Question

我正在创建一个REST服务，它接受输入作为PathParam并生成JSON响应。代码工作正常，我可以构建响应。在返回响应之后，REST正在抛出一个错误，例如“可能找不到写入器或DATASOURCEPROVIDER FOR（ResponseClass）和MediaType application / json”。感谢。

Answer 1

这就是我让Jackson 2.1.3与Wink一起作为JSON提供商工作的方式。

import java.util.HashSet;
import java.util.Set;
import javax.ws.rs.core.Application;

//see  http://www.ibm.com/developerworks/web/library/wa-aj-jackson/
import com.fasterxml.jackson.jaxrs.json.JacksonJaxbJsonProvider;
import com.fasterxml.jackson.databind.AnnotationIntrospector;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.introspect.JacksonAnnotationIntrospector;
import com.fasterxml.jackson.module.jaxb.JaxbAnnotationIntrospector;
import com.fasterxml.jackson.databind.type.TypeFactory;

/**
 * @see https://cwiki.apache.org/WINK/jax-rs-getting-started.html
 */
public class JaxrsApp extends Application {

@Override
public Set<Class<?>> getClasses() {
    Set<Class<?>> classes = new HashSet<Class<?>>();
    classes.add(YourJaxRSAnnotated.class);
    //...
    return classes;

}
 @Override
  public Set<Object> getSingletons() {
    Set<Object> s = new HashSet<Object>();

    // See http://wiki.fasterxml.com/JacksonJAXBAnnotations for more information
    ObjectMapper mapper = new ObjectMapper();
    AnnotationIntrospector primary = new JaxbAnnotationIntrospector( TypeFactory.defaultInstance() );
    AnnotationIntrospector secondary = new JacksonAnnotationIntrospector();
    AnnotationIntrospector pair = AnnotationIntrospector.pair(primary, secondary);
    mapper.getDeserializationConfig().with(pair);
    mapper.getSerializationConfig().with(pair);

    // Set up the provider
    JacksonJaxbJsonProvider jaxbProvider = new JacksonJaxbJsonProvider();
    jaxbProvider.setMapper(mapper);

    s.add(jaxbProvider);
    return s;
  }
}

然后，在web.xml中

<servlet>
    <servlet-name>JAX-RS Servlet</servlet-name>
    <servlet-class>org.apache.wink.server.internal.servlet.RestServlet</servlet-class>
    <!--  this param tells the RestServlet which custom Application sub-class
    will return a list of our classes that have JAX-RS annotations -->
    <init-param>
              <param-name>javax.ws.rs.Application</param-name>
              <param-value>com.example.JaxrsApp</param-value>
            </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>

Answer 2

我想你使用泽西岛。

首先，检查依赖项：http://jersey.java.net/nonav/documentation/latest/chapter_deps.html#d4e1716

这是我的pom.xml：

    <dependency>
        <groupId>com.sun.jersey</groupId>
        <artifactId>jersey-server</artifactId>
        <version>1.15</version>
    </dependency>
    <dependency>
        <groupId>com.sun.jersey</groupId>
        <artifactId>jersey-json</artifactId>
        <version>1.15</version>
    </dependency>
    <dependency>
        <groupId>com.sun.jersey</groupId>
        <artifactId>jersey-servlet</artifactId>
        <version>1.15</version>
    </dependency>

Answer 3

我自己发现WinkApplication没有正确加载。 web.xml中的restsdkservice配置不正确，因为 JacksonJaxbJsonProvider 未加载到Wink中。终于在2天后得到了它。
谢谢大家!!

REST找不到类型application / json的writer或datasourceprovider

3 个答案: