Rest Service 常见结构

Rest Service 常见结构

Restful API目前是非常常见的一种构建API的信息，下面是关于jaxrs/swagger 这种常见方式的一个介绍：
- API 类
- JSON Model 类
- Filter 类
- web.xml配置

API 类

一般的API类中包含：
- Path（请求路径）
- Http Method(请求方法)

如下例： 所有的请求路径，请求参数，都是一目了然的。同时返回也是Response也是标准的jaxrs Resp

@Path("/estimates")
@com.wordnik.swagger.annotations.Api(value = "/estimates", description = "the estimates API")
public class EstimatesApi {

  @GET
  @Path("/price")


  @com.wordnik.swagger.annotations.ApiOperation(value = "Price Estimates", notes = "The Price Estimates endpoint returns an estimated price range for each product offered at a given location. The price estimate is provided as a formatted string with the full price range and the localized currency symbol.

The response also includes low and high estimates, and the [ISO 4217](http://en.wikipedia.org/wiki/ISO_4217) currency code for situations requiring currency conversion. When surge is active for a particular product, its surge_multiplier will be greater than 1, but the price estimate already factors in this multiplier. ", response = PriceEstimate.class, responseContainer = "List")
  @com.wordnik.swagger.annotations.ApiResponses(value = { 
    @com.wordnik.swagger.annotations.ApiResponse(code = 200, message = "An array of price estimates by product"),

    @com.wordnik.swagger.annotations.ApiResponse(code = 0, message = "Unexpected error") })

  public Response estimatesPriceGet(@ApiParam(value = "Latitude component of start location.",required=true) @QueryParam("start_latitude") Double start_latitude,
    @ApiParam(value = "Longitude component of start location.",required=true) @QueryParam("start_longitude") Double start_longitude,
    @ApiParam(value = "Latitude component of end location.",required=true) @QueryParam("end_latitude") Double end_latitude,
    @ApiParam(value = "Longitude component of end location.",required=true) @QueryParam("end_longitude") Double end_longitude)
      throws NotFoundException {
      // do some magic!
      return Response.ok().entity(new ApiResponseMessage(ApiResponseMessage.OK, "magic!")).build();
  }

JSON Model 类

通过注解方式构建API的JSON Model 类,每个属性通过注解描述，都是非常清楚的

@ApiModel(description = "")
public class Activities  {

  private Integer offset = null;
  private Integer limit = null;
  private Integer count = null;
  private List history = new ArrayList() ;


  /**
   * Position in pagination.
   **/
  @ApiModelProperty(required = false, value = "Position in pagination.")
  @JsonProperty("offset")
  public Integer getOffset() {
    return offset;
  }
  public void setOffset(Integer offset) {
    this.offset = offset;
  }


  /**
   * Number of items to retrieve (100 max).
   **/
  @ApiModelProperty(required = false, value = "Number of items to retrieve (100 max).")
  @JsonProperty("limit")
  public Integer getLimit() {
    return limit;
  }
  public void setLimit(Integer limit) {
    this.limit = limit;
  }


  /**
   * Total number of items available.
   **/
  @ApiModelProperty(required = false, value = "Total number of items available.")
  @JsonProperty("count")
  public Integer getCount() {
    return count;
  }
  public void setCount(Integer count) {
    this.count = count;
  }


  /**
   **/
  @ApiModelProperty(required = false, value = "")
  @JsonProperty("history")
  public List getHistory() {
    return history;
  }
  public void setHistory(List history) {
    this.history = history;
  }



  @Override
  public String toString()  {
    StringBuilder sb = new StringBuilder();
    sb.append("class Activities {\n");

    sb.append("  offset: ").append(offset).append("\n");
    sb.append("  limit: ").append(limit).append("\n");
    sb.append("  count: ").append(count).append("\n");
    sb.append("  history: ").append(history).append("\n");
    sb.append("}\n");
    return sb.toString();
  }
}

Filter类

使用Filter类可以定制一些过滤器，如下例：

public class ApiOriginFilter implements javax.servlet.Filter {
    @Override
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        HttpServletResponse res = (HttpServletResponse) response;
        res.addHeader("Access-Control-Allow-Origin", "*");
        res.addHeader("Access-Control-Allow-Methods", "GET, POST, DELETE, PUT");
        res.addHeader("Access-Control-Allow-Headers", "Content-Type");
        chain.doFilter(request, response);
    }

    @Override
    public void destroy() {
    }

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }
}

上例没有做任何特殊的事情，只是给response 加了一些header

web.xml 配置

<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
  xmlns:j2ee="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

  <servlet>
    <servlet-name>jerseyservlet-name>
    <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainerservlet-class>
    <init-param>
      <param-name>com.sun.jersey.config.property.packagesparam-name>
      <param-value>com.wordnik.swagger.jaxrs.json;com.wordnik.swagger.jaxrs.listing;io.swagger.apiparam-value>
    init-param>
    <init-param>
      <param-name>com.sun.jersey.spi.container.ContainerRequestFiltersparam-name>
      <param-value>com.sun.jersey.api.container.filter.PostReplaceFilterparam-value>
    init-param>
    <init-param>
      <param-name>com.sun.jersey.api.json.POJOMappingFeatureparam-name>
      <param-value>trueparam-value>
    init-param>
    <load-on-startup>1load-on-startup>
  servlet>

  <servlet>
    <servlet-name>DefaultJaxrsConfigservlet-name>
    <servlet-class>com.wordnik.swagger.jaxrs.config.DefaultJaxrsConfigservlet-class>
    <init-param>
      <param-name>api.versionparam-name>
      <param-value>1.0.0param-value>
    init-param>
    <init-param>
      <param-name>swagger.api.titleparam-name>
      <param-value>Swagger Serverparam-value>
    init-param>
    <init-param>
      <param-name>swagger.api.basepathparam-name>
      <param-value>http://localhost:8002param-value>
    init-param>
    <load-on-startup>2load-on-startup>
  servlet>

  <servlet-mapping>
    <servlet-name>jerseyservlet-name>
    <url-pattern>/*url-pattern>
  servlet-mapping>
  <filter>
    <filter-name>ApiOriginFilterfilter-name>
    <filter-class>io.swagger.api.ApiOriginFilterfilter-class>
  filter>
  <filter-mapping>
    <filter-name>ApiOriginFilterfilter-name>
    <url-pattern>/*url-pattern>
  filter-mapping>
web-app>