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+package leetcode.symmetric_tree;%0A%0Aimport common.TreeNode;%0A%0Apublic class Solution %7B%0A%09public boolean isSymmetric(TreeNode root) %7B%0A%09%09if(root == null) return true;%0A%09%09return isSymmetric(root.left, root.right);%0A%09%7D%0A%09private static boolean isSymmetric(TreeNode left, TreeNode right) %7B%0A%09%09if(left == null && right == null) return true;%0A%09%09if(left != null && right == null) return false;%0A%09%09if(left == null && right != null) return false;%0A%09%09if(left.val != right.val) return false; %0A%09%09return isSymmetric(left.left, right.right) && isSymmetric(left.right, right.left);%0A%09%7D%0A%0A%7D%0A

Add java solution for 101. Symmetric Tree