first test check second NullPointException dont now why

Bank-Beispiel/src/de/hs_mannheim/informatik/bank/domain/Kunde.java

@@ -3,15 +3,15 @@ package de.hs_mannheim.informatik.bank.domain;
 import java.io.Serializable;
 import java.util.ArrayList;
 
-public class Kunde implements Serializable{
-	
+public class Kunde implements Serializable {
+
 	private static int id = 0;
 	private String vorname;
 	private String name;
 	private int alter;
 	private String wohnort;
 	private ArrayList<Konto> konten;
-	
+
 	public Kunde(String vorname, String name, int alter, String wohnort) {
 		this.vorname = vorname;
 		this.name = name;
@@ -19,22 +19,39 @@ public class Kunde implements Serializable{
 		this.wohnort = wohnort;
 		this.id++;
 	}
-	
+
+	public String getVorname() {
+		return vorname;
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	public int getAlter() {
+		return alter;
+	}
+
+	public String getWohnort() {
+		return wohnort;
+	}
+
 	public void kundeHatKonte(Konto k) {
 		konten.add(k);
 	}
-	
+
 	public int getId() {
 		return this.id;
 	}
-	
+
 	public ArrayList<Konto> getKonten() {
 		return konten;
 	}
 
 	@Override
 	public String toString() {
-		return "Vorname: " + this.vorname + " Name: " + this.name +" Alter: " + this.alter + " Wohnort: "+ this.wohnort;
+		return "Vorname: " + this.vorname + " Name: " + this.name + " Alter: " + this.alter + " Wohnort: "
+				+ this.wohnort;
 	}
 
 }

Bank-Beispiel/src/de/hs_mannheim/informatik/bank/domain/KundeTest.java

@@ -0,0 +1,38 @@
+package de.hs_mannheim.informatik.bank.domain;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.util.ArrayList;
+
+import org.junit.jupiter.api.Test;
+
+class KundeTest {
+
+	@Test
+	void testKontoBasic() {
+		Kunde k = new Kunde("TestVor","TestNam",20,"TestHeim");
+		assertEquals(1, k.getId());
+		assertEquals("TestVor", k.getVorname());
+		assertEquals("TestNam", k.getName());
+		assertEquals(20, k.getAlter());
+		assertEquals("TestHeim", k.getWohnort());
+
+	}
+	
+	@Test
+	void testKundeHatKonto() {
+		Kunde ku = new Kunde("TestVor","TestNam",20,"TestHeim");
+		Konto ko = new Konto("TestKonto",1);
+		Konto gi = new Girokonto("TestGiro",2);
+		Konto de = new Depot("Testdep",3);
+		ku.kundeHatKonte(ko);
+		ku.kundeHatKonte(gi);
+		ku.kundeHatKonte(de);
+		ArrayList<Konto> konten = new ArrayList<>();
+		konten.add(ko);
+		konten.add(gi);
+		konten.add(de);
+		assertTrue(konten.equals(ku.getKonten()));
+	}
+
+}