What spirit does this righteous poem express for the author?

Yi Shi expresses the poet's upright and indomitable revolutionary spirit, reveals the national integrity of the author who is unwilling to be enslaved and conquered by the people, deeply regrets that he cannot die in the battlefield of the Anti-Japanese War, is extremely worried about the future of the nation, and puts his personal life and death in danger.

Xia, the author of Yi Shi, was arrested by reactionaries in Hankou on February 8, 1928, and died heroically the next day. I wrote this heroic poem before the execution. Xia was arrested on February 8 1928. In prison, the enemy first tried to buy him off, but he resolutely replied, "No way. You can sacrifice my life and never give up my faith. " The enemy tortured him again. He would rather die than surrender. The enemy was at a loss and became angry from embarrassment. Finally, he killed Comrade Xia. Before the execution, the murderer asked him if he had any last words. He scribbled down this magnificent poem.