A seven year old who swears is learning the words and hearing them used somewhere. So, I'd check and make sure that his friends are appropriate, and that people at home are not using swearing to voice their opinions.
I'll likely get downvoted for this, but: swear words are just words much of the time. IMO, there is a world of difference between saying "Eff!" if he hurts himself and him being aggressive and saying "Eff YOU!" when he is angry at another person. "Eff you" is aggression and is for me, different than an expression of pain or fear. IF your child is aggressive, this advice is on the wrong track -- though to break the habit it works.
A swearing jar is a neutral way to help everyone in the family reduce swearing. The money comes from allowance for extras, not from money for school supplies, or other necessary items. All people have expenses and taking money from those expenses is not what I am talking about. It's the money for the candy, or potato snacks...
Every family member (even you) has a sliding scale for their swearing fine. A person who has 20 dollars a week spending money pays $1 a swear word. A person getting 5$ pays 25 cents. A parent might pay 2$. Make a semi-big deal when you have to pay a fine yourself, so that the seven year old sees that the rules apply to all. When there is a fair amount of money in the jar, buy something for everyone. The money is not yours or theirs, it belongs to the entire family.
It isn't that swearing is so bad, but is not appropriate in many situations. Most adults have learned to swear in the right place and time without thinking. We 'automatically' don't swear in a job interview, for example. Think of it as building vocabulary to make us look smarter. A person whose only adjective is the eff word sounds less intelligent, in spite of that being an assumption and not always the truth.
As for shouting, it is sort of like hitting and it is not recommended for child rearing. It teaches children that 'this is the way to solve problems'. If you can, try to limit shouting to danger situations. In my own experience, talking even more quietly than usual works really well.
There are other questions and answers in this site that discuss shouting or yelling. I do not of course know your situation, but if you need help to stop yelling, there are often parenting classes and counselling available, even for free though government and religious agencies.Here is one of many links on this site.