java - org.jboss.resteasy.core.NoMessageBodyWriterFoundFailure : Could not find MessageBodyWriter for response object of type

Question

我使用 undertow+resteasy+ajckson 开发 REST-service，当我使用 IDEA 运行它时，一切正常，但是当我使用 gradle 或 maven 创建“fat-jar”时，我在 GET 查询期间收到错误:

org.jboss.resteasy.core.NoMessageBodyWriterFoundFailure: Could not find MessageBodyWriter for response object of type at org.jboss.resteasy.core.ServerResponseWriter.writeNomapResponse(ServerResponseWriter.java:67) at org.jboss.resteasy.core.SynchronousDispatcher.writeResponse(SynchronousDispatcher.java:448) at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:397) at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:200) at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:220) at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:56) at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:51) at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)

我可以使用 gradle build 创建 jar，不会出现错误，并在 IDEA 中调试我的服务。

我的gradle文件:

apply plugin: 'application'
apply plugin: 'java'

sourceCompatibility = 1.8
targetCompatibility = 1.8

mainClassName = 'example.json.RestServer'

jar {
    manifest {
        attributes 'Implementation-Title': 'Rest-server',
                'Implementation-Version': '0.1',
                'Main-Class': 'example.json.RestServer'
    }
    from {
        configurations.compile.collect { it.isDirectory() ? it : zipTree(it) }
    }
}

repositories {
    jcenter()
}

dependencies {
    compile 'io.undertow:undertow-core:1.4.0.Final'
    compile 'io.undertow:undertow-servlet:1.4.0.Final'

    compile 'org.jboss.resteasy:jaxrs-api:3.0.12.Final'
    compile 'org.jboss.resteasy:resteasy-undertow:3.0.12.Final'
    compile 'org.jboss.resteasy:resteasy-jackson-provider:3.0.12.Final'

    testCompile 'junit:junit:4.12'
}

我的来源:

@Path("calculator")
public class Calculator {
    @GET
    @Path("squareRoot")
    @Produces(MediaType.APPLICATION_JSON)
    public Response squareRoot(@QueryParam("input") double input){
        Result result = new Result("Square Root");
        result.setInput(input);
        result.setOutput(Math.sqrt(result.getInput()));
        return Response.status(200).entity(result).build();
    }

Answer 1

尝试像下面这样更改您的最后一个代码 spinet，因为匿名 GenericEntity 子类需要为编写者提供正确的类型信息(否则会被编译器删除)。

@Path("calculator")
    public class Calculator {
        @GET
        @Path("squareRoot")
        @Produces(MediaType.APPLICATION_JSON)
        public Response squareRoot(@QueryParam("input") double input){
            Result result = new Result("Square Root");
            result.setInput(input);
            result.setOutput(Math.sqrt(result.getInput()));
    return Response.ok(
            new GenericEntity<Result >(result)
             )
        }

更多解释在这里JAX-RS NoMessageBodyWriterFoundFailure