iOS json data transmission problems

The correct data: {"display": ["images \ / background1 \ / glass \ / display \ / 1-3-001.png", "images \ / background1 \ / glass \ / display \ / 1-3 - 002.png "," images \ / background1 \ / glass \ / display \ / 1-3-003.png "], select": ["images \ / background1 \ / glass \ / select \ / 1-4-001 . png "," images \ / background1 \ / glass \ / select \ / 1-4-002.png "," images \ / background1 \ / glass \ / select \ / 1-4-003.png "]} < br />But sometimes the back of some characters will be truncated into {"display": ["images \ / background1 \ / glass \ / display \ / 1-3-001.png", "images \ / background1 \ / glass \ / display \ / 1-3-002.png "," images \ / background1 \ / glass \ / display \ / 1-3-003.png "], select": ["images \ / background1 \ / glass \ / select \ / 1-4-001.png "," images \ / background1 \ / glass \ / select \ / 1-4-002.png "," images \ / background
When a larger amount of data when the complete data transmission even lower probability of success. . May I ask how is this going?
Reply:
This data is not a big ah, is not what is the problem code, http transport finished it?