Nhập môn Java cần anh em giúp đỡ

Mình code bài tập này từ C giờ mình muốn chuyển nó sang java thi làm như thế nào vậy mấy bạn?

#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
#include <string.h>
/* HIDE FUNCTION FOR DEVELOPER: 205. Print current i */
char del1[8],del2[50];
struct student{
    char sid[8];
    char sname[50];
    char sdob[50];
    char semail[50];
    char sphone[50];
    char saddress[50];
} student_list [1000];
void add(int *i){
    g12:
    printf("Input student ID: "); fflush(stdin); gets(student_list[*i].sid);
    if (strlen(student_list[*i].sid)==7)
{
	int result1, result2, result3;
	result1 = strncmp(student_list[*i].sid,"GC", 2);
	result2 = strncmp(student_list[*i].sid,"GT", 2);
	int j=2;
	do {
   		 result3=isdigit(student_list[*i].sid[j]);
    		 j++;
   		 if (result3==0)
     		   break;
	   }
while (j< strlen(student_list[*i].sid)-1);
if ((result1 ==0) || (result2 ==0))
    {if (result3 !=0)
	goto g11;
    else
        {printf("The Student ID is not valid.(GTxxxxx or GCxxxxx)Press *Enter* to input again! "); getchar();
	goto g12;}}
    else
      	{printf("The Student ID is not valid.(GTxxxxx or GCxxxxx)Press *Enter* to input again! "); getchar();
	goto g12;}
}
	 else
      	{printf("The Student ID is not valid.(GTxxxxx or GCxxxxx)Press *Enter* to input again! (GTxxxxx or GCxxxxx)"); getchar();
	goto g12;}
g11:
    printf("Input student name: "); fflush(stdin); gets(student_list[*i].sname);
    printf("Input student date of birth: ");fflush(stdin); gets(student_list[*i].sdob);
    printf("Input student email: ");fflush(stdin); gets(student_list[*i].semail);
    printf("Input student sphone: ");fflush(stdin); gets(student_list[*i].sphone);
    printf("Input student address: ");fflush(stdin); gets(student_list[*i].saddress);
    *i=*i+1;
}
search (int i){
char *test;
char s[50],x1[50],x2[50];
int u=0;
printf("Please enter student's name or a part of it: "); fflush(stdin);gets(s);
int a;
for (a=0;a<i;a++)
{
    strcpy(x1,student_list[a].sname);
    strcpy(x2,s);
    test = strstr(strlwr(x1),strlwr(x2));
    if (test){
        printf("%s | %s | %s | %s | %s | %s |
",student_list[a].sid,student_list[a].sname,student_list[a].sdob,student_list[a].semail,student_list[a].sphone,student_list[a].saddress);
        u++;}
}
if (u==0) printf("No data found!");
getchar();
}
void update(int i){
int test;
char ud[8],x1[8],x2[8];
int u=0;
int c,up;
printf("Enter student ID: ");fflush(stdin); gets(ud);
int a;
for (a=0;a<i;a++)
{
    strcpy(x1,student_list[a].sid);
    strcpy(x2,ud);
    test = strcmp(strlwr(x1),strlwr(x2));
//a chinh la gia tri THUC cua position trong maang
if (test==0)
{
printf("Current student ID: %s
",student_list[a].sid);
printf("Enter 1 to update & 0 to keep: "); scanf("%d",&up);
if (up==1)
	 {printf("Enter a new ID: "); fflush(stdin);gets(student_list[a].sid);}
printf(" Current student name: %s
",student_list[a].sname);
printf("Enter 1 to update & 0 to keep: "); scanf("%d",&up);
if (up==1)
	 {printf("Enter a new name: "); fflush(stdin);gets(student_list[a].sname);}
printf(" Current student date of birth: %s
",student_list[a].sdob);
printf("Enter 1 to update & 0 to keep: "); scanf("%d",&up);
if (up==1)
	 {printf("Enter a new date of birth: "); fflush(stdin);gets(student_list[a].sdob);}
printf(" Current student email: %s
",student_list[a].semail);
printf("Enter 1 to update & 0 to keep: "); scanf("%d",&up);
if (up==1)
	 {printf("Enter a new email: "); fflush(stdin);gets(student_list[a].semail);}
printf(" Current student phone: %s
",student_list[a].sphone);
printf("Enter 1 to update & 0 to keep: "); scanf("%d",&up);
if (up==1)
	 {printf("Enter a new phone: "); fflush(stdin);gets(student_list[a].sphone);}
printf(" Current student address: %s
",student_list[a].saddress);
printf("Enter 1 to update & 0 to keep: "); scanf("%d",&up);
if (up==1)
	 {printf("Enter a new address: ");fflush(stdin); gets(student_list[a].saddress);}
printf("Successfully Update");
getchar();
}
}
}
void view(int i){
    int a;
    for (a=0;a<5;a++)
    printf("%s | %s | %s | %s | %s | %s |
",student_list[a].sid,student_list[a].sname,student_list[a].sdob,student_list[a].semail,student_list[a].sphone,student_list[a].saddress);
    if (i==0) printf("No data to show!
");
    getchar();
}
void del(int *i){
int test;
char del[8],x1[8],x2[8];
int u=0;
int c;
printf("Enter student ID: ");fflush(stdin); gets(del);
int a;
for (a=0;a<(*i);a++)
{
    strcpy(x1,student_list[a].sid);
    strcpy(x2,del);
    test = strcmp(strlwr(x1),strlwr(x2));
//a chinh la gia tri cua position trong mang
                if (test==0){
                                for ( c = a ; c < *i ; c++ )
                                    {strcpy(student_list[c].sid,student_list[c+1].sid);
                                     strcpy(student_list[c].sname,student_list[c+1].sname);
                                     strcpy(student_list[c].sdob,student_list[c+1].sdob);
                                     strcpy(student_list[c].semail,student_list[c+1].semail);
                                     strcpy(student_list[c].sphone,student_list[c+1].sdob);
                                     strcpy(student_list[c].saddress,student_list[c+1].saddress);}
                                 u++;
                                    {strcpy(student_list[*i].sid,del1);
                                     strcpy(student_list[*i].sname,del2);
                                     strcpy(student_list[*i].sdob,del2);
                                     strcpy(student_list[*i].semail,del2);
                                     strcpy(student_list[*i].sphone,del2);
                                     strcpy(student_list[*i].saddress,del2);}
                         }
}
if (u==0) printf("Student ID doesn't exist!");
getchar();
*i=*i-1;
}
void menu(){
    printf("		************************
");
    printf("		* 1. Add new student   *
");
    printf("		* 2. View all students *
");
    printf("		* 3. Search students   *
");
    printf("		* 4. Delete students   *
");
    printf("		* 5. Update student    *
");
    printf("		* 6. Exit              *
");
    printf("		************************
");
    printf("
");
}
int main(){
    int choice,i=0;
    g0:
    system("cls");
    menu();
//Kiem tra so nhap vao phai tu 1 den 6
    do {
    printf("Choose an option from 1 to 6: ");scanf("%d",&choice);}
    while (choice<1 || choice>6 && choice != 205);
    fflush(stdin);
    switch (choice){
        case 1: add(&i);
                break;
        case 2: view(i);
                break;
        case 3: search(i);
                break;
        case 4: del(&i);
                break;
        case 5: update(i);
                break;
        case 6: exit(0);
                break;
        case 205: 
        	printf("current i: %d",i); 
        	fflush(stdin); 
        	getchar();
        	break;
        default: ;
       
    }
    goto g0;
    getchar();
    return 0;
}