Jersey:如何将 Jackson 添加到 Servlet Holder [英] Jersey: How to Add Jackson to Servlet Holder
问题描述
我正在使用 Jersey 创建一个嵌入式 Jetty 网络应用程序.我不知道如何在此处为自动 JSON serde 添加 Jackson:
I am creating an embedded Jetty webapp with Jersey. I do not know how to add Jackson for automatic JSON serde here:
ServletHolder jerseyServlet = context.addServlet(
org.glassfish.jersey.servlet.ServletContainer.class, "/*");
jerseyServlet.setInitOrder(0);
jerseyServlet.setInitParameter(
ServerProperties.PROVIDER_CLASSNAMES,
StringUtils.join(
Arrays.asList(
HealthCheck.class.getCanonicalName(),
Rest.class.getCanonicalName()),
";"));
// Create JAX-RS application.
final Application application = new ResourceConfig()
.packages("com.example.application")
.register(JacksonFeature.class);
// what do I do now to tie this to the ServletHolder?
我如何将这个 ResourceConfig
注册到 ServletHolder 以便在使用注释 @Produces(MediaType.APPLICATION_JSON)
的地方使用 Jackson?这是嵌入式 Jetty 应用程序的完整主类
How do I register this ResourceConfig
with the ServletHolder so Jackson with be used where the annotation @Produces(MediaType.APPLICATION_JSON)
is used? Here is the full main class for the embedded Jetty application
package com.example.application.web;
import com.example.application.api.HealthCheck;
import com.example.application.api.Rest;
import com.example.application.api.Frontend;
import org.apache.commons.lang.StringUtils;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.servlet.ServletContextHandler;
import org.eclipse.jetty.servlet.ServletHolder;
import org.glassfish.jersey.jackson.JacksonFeature;
import org.glassfish.jersey.server.ResourceConfig;
import org.glassfish.jersey.server.ServerProperties;
import javax.ws.rs.core.Application;
import java.util.Arrays;
public class JettyStarter {
public static void main(String[] args) throws Exception {
ServletContextHandler context = new ServletContextHandler(ServletContextHandler.SESSIONS);
context.setContextPath("/");
Server jettyServer = new Server(9090);
jettyServer.setHandler(context);
ServletHolder jerseyServlet = context.addServlet(
org.glassfish.jersey.servlet.ServletContainer.class, "/*");
jerseyServlet.setInitOrder(0);
jerseyServlet.setInitParameter(
ServerProperties.PROVIDER_CLASSNAMES,
StringUtils.join(
Arrays.asList(
HealthCheck.class.getCanonicalName(),
Rest.class.getCanonicalName()),
";"));
// Create JAX-RS application.
final Application application = new ResourceConfig()
.packages("com.example.application")
.register(JacksonFeature.class);
try {
jettyServer.start();
jettyServer.join();
} catch (Exception e) {
System.out.println("Could not start server");
e.printStackTrace();
} finally {
jettyServer.destroy();
}
}
}
推荐答案
一种方法是将 ResourceConfig
包装在一个显式的 构造 ServletContainer
,如在此处看到.
One way is to just wrap the ResourceConfig
in an explicit construction of the ServletContainer
, as seen here.
用你的例子测试
public class RestServer {
public static void main(String[] args) throws Exception {
// Create JAX-RS application.
final ResourceConfig application = new ResourceConfig()
.packages("jersey.jetty.embedded")
.register(JacksonFeature.class);
ServletContextHandler context
= new ServletContextHandler(ServletContextHandler.SESSIONS);
context.setContextPath("/");
Server jettyServer = new Server(9090);
jettyServer.setHandler(context);
ServletHolder jerseyServlet = new ServletHolder(new
org.glassfish.jersey.servlet.ServletContainer(application));
jerseyServlet.setInitOrder(0);
context.addServlet(jerseyServlet, "/*");
// ... removed property (init-param) to compile.
try {
jettyServer.start();
jettyServer.join();
} catch (Exception e) {
System.out.println("Could not start server");
e.printStackTrace();
} finally {
jettyServer.destroy();
}
}
}
你也可以...
无需更改原始帖子中的任何其他内容,只需设置 init 参数即可扫描 Jackson 提供程序包
You could also...
without changing anything else in your original post, just set the init param to scan the Jackson provider package
jerseyServlet.setInitParameter(ServerProperties.PROVIDER_PACKAGES,
"com.fasterxml.jackson.jaxrs.json;"
+ "jersey.jetty.embedded" // my package(s)
);
请注意,您尝试使用 ResourceConfig
似乎有点多余,因为您已经在 init 参数中配置了您的类.或者,您也可以不显式添加每个类,而是像我一样扫描整个包.
Note your attempted use of ResourceConfig
seems a little redundant, as you are already configuring your classes in the the init param. You could alternatively get rid of adding each class explicitly and just scan entire packages as I have done.
只需使用您需要的 Jackson 提供程序类.您可以查看 jar,您将看到的不仅仅是编组/解组提供程序 (Jackson[JAXB]JsonProvider),例如 ExceptionMappers.您可能不喜欢这些映射器并且想要配置您自己的映射器.在这种情况下,就像我说的,只包括你需要的提供者.例如
just use the Jackson provider classes you need. You can look in the jar, and you will see more than just the marshalling/unmarhalling provider (Jackson[JAXB]JsonProvider), like a ExceptionMappers. You may not like these mappers and wand to configure your own. In which case, like I said, just include the provider you need. For example
jerseyServlet.setInitParameter(ServerProperties.PROVIDER_CLASSNAMES,
"com.fasterxml.jackson.jaxrs.json.JacksonJaxbJsonProvider");
jerseyServlet.setInitParameter(ServerProperties.PROVIDER_PACKAGES,
"jersey.jetty.embedded" // my package(s)
);
经过进一步测试...
不确定是什么版本的 Jersey,但我使用的是 Jersey 2.15(带有 jersey-media-json-jackson:2.15
),并且无需任何进一步的配置,只需扫描 myem> 包为我的资源类,杰克逊功能已经启用.这是自动发现功能的一部分.我相信这是在 2.8 或 2.9 中为 Jackson 功能启用的.因此,如果您使用的是后来的,我认为您不需要明确配置任何东西,至少从我测试过的内容来看 :-)
After further testing...
Not sure what version of Jersey, but I am using Jersey 2.15 (with jersey-media-json-jackson:2.15
), and without any further configuration from just scanning my package for my resource classes, the Jackson feature is already enabled. This is part of the auto discoverable features. I believe this was enable as of 2.8 or 2.9 for the Jackson feature. So if you are using a later one, I don't think you need to explicitly configure anything, at least from what I've tested :-)
以上所有示例均已使用以下 Maven pom.xml 进行了测试
All of the above examples have been tested with the below Maven pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.underdog.jersey</groupId>
<artifactId>jersey-jetty-embedded</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
<jersey.version>2.15</jersey.version>
<jetty.version>9.2.6.v20141205</jetty.version>
</properties>
<dependencies>
<dependency>
<groupId>org.glassfish.jersey.containers</groupId>
<artifactId>jersey-container-servlet</artifactId>
</dependency>
<dependency>
<groupId>org.glassfish.jersey.media</groupId>
<artifactId>jersey-media-json-jackson</artifactId>
</dependency>
<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-server</artifactId>
<version>${jetty.version}</version>
</dependency>
<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-servlet</artifactId>
<version>${jetty.version}</version>
</dependency>
<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-servlets</artifactId>
<version>${jetty.version}</version>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.glassfish.jersey</groupId>
<artifactId>jersey-bom</artifactId>
<version>${jersey.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
</project>
和资源类
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
@Path("/json")
public class JsonResource {
@GET
@Produces(MediaType.APPLICATION_JSON)
public Response getJson() {
Resource resource = new Resource();
resource.hello = "world";
return Response.ok(resource).build();
}
public static class Resource {
public String hello;
}
}
使用路径
http://localhost:9090/json
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