Question

MUST BE IN C++

The lab is called "7.5.9.1 Exceptions: including information in exceptions"

The lab is as follows:

Objectives

Familiarize the student with:

• using exceptions in real programs;
• the simplification of exception throwing;
• throwing exceptions in constructors.

Scenario

IP header – imagine you have a class or struct (choose one) describing an IP header which holds (apart from other fields) two string fields that contain Source IP Address and Destination IP Address. Check these two fields and throw an exception in a constructor, and using a special check method, try to write one version of this code only. The condition of the check method is that both IP numbers are valid. Start with simple checks – the IP number must consist of four numbers in the 0-255 range, separated by a dot. Append appropriate information about which of the IP numbers is invalid.

212.112.212.11, 212.112.212.12
212.112.212.333, 212.112.212.33

Valid IP Header.
Invalid IP Header - Source IP Address is invalid.

Answer 1

C++ CODE:

#include<iostream>
#include<sstream>
using namespace std;
class IPHeader
{
public:
string srcip;
string destip;
IPHeader(string s,string d)
{
srcip=s;
destip=d;
}
bool valid()
{
if(checkValid(srcip,"Source IP")&&checkValid(destip,"Destination IP"))
return true;
return false;
}
bool checkValid(string ip,string side)
{
try
{
int n=ip.size();
int d1=0,d2=0,d3=0;
int count=0;
for(int i=0;i<n;i++)
{
if(ip[i]=='.')
{
if(count==0)
d1=i;
else if(count==1)
d2=i;
else if(count==2)
d3=i;
count++;
}
}
if(count!=3)
throw side;
stringstream s1(ip.substr(0,d1));
stringstream s2(ip.substr(d1+1,d2-d1-1));
stringstream s3(ip.substr(d2+1,d3-d2-1));
stringstream s4(ip.substr(d3+1,n-d3-1));
int n1=0,n2=0,n3=0,n4=0;
s1>>n1;
s2>>n2;
s3>>n3;
s4>>n4;
if(n1<0||n1>255||n2<0||n2>255||n3<0||n3>255||n4<0||n4>255)
throw side;
return true;
}
catch(string side)
{
cout<<"Invalid IP Header - "<<side<<" Address is invalid"<<endl;
return false;
}
}
};
int main()
{
IPHeader obj1("212.112.212.11","212.112.212.12");
if(obj1.valid())
cout<<"Valid IP Header"<<endl;
IPHeader obj2("212.112.212.333","212.112.212.33");
if(obj2.valid())
cout<<"Valid IP Header"<<endl;
return 0;
}

Output: