update

[l21s-case-study] / src / DbMigration.java

diff --git a/src/DbMigration.java b/src/DbMigration.java
index 9357811ad90a2d791bf77018a9e03491b1005bcc..6265545dda375479db601488dafe4ed0d45eb085 100644 (file)
--- a/src/DbMigration.java
+++ b/src/DbMigration.java
@@ -5,45 +5,48 @@ import java.util.*;
 
 class DbMigration {
     // constants {{{
-    static final boolean CONFIG_PRINT_DB = false;
+    static final boolean CONFIG_PRINT_DB = true;
     static final String CSV_SEPARATOR = ",";
-    static final String DB_URL = "jdbc:postgresql:users";
+    static final String DB_URL = "jdbc:postgresql:migration";
+    static final int    DB_BATCH_SIZE = 10;
     static final String SQL_GET_USERS = "SELECT * FROM users;";
     static final String SQL_UPSERT_USER =
             """
-              INSERT INTO users VALUES (?, ?, ?, ?, ?)
-              ON CONFLICT (ID)
-              DO UPDATE SET
-                Mail = EXCLUDED.Mail,
-                CanRead = EXCLUDED.CanRead,
-                CanWrite = EXCLUDED.CanWrite,
-                CanDelete = EXCLUDED.CanDelete
-              ;
+            INSERT INTO users VALUES (?, ?, ?, ?, ?)
+            ON CONFLICT (USER_ID)
+            DO UPDATE SET
+                MAIL = EXCLUDED.MAIL,
+                CAN_READ = EXCLUDED.CAN_READ,
+                CAN_WRITE = EXCLUDED.CAN_WRITE,
+                CAN_DELETE = EXCLUDED.CAN_DELETE
+            ;
             """;
+
     // }}}
 
     // user {{{
+    public record Role(boolean read, boolean write, boolean delete) {
+        static final Role Default = new Role(false, false, false);
+    }
+
     public record User(int id, String mail, Role role) {
         public String toString() {
             return this.id + " " + this.mail + " " + this.role;
         }
     }
-    // }}}
 
-    // role {{{
-    public record Role(boolean read, boolean write, boolean delete) {
-        static final Role Default = new Role(false, false, false);
-    }
     // }}}
 
     // csv {{{
-    public static String[][] LoadCSV(String filename) throws IOException {
+    public static ArrayList<String[]> LoadCSV(String filename) throws IOException {
         var path = Paths.get(filename);
-        return Files.lines(path)
+        var list = Files.lines(path)
                 .skip(1)
                 .map(line -> line.split(CSV_SEPARATOR))
-                .toArray(String[][]::new);
+                .toList();
+        return new ArrayList<String[]>(list);
     }
+
     // }}}
 
     // db {{{
@@ -62,7 +65,7 @@ class DbMigration {
         var users = new ArrayList<User>();
 
         try (var st = conn.createStatement();
-                var rs = st.executeQuery(SQL_GET_USERS); ) {
+             var rs = st.executeQuery(SQL_GET_USERS); ) {
             while (rs.next()) {
                 var userId = rs.getInt(1);
                 var userMail = rs.getString(2);
@@ -73,9 +76,9 @@ class DbMigration {
 
         return users.toArray(User[]::new);
     }
+
     // }}}
 
-    // main {{{
     public static void main(String[] args) {
         // filenames from command line args {{{
         if (args.length != 2) {
@@ -87,8 +90,8 @@ class DbMigration {
         // }}}
 
         // read csvs {{{
-        String[][] csvUsers;
-        String[][] csvRoles;
+        ArrayList<String[]> csvUsers;
+        ArrayList<String[]> csvRoles;
         try {
             csvUsers = LoadCSV(filenameUsers);
             csvRoles = LoadCSV(filenameRoles);
@@ -97,8 +100,17 @@ class DbMigration {
             return;
         }
         // }}}
+        
+        // Sparkassen Nutzer aussortieren {{{
+        csvUsers.removeIf(row -> row[1].endsWith("@sparkasse.de"));
+        // }}}
 
         // process roles {{{
+        // - read roles.csv line by line
+        // - get user_id and role from each line
+        // - make sure user_id is in the HashMap
+        // - if not create default value with no roles
+        // - update the role specified in that line
         var roles = new HashMap<Integer, Role>();
         for (var row : csvRoles) {
             // get id and single role
@@ -125,7 +137,7 @@ class DbMigration {
             try (var conn = DriverManager.getConnection(DB_URL)) {
 
                 var users = getUsers(conn);
-                System.out.println("DB before update:");
+                System.out.println("Before update:");
                 for (var user : users) {
                     System.out.println(user);
                 }
@@ -139,8 +151,10 @@ class DbMigration {
 
         // open db connection for updating {{{
         try (var conn = DriverManager.getConnection(DB_URL);
-                var stmt = conn.prepareStatement(SQL_UPSERT_USER); ) {
+             var stmt = conn.prepareStatement(SQL_UPSERT_USER); ) {
+
             // batching
+            int batchIndex = 0;
             conn.setAutoCommit(false);
 
             // update db from csv
@@ -151,9 +165,16 @@ class DbMigration {
 
                 User user = new User(userId, userMail, userRoles);
                 insertUser(stmt, user);
+
+                // batching
+                batchIndex += 1;
+                if (batchIndex > DB_BATCH_SIZE) {
+                    stmt.executeBatch();
+                    batchIndex = 0;
+                }
             }
 
-            // commit batch
+            // commit all outstanding changes
             stmt.executeBatch();
             conn.commit();
         } catch (SQLException e) {
@@ -164,5 +185,4 @@ class DbMigration {
 
         System.out.println("Updated successfully");
     }
-    // }}}
 }