Kommentare 2: electric boogaloo

src/main/java/com/bib/essensbestellungsverwaltung/AccountMgr.java

@@ -1,7 +1,4 @@
 package com.bib.essensbestellungsverwaltung;
-/*
-    @author Malte Schulze Hobeling
- */
 
 import javax.crypto.SecretKeyFactory;
 import javax.crypto.spec.PBEKeySpec;
@@ -13,12 +10,18 @@ import java.util.ArrayList;
 import java.util.Base64;
 import java.util.List;
 
+/**
+ * A collection of functions loosely related to account management
+ * Acts as an abstraction layer to the database
+ * @author Malte Schulze Hobeling
+ */
 public class AccountMgr {
-    protected static double price = 5.0;
-    
+
     /**
      * creates a user with createUser(...) and adds its id to the 'worker' table
+     * @param worker the worker to be created
      * @return userid or -1
+     * @author Malte Schulze Hobeling
      */
     protected static long createWorker(Worker worker){
         long id = createUser(worker);
@@ -29,7 +32,9 @@ public class AccountMgr {
 
     /**
      * creates a user with createUser(...) and adds its id to the 'parent' table
+     * @param parent the parent to be created
      * @return userid or -1
+     * @author Malte Schulze Hobeling
      */
     protected static long createParent(Parent parent){
         long id = createUser(parent);
@@ -40,7 +45,9 @@ public class AccountMgr {
 
     /**
      * adds a user to the database
+     * @param user the user to be created
      * @return userid or -1
+     * @author Malte Schulze Hobeling
      */
     protected static long createUser(User user) {
         String[] userH = {"name", "firstname", "addressid", "password", "email"};
@@ -56,6 +63,12 @@ public class AccountMgr {
         return Database.insert("user", userH, userD);
     }
 
+    /**
+     * adds an address to the database
+     * @param address the address to be created
+     * @return id or -1
+     * @author Malte Schulze Hobeling
+     */
     protected static long createAddress(Address address){
         String[] addressH = {"street", "number", "plz", "city"};
         String[] addressD = {address.getStreet(),address.getNumber(),address.getPlz(),address.getCity()};
@@ -64,7 +77,9 @@ public class AccountMgr {
 
     /**
      * adds a child and allergies to the database
+     * @param child the child to be created
      * @return id of child or -1
+     * @author Malte Schulze Hobeling
      */
     protected static long createChild(Child child){
         String[] childH = {"name","firstname","addressid"};
@@ -81,8 +96,17 @@ public class AccountMgr {
         return id;
     }
 
+    /**
+     * returns a User(Worker | Parent) for a given id or null if no unique id was found
+     * @param id id of the User
+     * @return User(Worker | Parent) or null
+     * @author Malte Schulze Hobeling
+     */
     protected static User getUserById(long id){
         List<String> entry = Database.getEntryById("user",id);
+        if(entry.size() != 1){
+            return null;
+        }
         String[] parts = entry.get(0).split(":");
         Address address = getAddressById(id);
         if(isWorker(String.valueOf(id))){
@@ -100,8 +124,17 @@ public class AccountMgr {
         }
     }
 
+    /**
+     * returns a Child for a given id or null if no unique id was found
+     * @param id id of child
+     * @return Child or null
+     * @author Malte Schulze Hobeling
+     */
     protected static Child getChildById(long id){
         List<String> entry = Database.getEntryById("child",id);
+        if(entry.size() != 1){
+            return null;
+        }
         String[] parts = entry.get(0).split(":");
         String[] child_allergyH = {"childid"};
         String[] child_allergyD = {String.valueOf(id)};
@@ -117,8 +150,17 @@ public class AccountMgr {
         return new Child(id,parts[1],parts[2],getAddressById(Long.parseLong(parts[3])),allergySeverities);
     }
 
+    /**
+     * returns an Address for a given id or null if no unique id was found
+     * @param id id of the address
+     * @return Address or null
+     * @author Malte Schulze Hobeling
+     */
     protected static Address getAddressById(long id){
         List<String> entry = Database.getEntryById("address",id);
+        if(entry.size() != 1){
+            return null;
+        }
         String[] parts = entry.get(0).split(":");
         return new Address(Long.parseLong(parts[0]),parts[1],parts[2],parts[3],parts[4]);
     }
@@ -128,6 +170,7 @@ public class AccountMgr {
      * @param parentId id of parent
      * @param childId id of child
      * @return id of parent_child or -1
+     * @author Malte Schulze Hobeling
      */
     protected static long matchParentChild(String parentId, String childId){
         String[] parent_childH = {"parentuserid","childid"};
@@ -140,6 +183,7 @@ public class AccountMgr {
      * @param email email
      * @param pw password
      * @return id or -1
+     * @author Malte Schulze Hobeling
      */
     protected static long login(String email, String pw){
         String[] pwH = {"email"};
@@ -163,6 +207,7 @@ public class AccountMgr {
      * checks if id is in worker table
      * @param id userid
      * @return true if id is in worker table
+     * @author Malte Schulze Hobeling
      */
     protected static boolean isWorker(String id){
         String[] workerH = {"userid"};
@@ -175,6 +220,7 @@ public class AccountMgr {
      * checks if id is in parent table
      * @param id userid
      * @return true if id is in parent table
+     * @author Malte Schulze Hobeling
      */
     protected static boolean isParent(String id){
         String[] parentH = {"userid"};
@@ -187,6 +233,7 @@ public class AccountMgr {
      * returns a hashed and salted password
      * @param pw the password to hash
      * @return hashed and salted password
+     * @author Malte Schulze Hobeling
      */
     private static String hashAndSalt(String pw, String salt){
         Base64.Decoder dec = Base64.getDecoder();
@@ -205,6 +252,11 @@ public class AccountMgr {
         return hashedPw;
     }
 
+    /**
+     * generates a secure random salt, Base64 encoded
+     * @return String Base64 encoded
+     * @author Malte Schulze Hobeling
+     */
     private static String getSalt(){
         SecureRandom sec = new SecureRandom();
         byte[] salt = new byte[16];
@@ -218,11 +270,15 @@ public class AccountMgr {
      * @param date YYYY-MM the month
      * @param childId id of child
      * @return the invoice as a List
+     * @author Malte Schulze Hobeling
      */
     protected static List<String> getInvoice(String date, String childId){
         List<String> invoice = new ArrayList<>();
-        invoice.add("Monatsabrechnung " + date);
         List<String> child = Database.getEntryById("child", Long.parseLong(childId));
+        if(child.size() != 1){
+            return invoice;
+        }
+        invoice.add("Monatsabrechnung " + date);
         String[] childParts = child.get(0).split(":");
         invoice.add(childParts[1] + ", " + childParts[2]);
         String[] food_planH = {"date"};
@@ -241,18 +297,29 @@ public class AccountMgr {
                 invoice.add(line);
             }
         }
+        double price = getPrice();
         invoice.add("Total: " + (invoice.size()-2) + " X " + price + "€ = " + ((invoice.size()-2)*price) + "€");
         return invoice;
     }
 
-    protected static void getPriceFromDb(){
+    /**
+     * gets the price per meal from the database and converts it to double
+     * @return double price
+     * @author Malte Schulze Hobeling
+     */
+    protected static double getPrice(){
         List<String> priceEntry = Database.getEntryById("price",1);
-        price = Double.parseDouble(priceEntry.get(0).split(":")[1])/100.0;
+        return Double.parseDouble(priceEntry.get(0).split(":")[1])/100.0;
     }
 
-    protected static void setPriceInDb(){
+    /**
+     * converts the price per meal to integer and updates it in the database
+     * @param price double
+     * @author Malte Schulze Hobeling
+     */
+    protected static void setPrice(double price){
         String[] priceH = {"id","price"};
-        String[] priceD = {"1", String.valueOf(price*100)};
+        String[] priceD = {"1", String.valueOf((int)(price*100))};
         Database.update("price",priceH,priceD);
     }
 }