Adding onto the other Educator's response, I'll offer these additional similarities that I notice between the Hughes poem "Pushcart Man" and Joyce's Dubliners:

1. Some characters have no names and appear to live in shadows, like the titular Pushcart Man as well as the girl in Dubliners known only as Mangan's sister.

2. The poem "Pushcart Man" appears as part of a collection of stories in a literally poetic form, while Dubliners is a collection of stories written in highly poetic prose.

3. Both texts are rich in figurative language which creates a sense of exciting, almost magical motion, such as the line "pushing shadows away" from the poem and the line "shook music from the buckled harness" from Dubliners.

Also, since you asked for a contrast as well between the texts, let's notice how bright and joyful the tone is in "Pushcart Man," and how consistently dark and ominous the tone is throughout Dubliners.

Now, interestingly, Langston Hughes also wrote a short story called "Pushcart Man," which might have been the work you were originally asking about.

In that case, let's compare and contrast that story with those of James Joyce in Dubliners:

1. Some scenes in both texts take place in crowded cities, especially rowdy bars.

2. Both texts touch on serious issues of poverty, religion, violence, and childhood strife, as well as figurative blindness (and in the case of "Pushcart Man," literal blindness).

3. While the stories in Dubliners rely a great deal on narration and description, the "Pushcart Man" story relies almost entirely on dialogue.

4. In both texts, some characters are named, while others are simply known by various titles, such as, in the story "Pushcart Man," "the girl," "the Sport Shirt," and of course, the character known as "the Pushcart Man."

These are two very interesting texts to compare. On the face of it, "Pushcart Man" is a rather simplistic poem about the pushcart man who gives his name to the title of the poem and who brings with him a sense of happiness and makes the speaker realise how happy he is. As the speaker sees the pushcart man, "pushing shadows away," he seems to undergo a kind of epiphany whereby he realises how happy he is. Metaphorically, this is described through the description of a garden and fresh vegetables:

Look! Springtime I've found...
I've got a garden all day.
Carrots and string-beans,
Cabbages-greens!
Brocoli's like a bouquet!

The "garden" that the reader discovers is internal, and the verdant vegetables, that are compared to flowers are representative of his own happiness and joy in life. The reference to "Springtime I've found" clearly indicates the way in which the sight of the pushcart man has triggered off some inner-realisation of how happy the speaker is.

The central comparison that this poem has with Joyce's collection of short stories is that of epiphany. Whereas in "Pushcart Man" the epiphany is one of happiness, generally in these short stories the epiphany is one of great sadness. Consider the narrator in "Araby," for example, who spends most of the story lost in his own illusions about his relationship with Mangan's daughter and his romantic view of the bazaar he goes to. When he gets there, however, he sees himself for who he really is:

Gazing up into the darkness I saw myself as a creature driven and derided by vanity; and my eyes burned with anguish and anger.

The narrator of this text realises certain things about himself that bring self-knowledge but also immense pain. This is the chief point of comparison with "Pushcart Man" as both texts involve epiphanies but the nature of that epiphany is very different.