View Compilation Error

0_0_25306992_22008.cpp:1:1: error: 'import' does not name a type
 import java.math.BigInteger;
 ^
0_0_25306992_22008.cpp:2:1: error: 'import' does not name a type
 import java.util.*;
 ^
0_0_25306992_22008.cpp:6:5: error: 'HashMap' does not name a type
     HashMap<Character, Integer> m=new HashMap<>();
     ^
0_0_25306992_22008.cpp:26:1: error: expected ';' after class definition
 }
 ^
0_0_25306992_22008.cpp: In constructor 'a::a()':
0_0_25306992_22008.cpp:8:9: error: 'm' was not declared in this scope
     {   m.put('0',0);
         ^
0_0_25306992_22008.cpp: At global scope:
0_0_25306992_22008.cpp:29:1: error: expected unqualified-id before 'public'
 public class Main {
 ^