Jersey框架一:Jersey RESTful WebService框架简介

时间:2022-04-05 15:53:38

Jersey系列文章:

Jersey框架一:Jersey RESTful WebService框架简介

Jersey框架二:Jersey对JSON的支持

Jersey框架三:Jersey对HTTPS的支持

 

开发RESTful WebService意味着支持在多种媒体类型以及抽象底层的客户端-服务器通信细节,如果没有一个好的工具包可用,这将是一个困难的任务

为了简化使用JAVA开发RESTful WebService及其客户端,一个轻量级的标准被提出:JAX-RS API

Jersey RESTful WebService框架是一个开源的、产品级别的JAVA框架,支持JAX-RS API并且是一个JAX-RS(JSR 311和 JSR 339)的参考实现

Jersey不仅仅是一个JAX-RS的参考实现,Jersey提供自己的API,其API继承自JAX-RS,提供更多的特性和功能以进一步简化RESTful service和客户端的开发

 

Maven版本:3.1.0

Jersey版本:1.18

JDK版本:1.7.0_65

一,服务端

Maven配置如下:

<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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>JERSEY_SERVER</groupId>
<artifactId>JERSEY_SERVER</artifactId>
<version>1.0</version>
<dependencies>
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-server</artifactId>
<version>1.18</version>
</dependency>
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-grizzly2</artifactId>
<version>1.18</version>
</dependency>
</dependencies>
</project>

首先介绍几个注解:

@Path

用来为资源类或方法定义URI,当然除了静态URI也支持动态URI

@Path("service") 
public class MyResource {
@Path("{sub_path}")
@GET
public String getResource(@PathParam("sub_path") String resourceName) {
......

如果此时客户端请求的URI为http://127.0.0.1:10000/service/sean,则sub_path的值为sean

@PathParam用来将请求URI的一部分作为方法参数传入方法中

对URI的动态部分,可以自定义校验正则表达式,如果请求参数校验失败,容器返回404 Not Found

@Path("{sub_path:[A-Z]*}")

@GET

表明被注解的方法响应HTTP GET请求,@POST@PUT@DELETE同理

@Consumes

定义请求的媒体类型,如果不指定,则容器默认可接受任意媒体类型,容器负责确认被调用的方法可接受HTTP请求的媒体类型,否则返回415 Unsupported Media Type

方法级注解将覆盖类级注解

@Produces

定义响应媒体类型,如果不指定,则容器默认可接受任意媒体类型,容器负责确认被调用的方法可返回HTTP请求可以接受媒体类型,否则返回406 Not Acceptable

方法级注解将覆盖类级注解

@QueryParam

public String getResource(
@DefaultValue("Just a test!") @QueryParam("desc") String description) {
......
}

如果请求URI中包含desc参数,例如:http://127.0.0.1:10000/service/sean?desc=123456,则desc参数的值将会赋给方法的参数description,否则方法参数description的值将为@DefaultValue注解定义的默认值

@Context

将信息注入请求或响应相关的类,可注入的类有:Application,UriInfo,Request,HttpHeaders和SecurityContext

@Singleton@PerRequest

默认情况下,资源类的生命周期是per-request,也就是系统会为每个匹配资源类URI的请求创建一个实例,这样的效率很低,可以对资源类使用@Singleton注解,这样在应用范围内,只会创建资源类的一个实例

服务端程序如下:

package com.sean;

import java.io.IOException;
import java.net.URI;
import java.util.Iterator;

import javax.ws.rs.Consumes;
import javax.ws.rs.DefaultValue;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.HttpHeaders;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.Request;
import javax.ws.rs.core.UriBuilder;
import javax.ws.rs.core.UriInfo;

import org.glassfish.grizzly.http.server.HttpServer;

import com.sun.jersey.api.container.grizzly2.GrizzlyServerFactory;
import com.sun.jersey.api.core.PackagesResourceConfig;
import com.sun.jersey.api.core.ResourceConfig;
import com.sun.jersey.spi.resource.Singleton;

@Singleton
@Path("service")
public class MyResource {

@Path("{sub_path:[a-zA-Z0-9]*}")
@GET
@Consumes({MediaType.TEXT_PLAIN, MediaType.APPLICATION_JSON})
@Produces(MediaType.TEXT_PLAIN)
public String getResourceName(
@PathParam("sub_path") String resourceName,
@DefaultValue("Just a test!") @QueryParam("desc") String description,
@Context Request request,
@Context UriInfo uriInfo,
@Context HttpHeaders httpHeader) {
System.out.println(this.hashCode());

// 将HTTP请求打印出来
System.out.println("****** HTTP request ******");
StringBuilder strBuilder = new StringBuilder();
strBuilder.append(request.getMethod() + " ");
strBuilder.append(uriInfo.getRequestUri().toString() + " ");
strBuilder.append("HTTP/1.1[\\r\\n]");
System.out.println(strBuilder.toString());
MultivaluedMap<String, String> headers = httpHeader.getRequestHeaders();
Iterator<String> iterator = headers.keySet().iterator();
while(iterator.hasNext()){
String headName = iterator.next();
System.out.println(headName + ":" + headers.get(headName) + "[\\r\\n]");
}
System.out.println("[\\r\\n]");
String responseStr =resourceName + "[" + description + "]";
return responseStr;
}

public static void main(String[] args) {
URI uri = UriBuilder.fromUri("http://127.0.0.1").port(10000).build();
ResourceConfig rc = new PackagesResourceConfig("com.sean");
try {
HttpServer server = GrizzlyServerFactory.createHttpServer(uri, rc);
server.start();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (NullPointerException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
Thread.sleep(1000*1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}

 

二,客户端

Maven配置如下:

<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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>JERSEY_CLIENT</groupId>
<artifactId>JERSEY_CLIENT</artifactId>
<version>1.0</version>
<dependencies>
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-client</artifactId>
<version>1.18</version>
</dependency>
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-grizzly2</artifactId>
<version>1.18</version>
</dependency>
</dependencies>
</project>

客户端程序如下:

package com.sean;

import java.net.URI;
import java.util.Iterator;

import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.UriBuilder;

import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.WebResource;
import com.sun.jersey.api.client.config.ClientConfig;
import com.sun.jersey.api.client.config.DefaultClientConfig;

public class JerseyClient {

public static void main(String[] args) {
// 要使用Jersey Client API,必须首先创建Client的实例
// 有以下两种创建Client实例的方式

// 方式一
ClientConfig cc = new DefaultClientConfig();
cc.getProperties().put(ClientConfig.PROPERTY_CONNECT_TIMEOUT, 10*1000);
// Client实例很消耗系统资源,需要重用
// 创建web资源,创建请求,接受响应都是线程安全的
// 所以Client实例和WebResource实例可以在多个线程间安全的共享
Client client = Client.create(cc);

// 方式二
// Client client = Client.create();
// client.setConnectTimeout(10*1000);
// client.getProperties().put(ClientConfig.PROPERTY_CONNECT_TIMEOUT, 10*1000);

// WebResource将会继承Client中timeout的配置
WebResource resource = client.resource("http://127.0.0.1:10000/service/sean?desc=description");

String str = resource
.accept(MediaType.TEXT_PLAIN)
.type(MediaType.TEXT_PLAIN)
.get(String.class);
System.out.println("String:" + str);

URI uri = UriBuilder.fromUri("http://127.0.0.1/service/sean").port(10000)
.queryParam("desc", "description").build();
resource = client.resource(uri);

//header方法可用来添加HTTP头
ClientResponse response = resource.header("auth", "123456")
.accept(MediaType.TEXT_PLAIN)
.type(MediaType.TEXT_PLAIN)
.get(ClientResponse.class);
// 将HTTP响应打印出来
System.out.println("****** HTTP response ******");
StringBuilder strBuilder = new StringBuilder();
strBuilder.append("HTTP/1.1 ");
strBuilder.append(response.getStatus() + " ");
strBuilder.append(response.getStatusInfo() + "[\\r\\n]");
System.out.println(strBuilder.toString());
MultivaluedMap<String, String> headers = response.getHeaders();
Iterator<String> iterator = headers.keySet().iterator();
while(iterator.hasNext()){
String headName = iterator.next();
System.out.println(headName + ":" + headers.get(headName) + "[\\r\\n]");
}
System.out.println("[\\r\\n]");
System.out.println(response.getEntity(String.class) + "[\\r\\n]");
}
}

 

服务端日志如下:

二月 06, 2015 4:33:33 下午 com.sun.jersey.api.core.PackagesResourceConfig init
INFO: Scanning for root resource and provider classes in the packages:
com.sean
二月 06, 2015 4:33:33 下午 com.sun.jersey.api.core.ScanningResourceConfig logClasses
INFO: Root resource classes found:
class com.sean.Test
class com.sean.MyResource
二月 06, 2015 4:33:33 下午 com.sun.jersey.api.core.ScanningResourceConfig init
INFO: No provider classes found.
二月 06, 2015 4:33:33 下午 com.sun.jersey.server.impl.application.WebApplicationImpl _initiate
INFO: Initiating Jersey application, version 'Jersey: 1.18 11/22/2013 01:21 AM'
二月 06, 2015 4:33:34 下午 org.glassfish.grizzly.http.server.NetworkListener start
INFO: Started listener bound to [127.0.0.1:10000]
二月 06, 2015 4:33:34 下午 org.glassfish.grizzly.http.server.HttpServer start
INFO: [HttpServer] Started.
1814260800
****** HTTP request ******
GET http://127.0.0.1:10000/service/sean?desc=description HTTP/1.1[\r\n]
accept:[text/plain][\r\n]
content-type:[text/plain][\r\n]
user-agent:[Java/1.7.0_65][\r\n]
host:[127.0.0.1:10000][\r\n]
connection:[keep-alive][\r\n]
[\r\n]
1814260800
****** HTTP request ******
GET http://127.0.0.1:10000/service/sean?desc=description HTTP/1.1[\r\n]
auth:[123456][\r\n]
accept:[text/plain][\r\n]
content-type:[text/plain][\r\n]
user-agent:[Java/1.7.0_65][\r\n]
host:[127.0.0.1:10000][\r\n]
connection:[keep-alive][\r\n]
[\r\n]

客户端日志如下:

String:sean[description]
****** HTTP response ******
HTTP/1.1 200 OK[\r\n]
Transfer-Encoding:[chunked][\r\n]
Date:[Fri, 06 Feb 2015 08:33:38 GMT][\r\n]
Content-Type:[text/plain][\r\n]
[\r\n]
sean[description][\r\n]