Who knows the name of the fruit picked by the roadside?

Scientific name: Syzygium syzygium, Baidu pictures can verify it

Syzygium sylvestris, also called grapefruit, is an evergreen tree of the Myrtaceae family. Fruit tree native to Southeast Asia. There are wild grape peaches in Hainan and artificially cultivated grapes in South China. Grape peaches can be cultivated as windbreaks and the fruits are edible. Syzygium is also known as fragrant fruit, wind drum, water grape peach, and water pomegranate. In the subtropical areas of South China, it blooms from March to April every year, and the fruits mature from May to July. It has strong adaptability and does not have much choice in soil. It can be planted in various soils and grows well on sandy soil. Fertile, deep and moist soil is the best.