如前所述这里的关键，这是注射一些上下文对象
javax.inject.Provider，这使我们能够懒洋洋地检索对象。由于
ParamConverterProvider是由Jersey管理的组件，因此我们应该能够注入其他组件。
问题在于我们需要的组件将位于请求范围内。为了解决这个问题，我们注入
javax.inject.Provider<UriInfo>了提供者。当我们实际调用
get()中
Provider获得的实际情况
UriInfo，这将是在一个请求。对于需要请求范围的任何其他组件也是如此。
例如
public class InstantParamProvider implements ParamConverterProvider { @Inject private javax.inject.Provider<UriInfo> uriInfoProvider; @Override public <T> ParamConverter<T> getConverter(Class<T> rawType, Type genericType, Annotation[] annotations) { if (rawType != Instant.class) return null; return new ParamConverter<T>() { @Override public T fromString(String value) { UriInfo uriInfo = uriInfoProvider.get(); String format = uriInfo.getQueryParameters().getFirst("date-format"); if (format == null) { throw new WebApplicationException(Response.status(400) .entity("data-format query parameter required").build()); } else { try { // parse and return here } catch (Exception ex) { throw new WebApplicationException( Response.status(400).entity("Bad format " + format).build()); } } } @Override public String toString(T value) { return value.toString(); } }; } }更新
这是使用Jersey测试框架的完整示例
import java.lang.annotation.Annotation;import java.lang.reflect.Type;import java.time.LocalDate;import java.time.format.DateTimeFormatter;import java.util.logging.Logger;import javax.inject.Inject;import javax.ws.rs.GET;import javax.ws.rs.Path;import javax.ws.rs.QueryParam;import javax.ws.rs.WebApplicationException;import javax.ws.rs.core.Response;import javax.ws.rs.core.UriInfo;import javax.ws.rs.ext.ParamConverter;import javax.ws.rs.ext.ParamConverterProvider;import org.glassfish.jersey.filter.LoggingFilter;import org.glassfish.jersey.server.ResourceConfig;import org.glassfish.jersey.test.JerseyTest;import org.junit.Test;import static org.junit.Assert.*;import static org.junit.matchers.JUnitMatchers.*;public class LocalDateTest extends JerseyTest { public static class LocalDateParamProvider implements ParamConverterProvider { @Inject private javax.inject.Provider<UriInfo> uriInfoProvider; @Override public <T> ParamConverter<T> getConverter(Class<T> rawType, Type genericType, Annotation[] annotations) { if (rawType != LocalDate.class) { return null; } return new ParamConverter<T>() { @Override public T fromString(String value) { UriInfo uriInfo = uriInfoProvider.get(); String format = uriInfo.getQueryParameters().getFirst("date-format"); if (format == null) { throw new WebApplicationException(Response.status(400) .entity("date-format query parameter required").build()); } else { try { return (T) LocalDate.parse(value, DateTimeFormatter.ofPattern(format)); // parse and return here } catch (Exception ex) { throw new WebApplicationException( Response.status(400).entity("Bad format " + format).build()); } } } @Override public String toString(T value) { return value.toString(); } }; } } @Path("localdate") public static class LocalDateResource { @GET public String get(@QueryParam("since") LocalDate since) { return since.format(DateTimeFormatter.ofPattern("MM/dd/yyyy")); } } @Override public ResourceConfig configure() { return new ResourceConfig(LocalDateResource.class) .register(LocalDateParamProvider.class) .register(new LoggingFilter(Logger.getAnonymousLogger(), true)); } @Test public void should_return_bad_request_with_bad_format() { Response response = target("localdate") .queryParam("since", "09/20/2015") .queryParam("date-format", "yyyy/MM/dd") .request().get(); assertEquals(400, response.getStatus()); assertThat(response.readEntity(String.class), containsString("format yyyy/MM/dd")); response.close(); } @Test public void should_return_bad_request_with_no_date_format() { Response response = target("localdate") .queryParam("since", "09/20/2015") .request().get(); assertEquals(400, response.getStatus()); assertThat(response.readEntity(String.class), containsString("query parameter required")); response.close(); } @Test public void should_succeed_with_correct_format() { Response response = target("localdate") .queryParam("since", "09/20/2015") .queryParam("date-format", "MM/dd/yyyy") .request().get(); assertEquals(200, response.getStatus()); assertThat(response.readEntity(String.class), containsString("09/20/2015")); response.close(); }}这是测试依赖项
<dependency> <groupId>org.glassfish.jersey.test-framework.providers</groupId> <artifactId>jersey-test-framework-provider-grizzly2</artifactId> <version>${jersey2.version}</version> <scope>test</scope></dependency>
