update

springboot-main/src/main/java/com/alvin/util/ListUtil.java

@@ -0,0 +1,18 @@
+package com.alvin.util;
+
+import java.util.ArrayList;
+import java.util.Collections;
+
+public class ListUtil {
+    public static <T> ArrayList<T> newList(T... list) {
+        ArrayList<T> strings = new ArrayList<>();
+        Collections.addAll(strings, list);
+        return strings;
+    }
+
+    public static void main(String[] args) {
+        ArrayList<Integer> integers = newList(1, 2, 3);
+        ArrayList<String> strings = newList("323", "2234");
+        System.out.println(integers);
+    }
+}

springboot-main/src/main/java/com/alvin/util/MapBuilder.java

@@ -0,0 +1,27 @@
+package com.alvin.util;
+
+import java.util.HashMap;
+
+public class MapBuilder<T> {
+    private HashMap<String, T> map = new HashMap<>();
+
+    public MapBuilder() {
+    }
+
+    public MapBuilder<T> put(String key, T t) {
+        this.map.put(key, t);
+        return this;
+    }
+
+    public HashMap<String, T> build() {
+        return this.map;
+    }
+
+    public static void main(String[] args) {
+        HashMap<String, String> build = new MapBuilder<String>()
+                .put("test", "hhhhhh")
+                .put("hhh", "test2")
+                .build();
+        System.out.println(build);
+    }
+}