager
+                    .getConnection("jdbc:postgresql://"+
+                                    System.getenv("POSTGRES_IP")+"/"+System.getenv("POSTGRES_DB"),
+                            System.getenv("POSTGRES_USER"), System.getenv("POSTGRES_PASSWORD"));
+            // disable auto commits
+            c.setAutoCommit(false);
+
+            // create a new statement
+            stmt = c.prepareStatement("""
+                    WITH RECURSIVE targets AS (
+                      SELECT
+                        posts.id,
+                        posts.id AS parent,
+                        posts.author,
+                        posts.title,
+                        posts.content,
+                        posts.postdate,
+                        posts.postlocation[0] AS latitude,
+                        posts.postlocation[1] AS longitude,
+                        (SELECT count(*) FROM reactions WHERE reactions.post = posts.id AND reactions.positive = TRUE) AS positive,
+                        (SELECT count(*) FROM reactions WHERE reactions.post = posts.id AND reactions.positive = FALSE) AS negative
+                      FROM
+                        posts
+                      WHERE
+                        deleted IS NULL
+                        AND posts.id = (?)
+                        AND posts.id NOT IN (SELECT child FROM comments)
+                      UNION
+                      SELECT
+                        com.child,
+                        com.parent,
+                        com.author,
+                        com.title,
+                        com.content,
+                        com.postdate,
+                        com.postlocation[0],
+                        com.postlocation[1],
+                        (SELECT count(*) FROM reactions WHERE reactions.post = com.child AND reactions.positive = TRUE) AS positive,
+                        (SELECT count(*) FROM reactions WHERE reactions.post = com.child AND reactions.positive = FALSE) AS negative
+                      FROM
+                          (SELECT * FROM comments inner join posts ON comments.child = posts.id) com
+                              inner join targets ON targets.id = com.parent
+                    )
+                    SELECT * FROM targets LEFT JOIN (SELECT post, positive as reaction FROM reactions WHERE userid = (?)) ON post = id;""");
+
+            stmt.setObject(1, id);
+            stmt.setObject(2, userID);
+
+            // query recursively for posts inside a 10km radius
+            ResultSet rs = stmt.executeQuery();
+
+            // for all the posts found
+            while ( rs.next() ) {
+                // create a post from the author id
+                JodelPost post = new JodelPost(rs);
+
+                // get the posts parent
+                long parent = rs.getLong("parent");
+
+                // check if the parent is the own id
+                // if it is, it is a post
+                if (parent == post.id) {
+                    // add the post to the posts
+                    root_post = Optional.of(post);
+                }
+                // else it is a comment
+                else {
+                    // try to add the post to parent
+                    root_post.ifPresent(root -> root.addComment(post));
+                }
+            }
+
+            // close all connections to db
+            rs.close();
+            stmt.close();
+            c.close();
+        }
+
+        // else log the error
+        catch ( Exception e ) {
+            System.err.println( e.getClass().getName()+": "+ e.getMessage() );
+            throw new ResponseStatusException(HttpStatus.SERVICE_UNAVAILABLE, "Database is offline");
+        }
+
+        // calculate anonymous IDs for the post
+        Vector<Long> anonymousIDs = new Vector<Long>();
+        anonymousIDs.add(userID);
+        root_post.ifPresent(root -> root.anonymize(anonymousIDs));
+
+        // return the posts
+        if (root_post.isEmpty()) throw new ResponseStatusException(HttpStatus.NOT_FOUND, "No post found");
+        return root_post.get();
+    }
+
+    @PostMapping("/posts")
+    public JodelPost postPost(@RequestBody JodelPost post) {
+        // DB connection and statement
+        Connection c;
+        PreparedStatement stmt;
+
+        // try to get data from db
+        try {
+            // check for the driver
+            Class.forName("org.postgresql.Driver");
+            // get the connection with credentials from env variables
+            c = DriverManager
+                    .getConnection("jdbc:postgresql://"+
+                                    System.getenv("POSTGRES_IP")+"/"+System.getenv("POSTGRES_DB"),
+                            System.getenv("POSTGRES_USER"), System.getenv("POSTGRES_PASSWORD"));
+            // disable auto commits
+            c.setAutoCommit(false);
+
+            // create a new statement
+            stmt = c.prepareStatement("INSERT INTO Posts(author, title, content, postdate, postlocation) " +
+                    "VALUES (?, ?, ?, ?, Point(?, ?)) RETURNING id");
+
+            stmt.setObject(1, post.getAuthorID());
+            stmt.setObject(2, post.title);
+            stmt.setObject(3, post.content);
+            stmt.setObject(4, post.date);
+            stmt.setObject(5, post.location.latitude);
+            stmt.setObject(6, post.location.longitude);
+
+            // insert post and get its id
+            ResultSet rs = stmt.executeQuery();
+
+            // get the id of the new post
+            rs.next();
+            post.id = rs.getLong("id");
+
+            // check if there is a parent
+            if (post.parent.isPresent()) {
+                // create a new statement
+                stmt = c.prepareStatement("INSERT INTO comments(parent, child) VALUES (?, ?)");
+
+                // fill statement
+                stmt.setObject(1, post.parent.get());
+                stmt.setObject(2, post.id);
+
+                // execute statement
+                stmt.execute();
+            }
+
+            // commit the changes
+            c.commit();
+
+            // close all connections to db
+            stmt.close();
+            c.close();
+        }
+
+        // else log the error
+        catch ( Exception e ) {
+            System.err.println( e.getClass().getName()+": "+ e.getMessage() );
+            throw new ResponseStatusException(HttpStatus.SERVICE_UNAVAILABLE, "Database is offline");
+        }
+
+        // fill missing post values
+        if (post.parent.isEmpty()) post.parent = Optional.of(post.id);
+        post.reactions = new Reactions(0, 0);
+        post.reaction = Optional.empty();
+
+        // anonymize code
+        Vector<Long> anonymousIDs = new Vector<Long>();
+        anonymousIDs.add(0L);
+        post.anonymize(anonymousIDs);
+
+        return post;
+    }
+
+    @PatchMapping("/post/{id}")
+    public void reactToPost(@PathVariable long id, @RequestBody JodelPost post) {
+        System.out.println(post.reaction);
+        long userID = User.getID();
+
+        // DB connection and statement
+        Connection c;
+        PreparedStatement stmt;
+
+        // try to get data from db
+        try {
+            // check for the driver
+            Class.forName("org.postgresql.Driver");
+            // get the connection with credentials from env variables
+            c = DriverManager
+                    .getConnection("jdbc:postgresql://"+
+                                    System.getenv("POSTGRES_IP")+"/"+System.getenv("POSTGRES_DB"),
+                            System.getenv("POSTGRES_USER"), System.getenv("POSTGRES_PASSWORD"));
+            // disable auto commits
+            c.setAutoCommit(false);
+
+            // create a new statement
+            stmt = c.prepareStatement("UPDATE Reactions SET positive = (?) WHERE post = (?) AND userid = (?) RETURNING id, positive");
+
+            stmt.setObject(1, post.reaction.orElse(null));
+            stmt.setObject(2, id);
+            stmt.setObject(3, userID);
+
+            // insert post and get its id
+            ResultSet rs = stmt.executeQuery();
+
+            // check if there is a parent
+            if (!rs.next()) {
+                // create a new statement
+                stmt = c.prepareStatement("INSERT INTO Reactions(userid, post, positive) VALUES ((?), (?), (?))");
+
+                // fill statement
+                stmt.setObject(1, userID);
+                stmt.setObject(2, id);
+                stmt.setObject(3, post.reaction.orElse(null));
+
+                // execute statement
+                stmt.execute();
+            }
+
+            // commit the changes
+            c.commit();
+
+            // close all connections to db
+            stmt.close();
+            c.close();
+        }
+
+        // else log the error
+        catch ( Exception e ) {
+            System.err.println( e.getClass().getName()+": "+ e.getMessage() );
+            throw new ResponseStatusException(HttpStatus.SERVICE_UNAVAILABLE, "Database is offline");
+        }
+    }
+
+    @DeleteMapping("/post/{id}")
+    public void deletePost(@PathVariable long id) {
+        // DB connection and statement
+        Connection c;
+        PreparedStatement stmt;
+
+        // try to get data from db
+        try {
+            // check for the driver
+            Class.forName("org.postgresql.Driver");
+            // get the connection with credentials from env variables
+            c = DriverManager
+                    .getConnection("jdbc:postgresql://"+
+                                    System.getenv("POSTGRES_IP")+"/"+System.getenv("POSTGRES_DB"),
+                            System.getenv("POSTGRES_USER"), System.getenv("POSTGRES_PASSWORD"));
+            // disable auto commits
+            c.setAutoCommit(false);
+
+            // create a new statement
+            stmt = c.prepareStatement("UPDATE Posts SET deleted = now() WHERE id = ? AND author = (?) AND deleted IS NULL");
+
+            stmt.setObject(1, id);
+            stmt.setObject(2, User.getID());
+
+            // insert delete time
+            stmt.execute();
+
+            // close all connections to db
+            stmt.close();
+            c.commit();
+            c.close();
+        }
+
+        // else log the error
+        catch ( Exception e ) {
+            System.err.println( e.getClass().getName()+": "+ e.getMessage() );
+            throw new ResponseStatusException(HttpStatus.SERVICE_UNAVAILABLE, "Database is offline");
+        }
+    }
 }

src/main/java/de/anxietyprime/swajodel/SwaJodelApplication.java

@@ -2,6 +2,9 @@ package de.anxietyprime.swajodel;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import org.springframework.web.servlet.config.annotation.CorsRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 
 @SpringBootApplication
 public class SwaJodelApplication {

src/main/java/de/anxietyprime/swajodel/User.java

@@ -0,0 +1,77 @@
+package de.anxietyprime.swajodel;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.security.core.context.SecurityContextHolder;
+import org.springframework.web.server.ResponseStatusException;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+
+public class User {
+    static public String getUUID () {
+        return SecurityContextHolder.getContext().getAuthentication().getName();
+    }
+
+    static public Long getID() {
+        String uuid = SecurityContextHolder.getContext().getAuthentication().getName();
+        long id;
+
+        // DB connection and statement
+        Connection c;
+        PreparedStatement stmt;
+
+        // try to get data from db
+        try {
+            // check for the driver
+            Class.forName("org.postgresql.Driver");
+            // get the connection with credentials from env variables
+            c = DriverManager
+                    .getConnection("jdbc:postgresql://"+
+                                    System.getenv("POSTGRES_IP")+"/"+System.getenv("POSTGRES_DB"),
+                            System.getenv("POSTGRES_USER"), System.getenv("POSTGRES_PASSWORD"));
+            // disable auto commits
+            c.setAutoCommit(false);
+
+            // create a new statement
+            stmt = c.prepareStatement("SELECT id FROM users WHERE username = (?)");
+
+            stmt.setObject(1, uuid);
+
+            // insert post and get its id
+            ResultSet rs = stmt.executeQuery();
+
+            // check if there is a parent
+            if (!rs.next()) {
+                // create a new statement
+                stmt = c.prepareStatement("INSERT INTO users(username, password) VALUES (?, 'unused') RETURNING id");
+
+                // fill statement
+                stmt.setObject(1, uuid);
+
+                // execute statement
+                rs = stmt.executeQuery();
+
+                // commit the changes
+                c.commit();
+
+                rs.next();
+            }
+
+            id = rs.getLong("id");
+
+            // close all connections to db
+            stmt.close();
+            c.close();
+        }
+
+        // else log the error
+        catch ( Exception e ) {
+            System.err.println( e.getClass().getName()+": "+ e.getMessage() );
+            throw new ResponseStatusException(HttpStatus.SERVICE_UNAVAILABLE, "Database is offline");
+        }
+
+        return id;
+    }
+}

src/main/java/de/anxietyprime/swajodel/security/JwtConverter.java

@@ -0,0 +1,60 @@
+package de.anxietyprime.swajodel.security;
+
+import org.springframework.core.convert.converter.Converter;
+import org.springframework.security.authentication.AbstractAuthenticationToken;
+import org.springframework.security.core.GrantedAuthority;
+import org.springframework.security.core.authority.SimpleGrantedAuthority;
+import org.springframework.security.oauth2.jwt.Jwt;
+import org.springframework.security.oauth2.jwt.JwtClaimNames;
+import org.springframework.security.oauth2.server.resource.authentication.JwtAuthenticationToken;
+import org.springframework.security.oauth2.server.resource.authentication.JwtGrantedAuthoritiesConverter;
+import org.springframework.stereotype.Component;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+@Component
+public class JwtConverter implements Converter<Jwt, AbstractAuthenticationToken> {
+
+    private final JwtGrantedAuthoritiesConverter jwtGrantedAuthoritiesConverter = new JwtGrantedAuthoritiesConverter();
+
+    private final JwtConverterProperties properties;
+
+    public JwtConverter(JwtConverterProperties properties) {
+        this.properties = properties;
+    }
+
+    @Override
+    public AbstractAuthenticationToken convert(Jwt jwt) {
+        Collection<GrantedAuthority> authorities = Stream.concat(
+                jwtGrantedAuthoritiesConverter.convert(jwt).stream(),
+                extractResourceRoles(jwt).stream()).collect(Collectors.toSet());
+        return new JwtAuthenticationToken(jwt, authorities, getPrincipalClaimName(jwt));
+    }
+
+    private String getPrincipalClaimName(Jwt jwt) {
+        String claimName = JwtClaimNames.SUB;
+        if (properties.getPrincipalAttribute() != null) {
+            claimName = properties.getPrincipalAttribute();
+        }
+        return jwt.getClaim(claimName);
+    }
+
+    private Collection<? extends GrantedAuthority> extractResourceRoles(Jwt jwt) {
+        Map<String, Object> resourceAccess = jwt.getClaim("resource_access");
+        Map<String, Object> resource;
+        Collection<String> resourceRoles;
+
+        if (resourceAccess == null
+                || (resource = (Map<String, Object>) resourceAccess.get(properties.getResourceId())) == null
+                || (resourceRoles = (Collection<String>) resource.get("roles")) == null) {
+            return Set.of();
+        }
+        return resourceRoles.stream()
+                .map(role -> new SimpleGrantedAuthority("ROLE_" + role))
+                .collect(Collectors.toSet());
+    }
+}

src/main/java/de/anxietyprime/swajodel/security/JwtConverterProperties.java

@@ -0,0 +1,19 @@
+package de.anxietyprime.swajodel.security;
+
+
+import lombok.Data;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.validation.annotation.Validated;
+
+@Data
+@Validated
+@Configuration
+@ConfigurationProperties(prefix = "jwt.auth.converter")
+
+
+public class JwtConverterProperties {
+
+    private String resourceId;
+    private String principalAttribute;
+}

src/main/java/de/anxietyprime/swajodel/security/SecurityConfig.java

@@ -0,0 +1,33 @@
+package de.anxietyprime.swajodel.security;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.http.HttpMethod;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
+import org.springframework.security.config.http.SessionCreationPolicy;
+import org.springframework.security.web.SecurityFilterChain;
+
+@RequiredArgsConstructor
+@Configuration
+ @EnableWebSecurity
+public class SecurityConfig {
+
+    public static final String ADMIN = "admin";
+    public static final String USER = "user";
+    private final JwtConverter jwtConverter;
+    @Bean
+    public SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {
+        http.authorizeHttpRequests((authz) ->
+                authz.requestMatchers(HttpMethod.GET, "/messages/").permitAll()
+                        .anyRequest().authenticated());
+
+        http.sessionManagement(sess -> sess.sessionCreationPolicy(
+                SessionCreationPolicy.STATELESS));
+        http.oauth2ResourceServer(oauth2 -> oauth2.jwt(jwt -> jwt.jwtAuthenticationConverter(jwtConverter)));
+
+        return http.build();
+    }
+
+}

src/main/resources/application.properties

@@ -1 +1,5 @@
 spring.application.name=SWA-Jodel
+
+# Security Configuration
+spring.security.oauth2.resourceserver.jwt.issuer-uri=https://${KC_HOSTNAME}/realms/Jodel
+spring.security.oauth2.resourceserver.jwt.jwk-set-uri=${spring.security.oauth2.resourceserver.jwt.issuer-uri}/protocol/openid-connect/certs

src/test/java/de/anxietyprime/swajodel/SwaJodelApplicationTests.java

@@ -3,44 +3,9 @@ package de.anxietyprime.swajodel;
 import org.junit.jupiter.api.Test;
 import org.springframework.boot.test.context.SpringBootTest;
 
-import java.util.Optional;
+import java.util.Vector;
 
 @SpringBootTest
 class SwaJodelApplicationTests {
 
-    @Test
-    void anonymousTest() {
-        JodelPost post = new JodelPost(1000);
-        post.comments.add(new JodelPost(1001));
-        post.comments.add(new JodelPost(1002));
-        post.comments.get(0).comments.add(new JodelPost(1000));
-        post.comments.get(0).comments.add(new JodelPost(1001));
-        post.comments.get(0).comments.add(new JodelPost(1000));
-        post.comments.add(new JodelPost(1003));
-        post.comments.get(2).comments.add(new JodelPost(1001));
-        post.comments.get(2).comments.add(new JodelPost(1002));
-        post.comments.get(2).comments.add(new JodelPost(1003));
-        post.comments.get(2).comments.add(new JodelPost(1000));
-        post.comments.add(new JodelPost(1000));
-        post.comments.add(new JodelPost(1001));
-        post.comments.add(new JodelPost(1001));
-
-        post.anonymize(Optional.empty());
-
-        assert (post.anonymousID == 0);
-        assert (post.comments.get(0).anonymousID == 1);
-        assert (post.comments.get(1).anonymousID == 2);
-        assert (post.comments.get(2).anonymousID == 3);
-        assert (post.comments.get(3).anonymousID == 0);
-        assert (post.comments.get(4).anonymousID == 1);
-        assert (post.comments.get(5).anonymousID == 1);
-        assert (post.comments.get(0).comments.get(0).anonymousID == 0);
-        assert (post.comments.get(0).comments.get(1).anonymousID == 1);
-        assert (post.comments.get(0).comments.get(2).anonymousID == 0);
-        assert (post.comments.get(2).comments.get(0).anonymousID == 1);
-        assert (post.comments.get(2).comments.get(1).anonymousID == 2);
-        assert (post.comments.get(2).comments.get(2).anonymousID == 3);
-        assert (post.comments.get(2).comments.get(3).anonymousID == 0);
-    }
-
 }