Apache CXF实现Web Service（2）——不借助重量级Web容器和Spring实现一个纯的JAX-RS(RESTful) web service

2023-01-09 08:51:38

实现目标

http://localhost:9000/rs/roomservice 为入口，
http://localhost:9000/rs/roomservice/room为房间列表,
http://localhost:9000/rs/roomservice/room/001/ 为001号房间的信息，
http://localhost:9000/rs/roomservice/room/001/person 为在001号房间主的人的列表

在Eclipse中新建一个Java Project

（可以不是WTP的Dynamic Web Project）参考文章：Apache CXF实现Web Service（1）中的介绍

再看pom.xml

<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/maven-v4_0_0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>com.cnblog.richaaaard.cxfstudy</groupId>

    <artifactId>cxf-test-standalone-rs-helloworld</artifactId>

    <packaging>war</packaging>

    <version>1.0-SNAPSHOT</version>

    <name>cxf-test-standalone-rs-helloworld Maven Webapp</name>

    <url>http://maven.apache.org</url>  

    <properties>

<!--         <cxf.version>2.7.18</cxf.version> -->

        <cxf.version>3.1.4</cxf.version>

    </properties>  

    <dependencies>

        <dependency>

            <groupId>org.apache.cxf</groupId>

            <artifactId>cxf-rt-transports-http</artifactId>

            <version>${cxf.version}</version>

        </dependency>

        <dependency>

            <groupId>org.apache.cxf</groupId>

            <artifactId>cxf-rt-transports-http-jetty</artifactId>

            <version>${cxf.version}</version>

        </dependency>

        <dependency>

            <groupId>org.apache.cxf</groupId>

            <artifactId>cxf-rt-ws-security</artifactId>

            <version>${cxf.version}</version>

        </dependency>

        <dependency>

            <groupId>org.apache.cxf</groupId>

            <artifactId>cxf-rt-ws-policy</artifactId>

            <version>${cxf.version}</version>

        </dependency>

<!--         <dependency>   -->

<!--             <groupId>org.apache.cxf</groupId>   -->

<!--             <artifactId>cxf-bundle-jaxrs</artifactId>   -->

<!--             <version>${cxf.version}</version>   -->

<!--         </dependency>   -->

 	<dependency>

            <groupId>org.apache.cxf</groupId>

            <artifactId>cxf-rt-frontend-jaxrs</artifactId>

            <version>${cxf.version}</version>

        </dependency>

        <dependency>

            <groupId>javax.ws.rs</groupId>

            <artifactId>jsr311-api</artifactId>

            <version>1.1.1</version>

        </dependency>

        <dependency>

            <groupId>org.slf4j</groupId>

            <artifactId>slf4j-api</artifactId>

            <version>1.5.8</version>

        </dependency>

        <dependency>

            <groupId>org.slf4j</groupId>

            <artifactId>slf4j-simple</artifactId>

            <version>1.5.8</version>

        </dependency>

        <dependency>

            <groupId>commons-httpclient</groupId>

            <artifactId>commons-httpclient</artifactId>

            <version>3.0</version>

        </dependency>

        <dependency>

            <groupId>commons-io</groupId>

            <artifactId>commons-io</artifactId>

            <version>2.3</version>

        </dependency>

        <dependency>

            <groupId>junit</groupId>

            <artifactId>junit</artifactId>

            <version>4.8.1</version>

            <scope>test</scope>

        </dependency>

    </dependencies>  

    <build>

        <finalName>cxfstudy</finalName>

        <resources>

            <resource>

                <directory>src/main/resources</directory>

            </resource>

            <resource>

                <directory>src/main/java</directory>

                <includes>

                    <include>**</include>

                </includes>

                <excludes>

                    <exclude>**/*.java</exclude>

                </excludes>

            </resource>

        </resources>

        <plugins>

            <plugin>

                <groupId>org.mortbay.jetty</groupId>

                <artifactId>maven-jetty-plugin</artifactId>

                <configuration>

                    <contextPath>/</contextPath>

                    <connectors>

                        <connector implementation="org.mortbay.jetty.nio.SelectChannelConnector">

                            <port>9000</port>

                        </connector>

                    </connectors>

                </configuration>

            </plugin>

            <plugin>

                <groupId>org.apache.maven.plugins</groupId>

                <artifactId>maven-compiler-plugin</artifactId>

                <configuration>

                    <source>1.7</source>

                    <target>1.7</target>

                </configuration>

            </plugin>

        </plugins>

    </build>  

</project>

　　与（1）中介绍的类同，JAXRSServerFactoryBean存在于cxf-rt-frontend-jaxrs中，而集合包cxf-bundle-jaxrs是不必要的

供资源使用的实体类Room和Person

package com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model;

import java.util.HashMap;

import java.util.Map;

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="Room")

public class Room {

    public Room()

    {

        persons=new HashMap<String,Person>();

    }

    String id;

    Map<String,Person> persons;  

    public String getId() {

        return id;

    }

    public void setId(String id) {

        this.id = id;

    }

    public Map<String, Person> getPersons() {

        return persons;

    }

    public void setPersons(Map<String, Person> persons) {

        this.persons = persons;

    }

}

　　注意不要漏掉@XmlRootElement

package com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model;

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="Person")

public class Person {

    private String name;

    private String sex;

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public String getSex() {

        return sex;

    }

    public void setSex(String sex) {

        this.sex = sex;

    }  

}

　　为了解决“No message body writer found for class”，即非简单对象无法序列化的问题，我们暂时先加两个Wrapper类作为Room的集合类和Person集合类，后面会专门介绍如何更优雅的解决这个问题。

Rooms.java

 package com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model;

 import java.util.Map;

 import javax.xml.bind.annotation.XmlRootElement;

 import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.dao.RoomDAO;

 @XmlRootElement(name="rooms")

 public class Rooms {

     Map<String,Room> rooms;

     public Rooms()

     {

         rooms=RoomDAO.getMapOfRooms();

     }

     public Map<String, Room> getRooms() {

         return rooms;

     }

     public void setRooms(Map<String, Room> rooms) {

         this.rooms = rooms;

     }

 }

Persons.java

package com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model;

import java.util.Map;

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="persons")

public class Persons {

    Map<String,Person> persons;

    public Persons()

    {

        persons=null;

    }

    public Persons(Room room)

    {

        persons=room.getPersons();

    }

    public Map<String, Person> getPersons() {

        return persons;

    }

    public void setPersons(Map<String, Person> persons) {

        this.persons = persons;

    }

}

实体有了，需要数据，我们虚拟了一个DAO（原本DAO是数据访问层），这里我们直接将所需要测试的数据创建其中

 package com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.dao;

 import java.util.HashMap;

 import java.util.Map;

 import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Person;

 import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Room;

 import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Rooms;

 public class RoomDAO {

     private static Map<String, Room> rooms;

     static {

         rooms = new HashMap<String, Room>();  

         Person p1=new Person();

         p1.setName("Boris");

         p1.setSex("male");  

         Room r=new Room();

         r.setId("001");

         r.getPersons().put(p1.getName(), p1);

         rooms.put("001", r);

     }  

     public static void addRoom(Room room) {

         rooms.put(room.getId(), room);

     }  

     public static void deleteRoom(String id) {

         if (rooms.containsKey(id)) {

             rooms.remove(id);

         }  

     }  

     public static void updateRoom(String id,Room room) {

         rooms.remove(id);

         rooms.put(room.getId(), room);

     }  

     public static Room getRoom(String id) {

         if (rooms.containsKey(id)) {

             return rooms.get(id);

         } else {

             return null;

         }

     }

     /*operations to persons*/

     public static void addPerson(String id_room,Person person) {

         if(rooms.containsKey(id_room))

         {

             Room room=rooms.get(id_room);

             room.getPersons().put(person.getName(), person);

         }

     }  

     public static Rooms getRooms()

     {

         return new Rooms();

     }  

     public static void deletePerson(String id_room,String name)

     {

         if(rooms.containsKey(id_room))

         {

             Room room=rooms.get(id_room);

             room.getPersons().remove(name);

         }

     }  

     public static Map<String, Room> getMapOfRooms()

     {

         return rooms;

     }

 }

到这里，我们基本已经完成准备工作

那么如何写一个RESTful Web Service呢？

package com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.service;

import javax.ws.rs.Consumes;

import javax.ws.rs.DELETE;

import javax.ws.rs.GET;

import javax.ws.rs.POST;

import javax.ws.rs.PUT;

import javax.ws.rs.Path;

import javax.ws.rs.PathParam;

import javax.ws.rs.Produces;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.dao.RoomDAO;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Person;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Persons;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Room;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Rooms;

@Path("/roomservice")

@Produces("application/xml")

public class RoomService {  

    @GET

    @Path("/room/{id}")

    @Consumes("application/xml")

    public Room getRoom(@PathParam("id")String id )

    {

        System.out.println("get room by id= "+id);

        Room room=RoomDAO.getRoom(id);

        return room;

    }

    @GET

    @Path("/room")

    @Consumes("application/xml")

    public Rooms getAllRoom()

    {

        System.out.println("get all room");

        Rooms rooms=RoomDAO.getRooms();

        return rooms;

    }  

    @POST

    @Path("/room")

    @Consumes("application/xml")

    public void addRoom(Room room)

    {

        System.out.println("add room which id is:"+room.getId());

        RoomDAO.addRoom(room);

    }

    @PUT

    @Path("/room/{id}")

    @Consumes("application/xml")

    public void updateRoom(@PathParam("id")String id,Room room)

    {

        System.out.println("update room which original id is:"+room.getId());

        RoomDAO.updateRoom(id,room);

    }

    @DELETE

    @Path("/room/{id}")

    @Consumes("application/xml")

    public void deleteRoom(@PathParam("id")String id)

    {

        System.out.println("remove room by id= "+id);

        RoomDAO.deleteRoom(id);

    }

    @POST

    @Path("/room/{id}")

    @Consumes("application/xml")

    public void addPerson(@PathParam("id") String id,Person person)

    {

        System.out.println("add person who's name is:"+person.getName());

        RoomDAO.addPerson(id, person);

    }  

    @GET

    @Path("/room/{id}/person")

    @Consumes("application/xml")

    public Persons getAllPersonOfRoom(@PathParam("id") String id)

    {

//         System.out.println("get room by id= "+id);

//         Room room=RoomDAO.getRoom(id);

//         return room.getPersons();

//        TODO No message body writer HashMap

         System.out.println("get room by id= "+id);

         Room room=RoomDAO.getRoom(id);

         return new Persons(room);

    }  

    @DELETE

    @Path("/room/{id}/{name}")

    @Consumes("application/xml")

    public void deletePerson(@PathParam("id")String id,@PathParam("name")String name)

    {

        System.out.println("remove person who's name is: "+name);

        RoomDAO.deletePerson(id, name);

    }

}

注意在类头上的Annotation @Path和@Produces

@Path("/roomservice")——指这个服务的根路径，用于区分其他服务

@Produces("application/xml")——指这个服务生产xml的响应

最后我们还需一个服务

我们使用与（1）类似的方法，用JAXRSServerFactoryBean来启动一个服务

package com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.server;

import org.apache.cxf.jaxrs.JAXRSServerFactoryBean;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Person;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Persons;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Room;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Rooms;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.service.RoomService;

public class Server {  

    public static void main(String[] args) {

        RoomService service = new RoomService();  

        // Service instance

        JAXRSServerFactoryBean restServer = new JAXRSServerFactoryBean();

        restServer.setResourceClasses(Room.class, Person.class, Rooms.class, Persons.class);

        restServer.setServiceBean(service);

        restServer.setAddress("http://localhost:9000/rs");

        restServer.create();

    }

}

运行服务Run As... -> Java Application

124 [main] WARN org.apache.cxf.jaxrs.utils.ResourceUtils - No resource methods have been found for resource class com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Room

124 [main] WARN org.apache.cxf.jaxrs.utils.ResourceUtils - No resource methods have been found for resource class com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Person

125 [main] WARN org.apache.cxf.jaxrs.utils.ResourceUtils - No resource methods have been found for resource class com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Rooms

125 [main] WARN org.apache.cxf.jaxrs.utils.ResourceUtils - No resource methods have been found for resource class com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Persons

222 [main] INFO org.apache.cxf.endpoint.ServerImpl - Setting the server's publish address to be http://localhost:9000/rs

284 [main] INFO org.eclipse.jetty.util.log - Logging initialized @500ms

318 [main] INFO org.eclipse.jetty.server.Server - jetty-9.2.11.v20150529

330 [main] WARN org.eclipse.jetty.server.handler.AbstractHandler - No Server set for org.apache.cxf.transport.http_jetty.JettyHTTPServerEngine$1@49e202ad

357 [main] INFO org.eclipse.jetty.server.ServerConnector - Started ServerConnector@7364985f{HTTP/1.1}{localhost:9000}

357 [main] INFO org.eclipse.jetty.server.Server - Started @582ms

362 [main] WARN org.eclipse.jetty.server.handler.ContextHandler - Empty contextPath

369 [main] INFO org.eclipse.jetty.server.handler.ContextHandler - Started o.e.j.s.h.ContextHandler@351d0846{/,null,AVAILABLE}

　　暂时忽略WARN里面的日志

然后我们通过浏览器测试

（测试方式有多种，原则上能对http Interceptor的工具都可以对web service进行测试，eclipse里有自带的工具，TcpTrace、SoapUI也都是比较好用的小工具）

*扩展，RESTful用json格式

我们将RoomService.java中所有的"application/xml"替换成"application.json"，然后重启服务。

浏览器访问会出现一行错误提示

No message body writer has been found for class com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Rooms, ContentType: application/json

这是因为，CXF默认有xml的序列化provider，我们需要显性指定一个JsonProvider，这里我们先用一个业界比较流行的Jackson来支持。

先在pom中加入依赖

<dependency>

　　<groupId>com.fasterxml.jackson.jaxrs</groupId>

　　<artifactId>jackson-jaxrs-json-provider</artifactId>

　　<version>2.6.3</version>

</dependency>

然后为我们的server实例指定一个JsonProvider: JacksonJsonProvider

package com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.server;

import org.apache.cxf.jaxrs.JAXRSServerFactoryBean;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Person;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Persons;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Room;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Rooms;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.service.RoomService;

import com.fasterxml.jackson.jaxrs.json.JacksonJsonProvider;

public class Server {  

    public static void main(String[] args) {

        RoomService service = new RoomService();  

        // Service instance

        JAXRSServerFactoryBean restServer = new JAXRSServerFactoryBean();

        restServer.setResourceClasses(Room.class, Person.class, Rooms.class, Persons.class);

        restServer.setServiceBean(service);

        restServer.setAddress("http://localhost:9000/rs");

        restServer.setProvider(new JacksonJsonProvider());

        restServer.create();

    }

}

返回浏览器，访问地址：http://localhost:9000/rs/roomservice/room 查看，这时我们看到json格式的数据正常返回了。

追问：如果我们用cxf自己的JSONProvider会怎样？

如果用cxf自己的JSONProvider，我们需要引入

cxf-rt-rs-extension-providers.jar

而这个jar在运行时还会依赖jettison里面的TypeConverter，所以我们需要引入

jettison.jar

<dependency>

    <groupId>org.apache.cxf</groupId>

　　<artifactId>cxf-rt-rs-extension-providers</artifactId>

　　<version>${cxf.version}</version>

</dependency>

<dependency>

　　<groupId>org.codehaus.jettison</groupId>

　　<artifactId>jettison</artifactId>

　　<version>1.3.7</version>

</dependency>

完事之后将Server里面的Provider换掉

package com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.server;

import org.apache.cxf.jaxrs.JAXRSServerFactoryBean;

import org.apache.cxf.jaxrs.provider.json.JSONProvider;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Person;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Persons;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Room;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.model.Rooms;

import com.cnblog.richaaaard.cxftest.standalone.rs.helloworld.service.RoomService;

public class Server {

    public static void main(String[] args) {

        RoomService service = new RoomService();

        // Service instance

        JAXRSServerFactoryBean restServer = new JAXRSServerFactoryBean();

        restServer.setResourceClasses(Room.class, Person.class, Rooms.class, Persons.class);

        restServer.setServiceBean(service);

        restServer.setAddress("http://localhost:9000/rs");

//        restServer.setProvider(new JacksonJsonProvider());

        restServer.setProvider(new JSONProvider<Object>());

        restServer.create();

    }

}

从浏览器访问，也同样得到了序列化的json：

不知道有没有人注意两个json string不太一样。这是因为不同库的实现方式不同，Jettison生成的字符串明显≥Jackson的实现。

那么问题来了

如何选择json的实现呢？在实际应用中，xml好还是json或是其他格式会更好呢？

参考：

http://www.cnblogs.com/ggjucheng/p/3352477.html

https://cwiki.apache.org/confluence/display/CXF20DOC/JAXRS+Services+Configuration

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