add a method to read in csv file and count

fishercoder1534 · fishercoder1534 · commit 9831290d31cc · 2024-01-29T18:22:10.000-08:00
diff --git a/src/main/java/IO_example/JavaFileIOExample.java b/src/main/java/IO_example/JavaFileIOExample.java
@@ -2,6 +2,8 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Scanner;
 
 import static org.junit.jupiter.api.Assertions.assertTrue;
@@ -11,6 +13,7 @@ public class JavaFileIOExample {
     public static void main(String... args) throws IOException {
         System.out.println("Program started.");
         readFileOnDisk();
+        findUniqueCityNames();
         System.out.println("Program finished.");
     }
 
@@ -26,4 +29,22 @@ private static void readFileOnDisk() throws IOException {
 
         scanner.close();
     }
+
+    private static void findUniqueCityNames() throws IOException {
+        String file = "src/test/resources/city_names.csv";
+        Scanner scanner = new Scanner(new File(file));
+        scanner.useDelimiter(",");
+        Map<String, Integer> map = new HashMap<>();
+        while (scanner.hasNext()) {
+            String city = scanner.next();
+            map.put(city, map.getOrDefault(city, 0) + 1);
+        }
+        scanner.close();
+        System.out.println("Unique city names are: ");
+        for (String city : map.keySet()) {
+            if (map.get(city) == 1) {
+                System.out.println(city);
+            }
+        }
+    }
 }
diff --git a/src/test/resources/city_names.csv b/src/test/resources/city_names.csv
@@ -0,0 +1 @@
+NYC,NYC,NYC,Cedar Park,NYC,NYC,NYC,NYC,San Jose,San Jose,San Jose,San Jose,McKinney,San Jose,SF,LA,LA,LA,LA,LA,San Diego,San Diego,San Diego,Seattle,Portland,Portland,Portland,Boston,D.C,D.C,D.C,Miami,Dallas,Cedar Park,McKinney,Melissa,Sacramento,Sacramento

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+NYC,NYC,NYC,Cedar Park,NYC,NYC,NYC,NYC,San Jose,San Jose,San Jose,San Jose,McKinney,San Jose,SF,LA,LA,LA,LA,LA,San Diego,San Diego,San Diego,Seattle,Portland,Portland,Portland,Boston,D.C,D.C,D.C,Miami,Dallas,Cedar Park,McKinney,Melissa,Sacramento,Sacramento`