Jersey—— 一个基于Rest风格的Web Service开发框架

一、什么是Jersey

   Jersey 是一个Java规范（JAX-RS）下的基于Rest风格的Web Service开发框架。

   说的直白一点，主要应用于移动项目，用来给移动终端和服务端传递数据。

   Rest则是一种目前主流的软件架构风格，它可以通过一套统一的接口为 Web，iOS和Android提供服务。因为有些平台不需要显式的前端，只需要一套提供服务的接口，于是就有了Rest风格的软件架构。

二、Jersey+Spring+Mybatis搭建一个简单的Web Service

1、在Eclipse下创建一个Maven工程

工程目录结构如下图：



   上图中——com.zy包下存放业务代码
              ——resources文件夹下存放资源文件
              ——其它主要有Web.xml和Pom.xml文件

2、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.zy</groupId>
<artifactId>jersey</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>jersey Maven Webapp</name>
<url>http://maven.apache.org</url>

<properties>
<!-- 指明使用JDK8 -->
<java-version>1.8</java-version>
<!-- 指明使用utf-8编码 -->
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<spring3.version>4.2.6.RELEASE</spring3.version>
<jersey.version>2.22.2</jersey.version>
</properties>

<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>2.9.0</version>
</dependency>
<!-- Jersey依赖 -->
<dependency>
<groupId>org.glassfish.jersey.containers</groupId>
<artifactId>jersey-container-servlet</artifactId>
<version>${jersey.version}</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring3.version}</version>
<scope>compile</scope>
</dependency>

<dependency>
<groupId>org.glassfish.jersey.ext</groupId>
<artifactId>jersey-spring3</artifactId>
<version>${jersey.version}</version>
</dependency>

<dependency>
<groupId>org.glassfish.jersey.media</groupId>
<artifactId>jersey-media-json-jackson</artifactId>
<version>${jersey.version}</version>
</dependency>
<!-- 加入mysql驱动依赖包 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.27</version>
</dependency>

<!-- 引入mybatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.1.1</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.2.8</version>
</dependency>
<!-- 引入数据源 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.0.1</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.7.4</version>
</dependency>
<!-- 加入fastjson依赖包 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.1.37</version>
</dependency>

<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
<v
d4dc
ersion>3.7.6</version>
</dependency>
<dependency>
<groupId>cglib</groupId>
<artifactId>cglib</artifactId>
<version>2.2.2</version>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.4</version>
</dependency>
<dependency>
<groupId>org.glassfish.jersey.ext</groupId>
<artifactId>jersey-bean-validation</artifactId>
<version>2.22.2</version>
<exclusions>
<exclusion>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>commons-beanutils</groupId>
<artifactId>commons-beanutils</artifactId>
<version>1.7.0</version>
</dependency>

<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.5</version>
</dependency>
<!-- E起充解码包 -->
<dependency>
<groupId>com.extracme.evready</groupId>
<artifactId>decode</artifactId>
<version>1.1.6</version>
</dependency>
<dependency>
<groupId>com.extracme</groupId>
<artifactId>evreadyHelp</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
<!-- disconf注解插件 -->
<dependency>
<groupId>com.baidu.disconf</groupId>
<artifactId>disconf-client</artifactId>
<version>2.6.36</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.2</version>
</dependency>
</dependencies>

<build>
<finalName>jersey</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.18.1</version>
<configuration>
<skipTests>true</skipTests>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<skipTests>true</skipTests>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
</project>

以上就是项目所依赖的jar包，其中有一些是项目需要的可以忽略，重点是Jersey和spring以及mybatis的依赖，上面有相关的注释。

3、web.xml

<!-- <!DOCTYPE web-app PUBLIC -->
<!--  "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" -->
<!--  "http://java.sun.com/dtd/web-app_2_3.dtd" > -->
<web-app>

<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<listener>
<listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
</listener>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring.xml</param-value>
</context-param>
<servlet>
<servlet-name>jersey</servlet-name>
<servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
<init-param>
<param-name>javax.ws.rs.Application</param-name>
<param-value>com.zy.StartApplication</param-value>

</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>jersey</servlet-name>
<url-pattern>/*</url-pattern>
</servlet-mapping>
</web-app>

以上是web.xml的配置。
——listener定义了Spring框架中的Bean随着Web容器启动而被创建。
——context-param定义了Spring.xml的位置。
——servlet定义了org.glassfish.jersey.servlet.ServletContainer，相当于对客户端的请求（/*）进行了拦截，同时还有一个启动参数，它是Application类的实现，需要我们自己定义，利用它来注册资源，实现如下：

public class StartApplication extends ResourceConfig {

/**
* Register JAX-RS application components.
*/
public StartApplication() {
//register(AuthRequestFilter.class);
packages("com.zy.resource");

}
}

4、spring-mybatis.xml和mybatis-config.xml以及spring.xml

Spring-mybatis.xml如下：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:c="http://www.springframework.org/schema/c" xmlns:cache="http://www.springframework.org/schema/cache"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:jee="http://www.springframework.org/schema/jee"
xmlns:lang="http://www.springframework.org/schema/lang" xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:p="http://www.springframework.org/schema/p" xmlns:task="http://www.springframework.org/schema/task"
xmlns:tx="http://www.springframework.org/schema/tx" xmlns:util="http://www.springframework.org/schema/util"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee.xsd http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd"> 
<!-- 配置测试环境数据源 -->
<bean name="test-dataSource" class="com.alibaba.druid.pool.DruidDataSource"
init-method="init" destroy-method="close">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/jersey-test?useUnicode=true&characterEncoding=UTF-8" />
<property name="username" value="root" />
<property name="password" value="" />

<!-- 初始化连接大小 -->
<property name="initialSize" value="0" />
<!-- 连接池最大使用连接数量 -->
<property name="maxActive" value="20" />
<!-- 连接池最小空闲 -->
<property name="minIdle" value="0" />
<!-- 获取连接最大等待时间 -->
<property name="maxWait" value="60000" />

<property name="testOnBorrow" value="false" />
<property name="testOnReturn" value="false" />
<property name="testWhileIdle" value="true" />

<!-- 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 -->
<property name="timeBetweenEvictionRunsMillis" value="60000" />
<!-- 配置一个连接在池中最小生存的时间，单位是毫秒 -->
<property name="minEvictableIdleTimeMillis" value="25200000" />

<!-- 打开removeAbandoned功能 -->
<property name="removeAbandoned" value="true" />
<!-- 1800秒，也就是30分钟 -->
<property name="removeAbandonedTimeout" value="1800" />
<!-- 关闭abanded连接时输出错误日志 -->
<property name="logAbandoned" value="true" />

<!-- 监控数据库 -->
<!-- <property name="filters" value="mergeStat" /> -->
<property name="filters" value="stat" />
</bean>

<!--根据dataSource和configLocation创建一个sqlSessionFactory -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="test-dataSource" />
<property name="configLocation" value="classpath:mybatis-config.xml"></property>
</bean>
<bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate"
scope="prototype">
<constructor-arg index="0" ref="sqlSessionFactory" />
</bean>
<!-- 配置事务管理器 -->
<bean name="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="test-dataSource"></property>
</bean>

<!-- 注解方式配置事物 -->
<tx:annotation-driven transaction-manager="transactionManager" />

<bean id="sqlSessionCache" class="com.zy.utils.SqlSessionCache"
init-method="initMapper">
<!-- 扫描的映射mapper.xml的文件路径 -->
<property name="packageSearchPath" value="classpath*:com/zy/*/sql/*.xml"></property>
<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
</bean>
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.zy.*.mapper" />
</bean>

<bean id="framelnterceptor" class="com.zy.utils.Framelnterceptor" />
<aop:aspectj-autoproxy/>
</beans>

mybatis-config.xml如下：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC
"-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!-- 	<properties resource="project.properties" /> -->
<settings>
<setting name="cacheEnabled" value="true" />
<setting name="lazyLoadingEnabled" value="true" />
<setting name="multipleResultSetsEnabled" value="true" />
<setting name="useColumnLabel" value="true" />
<setting name="useGeneratedKeys" value="false" />
<setting name="autoMappingBehavior" value="PARTIAL" />
<setting name="defaultExecutorType" value="SIMPLE" />
<setting name="defaultStatementTimeout" value="25" />
<setting name="safeRowBoundsEnabled" value="false" />
<setting name="mapUnderscoreToCamelCase" value="false" />
<setting name="localCacheScope" value="SESSION" />
<!-- <setting name="logImpl" value="STDOUT_LOGGING" /> -->
<setting name="jdbcTypeForNull" value="OTHER" />
<setting name="lazyLoadTriggerMethods" value="equals,clone,hashCode,toString" />
</settings></configuration>

Spring.xml的配置如下：

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd" >
<!-- 自动扫描dao和service包(自动注入) -->
<context:component-scan base-package="com.zy.*" />
<import resource="classpath:spring-mybatis.xml" />
</beans>

注意：在spring-mybatis.xml配置文件的底部配置了一个拦截器——<bean id="framelnterceptor" class="com.zy.utils.Framelnterceptor" />
          ——作用是输出请求接口的信息和接口返回的信息，以及获取某些与Token相关的信息。

5、请求过程

Resources

package com.zy.resource;

import javax.ws.rs.Consumes;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

@Path("/helloworld")
public class RestHelloWorld {

@GET
@Consumes(MediaType.APPLICATION_JSON)
@Produces("application/json;charset=UTF-8")
public String sayHelloWorld(){
return "Hello ZY!!!大苏打";
}
}

————这是一个简单的获取资源，使用GET方式获取，屏幕输出     Hello ZY!!!大苏打 。

资源类是一个简单的 Java 对象 (POJO)，可以实现任何接口，简单、可重用性强。

资源类上的常用注解有：

@Path，标注资源类或者方法的相对路径

@GET，@PUT，@POST，@DELETE，标注方法是HTTP请求的类型。

@Produces，标注返回的MIME媒体类型

@Consumes，标注可接受请求的MIME媒体类型

@PathParam，@QueryParam，@HeaderParam，@CookieParam，@MatrixParam，@FormParam
分别标注方法的参数来自于HTTP请求的不同位置，例如

@PathParam来自于URL的路径，

@QueryParam来自于URL的查询参数，

@HeaderParam来自于HTTP请求的头信息，

@CookieParam来自于HTTP请求的Cookie。

总结：以上就是一个简单的Jersey框架搭建过程，其中涉及到的很多东西这里没有详细解释，日后深入理解再详谈。