View Compilation Error

0_0_21003722_19231.cpp:1:1: error: 'import' does not name a type
 import java.io.*;
 ^
0_0_21003722_19231.cpp:2:1: error: 'import' does not name a type
 import java.util.*;
 ^
0_0_21003722_19231.cpp:3:1: error: 'import' does not name a type
 import java.math.BigInteger;//声明BigInteger大数类
 ^
0_0_21003722_19231.cpp:4:1: error: 'import' does not name a type
 import java.lang.*;
 ^
0_0_21003722_19231.cpp:5:1: error: expected unqualified-id before 'public'
 public class Main
 ^