Since then, his 'revolutionary tradition and national moral excellence' have been lauded in the official media by senior cadres fearful that China's establishment of a socialist market economy has gone hand in hand with society's complete moral disintegration. The market economy being the force it is these days, however, the whole hero experience is proving increasingly profitable for Mr Xu.
The front page of yesterday's People's Daily featured the party chief, Jiang Zemin, and the Prime Minister, Li Peng, both applauding young Mr Xu - a 'heroic soldier who defies brutal force and takes up the cudgels for a just cause', according to the Prime Minister.
In the highest accolade, Mr Xu is being heralded as China's new Lei Feng. Mr Lei was a young soldier who died in 1962 at the age of 22 when a wooden pole fell on his head. It was not until the following year that his 'found' diary conveniently revealed that his earlier life had been considerably more politically correct than the manner of his death.
His overwhelming desire had been to be 'a rustless screw in the machine of the revolution', something he was deemed to have achieved by a blameless life helping the poor, doing menial jobs and devoting himself to the revolutionary cause.
In 1963 Mao Tse-tung launched the 'Learn from Lei Feng' campaign that dogged the upbringing of a generation of Chinese. In 1990, in the wake of the Tiananmen Square crackdown, the party tried to revive the Lei Feng myth, but after a decade of economic reform it proved rather a flop.
So now it is 'Learn from Xu Honggang'. Mr Xu, by happy coincidence also 22 and also a People's Liberation Army soldier, has now taken up the job of preaching social responsibility. Amid rising corruption, crime and an apparent moral vacuum in contemporary China, serving the people has gone out of fashion. 'People just want to make money and only think of themselves,' said one old man.
The media campaign is rather like a Chinese version of 'back to basics'. The public hero status of Mr Xu was apparently sanctioned at as high a level as Mr Zemin. Television features, newspaper profiles, public lectures now all focus on Xu Honggang.
It was last August that Mr Xu was on a bus in Sichan province when four men demanded money from a woman and assaulted her. According to an official version, her husband was too timid to take on the 'rascals'. Mr Xu, not in uniform, went to her rescue and was stabbed 14 times. But he still chased the men 50 yards and was then rushed to hospital. The robbers were caught and one later executed.
Even heroes need some incentives in modern China, however. Last June the Chinese government set up a fund to encourage and reward brave citizens. Last August, honorary titles were awarded to 119 brave people in Peking. All over the country, provinces are setting up bravery funds so that heroes know there is hard cash at the end of the day.
Mr Xu is not doing too badly. He reportedly received on average 180 visitors a day during his month in hospital. And, by the beginning of this year, well-wishers had given him more than pounds 1,000 - about two and a half years of his soldier's salary.