如何使用Gson在Java中将Java数组或ArrayList转换为JsonArray？

import com.google.gson.*;
import java.util.*;
public class JavaArrayToJsonArrayTest {
   public static void main(String args[]) {
      String[][] strArray = {{"elem1-1", "elem1-2"}, {"elem2-1", "elem2-2"}};
      ArrayList<ArrayList<String>> arrayList = new ArrayList<>();
      for(int i = 0; i < strArray.length; i++) {
         ArrayList<String> nextElement = new ArrayList<>();
         for(int j = 0; j < strArray[i].length; j++) {
            nextElement.add(strArray[i][j] + "-B");
         }
         arrayList.add(nextElement);
      }
      JsonObject jsonObj = new JsonObject();
      // array to JsonArray
      JsonArray jsonArray1 = new Gson().toJsonTree(strArray).getAsJsonArray();
      // ArrayList to JsonArray
      JsonArray jsonArray2 = new Gson().toJsonTree(arrayList).getAsJsonArray();
      jsonObj.add("jsonArray1", jsonArray1);
      jsonObj.add("jsonArray2", jsonArray2);
      System.out.println(jsonObj.toString());
   }
}

{"jsonArray1":[["elem1-1","elem1-2"],["elem2-1","elem2-2"]],"jsonArray2":[["elem1-1-B","elem1-2-B"],["elem2-1-B","elem2-2-B"]]}