Jersey: Checking for Not null request payload

Question

如何确保null请求有效载荷不会发送到任何POST或PUT请求？

Answer 1

You could try implementing a ContainerRequestFilter and abort the request if the payload is null.

requestContext.abortWith(Response.status(Response.Status.BAD_REQUEST)
                .entity("Payload is null")
                .build());

https://jersey.java.net/documentation/latest/filters-and-interceptors.html

Answer 2

        /*Name Binding meta annotation*/
        package com.avinash.api;

        import java.lang.annotation.ElementType;
        import java.lang.annotation.Retention;
        import java.lang.annotation.RetentionPolicy;
        import java.lang.annotation.Target;

        import javax.ws.rs.NameBinding;

        @Target({ ElementType.TYPE, ElementType.METHOD })
        @Retention(value = RetentionPolicy.RUNTIME)
        @NameBinding
        public @interface NullPayloadDetection {}

        /* Decorate your filter with name-binding (NullPayloadDetection) annotation*/
        package com.avinash.api; 

        import java.io.ByteArrayInputStream;
        import java.io.ByteArrayOutputStream;
        import java.io.IOException;
        import java.io.InputStream;

        import javax.ws.rs.container.ContainerRequestContext;
        import javax.ws.rs.container.ContainerRequestFilter;
        import javax.ws.rs.core.Response;
        import javax.ws.rs.ext.Provider;

        @Provider
        @NullPayloadDetection
        public class NullPayloadDetectionFilter implements ContainerRequestFilter {

            @Override
            public void filter(ContainerRequestContext requestContext) throws IOException {

                String entityStream = read(requestContext.getEntityStream());

                if( (!requestContext.hasEntity() && requestContext.getLength() == 0) 
    ||  isEmpty(entityStream)) {
                    String path = requestContext.getUriInfo().getRequestUri().getPath();
                    System.out.println("Null payload detected for "+path);

requestContext.abortWith(Response.status(Response.Status.BAD_REQUEST).entity("Null payload").build());

                } else {
                    System.out.println("Nothing wrong with the request");
                    InputStream targetStream = new ByteArrayInputStream(entityStream.getBytes());
                    requestContext.setEntityStream(targetStream);
                }
            }

            private String read(InputStream inputStream) throws IOException {

                ByteArrayOutputStream into = new ByteArrayOutputStream();
                byte[] buf = new byte[4096];
                for (int n; 0 < (n = inputStream.read(buf));) {
                    into.write(buf, 0, n);
                }
                into.close();
                String str = new String(into.toByteArray(), "UTF-8");
                System.out.println(str);
                return str;
            }

            private boolean isEmpty(String str) {
                boolean bool = "".equals(str);
                System.out.println("isEmpty: "+bool);
                return bool;
            }
        }

        /*
        name-binding annotation is applied to the resource method to which the name-bound JAX-RS provider(s) should be bound to
        */
        package com.avinash.api;

        import javax.ws.rs.Consumes;
        import javax.ws.rs.POST;
        import javax.ws.rs.Path;
        import javax.ws.rs.Produces;
        import javax.ws.rs.core.MediaType;
        import javax.ws.rs.core.Response;


        @Path("status")
        public class Status {

            @POST
            @Consumes(MediaType.APPLICATION_JSON)
            @Produces(MediaType.APPLICATION_JSON)
            @NullPayloadDetection
            public Response status(MyRequestModel request)  {
                // your business logic
            }

        }