RESTEasy实例

时间 2019-12-07

标签 resteasy 实例繁體版

原文原文链接

RESTEasy是JBoss的开源项目之一，是一个RESTful Web Services框架。java

趁今天有空，学习一下RESTEasy。看了两篇博客后，本身写了一个demo。web

1. 新建一个maven的web项目。

依赖以下：apache

<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.fengyuan</groupId>
<artifactId>RESTEasyDemo</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>RESTEasyDemo Maven Webapp</name>
<url>http://maven.apache.org</url>

<dependencies>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.4</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.14.4</version>
    </dependency>
    <dependency>
        <groupId>org.jboss.resteasy</groupId>
        <artifactId>resteasy-jaxrs</artifactId>
        <version>2.2.3.GA</version>
    </dependency>
    <dependency>
        <groupId>org.jboss.resteasy</groupId>
        <artifactId>resteasy-jackson-provider</artifactId>
        <version>2.2.3.GA</version>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <source>1.7</source>
                <target>1.7</target>
                <encoding>UTF-8</encoding>
            </configuration>
        </plugin>
    </plugins>
</build>
</project>

2. 接着建立两个服务，messageservice和userservice：

UserService.java:json

package com.fengyuan.restapi;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;

import com.fengyuan.domain.User;

@Path("userservice") // 服务路径
public class UserService {
    /**
     * 初始化三个用户数据，存入map中，key为用户id，value为用户对象
     */
    static Map<Integer, User> userMap = new HashMap<>();
    static {
        User user1 = new User("Lee", 24, "138***");
        userMap.put(1, user1);
        User user2 = new User("Cathy", 25, "188***");
        userMap.put(2, user2);
        User user3 = new User("Aaron", 26, "186***");
        userMap.put(3, user3);
    }

    /**
     * 获取指定id的用户
     * 
     * @param id
     * @return
     */
    @GET
    @Path("user/{id}") // 具体服务的路径, id是入参
    @Produces("application/json") // 返回的格式
    public User getById(@PathParam("id") Integer id) {
        return (User) userMap.get(id);
    }

    /**
     * 以json格式返回全部用户
     * 
     * @return
     */
    @GET
    @Path("users")
    @Produces("application/json")
    public List<User> getUsers() {
        List<User> userList = new ArrayList<User>();
        for (Entry<Integer, User> user : userMap.entrySet()) {
            userList.add(user.getValue());
        }
        return userList;
    }
}

MessageService.java:api

package com.fengyuan.restapi;
import javax.ws.rs.GET;
import javax.ws.rs.Path;  
import javax.ws.rs.PathParam;  
import javax.ws.rs.core.Response;  
   
@Path("/messageservice")  
public class MessageService {  
   public MessageService(){} 
    @GET 
    @Path("/{param}")  
    public Response printMessage(@PathParam("param") String msg) {  
        String result = "Hello : " + msg;  
   
        return Response.status(200).entity(result).build();  
    }  
}

User.java:浏览器

package com.fengyuan.domain;

import lombok.AllArgsConstructor;
import lombok.Data;

public @Data @AllArgsConstructor class User {
    private String name;
    private int age;
    private String tel;
}

3. 配置web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">
  <display-name>Restful Web Application</display-name>
  <context-param>
    <param-name>resteasy.scan</param-name>
    <param-value>true</param-value>
  </context-param>
  <!-- <context-param>
    <param-name>resteasy.resources</param-name>
    <param-value>com.fengyuan.restapi.MessageService, com.fengyuan.restapi.UserService</param-value>
  </context-param> -->
  <context-param>
    <param-name>resteasy.servlet.mapping.prefix</param-name>
    <param-value>/rest</param-value>
  </context-param>
  <listener>
    <listener-class>org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap</listener-class>
  </listener>
  <servlet>
    <servlet-name>resteasy-servlet</servlet-name>
    <servlet-class>org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>resteasy-servlet</servlet-name>
    <url-pattern>/rest/*</url-pattern>
  </servlet-mapping>
</web-app>

配置resteasy.scan为true表示自动扫描服务。若是不配置，也能够手动指定resteasy.resources，见注释掉的部分。tomcat

4. 启动tomcat，在浏览器输入服务的url：

5. 除了能够在浏览器直接访问以外，也能够用代码调用：

package com.fengyuan.test;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

import junit.framework.TestCase;  
  
public class TestUserAPI extends TestCase {  
    public static final String USER_API =   
        "http://127.0.0.1:8080/resteasy-demo/rest/userservice/users";  
  
    public void testCreateUserAndGetUser() throws IOException {  
        URL url =   
            new URL(USER_API);  
        HttpURLConnection connection =   
            (HttpURLConnection) url.openConnection();  
        connection.setRequestMethod("GET");  
        connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");  
        connection.setConnectTimeout(1000);  
  
        byte[] bytes = new byte[1024];
        //读取请求返回值
        InputStream inStream=connection.getInputStream();
        inStream.read(bytes, 0, inStream.available());
        System.out.println(new String(bytes, "utf-8"));
        
        connection.disconnect();  
    }  
}

控制台输出：app

[{"name":"Lee","tel":"138***","age":24},{"name":"Cathy","tel":"188***","age":25},{"name":"Aaron","tel":"186***","age":26}]

固然，这里只是简单了测试了GET类型的服务，还有POST等类型的服务等有空了再补充。框架

另外，我在写这个demo项目的时候，发现若是使用了2.1.多版本的resteasy-jackson-provider和resteasy-jaxrs包，而且在web.xml中配置了resteasy.scan为true的话，会出一些问题，这边提醒一下，让看这篇博文的同窗不用再踩进这个坑~。dom