双曲线\(C: \dfrac {x^{2}}{a^{2}}- \dfrac {y^{2}}{b^{2}}=1(a > 0,b > 0)\)的左、右焦点分别为\(F _{1} (-c , 0)\)、\(F _{2} (c , 0)\),过\(F _{1}\)且斜率为\( \sqrt {3}\)的直线与双曲线的左、右两支分别交于点\(A\)、\(B(B\)在右侧\()\),若\(( \overrightarrow {BA}+ \overrightarrow {BF_{2}})\cdot \overrightarrow {AF_{2}}=0\),则\(C\)的离心率为______.