What is the meaning of "Pear Blossom Ode" in "Wang Changling's Collected Poems"

"Ode to Pear Blossoms" is a poem written by Wang Changling when he went to Jiangning to take office in the 29th year of Kaiyuan (741). Although Lingnan was pardoned and Jiang Ningcheng was re-appointed, Wang Changling saw clearly the corruption of the court, so he used the whiteness of pear blossoms to praise the upright, pure and noble character and encourage himself.