[[uricomponents]] = UriComponents [.small]#Spring MVC and Spring WebFlux# `UriComponentsBuilder` helps to build URI's from URI templates with variables, as the following example shows: [tabs] ====== Java:: + [source,java,indent=0,subs="verbatim,quotes",role="primary"] ---- UriComponents uriComponents = UriComponentsBuilder .fromUriString("https://example.com/hotels/{hotel}") // <1> .queryParam("q", "{q}") // <2> .encode() // <3> .build(); // <4> URI uri = uriComponents.expand("Westin", "123").toUri(); // <5> ---- <1> Static factory method with a URI template. <2> Add or replace URI components. <3> Request to have the URI template and URI variables encoded. <4> Build a `UriComponents`. <5> Expand variables and obtain the `URI`. Kotlin:: + [source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"] ---- val uriComponents = UriComponentsBuilder .fromUriString("https://example.com/hotels/{hotel}") // <1> .queryParam("q", "{q}") // <2> .encode() // <3> .build() // <4> val uri = uriComponents.expand("Westin", "123").toUri() // <5> ---- <1> Static factory method with a URI template. <2> Add or replace URI components. <3> Request to have the URI template and URI variables encoded. <4> Build a `UriComponents`. <5> Expand variables and obtain the `URI`. ====== The preceding example can be consolidated into one chain and shortened with `buildAndExpand`, as the following example shows: [tabs] ====== Java:: + [source,java,indent=0,subs="verbatim,quotes",role="primary"] ---- URI uri = UriComponentsBuilder .fromUriString("https://example.com/hotels/{hotel}") .queryParam("q", "{q}") .encode() .buildAndExpand("Westin", "123") .toUri(); ---- Kotlin:: + [source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"] ---- val uri = UriComponentsBuilder .fromUriString("https://example.com/hotels/{hotel}") .queryParam("q", "{q}") .encode() .buildAndExpand("Westin", "123") .toUri() ---- ====== You can shorten it further by going directly to a URI (which implies encoding), as the following example shows: [tabs] ====== Java:: + [source,java,indent=0,subs="verbatim,quotes",role="primary"] ---- URI uri = UriComponentsBuilder .fromUriString("https://example.com/hotels/{hotel}") .queryParam("q", "{q}") .build("Westin", "123"); ---- Kotlin:: + [source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"] ---- val uri = UriComponentsBuilder .fromUriString("https://example.com/hotels/{hotel}") .queryParam("q", "{q}") .build("Westin", "123") ---- ====== You can shorten it further still with a full URI template, as the following example shows: [tabs] ====== Java:: + [source,java,indent=0,subs="verbatim,quotes",role="primary"] ---- URI uri = UriComponentsBuilder .fromUriString("https://example.com/hotels/{hotel}?q={q}") .build("Westin", "123"); ---- Kotlin:: + [source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"] ---- val uri = UriComponentsBuilder .fromUriString("https://example.com/hotels/{hotel}?q={q}") .build("Westin", "123") ---- ====== [[uribuilder]] = UriBuilder [.small]#Spring MVC and Spring WebFlux# <> implements `UriBuilder`. You can create a `UriBuilder`, in turn, with a `UriBuilderFactory`. Together, `UriBuilderFactory` and `UriBuilder` provide a pluggable mechanism to build URIs from URI templates, based on shared configuration, such as a base URL, encoding preferences, and other details. You can configure `RestTemplate` and `WebClient` with a `UriBuilderFactory` to customize the preparation of URIs. `DefaultUriBuilderFactory` is a default implementation of `UriBuilderFactory` that uses `UriComponentsBuilder` internally and exposes shared configuration options. The following example shows how to configure a `RestTemplate`: [tabs] ====== Java:: + [source,java,indent=0,subs="verbatim,quotes",role="primary"] ---- // import org.springframework.web.util.DefaultUriBuilderFactory.EncodingMode; String baseUrl = "https://example.org"; DefaultUriBuilderFactory factory = new DefaultUriBuilderFactory(baseUrl); factory.setEncodingMode(EncodingMode.TEMPLATE_AND_VALUES); RestTemplate restTemplate = new RestTemplate(); restTemplate.setUriTemplateHandler(factory); ---- Kotlin:: + [source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"] ---- // import org.springframework.web.util.DefaultUriBuilderFactory.EncodingMode val baseUrl = "https://example.org" val factory = DefaultUriBuilderFactory(baseUrl) factory.encodingMode = EncodingMode.TEMPLATE_AND_VALUES val restTemplate = RestTemplate() restTemplate.uriTemplateHandler = factory ---- ====== The following example configures a `WebClient`: [tabs] ====== Java:: + [source,java,indent=0,subs="verbatim,quotes",role="primary"] ---- // import org.springframework.web.util.DefaultUriBuilderFactory.EncodingMode; String baseUrl = "https://example.org"; DefaultUriBuilderFactory factory = new DefaultUriBuilderFactory(baseUrl); factory.setEncodingMode(EncodingMode.TEMPLATE_AND_VALUES); WebClient client = WebClient.builder().uriBuilderFactory(factory).build(); ---- Kotlin:: + [source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"] ---- // import org.springframework.web.util.DefaultUriBuilderFactory.EncodingMode val baseUrl = "https://example.org" val factory = DefaultUriBuilderFactory(baseUrl) factory.encodingMode = EncodingMode.TEMPLATE_AND_VALUES val client = WebClient.builder().uriBuilderFactory(factory).build() ---- ====== In addition, you can also use `DefaultUriBuilderFactory` directly. It is similar to using `UriComponentsBuilder` but, instead of static factory methods, it is an actual instance that holds configuration and preferences, as the following example shows: [tabs] ====== Java:: + [source,java,indent=0,subs="verbatim,quotes",role="primary"] ---- String baseUrl = "https://example.com"; DefaultUriBuilderFactory uriBuilderFactory = new DefaultUriBuilderFactory(baseUrl); URI uri = uriBuilderFactory.uriString("/hotels/{hotel}") .queryParam("q", "{q}") .build("Westin", "123"); ---- Kotlin:: + [source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"] ---- val baseUrl = "https://example.com" val uriBuilderFactory = DefaultUriBuilderFactory(baseUrl) val uri = uriBuilderFactory.uriString("/hotels/{hotel}") .queryParam("q", "{q}") .build("Westin", "123") ---- ====== [[uri-encoding]] = URI Encoding [.small]#Spring MVC and Spring WebFlux# `UriComponentsBuilder` exposes encoding options at two levels: * {api-spring-framework}/web/util/UriComponentsBuilder.html#encode--[UriComponentsBuilder#encode()]: Pre-encodes the URI template first and then strictly encodes URI variables when expanded. * {api-spring-framework}/web/util/UriComponents.html#encode--[UriComponents#encode()]: Encodes URI components _after_ URI variables are expanded. Both options replace non-ASCII and illegal characters with escaped octets. However, the first option also replaces characters with reserved meaning that appear in URI variables. TIP: Consider ";", which is legal in a path but has reserved meaning. The first option replaces ";" with "%3B" in URI variables but not in the URI template. By contrast, the second option never replaces ";", since it is a legal character in a path. For most cases, the first option is likely to give the expected result, because it treats URI variables as opaque data to be fully encoded, while the second option is useful if URI variables do intentionally contain reserved characters. The second option is also useful when not expanding URI variables at all since that will also encode anything that incidentally looks like a URI variable. The following example uses the first option: [tabs] ====== Java:: + [source,java,indent=0,subs="verbatim,quotes",role="primary"] ---- URI uri = UriComponentsBuilder.fromPath("/hotel list/{city}") .queryParam("q", "{q}") .encode() .buildAndExpand("New York", "foo+bar") .toUri(); // Result is "/hotel%20list/New%20York?q=foo%2Bbar" ---- Kotlin:: + [source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"] ---- val uri = UriComponentsBuilder.fromPath("/hotel list/{city}") .queryParam("q", "{q}") .encode() .buildAndExpand("New York", "foo+bar") .toUri() // Result is "/hotel%20list/New%20York?q=foo%2Bbar" ---- ====== You can shorten the preceding example by going directly to the URI (which implies encoding), as the following example shows: [tabs] ====== Java:: + [source,java,indent=0,subs="verbatim,quotes",role="primary"] ---- URI uri = UriComponentsBuilder.fromPath("/hotel list/{city}") .queryParam("q", "{q}") .build("New York", "foo+bar"); ---- Kotlin:: + [source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"] ---- val uri = UriComponentsBuilder.fromPath("/hotel list/{city}") .queryParam("q", "{q}") .build("New York", "foo+bar") ---- ====== You can shorten it further still with a full URI template, as the following example shows: [tabs] ====== Java:: + [source,java,indent=0,subs="verbatim,quotes",role="primary"] ---- URI uri = UriComponentsBuilder.fromUriString("/hotel list/{city}?q={q}") .build("New York", "foo+bar"); ---- Kotlin:: + [source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"] ---- val uri = UriComponentsBuilder.fromUriString("/hotel list/{city}?q={q}") .build("New York", "foo+bar") ---- ====== The `WebClient` and the `RestTemplate` expand and encode URI templates internally through the `UriBuilderFactory` strategy. Both can be configured with a custom strategy, as the following example shows: [tabs] ====== Java:: + [source,java,indent=0,subs="verbatim,quotes",role="primary"] ---- String baseUrl = "https://example.com"; DefaultUriBuilderFactory factory = new DefaultUriBuilderFactory(baseUrl) factory.setEncodingMode(EncodingMode.TEMPLATE_AND_VALUES); // Customize the RestTemplate.. RestTemplate restTemplate = new RestTemplate(); restTemplate.setUriTemplateHandler(factory); // Customize the WebClient.. WebClient client = WebClient.builder().uriBuilderFactory(factory).build(); ---- Kotlin:: + [source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"] ---- val baseUrl = "https://example.com" val factory = DefaultUriBuilderFactory(baseUrl).apply { encodingMode = EncodingMode.TEMPLATE_AND_VALUES } // Customize the RestTemplate.. val restTemplate = RestTemplate().apply { uriTemplateHandler = factory } // Customize the WebClient.. val client = WebClient.builder().uriBuilderFactory(factory).build() ---- ====== The `DefaultUriBuilderFactory` implementation uses `UriComponentsBuilder` internally to expand and encode URI templates. As a factory, it provides a single place to configure the approach to encoding, based on one of the below encoding modes: * `TEMPLATE_AND_VALUES`: Uses `UriComponentsBuilder#encode()`, corresponding to the first option in the earlier list, to pre-encode the URI template and strictly encode URI variables when expanded. * `VALUES_ONLY`: Does not encode the URI template and, instead, applies strict encoding to URI variables through `UriUtils#encodeUriVariables` prior to expanding them into the template. * `URI_COMPONENT`: Uses `UriComponents#encode()`, corresponding to the second option in the earlier list, to encode URI component value _after_ URI variables are expanded. * `NONE`: No encoding is applied. The `RestTemplate` is set to `EncodingMode.URI_COMPONENT` for historic reasons and for backwards compatibility. The `WebClient` relies on the default value in `DefaultUriBuilderFactory`, which was changed from `EncodingMode.URI_COMPONENT` in 5.0.x to `EncodingMode.TEMPLATE_AND_VALUES` in 5.1.