If you attend court and go into the witness box they will put your original statement to you hearsay and he will be convicted.
The lessons are these
1 Never call the police to a domestic squabble unless you want to end the relationship.
2 If you have done that, never make a statement. That includes not signing officer's notebooks. If the police meet with a wall of silence its game over for the Crown.
3 If you have done that, never tell them you want to withdraw. If you do so, they will use it to get a summons against you whereas if you'd kept quiet they would not have got one.
The potential solutions are these
1 Ignore the summons. Many women do so. I would not really advise it not least because they can send you to prison for three months for contempt of court. They never prosecute but you cannot ignore the risk.
2 There is a debate over whether or not attending court and refusing to go into the witness box amounts to a contempt of court. If all witnesses do that it is very effective because the prosecution cannot carry on. The trouble with it is that sometimes witnesses do break.
3 On no account give evidence though unless you want him to be convicted. Your retraction statement will be disbelieved.
Also, you do need to note this. They can make a restraining order to prevent him having contact with his wife even if he is acquitted. If this is the first incident then it probably won't happen but if she calls the police again to another domestic row, he will go on a restraining order for certain.
The days when people could call the police and then control events thereafter have gone I'm afraid.