{"id":831,"date":"2016-06-26T06:00:40","date_gmt":"2016-06-26T09:00:40","guid":{"rendered":"https:\/\/www.semeru.com.br\/blog\/?p=831"},"modified":"2022-12-21T11:32:49","modified_gmt":"2022-12-21T14:32:49","slug":"aplicacoes-restfull-hateoas-com-springboot","status":"publish","type":"post","link":"https:\/\/www.semeru.com.br\/blog\/aplicacoes-restfull-hateoas-com-springboot\/","title":{"rendered":"Aplica\u00e7\u00f5es RESTful HATEOAS com SpringBoot"},"content":{"rendered":"

 <\/p>\n

O HATEOAS<\/strong>, \u00e9 uma das principais constraints arquiteturais do REST<\/strong> e possibilita a navega\u00e7\u00e3o entre recursos, que s\u00e3o representa\u00e7\u00f5es dos modelos de neg\u00f3cio da aplica\u00e7\u00e3o. Esse post \u00e9 bem m\u00e3o na massa e se quiser aprofundar um pouco mais em conceitos te\u00f3ricos de HATEOAS<\/strong> confira o nosso post Entendendo HATEOAS<\/strong><\/a>. Vamos tomar como base a aplica\u00e7\u00e3o desenvolvida no nosso outro post Documentando aplica\u00e7\u00f5es REST com SpringBoot e Swagger<\/a>. Para come\u00e7ar voc\u00ea pode baixar o c\u00f3digo deste post aqui<\/a> e descompactar o arquivo zip e importar na sua IDE preferida ou clonar usando Git:<\/p>\n

 <\/p>\n

\ngit clone https:\/\/github.com\/leandrocgsi\/simple-rest-example-swagger.git\n<\/pre>\n
 <\/p>\n
Primeiro altere o pom.xml<\/em><\/strong> adicionando os trechos destacados por coment\u00e1rios abaixo.<\/p>\n
 <\/p>\n
\n<project xmlns="http:\/\/maven.apache.org\/POM\/4.0.0" xmlns:xsi="http:\/\/www.w3.org\/2001\/XMLSchema-instance" xsi:schemalocation="http:\/\/maven.apache.org\/POM\/4.0.0 http:\/\/maven.apache.org\/xsd\/maven-4.0.0.xsd">\n    <modelversion>4.0.0<\/modelversion>\n\n    <groupid>br.com.erudio<\/groupid>\n    <artifactid>simple-rest-example-hateoas<\/artifactid>\n    <version>0.0.1-SNAPSHOT<\/version>\n\n    <parent>\n        <groupid>org.springframework.boot<\/groupid>\n        <artifactid>spring-boot-starter-parent<\/artifactid>\n        <version>1.3.3.RELEASE<\/version>\n    <\/parent>\n\n    <dependencies>\n\n        <dependency>\n            <groupid>org.springframework.boot<\/groupid>\n            <artifactid>spring-boot-starter-web<\/artifactid>\n        <\/dependency>\n        <dependency>\n            <groupid>org.springframework.boot<\/groupid>\n            <artifactid>spring-boot-starter-actuator<\/artifactid>\n        <\/dependency>\n\n        <!-- Adicione a dependencia de HATEOAS-->\n        <dependency>\n            <groupid>org.springframework.boot<\/groupid>\n            <artifactid>spring-boot-starter-hateoas<\/artifactid>\n        <\/dependency>\n\n        <dependency>\n            <groupid>com.mangofactory<\/groupid>\n            <artifactid>swagger-springmvc<\/artifactid>\n            <version>1.0.0<\/version>\n        <\/dependency>\n        <dependency>\n            <groupid>org.ajar<\/groupid>\n            <artifactid>swagger-spring-mvc-ui<\/artifactid>\n            <version>0.4<\/version>\n        <\/dependency>\n        <dependency>\n            <groupid>org.apache.tomcat.embed<\/groupid>\n            <artifactid>tomcat-embed-jasper<\/artifactid>\n            <scope>provided<\/scope>\n        <\/dependency>\n\n        <!-- Adicione as dependencias de teste -->\n        <dependency>\n            <groupid>org.springframework.boot<\/groupid>\n            <artifactid>spring-boot-starter-test<\/artifactid>\n            <scope>test<\/scope>\n        <\/dependency>\n        <dependency>\n            <groupid>com.jayway.jsonpath<\/groupid>\n            <artifactid>json-path<\/artifactid>\n            <scope>test<\/scope>\n        <\/dependency>        \n\n    <\/dependencies>\n\n    <properties>\n        <java.version>1.8<\/java.version>\n    <\/properties>\n\n    <build>\n        <plugins>\n            <plugin>\n                <groupid>org.springframework.boot<\/groupid>\n                <artifactid>spring-boot-maven-plugin<\/artifactid>\n            <\/plugin>\n        <\/plugins>\n    <\/build>\n\n    <repositories>\n        <repository>\n            <id>spring-releases<\/id>\n            <url>https:\/\/repo.spring.io\/libs-release<\/url>\n        <\/repository>\n        <repository>\n            <id>jcenter-release<\/id>\n            <name>jcenter<\/name>\n            <url>http:\/\/oss.jfrog.org\/artifactory\/oss-release-local\/<\/url>\n        <\/repository>\n    <\/repositories>\n\n    <pluginrepositories>\n        <pluginrepository>\n            <id>spring-releases<\/id>\n            <url>https:\/\/repo.spring.io\/libs-release<\/url>\n        <\/pluginrepository>\n    <\/pluginrepositories>\n\n<\/project>\n<\/pre>\n
 <\/p>\n
Primeiro vamos alterar a classe Greeting<\/strong> que agora ira extender ResourceSupport<\/strong>.<\/p>\n
 <\/p>\n
\npackage br.com.erudio.models;\n\nimport org.springframework.hateoas.ResourceSupport;\n\nimport com.fasterxml.jackson.annotation.JsonCreator;\nimport com.fasterxml.jackson.annotation.JsonProperty;\n\npublic class Greeting extends ResourceSupport {\n\n    private final long idGreeting;\n    private final String content;\n\n    @JsonCreator\n    public Greeting(@JsonProperty("id") long id, @JsonProperty("content") String content) {\n        this.idGreeting = id;\n        this.content = content;\n    }\n\n    public long getIdGreeting() {\n        return idGreeting;\n    }\n\n    public String getContent() {\n        return content;\n    }\n}\n\n<\/pre>\n
 <\/p>\n
Agora adicione os trechos comentados a classe GreetingController<\/strong>.<\/p>\n
 <\/p>\n
\npackage br.com.erudio.web.controllers;\n\nimport static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo;\nimport static org.springframework.hateoas.mvc.ControllerLinkBuilder.methodOn;\n\nimport java.util.concurrent.atomic.AtomicLong;\n\nimport org.springframework.http.HttpEntity;\nimport org.springframework.http.HttpStatus;\nimport org.springframework.http.MediaType;\nimport org.springframework.http.ResponseEntity;\nimport org.springframework.web.bind.annotation.RequestMapping;\nimport org.springframework.web.bind.annotation.RequestMethod;\nimport org.springframework.web.bind.annotation.RequestParam;\nimport org.springframework.web.bind.annotation.ResponseStatus;\nimport org.springframework.web.bind.annotation.RestController;\n\nimport com.wordnik.swagger.annotations.Api;\nimport com.wordnik.swagger.annotations.ApiOperation;\n\nimport br.com.erudio.models.Greeting;\n\n@Api(value = "greeting")\n@RestController\n@RequestMapping("\/greeting")\npublic class GreetingController {\n\n    private static final String template = "Hello, %s!";\n    private final AtomicLong counter = new AtomicLong();\n\n\t@ApiOperation(value = "Show Greeting Message" )\n\t@ResponseStatus(HttpStatus.OK)\n    @RequestMapping(method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)\n    public HttpEntity<greeting> greeting(@RequestParam(value="name", defaultValue="World") String name) {\n\t\tGreeting greeting = new Greeting(counter.incrementAndGet(), String.format(template, name));\n\n\t\t\/\/ Na pr\u00e1tica essa linha adiciona uma auto refer\u00eancia ao pr\u00f3prio endpoint\n\t\t\/\/ e apenas esse pequeno trecho de c\u00f3digo j\u00e1 \u00e9 o suficiente para que o endpoint\n\t\t\/\/ greeting seja HATEOAS\n\t\tgreeting.add(linkTo(methodOn(GreetingController.class).greeting(name)).withSelfRel());\n\n\t\treturn new ResponseEntity<greeting>(greeting, HttpStatus.OK);\n    }\n}\n<\/pre>\n
 <\/p>\n
Se voc\u00ea iniciar a aplica\u00e7\u00e3o e acessar o endere\u00e7o localhost:8080\/greeting<\/strong><\/em> ver\u00e1 algo similar a imagem abaixo.<\/p>\n
\"postagem_4_0\"<\/a><\/p>\n
 <\/p>\n
\npackage br.com.erudio.models;\n\nimport java.io.Serializable;\n\nimport org.springframework.hateoas.ResourceSupport;\n\nimport com.fasterxml.jackson.annotation.JsonIgnoreProperties;\n\n\/\/ Adicione a anota\u00e7\u00e3o @JsonIgnoreProperties\n@JsonIgnoreProperties(ignoreUnknown = true)\n\n\/\/Extenda ResourceSupport\npublic class Person extends ResourceSupport implements Serializable{\n\n    private static final long serialVersionUID = 1L;\n\n\t\/\/ Por padr\u00e3o implementa\u00e7\u00e3o HATEOAS do Spring tem um atributo id\n\t\/\/ como default por isso o ID de nossa entidade deve ser alterado\n    private Long idPerson;\n    private String firstName;\n    private String lastName;\n    private String address;\n\n    public Person() {}\n\n\tpublic Long getIdPerson() {\n        return idPerson;\n    }\n\n    public void setIdPerson(Long id) {\n        this.idPerson = id;\n    }\n\n    public String getFirstName() {\n        return firstName;\n    }\n\n    public void setFirstName(String firstName) {\n        this.firstName = firstName;\n    }\n\n    public String getLastName() {\n        return lastName;\n    }\n\n    public void setLastName(String lastName) {\n        this.lastName = lastName;\n    }\n\n    public String getAddress() {\n        return address;\n    }\n\n    public void setAddress(String address) {\n        this.address = address;\n    }\n}\n<\/pre>\n
 <\/p>\n
Agora vamos alterar a classe PersonController<\/strong>:<\/p>\n
 <\/p>\n
\npackage br.com.erudio.web.controllers;\n\nimport static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo;\nimport static org.springframework.hateoas.mvc.ControllerLinkBuilder.methodOn;\n\nimport java.util.ArrayList;\nimport java.util.List;\n\nimport org.springframework.beans.factory.annotation.Autowired;\nimport org.springframework.http.HttpStatus;\nimport org.springframework.http.MediaType;\nimport org.springframework.web.bind.annotation.PathVariable;\nimport org.springframework.web.bind.annotation.RequestBody;\nimport org.springframework.web.bind.annotation.RequestMapping;\nimport org.springframework.web.bind.annotation.RequestMethod;\nimport org.springframework.web.bind.annotation.ResponseStatus;\nimport org.springframework.web.bind.annotation.RestController;\n\nimport com.wordnik.swagger.annotations.Api;\nimport com.wordnik.swagger.annotations.ApiOperation;\n\nimport br.com.erudio.models.Person;\nimport br.com.erudio.services.PersonService;\n\n@Api(value = "person")\n@RestController\n@RequestMapping("\/person\/")\npublic class PersonController {\n\n    @Autowired\n    private PersonService personService;\n\t@ApiOperation(value = "Find person by ID" )\n    @ResponseStatus(HttpStatus.OK)\n    @RequestMapping(value = "\/{personId}", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)\n    public Person get(@PathVariable(value = "personId") String personId){\n        Person person = personService.findById(personId);\n\n\t\t\/\/Adicione uma auto referencia ao m\u00e9todo get do controller passando o ID como par\u00e2metro\n        person.add(linkTo(methodOn(PersonController.class).get(personId)).withSelfRel());\n\t\treturn person;\n    }\n\n    .\n    .\n    .\n\n}\n<\/pre>\n
 <\/p>\n
Note que ao acessar esse recurso com uma ferramenta como o POSTman<\/strong> teremos uma resultado similar a imagem abaixo.<\/p>\n
 <\/p>\n
\"postagem_4_1\"<\/a><\/p>\n
 <\/p>\n
Agora vamos alterar o findAll<\/strong><\/em>:<\/p>\n
 <\/p>\n
\npackage br.com.erudio.web.controllers;\n\nimport static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo;\nimport static org.springframework.hateoas.mvc.ControllerLinkBuilder.methodOn;\n\nimport java.util.ArrayList;\nimport java.util.List;\n\nimport org.springframework.beans.factory.annotation.Autowired;\nimport org.springframework.http.HttpStatus;\nimport org.springframework.http.MediaType;\nimport org.springframework.web.bind.annotation.PathVariable;\nimport org.springframework.web.bind.annotation.RequestBody;\nimport org.springframework.web.bind.annotation.RequestMapping;\nimport org.springframework.web.bind.annotation.RequestMethod;\nimport org.springframework.web.bind.annotation.ResponseStatus;\nimport org.springframework.web.bind.annotation.RestController;\n\nimport com.wordnik.swagger.annotations.Api;\nimport com.wordnik.swagger.annotations.ApiOperation;\n\nimport br.com.erudio.models.Person;\nimport br.com.erudio.services.PersonService;\n\n@Api(value = "person")\n@RestController\n@RequestMapping("\/person\/")\npublic class PersonController {\n\n\t@Autowired\n\tprivate PersonService personService;\n\n\t.\n\t.\n\t.\n\n\t@ApiOperation(value = "Find all persons" )\n\t@ResponseStatus(HttpStatus.OK)\n\t@RequestMapping(value = "\/findAll", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)\n\tpublic List<person> findAll(){\n\t\tList<person> persons = personService.findAll();\n\t\tArrayList<person> personsReturn = new ArrayList<person>();\n\t\tfor (Person person : persons) {\n\t\t\tString idPerson = person.getIdPerson().toString();\n\n\t\t\t\/\/ Adicione uma referencia ao m\u00e9todo get do controller passando o ID como par\u00e2metro\n\t\t\t\/\/ isso \u00e9 feito para todos os elementos da lista\n\t\t\tperson.add(linkTo(methodOn(PersonController.class).get(idPerson)).withSelfRel());\n\t\t\tpersonsReturn.add(person);\n\t\t}\n\t\treturn personsReturn;\n\t}\n\n\t.\n\t.\n\t.\n\n}\n<\/pre>\n
 <\/p>\n
A imagem abaixo nos mostra o resultado dessa mudan\u00e7a. A nossa lista nos tras referencias \u00fanicas para cada um dos recursos.<\/p>\n
 <\/p>\n
\"postagem_4_2\"<\/a><\/p>\n
 <\/p>\n
Agora vamos adicionar o suporte a HATEOAS<\/strong> ao verbo POST<\/strong> da nossa aplica\u00e7\u00e3o.<\/p>\n
 <\/p>\n
\npackage br.com.erudio.web.controllers;\n\nimport static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo;\nimport static org.springframework.hateoas.mvc.ControllerLinkBuilder.methodOn;\n\nimport java.util.ArrayList;\nimport java.util.List;\n\nimport org.springframework.beans.factory.annotation.Autowired;\nimport org.springframework.http.HttpStatus;\nimport org.springframework.http.MediaType;\nimport org.springframework.web.bind.annotation.PathVariable;\nimport org.springframework.web.bind.annotation.RequestBody;\nimport org.springframework.web.bind.annotation.RequestMapping;\nimport org.springframework.web.bind.annotation.RequestMethod;\nimport org.springframework.web.bind.annotation.ResponseStatus;\nimport org.springframework.web.bind.annotation.RestController;\n\nimport com.wordnik.swagger.annotations.Api;\nimport com.wordnik.swagger.annotations.ApiOperation;\n\nimport br.com.erudio.models.Person;\nimport br.com.erudio.services.PersonService;\n\n@Api(value = "person")\n@RestController\n@RequestMapping("\/person\/")\npublic class PersonController {\n\n\t@Autowired\n\tprivate PersonService personService;\n\n\t.\n\t.\n\t.\n\n\t@ApiOperation(value = "Create a new person" )\n\t@ResponseStatus(HttpStatus.OK)\n\t@RequestMapping(method = RequestMethod.POST, consumes = MediaType.APPLICATION_JSON_VALUE, produces = MediaType.APPLICATION_JSON_VALUE)\n\tpublic Person create(@RequestBody Person person){\n\t\tPerson createdPerson = personService.create(person);\n\t\tString idPerson = createdPerson.getIdPerson().toString();\n\n\t\t\/\/ Ap\u00f3s criarmos um novo recurso do tipo Person n\u00f3s recuperamos seu ID e adicionamos\n\t\t\/\/ uma referencia ao m\u00e9todo get do controller passando o ID como par\u00e2metro\n\t\tcreatedPerson.add(linkTo(methodOn(PersonController.class).get(idPerson)).withSelfRel());\n\t\treturn createdPerson;\n\t}\n\n\t.\n\t.\n\t.\n\n}\n<\/pre>\n
 <\/p>\n
Como se pode ver na imagem ap\u00f3s salvar uma nova pessoa a aplica\u00e7\u00e3o retorna um link para que as informa\u00e7\u00f5es da mesma possam ser acessadas.<\/p>\n
 <\/p>\n
\"postagem_4_3\"<\/a><\/p>\n
 <\/p>\n
Agora vamos modificar o verbo PUT<\/strong>.<\/p>\n
 <\/p>\n
\npackage br.com.erudio.web.controllers;\n\nimport static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo;\nimport static org.springframework.hateoas.mvc.ControllerLinkBuilder.methodOn;\n\nimport java.util.ArrayList;\nimport java.util.List;\n\nimport org.springframework.beans.factory.annotation.Autowired;\nimport org.springframework.http.HttpStatus;\nimport org.springframework.http.MediaType;\nimport org.springframework.web.bind.annotation.PathVariable;\nimport org.springframework.web.bind.annotation.RequestBody;\nimport org.springframework.web.bind.annotation.RequestMapping;\nimport org.springframework.web.bind.annotation.RequestMethod;\nimport org.springframework.web.bind.annotation.ResponseStatus;\nimport org.springframework.web.bind.annotation.RestController;\n\nimport com.wordnik.swagger.annotations.Api;\nimport com.wordnik.swagger.annotations.ApiOperation;\n\nimport br.com.erudio.models.Person;\nimport br.com.erudio.services.PersonService;\n\n@Api(value = "person")\n@RestController\n@RequestMapping("\/person\/")\npublic class PersonController {\n\n\t@Autowired\n\tprivate PersonService personService;\n\n\t.\n\t.\n\t.\n\n\t@ApiOperation(value = "Update an existing person")\n\t@ResponseStatus(HttpStatus.OK)\n\t@RequestMapping(method = RequestMethod.PUT,consumes = MediaType.APPLICATION_JSON_VALUE)\n\tpublic Person update(@RequestBody Person person){\n\t\tPerson updatedPerson = personService.update(person);\n\t\tString idPerson = updatedPerson.getIdPerson().toString();\n\n\t\t\/\/ Ap\u00f3s atualizarmos um recurso n\u00f3s recuperamos seu ID e adicionamos\n\t\t\/\/ uma referencia ao m\u00e9todo get do controller passando o ID como par\u00e2metro\n\t\tupdatedPerson.add(linkTo(methodOn(PersonController.class).get(idPerson)).withSelfRel());\n\t\treturn updatedPerson;\n\t}\n\n\t.\n\t.\n\t.\n\n}\n<\/pre>\n
 <\/p>\n
Da mesma forma que com o verbo POST<\/strong> ap\u00f3s atualizar uma pessoa a aplica\u00e7\u00e3o retorna um link para que as informa\u00e7\u00f5es da mesma possam ser acessadas.<\/p>\n
 <\/p>\n
\"postagem_4_4\"<\/a><\/p>\n
 <\/p>\n
Como o verbo DELETE<\/strong> exclui um recurso n\u00e3o h\u00e1 necessidade de adicionar suporte a HATEOAS<\/strong> nele. Sendo assim fechamos a nossa implementa\u00e7\u00e3o e podemos dizer que a nossa API<\/strong> \u00e9 finalmente RESTful<\/strong>. Assim como nos posts anteriores voc\u00ea pode baixar o c\u00f3digo deste post aqui<\/a> e descompactar o arquivo zip e importar na sua IDE preferida ou clonar usando Git:<\/p>\n
\ngit clone https:\/\/github.com\/leandrocgsi\/simple-rest-example-hateoas.git\n<\/pre>\n
 <\/p>\n
\u00c9 isso a\u00ed bons estudos e continuem ligados no blog para mais novidades \ud83d\ude09<\/p>\n
 <\/p>\n
Treinamentos relacionados com este post<\/h2>\n
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\n<\/a><\/p>\n<\/person><\/person><\/person><\/person><\/greeting><\/greeting><\/p>\n
<\/div><\/div><\/div>","protected":false},"excerpt":{"rendered":"
  O HATEOAS, \u00e9 uma das principais constraints arquiteturais do REST e possibilita a navega\u00e7\u00e3o entre recursos, que s\u00e3o representa\u00e7\u00f5es dos modelos de neg\u00f3cio da aplica\u00e7\u00e3o. Esse post \u00e9 bem m\u00e3o na massa e se quiser aprofundar um pouco mais em conceitos te\u00f3ricos de HATEOAS confira o nosso post Entendendo HATEOAS. Vamos tomar como base […]<\/p>\n
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<\/div>\n<\/div>\n<\/div>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[117,213,116,63,208,115,211,105],"tags":[205,214,161,209,203,194],"_links":{"self":[{"href":"https:\/\/www.semeru.com.br\/blog\/wp-json\/wp\/v2\/posts\/831"}],"collection":[{"href":"https:\/\/www.semeru.com.br\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.semeru.com.br\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.semeru.com.br\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.semeru.com.br\/blog\/wp-json\/wp\/v2\/comments?post=831"}],"version-history":[{"count":20,"href":"https:\/\/www.semeru.com.br\/blog\/wp-json\/wp\/v2\/posts\/831\/revisions"}],"predecessor-version":[{"id":1540,"href":"https:\/\/www.semeru.com.br\/blog\/wp-json\/wp\/v2\/posts\/831\/revisions\/1540"}],"wp:attachment":[{"href":"https:\/\/www.semeru.com.br\/blog\/wp-json\/wp\/v2\/media?parent=831"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.semeru.com.br\/blog\/wp-json\/wp\/v2\/categories?post=831"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.semeru.com.br\/blog\/wp-json\/wp\/v2\/tags?post=831"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}