public boolean fileExists(String uri) {
		Assert.hasText(uri, "uri can not be empty nor null");
		return shell.test(uri);
	}
Verifies that the file exists.

@param uri The uri of the file to verify.
@return True if it exists else false.
spring-xd-integration-test/src/main/java/org/springframework/xd/integration/util/HadoopUtils.java