http

什么是Dubbo Http

基于 spring web 和 resteasy 注解编码风格，通过http协议进行服务间调用互通，dubbo protocol扩展实现的协议

为什么选择Dubbo Http

dubbo http 可以实现微服务与dubbo之间的互通
多协议发布服务，可以实现服务协议的平滑迁移
http的通用性，解决跨语言互通
最新版本的http 无需添加其他组件，更轻量
resteasy以及spring web的编码风格，上手更快

协议规范

Reuqest

相对于原生的http协议dubbo http 请求增加version和group两个header用于确定服务的唯一且是必传header,如果使用dubbo http的RestClient这两个header将会默认通过attachment传递为区别于其他的header，attachment将会增加#rest#前缀，因此通过其他形式的http client调用 dubbo http服务需要传递 #rest#version 和 #rest#group 两个header

POST /test/path  HTTP/1.1
Host: localhost:8080
Content-type: application/json
Accept: text/html
#rest#version: 1.0.0
#rest#group: dubbo

{"name":"dubbo","age":10,"address":"hangzhou"}

Response

HTTP/1.1 200
Content-Type: text/html
Content-Length: 4
Date: Fri, 28 Apr 2023 14:16:42 GMT

"success"

content-type支持
- application/json
- application/x-www-form-urlencoded
- text/plain
- text/xml

目前支持以上media，后面还会对type进行扩展

3.2与3.0对比

因为dubbo3.2内部移除了原本resteasy的实现，因此在对resteasy 内置的Response,extend,ExceptionMapper支持上将会有所变化 ExceptionMapper 转换成了org.apache.dubbo.rpc.protocol.rest.exception.mapper.ExceptionHandler,Response后面也会做适配处理

版本	JaxRs	j2ee	web容器（tomcat/jetty）	spring web	http client(okhttp/httpclient/jdk URLConnnection )
3.0	依赖与resteasy的client和server	遵循j2ee规范	依赖常见web容器	不依赖	不依赖
3.2	不依赖（仅需要JaxRs注解包）	不遵循	netty实现的http服务器	仅依赖spring web注解	内部实现RestClient依赖http client（默认为okhttp）

##快速入门详细的依赖以及spring配置，可以参见dubbo 项目的duubo-demo-xml模块 https://github.com/apache/dubbo/tree/3.2/dubbo-demo/dubbo-demo-xml

spring web 编码在使用dubbo http的spring web编码时，类注解我们要求必须出现@RequestMapping或者@Controller,以此来判断用户使用的编码风格，决定使用对应的SpringMvcServiceRestMetadataResolver 注解解析器进行元注解解析，Provider一侧我们允许用户使用实现类作为Dubbo Service(相比之前dubbo service export时service必须是接口的要求)

API

@RequestMapping("/spring/demo/service")
public interface SpringRestDemoService {

    @RequestMapping(method = RequestMethod.GET, value = "/hello")
    Integer hello(@RequestParam("a") Integer a, @RequestParam("b") Integer b);

    @RequestMapping(method = RequestMethod.GET, value = "/error")
    String error();

    @RequestMapping(method = RequestMethod.POST, value = "/say")
    String sayHello(@RequestBody String name);

    @RequestMapping(method = RequestMethod.POST, value = "/testFormBody", consumes = MediaType.APPLICATION_FORM_URLENCODED_VALUE)
    Long testFormBody(@RequestBody Long number);

    @RequestMapping(method = RequestMethod.POST, value = "/testJavaBeanBody", consumes = MediaType.APPLICATION_FORM_URLENCODED_VALUE)
    User testJavaBeanBody(@RequestBody User user);


    @RequestMapping(method = RequestMethod.GET, value = "/primitive")
    int primitiveInt(@RequestParam("a") int a, @RequestParam("b") int b);

    @RequestMapping(method = RequestMethod.GET, value = "/primitiveLong")
    long primitiveLong(@RequestParam("a") long a, @RequestParam("b") Long b);

    @RequestMapping(method = RequestMethod.GET, value = "/primitiveByte")
    long primitiveByte(@RequestParam("a") byte a, @RequestParam("b") Long b);


    @RequestMapping(method = RequestMethod.POST, value = "/primitiveShort")
    long primitiveShort(@RequestParam("a") short a, @RequestParam("b") Long b, @RequestBody int c);


    @RequestMapping(method = RequestMethod.GET, value = "/testMapParam")
    String testMapParam(@RequestParam Map<String, String> params);

    @RequestMapping(method = RequestMethod.GET, value = "/testMapHeader")
    String testMapHeader(@RequestHeader Map<String, String> headers);

    @RequestMapping(method = RequestMethod.POST, value = "/testMapForm", consumes = MediaType.APPLICATION_FORM_URLENCODED_VALUE)
    List<String> testMapForm(MultiValueMap<String, String> params);


    @RequestMapping(method = RequestMethod.GET, value = "/headerInt")
    int headerInt(@RequestHeader("header") int header);


}

Provider

  @DubboService(interfaceClass = SpringRestDemoService.class ,protocol = "rest")
public class SpringRestDemoServiceImpl implements SpringRestDemoService {

  @Override
  public String sayHello(String name) {
    return "Hello, " + name;
  }

  @Override
  public Long testFormBody(Long number) {
    return number;
  }

  @Override
  public User testJavaBeanBody(User user) {
    return user;
  }


  @Override
  public int primitiveInt(int a, int b) {
    return a + b;
  }

  @Override
  public long primitiveLong(long a, Long b) {
    return a + b;
  }

  @Override
  public long primitiveByte(byte a, Long b) {
    return a + b;
  }

  @Override
  public long primitiveShort(short a, Long b, int c) {
    return a + b;
  }


  @Override
  public String testMapParam(Map<String, String> params) {
    return params.get("param");
  }

  @Override
  public String testMapHeader(Map<String, String> headers) {
    return headers.get("header");
  }

  @Override
  public List<String> testMapForm(MultiValueMap<String, String> params) {
    return params.get("form");
  }


  @Override
  public int headerInt(int header) {
    return header;
  }


  @Override
  public Integer hello(Integer a, Integer b) {
    return a + b;
  }


  @Override
  public String error() {
    throw new RuntimeException("test error");
  }

}

Consumer

@Component
public class SpringRestDemoServiceConsumer {
    @DubboReference(interfaceClass = SpringRestDemoService.class )
    SpringRestDemoService springRestDemoService;

    public void invoke(){
        String hello = springRestDemoService.sayHello("hello");
        assertEquals("Hello, hello", hello);
        Integer result = springRestDemoService.primitiveInt(1, 2);
        Long resultLong = springRestDemoService.primitiveLong(1, 2l);
        long resultByte = springRestDemoService.primitiveByte((byte) 1, 2l);
        long resultShort = springRestDemoService.primitiveShort((short) 1, 2l, 1);

        assertEquals(result, 3);
        assertEquals(resultShort, 3l);
        assertEquals(resultLong, 3l);
        assertEquals(resultByte, 3l);

        assertEquals(Long.valueOf(1l), springRestDemoService.testFormBody(1l));

        MultiValueMap<String, String> forms = new LinkedMultiValueMap<>();
        forms.put("form", Arrays.asList("F1"));

        assertEquals(Arrays.asList("F1"), springRestDemoService.testMapForm(forms));
        assertEquals(User.getInstance(), springRestDemoService.testJavaBeanBody(User.getInstance()));
    }

    private  void assertEquals(Object returnStr, Object exception) {
        boolean equal = returnStr != null && returnStr.equals(exception);

        if (equal) {
            return;
        } else {
            throw new RuntimeException();
        }
    }


}

JaxRs 编码 JaxRs注解使用的时候我们要求service 类上必须使用@Path注解，来确定使用JAXRSServiceRestMetadataResolver 注解解析器来解析注解元信息

API

@Path("/jaxrs/demo/service")
public interface JaxRsRestDemoService {
    @GET
    @Path("/hello")
    Integer hello(@QueryParam("a") Integer a, @QueryParam("b") Integer b);

    @GET
    @Path("/error")
    String error();

    @POST
    @Path("/say")
    String sayHello(String name);





    @POST
    @Path("/testFormBody")
    Long testFormBody(@FormParam("number") Long number);

    @POST
    @Path("/testJavaBeanBody")
    @Consumes({MediaType.APPLICATION_JSON})
    User testJavaBeanBody(User user);



    @GET
    @Path("/primitive")
    int primitiveInt(@QueryParam("a") int a, @QueryParam("b") int b);

    @GET
    @Path("/primitiveLong")
    long primitiveLong(@QueryParam("a") long a, @QueryParam("b") Long b);

    @GET
    @Path("/primitiveByte")
    long primitiveByte(@QueryParam("a") byte a, @QueryParam("b") Long b);

    @POST
    @Path("/primitiveShort")
    long primitiveShort(@QueryParam("a") short a, @QueryParam("b") Long b, int c);

    @GET
    @Path("testMapParam")
    @Produces({MediaType.TEXT_PLAIN})
    @Consumes({MediaType.TEXT_PLAIN})
    String testMapParam(@QueryParam("test") Map<String, String> params);

    @GET
    @Path("testMapHeader")
    @Produces({MediaType.TEXT_PLAIN})
    @Consumes({MediaType.TEXT_PLAIN})
    String testMapHeader(@HeaderParam("test") Map<String, String> headers);

    @POST
    @Path("testMapForm")
    @Produces({MediaType.APPLICATION_JSON})
    @Consumes({MediaType.APPLICATION_FORM_URLENCODED})
    List<String> testMapForm(MultivaluedMap<String, String> params);

    @POST
    @Path("/header")
    @Consumes({MediaType.TEXT_PLAIN})
    String header(@HeaderParam("header") String header);

    @POST
    @Path("/headerInt")
    @Consumes({MediaType.TEXT_PLAIN})
    int headerInt(@HeaderParam("header") int header);


}