JSON中get和opt的区别

　　get()取值不正确会抛出异常，必须用try catch或者throw包起
　　而opt()取值不正确则会试图进行转化或者输出友好值，不会抛出异常
　　opt
　　public java.lang.Object opt(java.lang.String key)

　　Get an optional value associated with a key.
　　

　　Parameters:
　　key - A key string.
　　Returns:
　　An object which is the value, or null if there is no value.
　　
　　optDouble
　　public double optDouble(java.lang.String key)

　　Get an optional double associated with a key, or NaN if there is no such key or if its value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.
　　optBoolean
　　public boolean optBoolean(java.lang.String key)

　　Get an optional boolean associated with a key. It returns false if there is no such key, or if the value is not
　　optInt
　　public int optInt(java.lang.String key)

　　Get an optional int value associated with a key, or zero if there is no such key or if the value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.

应该是post吧，这个是两种请求的区别，跟json没关系的