refactor[DbWrapper&ParameterValidator]: move parameter validation in …

…exports to ParameterValidator class
Group-5 · Apr 9, 2026 · ab64cda · ab64cda
1 parent c3b0555
commit ab64cda
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Showing 2 changed files with 50 additions and 38 deletions.
diff --git a/src/main/java/edu/group5/app/model/wrapper/DbWrapper.java b/src/main/java/edu/group5/app/model/wrapper/DbWrapper.java
@@ -1,5 +1,6 @@
 package edu.group5.app.model.wrapper;
 
+import java.lang.reflect.Parameter;
 import java.math.BigDecimal;
 import java.sql.Connection;
 import java.sql.DriverManager;
@@ -15,6 +16,8 @@
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
+import edu.group5.app.utils.ParameterValidator;
+
 /**
  * A class for wrapping the database.
  */
@@ -137,30 +140,11 @@ public List<Object[]> importUsers() {
    */
   public int exportUsers(List<Object[]> data) throws IllegalArgumentException {
     this.importUsers();
-
-    if (data == null) {
-      throw new IllegalArgumentException("data can't be null");
-    }
+
     if (data.isEmpty()) {
       return 0;
     }
-    // TODO: change to check length for every row.
-    if (data.get(0).length != 6) {
-      throw new IllegalArgumentException("data's arrays must have a length of 6");
-    }
-    if (data.stream().anyMatch(i -> Arrays.asList(i).contains(null))) {
-      throw new IllegalArgumentException("One or more rows in data contains null values");
-    }
-    // TODO: change how existing rows are checked.
-    if (this.users.size() > 0) {
-      if ((int) data.getLast()[0] <= (int) this.users.getLast()[0]) {
-        throw new IllegalArgumentException("data can't contain existing rows");
-      }
-    }
-    Set<Object> ids = new HashSet<>();
-    if (data.stream().anyMatch(i -> !ids.add(i[0]))) {
-      throw new IllegalArgumentException("data can't contain duplicate rows");
-    }
+    ParameterValidator.exportChecker(data, "data", this.users);
 
 
     PreparedStatement ps = null;
@@ -258,26 +242,11 @@ private List<Object[]> importDonations(int user_id, boolean all) {
    */
   public int exportDonations(List<Object[]> data) throws IllegalArgumentException {
     this.fetchAllDonations();
-
-    if (data == null) {
-      throw new IllegalArgumentException("data can't be null");
-    }
+
     if (data.isEmpty()) {
       return 0;
     }
-    if (data.get(0).length != 6) {
-      throw new IllegalArgumentException("data's arrays must have a length of 6");
-    }
-    if (data.stream().anyMatch(i -> Arrays.asList(i).contains(null))) {
-      throw new IllegalArgumentException("One or more rows in data contains null values");
-    }
-    if (this.donations.size() > 0 && (int) data.getLast()[0] <= (int) this.donations.getLast()[0]) {
-      throw new IllegalArgumentException("data can't contain existing rows");
-    }
-    Set<Object> ids = new HashSet<>();
-    if (data.stream().anyMatch(i -> !ids.add(i[0]))) {
-      throw new IllegalArgumentException("data can't contain duplicate rows");
-    }
+    ParameterValidator.exportChecker(data, "data", this.donations);
 
     PreparedStatement ps = null;
     int rowsAffected = 0;

diff --git a/src/main/java/edu/group5/app/utils/ParameterValidator.java b/src/main/java/edu/group5/app/utils/ParameterValidator.java
@@ -1,6 +1,10 @@
 package edu.group5.app.utils;
 
 import java.math.BigDecimal;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
 
 /**
  * ParameterValidator is a utility class that provides static methods for validating various types
@@ -82,4 +86,43 @@ private static final void nullCheck(Object variable, String variableName)
       throw new IllegalArgumentException(String.format("%s can't be null", variableName));
     }
   }
+
+  /**
+   * A method for checking if the data to be exported is valid.
+   * 
+   * @param data The data to export.
+   * @param dataName The name of the variable of the data to export.
+   * @param oldData The existing data to compare to for checking row existence.
+   * @throws IllegalArgumentException This exception is thrown when data is null, its rows are not
+   *      of length 6, any of the rows are null, any of the rows are duplicates or existing rows in
+   *      the database, or any of the values in the rows can't be cast to the correct data-types.
+   */
+  public static final void exportChecker(
+      List<Object[]> data, String dataName, List<Object[]> oldData
+  ) throws IllegalArgumentException {
+    if (data == null) {
+      throw new IllegalArgumentException(String.format("%s can't be null", dataName));
+    }
+    // TODO: change to check length for every row.
+    if (data.get(0).length != 6) {
+      throw new IllegalArgumentException(
+        String.format("%s's arrays must have a length of 6", dataName)
+      );
+    }
+    if (data.stream().anyMatch(i -> Arrays.asList(i).contains(null))) {
+      throw new IllegalArgumentException(
+        String.format("One or more rows in %s contains null values", dataName)
+      );
+    }
+    // TODO: change how existing rows are checked.
+    if (oldData.size() > 0) {
+      if ((int) data.getLast()[0] <= (int) oldData.getLast()[0]) {
+        throw new IllegalArgumentException("data can't contain existing rows");
+      }
+    }
+    Set<Object> ids = new HashSet<>();
+    if (data.stream().anyMatch(i -> !ids.add(i[0]))) {
+      throw new IllegalArgumentException("data can't contain duplicate rows");
+    }
+  }
 }