Comparing what RFC6570 based and "simple" URI template implementations can do.

UriTemplateCollectionExamples.java

/*
 * RFC6570
 */

Map<String, Object> values = new HashMap<String, Object>();
		values.put("count", Arrays.asList("one","two","three"));

UriComponentsBuilder.fromPath("{/count*}")
	.buildAndExpand(values).encode().toUriString(); // "/one/two/three"
				
UriComponentsBuilder.fromPath("{?count*}")
	.buildAndExpand(values).encode().toUriString(); // "?count=one&count=two&count=three"

UriComponentsBuilder.fromPath("{;count*}")
	.buildAndExpand(values).encode().toUriString(); // ";count=one;count=two;count=three"

/*
 * Current implementation
 */

UriTemplateMapExamples.java

/*
 * RFC6570
 */
Map<String, Object> keys = new HashMap<String, Object>();
keys.put("foo","bar");
keys.put("uri","template");
keys.put("rfc","6570");

Map<String, Object> values = new HashMap<String, Object>();
values.put("keys", keys);

UriComponentsBuilder.fromPath("{?keys*}")
	.buildAndExpand(values).encode().toUriString(); // "?foo=bar&uri=template&rfc=6570"

/*
 * Current implementation
 */

UriTemplateSimpleExamples.java

/*
 * RFC6570
 */
Map<String, Object> keys = new HashMap<String, Object>();
keys.put("foo","fooval");
keys.put("bar","barval");
keys.put("baz","bazval");

Map<String, Object> values = new HashMap<String, Object>();
values.put("keys", keys);
UriComponentsBuilder.fromPath("{/foo,/bar,/baz}") // same as "/{foo}/{bar}/{baz}"
  .buildAndExpand(values).encode().toUriString(); // "/fooval/barval/bazval"

/*
 * Current implementation
 */

UriComponentsBuilder.fromPath("{foo}").pathSegment("{bar}")
  .pathSegment("baz").buildAndExpand(values).encode().toUriString(); // "/fooval/barval/bazval"