Jersey构建REST服务实战

小灰灰 2022-09-24 12:16 285阅读 0赞

**由于参与移动项目，需要移动终端和服务端传递数据，经过技术对比分析，觉得基于REST模式的Web服务比较简洁易用，于是采取了Jersey开发， 一个[Java][]规范下REST风格Web Service开发框架。最初选择的是Jersey1.8，后来由于运行环境的升级，导致Jersey也要升级到最新版本2.5.1。由于jersey2.x 版本实现的是JAX-RS 2.0规范，与 jersey1.x 相比有很大的改变，JSON转换也有不同。现把实现过程整理下来，供有需要的朋友参考！**

**一：环境介绍**

**（1）Jersey2.5.1**

**（2）Eclipse 3.7 +Tomcat 7 +JDK 7**

**二：搭建步骤**

**（1）通过地址[https://jersey.java.net/][https_jersey.java.net] 下载jaxrs-ri-2.5.1.zip。**

**（2）****通过Eclipse 创建动态工程RestDemo。**

**（3）解压jaxrs-ri-2.5.1.zip，拷贝下图列表中的JAR包到RestDemo\\WebContent\\WEB-INF\\lib下。**

**![20140114095147500][]**

**（4）创建包路径 cn.com.vs.vo，创建User.java：**

<table style="width:382px; height:438px"> 
 <tbody> 
 <tr> 
 <td> package cn.com.vs.vo; import javax.xml.bind.annotation.XmlRootElement; @XmlRootElement public class User { &nbsp; &nbsp;private String name; &nbsp; &nbsp;private String age; &nbsp; &nbsp;private String sex; &nbsp; &nbsp;public String getName() { &nbsp;&nbsp;return name; &nbsp;} &nbsp;public void setName(String name) { &nbsp;&nbsp;this.name = name; &nbsp;} &nbsp;public String getAge() { &nbsp;&nbsp;return age; &nbsp;} &nbsp;public void setAge(String age) { &nbsp;&nbsp;this.age = age; &nbsp;} &nbsp;public String getSex() { &nbsp;&nbsp;return sex; &nbsp;} &nbsp;public void setSex(String sex) { &nbsp;&nbsp;this.sex = sex; &nbsp;} } </td> 
 </tr> 
 </tbody> 
</table>

**（5）创建包路径 cn.com.vs.service，创建RestService.java:**

<table style="width:382px; height:527px"> 
 <tbody> 
 <tr> 
 <td> package cn.com.vs.service; import javax.ws.rs.GET; import javax.ws.rs.Path; import javax.ws.rs.Produces; import javax.ws.rs.core.MediaType; import cn.com.vs.vo.User; @Path("/restService") public class RestService { &nbsp;@GET &nbsp;@Path("/getUserText") &nbsp;@Produces(MediaType.TEXT_PLAIN) &nbsp;public String getUserText() { &nbsp;&nbsp;return "Hello,World!"; &nbsp;} &nbsp; &nbsp;@GET &nbsp;@Path("/getUserXml") &nbsp;@Produces(MediaType.APPLICATION_XML) &nbsp;public User getUserXml() { &nbsp;&nbsp;User user&nbsp; = new User(); &nbsp;&nbsp;user.setName("snail"); &nbsp;&nbsp;user.setAge("22"); &nbsp;&nbsp;user.setSex("male"); &nbsp;&nbsp;return user; &nbsp;} &nbsp; &nbsp;@GET &nbsp;@Path("/getUserJson") &nbsp;@Produces(MediaType.APPLICATION_JSON) &nbsp;public User getUserJson() { &nbsp;&nbsp;User user&nbsp; = new User(); &nbsp;&nbsp;user.setName("snail"); &nbsp;&nbsp;user.setAge("22"); &nbsp;&nbsp;user.setSex("male"); &nbsp;&nbsp;return user; &nbsp;} } </td> 
 </tr> 
 </tbody> 
</table>

**（6）在 cn.com.vs 包路径下创建类 RestApplication.java**

<table style="width:382px; height:184px"> 
 <tbody> 
 <tr> 
 <td> package cn.com.vs; import org.glassfish.jersey.filter.LoggingFilter; import org.glassfish.jersey.server.ResourceConfig; public class RestApplication extends ResourceConfig { &nbsp;&nbsp;&nbsp; public RestApplication() { &nbsp;&nbsp;&nbsp; &nbsp;//服务类所在的包路径 &nbsp;&nbsp;&nbsp; &nbsp;packages("cn.com.vs.service"); &nbsp;&nbsp;&nbsp; &nbsp; //打印访问日志，便于跟踪调试，正式发布可清除 &nbsp;&nbsp;&nbsp; &nbsp;register(LoggingFilter.class); &nbsp;&nbsp;&nbsp; } } </td> 
 </tr> 
 </tbody> 
</table>

**（7）修改web.xml，内容如下：**

<table style="width:385px; height:365px"> 
 <tbody> 
 <tr> 
 <td> &lt;?xml version="1.0" encoding="UTF-8"?&gt; &lt;web-app xmlns:xsi="<a href="http://www.w3.org/2001/XMLSchema-instance" rel="nofollow">http://www.w3.org/2001/XMLSchema-instance</a>" xmlns="<a href="http://java.sun.com/xml/ns/javaee" rel="nofollow">http://java.sun.com/xml/ns/javaee</a>" xmlns:web="<a href="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" rel="nofollow">http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd</a>" xsi:schemaLocation="<a href="http://java.sun.com/xml/ns/javaee" rel="nofollow">http://java.sun.com/xml/ns/javaee</a><a href="http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" rel="nofollow">http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd</a>" id="WebApp_ID" version="3.0"&gt; &nbsp; &lt;display-name&gt;RestDemo&lt;/display-name&gt; &nbsp; &lt;servlet&gt; &nbsp;&nbsp;&lt;servlet-name&gt;mobile&lt;/servlet-name&gt; &nbsp;&nbsp;&lt;servlet-class&gt;org.glassfish.jersey.servlet.ServletContainer&lt;/servlet-class&gt; &nbsp;&nbsp; &lt;init-param&gt; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;param-name&gt;javax.ws.rs.Application&lt;/param-name&gt; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;param-value&gt;cn.com.vs.RestApplication&lt;/param-value&gt; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;/init-param&gt; &nbsp;&nbsp;&lt;load-on-startup&gt;1&lt;/load-on-startup&gt; &nbsp;&lt;/servlet&gt; &nbsp;&lt;servlet-mapping&gt; &nbsp;&nbsp;&lt;servlet-name&gt;mobile&lt;/servlet-name&gt; &nbsp;&nbsp;&lt;url-pattern&gt;/rest/*&lt;/url-pattern&gt; &nbsp;&lt;/servlet-mapping&gt; &nbsp; &lt;welcome-file-list&gt; &nbsp;&nbsp;&nbsp; &lt;welcome-file&gt;index.html&lt;/welcome-file&gt; &nbsp; &lt;/welcome-file-list&gt; &lt;/web-app&gt; </td> 
 </tr> 
 </tbody> 
</table>

**（8）在 Tomcat7 中部署运行，查看发布效果：**

**获取 文本数据：**

**![20140114102058468][]**

**获取XML数据：**

**![20140114122326468][]**

**获取JSON数据：[http://localhost:8080/RestDemo/rest/restService/getUserJson][http_localhost_8080_RestDemo_rest_restService_getUserJson] ，会出现如下异常：**

<table style="width:409px; height:91px"> 
 <tbody> 
 <tr> 
 <td>[org.glassfish.jersey.message.internal.MessageBodyProviderNotFoundException: MessageBodyWriter not found for media type=application/json, type=class cn.com.vs.vo.User, genericType=class cn.com.vs.vo.User.] with root cause org.glassfish.jersey.message.internal.MessageBodyProviderNotFoundException: MessageBodyWriter not found for media type=application/json, type=class cn.com.vs.vo.User, genericType=class cn.com.vs.vo.User.</td> 
 </tr> 
 </tbody> 
</table>

说明：如果通过glassfish-4.0运行的话，是没任何问题的！如果通过tomcat，需要添加JSON转换器。

（9）解决获取JSON数据的异常，途径一：

a)下载 [ jackson-all-1.9.11.jar][jackson-all-1.9.11.jar] ，放到lib下。

b)修改RestApplication.java，内容如下：

<table style="width:439px; height:245px"> 
 <tbody> 
 <tr> 
 <td> package cn.com.vs; import org.codehaus.jackson.jaxrs.JacksonJsonProvider; import org.glassfish.jersey.filter.LoggingFilter; import org.glassfish.jersey.server.ResourceConfig; public class RestApplication extends ResourceConfig { &nbsp;&nbsp;&nbsp; public RestApplication() { &nbsp;&nbsp;&nbsp; &nbsp;//服务类所在的包路径 &nbsp;&nbsp;&nbsp; &nbsp;packages("cn.com.vs.service"); &nbsp;&nbsp;&nbsp; &nbsp;//注册JSON转换器 &nbsp;&nbsp;&nbsp; &nbsp;register(JacksonJsonProvider.class); &nbsp;&nbsp;&nbsp; &nbsp; //打印访问日志，便于跟踪调试，正式发布可清除 &nbsp;&nbsp;&nbsp; &nbsp;register(LoggingFilter.class); &nbsp;&nbsp;&nbsp; } } </td> 
 </tr> 
 </tbody> 
</table>

（10）解决获取JSON数据的异常，途径二：

a) 下载 [ glassfish-4.0.zip][glassfish-4.0.zip] ，解压，拷贝下列JAR到lib下：

![20140114105945359][]

b)修改RestApplication.java，内容如下：

<table style="width:430px; height:220px"> 
 <tbody> 
 <tr> 
 <td> package cn.com.vs; import org.glassfish.jersey.filter.LoggingFilter; import org.glassfish.jersey.jackson.JacksonFeature; import org.glassfish.jersey.server.ResourceConfig; public class RestApplication extends ResourceConfig { &nbsp;&nbsp;&nbsp; public RestApplication() { &nbsp;&nbsp;&nbsp; &nbsp;//服务类所在的包路径 &nbsp;&nbsp;&nbsp; &nbsp;packages("cn.com.vs.service"); &nbsp;&nbsp;&nbsp; &nbsp;//注册JSON转换器 &nbsp;&nbsp;&nbsp; &nbsp;register(JacksonFeature.class); &nbsp;&nbsp;&nbsp; &nbsp; //打印访问日志，便于跟踪调试，正式发布可清除 &nbsp;&nbsp;&nbsp; &nbsp;register(LoggingFilter.class); &nbsp;&nbsp;&nbsp; } } </td> 
 </tr> 
 </tbody> 
</table>

（11）选择上述途径中的一种，然后发布启动，获取JSON数据，即可成功，如下：

![20140114122333593][]

[Java]: http://lib.csdn.net/base/17
[https_jersey.java.net]: https://jersey.java.net/
[20140114095147500]: /images/20220719/954c01d150b540a982b8aebf360f32e1.png
[20140114102058468]: /images/20220719/c8ca04b3c99f43e6b6adafa2d5096e0d.png
[20140114122326468]: /images/20220719/f1c0a1d40caf48a38b036b5f546450dc.png
[http_localhost_8080_RestDemo_rest_restService_getUserJson]: http://localhost:8080/RestDemo/rest/restService/getUserJson
[jackson-all-1.9.11.jar]: http://wiki.fasterxml.com/JacksonDownload
[glassfish-4.0.zip]: https://glassfish.java.net/
[20140114105945359]: /images/20220719/8e466c8b9b2a4243a447087bdea61826.png
[20140114122333593]: /images/20220719/f72dec34005541b398cc123c164922ae.png