avoid nullpointers in list-typed fields

src/main/java/de/adorsys/smartanalytics/api/AnalyticsRequest.java

@@ -22,6 +22,7 @@
 import lombok.NoArgsConstructor;
 
 import java.time.LocalDate;
+import java.util.ArrayList;
 import java.util.List;
 
 @Data
@@ -30,9 +31,8 @@
 @NoArgsConstructor
 public class AnalyticsRequest {
 
-    private List<Booking> bookings;
-    private List<Rule> customRules;
+    private List<Booking> bookings = new ArrayList<>();
+    private List<Rule> customRules = new ArrayList<>();
     private GroupConfig groupConfig;
-    private List<String> contractBlackListMatcher;
-
+    private List<String> contractBlackListMatcher = new ArrayList<>();
 }

src/main/java/de/adorsys/smartanalytics/api/AnalyticsResult.java

@@ -30,6 +30,6 @@ public class AnalyticsResult {
 
     private RulesStatus rulesStatus;
     private List<WrappedBooking> bookings = new ArrayList<>();
-    private List<BookingGroup> bookingGroups;
+    private List<BookingGroup> bookingGroups = new ArrayList<>();
 
 }

src/main/java/de/adorsys/smartanalytics/api/BookingGroup.java

@@ -21,6 +21,7 @@
 
 import java.math.BigDecimal;
 import java.time.LocalDate;
+import java.util.ArrayList;
 import java.util.List;
 
 @Data
@@ -35,7 +36,7 @@ public class BookingGroup {
 
     protected Cycle cycle;
     private BigDecimal amount;
-    private List<BookingPeriod> bookingPeriods;
+    private List<BookingPeriod> bookingPeriods = new ArrayList<>();
 
     private String mainCategory;
     private String subCategory;

src/main/java/de/adorsys/smartanalytics/api/BookingPeriod.java

@@ -5,6 +5,7 @@
 
 import java.math.BigDecimal;
 import java.time.LocalDate;
+import java.util.ArrayList;
 import java.util.List;
 
 @Data
@@ -14,5 +15,5 @@ public class BookingPeriod {
     private LocalDate start;
     private LocalDate end;
     private BigDecimal amount;
-    private List<ExecutedBooking> bookings;
+    private List<ExecutedBooking> bookings = new ArrayList<>();
 }

src/main/java/de/adorsys/smartanalytics/api/Group.java

@@ -21,6 +21,7 @@
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
+import java.util.ArrayList;
 import java.util.List;
 
 @Data
@@ -35,7 +36,8 @@ public enum Type {
 
     private String name;
     private Type type;
-    private List<String> whitelistMatcher;
-    private List<String> blacklistMatcher;
+
+    private List<String> whitelistMatcher = new ArrayList<>();
+    private List<String> blacklistMatcher = new ArrayList<>();
 
 }

src/main/java/de/adorsys/smartanalytics/api/GroupConfig.java

@@ -5,6 +5,7 @@
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
+import java.util.ArrayList;
 import java.util.List;
 
 @Data
@@ -13,7 +14,7 @@
 @NoArgsConstructor
 public class GroupConfig {
 
-    private List<Group> groups;
-    private List<String> recurrentWhiteListMatcher;
+    private List<Group> groups = new ArrayList<>();
+    private List<String> recurrentWhiteListMatcher = new ArrayList<>();
 
 }

src/main/java/de/adorsys/smartanalytics/api/Rule.java

@@ -18,6 +18,7 @@
 
 import lombok.Data;
 
+import java.util.HashMap;
 import java.util.Map;
 
 @Data
@@ -42,7 +43,7 @@ public enum SIMILARITY_MATCH_TYPE {
     private String homepage;
     private String email;
 
-    private Map<String, String> custom;
+    private Map<String, String> custom = new HashMap<>();
 
     private boolean stop;
     private boolean incoming;

src/main/java/de/adorsys/smartanalytics/api/WrappedBooking.java

@@ -22,6 +22,7 @@
 
 import java.math.BigDecimal;
 import java.time.LocalDate;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
@@ -42,7 +43,7 @@ public class WrappedBooking implements Cloneable {
     private String homepage;
     private String hotline;
     private String email;
-    private Map<String, String> custom;
+    private Map<String, String> custom = new HashMap<>();
     private Set<String> usedRules = new HashSet<>();
     // *****************************************