cxf开发Restful Web Services

一、restful web services

　　rest全称是Representation State Transfer（表述性状态转移）。它是一种软件架构风格，只是提供了一组设计原则和约束条件。在restful web services的设计原则中，所有的事物都应该拥有唯一的URI，通过对URI的请求访问，完成相应的操作。访问的方法与http协议中的若干方法相对应。如下：

• 创建资源，使用 POST 方法。
• 获取某个资源，使用 GET 方法。
• 对资源进行更新，使用 PUT 方法。
• 删除某个资源，使用 DELETE 方法。

二、使用cxf进行构建

　　1、服务器端

　　新建工程，添加cxf的依赖jar包。添加netty-all依赖，这里使用到的是netty-all-4.0.25.Final，下载地址为:http://netty.io/downloads.html 。

　　实体类Address：

package com.cxf.jaxrs;

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name = "address")
public class Address {

    private int id;
    private String city;
    private String street;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public String getStreet() {
        return street;
    }

    public void setStreet(String street) {
        this.street = street;
    }

}

　　实体类Person：

package com.cxf.jaxrs;

import java.util.Date;

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name = "person")
public class Person {

    private int id;
    private String name;
    private Date date;

    private Address address;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }

    public Address getAddress() {
        return address;
    }

    public void setAddress(Address address) {
        this.address = address;
    }

}

　　服务接口MyService：

package com.cxf.jaxrs;

import java.util.Date;
import java.util.List;

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;

@Path("/person/")
// @Produces("text/xml") //只返回xml类型
// @Produces("application/json") //只返回json类型
@Produces("*/*") //表示可返回所有类型
public class MyService {

    @GET  //get方法请求
    @Path("/{id}/") //路径
    public Person getById(@PathParam("id") int id) {
        Person person = new Person();
        person.setId(id);
        person.setName("zhangsan");
        person.setDate(new Date());

        Address add = new Address();
        add.setId(22);
        add.setCity("shanghai");
        add.setStreet("pudong");
        person.setAddress(add);

        return person;
    }

    @GET  //get方法请求
    @Path("/") //路径
    public List<Person> getAll() {
        List<Person> persons = new java.util.ArrayList<Person>();
        Person person = new Person();
        person.setId(111);
        person.setName("zhangsan");
        person.setDate(new Date());

        Person person2 = new Person();
        person2.setId(222);
        person2.setName("lisi");
        person2.setDate(new Date());
        persons.add(person);
        persons.add(person2);
        return persons;
    }

    @DELETE //delete方法请求
    @Path("/{id}") //路径
    public Person removeById(@PathParam("id") int id) {
        Person person = new Person();
        person.setId(111);
        person.setName("zhangsan");
        person.setDate(new Date());
        return person;
    }

    @POST  //post方法请求
    @Path("/") //路径
    public Person add(Person person) {
        System.out.println(person.getDate());
        return person;
    }

    @PUT  //put方法请求
    @Path("/{id}/") //路径
    public Person update(@PathParam("id") int id, Person person) {
        System.out.println("put id : " + id);
        System.out.println(person.getDate());
        return person;
    }
}

　　对于服务类，我们也可定义一个接口，在接口里面写annotation，再定义一个实现类，实现类之完成具体业务逻辑。这样也是可以的。

　　服务器启动类Server：

package com.cxf.jaxrs;

import org.apache.cxf.interceptor.LoggingInInterceptor;
import org.apache.cxf.interceptor.LoggingOutInterceptor;
import org.apache.cxf.jaxrs.JAXRSServerFactoryBean;
import org.apache.cxf.jaxrs.lifecycle.SingletonResourceProvider;

public class Server {
    public static void main(String[] args) {

        JAXRSServerFactoryBean factoryBean = new JAXRSServerFactoryBean();
        factoryBean.setAddress("http://localhost:9000/myservice");

        factoryBean.setResourceClasses(MyService.class);
        factoryBean.setResourceProvider(MyService.class,
                new SingletonResourceProvider(new MyService()));
        factoryBean.getInInterceptors().add(new LoggingInInterceptor());
        factoryBean.getOutInterceptors().add(new LoggingOutInterceptor());
        factoryBean.create();
    }
}

　　2、客户端

　　对于客户端访问，使用apache的httpclient进行请求。cxf的lib目录总已经有httpclient jar包，这里可以直接使用。

　　访问代码如下：

package com.cxf.jaxrs;

import java.io.IOException;
import java.io.InputStream;
import java.io.StringWriter;
import java.text.SimpleDateFormat;
import java.util.Date;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.TransformerFactoryConfigurationError;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.apache.cxf.helpers.IOUtils;
import org.apache.cxf.io.CachedOutputStream;
import org.apache.http.HttpEntity;
import org.apache.http.HttpStatus;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpDelete;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpPut;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

public class Client {

    public static SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");

    public static void main(String[] args) throws Exception {

        System.out.println("===========================get by url =================================");
        String getResult = get("http://localhost:9000/myservice/person/1");
        System.out.println(getResult);

        System.out.println("===========================get===================================");
        String getsResult = get("http://localhost:9000/myservice/person");
        System.out.println(getsResult);

        System.out.println("===========================delete===================================");
        String deleteResult = delete("http://localhost:9000/myservice/person/1");
        System.out.println(deleteResult);

        System.out.println("===========================post=================================");
        Person person = new Person();
        person.setId(3435);
        person.setName("lisi");
        person.setDate(new Date());

        Document document = coverPersonToDocument(person);

        String data = coverDocumentToString(document);

        System.out.println("request data: ");
        System.out.println(data);

        String postResult = post("http://localhost:9000/myservice/person", data);
        System.out.println("response data: ");
        System.out.println(postResult);

        System.out.println("===========================put===================================");
        Person person2 = new Person();
        person2.setId(3435);
        person2.setName("lisi");
        person2.setDate(new Date());

        document = coverPersonToDocument(person);

        data = coverDocumentToString(document);

        System.out.println("request data: ");

        String putResult = put("http://localhost:9000/myservice/person/1", data);
        System.out.println("response data: ");
        System.out.println(putResult);

    }

    /**
     * 发送get 方法请求，并返回结果
     * @param url
     * @return
     * @throws IOException
     * @throws ParserConfigurationException
     */
    private static String get(String url) throws IOException,
            ParserConfigurationException {
        HttpGet get = new HttpGet(url);
        get.setHeader("Accept", "application/json");//接受json数据返回类型
        CloseableHttpClient client = HttpClients.createDefault();
        String responseContent = null;
        CloseableHttpResponse response = null;
        try {
            response = client.execute(get);
            HttpEntity entity = response.getEntity();//响应体
            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {//响应状态码
                responseContent = EntityUtils.toString(entity, "UTF-8");
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        }

        return responseContent;
    }

    /**
     *  发送delete 方法请求，并返回结果
     * @param url
     * @return
     * @throws IOException
     * @throws ParserConfigurationException
     */
    private static String delete(String url) throws IOException,
            ParserConfigurationException {
        HttpDelete delete = new HttpDelete(url);
        CloseableHttpClient client = HttpClients.createDefault();
        CloseableHttpResponse response = null;
        String responseContent = null;
        try {
            response = client.execute(delete);
            HttpEntity entity = response.getEntity();//响应体
            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {//响应状态码
                responseContent = EntityUtils.toString(entity, "UTF-8");
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        }
        return responseContent;
    }

    /**
     *  发送post 方法请求，并返回结果
     * @param url
     * @param data
     * @return
     * @throws IOException
     * @throws ParserConfigurationException
     */
    private static String post(String url, String data) throws IOException,
            ParserConfigurationException {
        HttpPost post = new HttpPost(url);

        StringEntity myEntity = new StringEntity(data,
                ContentType.APPLICATION_XML);//请求体数据，xml类型
        post.setEntity(myEntity);

        CloseableHttpClient client = HttpClients.createDefault();
        String responseContent = null;
        CloseableHttpResponse response = null;
        try {
            response = client.execute(post);
            HttpEntity entity = response.getEntity();//响应体
            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {//响应状态码
                responseContent = EntityUtils.toString(entity, "UTF-8");
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        }
        return responseContent;
    }

    /**
     *  发送put 方法请求，并返回结果
     * @param url
     * @param data
     * @return
     * @throws ParserConfigurationException
     * @throws IOException
     */
    private static String put(String url, String data)
            throws ParserConfigurationException, IOException {
        HttpPut put = new HttpPut(url);
        StringEntity myEntity = new StringEntity(data,
                ContentType.APPLICATION_XML);
        put.setEntity(myEntity);
        put.setHeader("Accept", "application/json");//接受json数据返回类型
        CloseableHttpClient client = HttpClients.createDefault();
        String responseContent = null;
        CloseableHttpResponse response = null;
        try {
            response = client.execute(put);
            HttpEntity entity = response.getEntity();//响应体
            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {//响应状态码
                responseContent = EntityUtils.toString(entity, "UTF-8");
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        }
        return responseContent;
    }

    /**
     * 使用对象构造xml文档对象，并返回
     * @param person
     * @return
     * @throws ParserConfigurationException
     */
    private static Document coverPersonToDocument(Person person)
            throws ParserConfigurationException {
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = factory.newDocumentBuilder();
        Document document = builder.newDocument();
        Element root = document.createElement("person");
        Element node = document.createElement("id");
        node.setTextContent(String.valueOf(person.getId()));

        Element node2 = document.createElement("name");
        node2.setTextContent(person.getName());

        Element node3 = document.createElement("date");
        node3.setTextContent(format.format(person.getDate()));

        root.appendChild(node);
        root.appendChild(node2);
        root.appendChild(node3);

        document.appendChild(root);
        return document;
    }

    /**
     * 将xml文档对象转换成String，并返回
     * @param document
     * @return
     * @throws TransformerFactoryConfigurationError
     */
    private static String coverDocumentToString(Document document)
            throws TransformerFactoryConfigurationError {
        StreamResult strResult = new StreamResult(new StringWriter());
        TransformerFactory tfac = TransformerFactory.newInstance();
        try {
            javax.xml.transform.Transformer t = tfac.newTransformer();
            t.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
            t.setOutputProperty(OutputKeys.INDENT, "yes");
            t.setOutputProperty(OutputKeys.METHOD, "xml"); // xml, html,
            t.transform(new DOMSource(document.getDocumentElement()), strResult);
        } catch (Exception e) {
            System.err.println("XML.toString(Document): " + e);
        }
        String data = strResult.getWriter().toString();
        return data;
    }
}

　　请求的结果如下：