add Check Permutation java solution

lcci/01.02.Check Permutation/README.md

@@ -41,7 +41,18 @@ class Solution:
 <!-- 这里可写当前语言的特殊实现逻辑 -->
 
 ```java
-
+class Solution {
+    public boolean checkPermutation(String s1, String s2) {
+        if (s1 == null || s2 == null || s1.length() != s2.length()) {
+            return false;
+        }
+        char[] c1 = s1.toCharArray();
+        char[] c2 = s2.toCharArray();
+        Arrays.sort(c1);
+        Arrays.sort(c2);
+        return Arrays.equals(c1, c2);
+    }
+}
 ```
 
 ### ...

lcci/01.02.Check Permutation/README_EN.md

@@ -56,7 +56,18 @@ class Solution:
 ### Java
 
 ```java
-
+class Solution {
+    public boolean CheckPermutation(String s1, String s2) {
+        if (s1 == null || s2 == null || s1.length() != s2.length()) {
+            return false;
+        }
+        char[] c1 = s1.toCharArray();
+        char[] c2 = s2.toCharArray();
+        Arrays.sort(c1);
+        Arrays.sort(c2);
+        return Arrays.equals(c1, c2);
+    }
+}
 ```
 
 ### ...

lcci/01.02.Check Permutation/Solution.java

@@ -0,0 +1,12 @@
+class Solution {
+    public boolean CheckPermutation(String s1, String s2) {
+        if (s1 == null || s2 == null || s1.length() != s2.length()) {
+            return false;
+        }
+        char[] c1 = s1.toCharArray();
+        char[] c2 = s2.toCharArray();
+        Arrays.sort(c1);
+        Arrays.sort(c2);
+        return Arrays.equals(c1, c2);
+    }
+}