Merge pull request #2335 from W-ay/master

添加kama54.替换数字 Java版本

problems/kama54.替换数字.md

@@ -143,6 +143,23 @@ for (int i = 0; i < a.size(); i++) {
 
 ### Java：
 
+```java
+import java.util.Scanner;
+
+class Main {
+    public static void main(String[] args) {
+        Scanner in = new Scanner(System.in);
+        String s = in.nextLine();
+        StringBuilder sb = new StringBuilder();
+        for (int i = 0; i < s.length(); i++) {
+            if (Character.isDigit(s.charAt(i))) {
+                sb.append("number");
+            }else sb.append(s.charAt(i));
+        }
+        System.out.println(sb);
+    }
+}
+```
 
 ### Go：