In the short story "The Escape", by J. B. Stamper identify the theme, type of conflict, types of characters, any foreshadowing, and any cliffhangers?

The theme of "The Escape" by J. B. Stamper is punishment. Boris is being punished for what's described as a terrible crime. He fully admits that he did it. He decides to escape that punishment—and finds an even worse punishment for a man with his phobias.
Boris laments his punishment, despite deserving it. Though he doesn't try to pretend innocence, he still chooses to escape what is clearly a just imprisonment. He's willing to take any chance to escape and feels hope on his first night in solitary when he sees a crack in the cement around a stone on the wall.
Ultimately, however, each escape attempt only leads to a worse punishment. Boris is sent to solitary confinement because of his first attempt to escape. His second attempt leaves him trapped in a small area, surrounded by his greatest fear—rats. He creates his own punishment three times: first by committing a crime and the next two times by trying to escape.
There is both an internal and an external conflict in "The Escape." The internal conflict is Boris's choice whether to escape into the tunnel or not. He wrestles internally with his fear of rats, which he knows he'll face if he enters the passageway. The external conflict is the actual act of trying to escape from prison—he has to overcome obstacles like rats, small spaces, and an uncertain path. The encouraging note from the previous occupant of the cell is what enables him to go forward from his internal conflict to begin dealing with the external conflict.
The only important character in "The Escape" is Boris, the convict. He's a static character because he doesn't change during the story. He's also the protagonist, the leading character in the story. Boris is not a good man; he thinks to himself that he committed "a crime so terrible that even he could not believe he had done it" (6).
Despite the awfulness of his crime, Boris wants to escape from prison. He tries once and is thwarted by a guard. His punishment is being put into solitary confinement. There, he finds another escape route.
The reason Boris is a flat character is clear when you examine his personality and desires at the beginning and end of the story. He doesn't change; being trapped doesn't make him regret his crime. He doesn't accept his punishment. Being caught in the first escape attempt doesn't stop him from attempting to escape a second time. 
A secondary character in the story is the guard, who is there only to take Boris to solitary confinement and to reaffirm to the reader that Boris's crime was a bad one. He says, "I know what you did to get inside. You don't deserve anyone's pity." The guard is a kind of stock character, which means he's a character recognizable to most readers. There is no character development for him, and he has no individual personality traits. He just functions as a prison guard.
Foreshadowing is when an author hints at something that will take place later in the story. There are several examples of foreshadowing in "The Escape." Each of them is a clue to the reader about how Boris's story will end.
Even the first sentence is a hint about where Boris will be stuck at the end of the story. Stamper writes, "Boris looked down the long, dark hallway of the prison. It looked endless" (4). When the story reaches its conclusion, Boris is trapped by a long, dark tunnel that he will likely never escape.
Soon after, Stamper writes of Boris, "He knew there was no hope for him" (6). This could be a clue indicating that Boris ends up stuck in a place where he will likely die. The last sentence of the story echoes this line when he recognizes he can't escape. 
Another hint lies in Boris's thoughts about his situation. He thinks, "He was trapped like an animal in a cage" (6). By the end of the story, he is literally trapped with animals. He's kept from going back by the tunnel and kept from moving forward by a gate.
Stamper also uses Boris's fear of rats to foreshadow what will happen to him when he tries to escape. It also heightens his internal conflict, because entering the tunnel could—and actually does—mean the realization of his biggest fear. Stamper writes,

Thunder woke Boris from a terrible nightmare. In the meantime, rats were running at him, screeching.
He opened his eyes. He was afraid the rats were really there. He hated rats more than anything. It was his biggest worry . . . that there might be rats in solitary. (9)

Stamper uses Boris's biggest fear to foreshadow what will happen to him when he escapes into the tunnel.
It could be argued that there aren't any cliffhangers in "The Escape." A cliffhanger is a part of a story that ends with suspense to keep the reader excited and interested to read the next part. Since "The Escape" is a short story and there is no continuation, the reader is with Boris for his entire story. The climax—when Boris discovers the skeleton of the prisoner and realizes he's stuck in the tunnel permanently—is the highest point of tension for the story.
Though it's possible that Boris could be saved from the tunnel, there is no indication in the story that it will happen. Readers can be left to assume that he will share the tunnel with the rats until he dies. Stamper writes,

There was no escape. There was no going back. Just Boris . . . and the rats. (15)

Since the reader knows Boris's fate and there is no second act to the story, there is no cliffhanger.