RestEasy编写API

我是从这篇文章学习的RESTEASY
https://www.cnblogs.com/langtianya/p/7624647.html

1. 现实需求

任务：发送请求给服务器，解析请求，返回结果
请求内容：user_id, 图片

2. 分析

1）首先要指定url，参数列表，请求方式，提供一个对外开放接口；

2）业务逻辑在接口中，返回数据；

3）调用方会根据提供的接口url，指定的参数列表，请求方式post/get调用接口。

3. 实现过程

1） pom.xml部署依赖

 <dependency><groupId>org.jboss.resteasy</groupId><artifactId>jaxrs-api</artifactId><version>3.0.7.Final</version></dependency><dependency><groupId>org.jboss.resteasy</groupId><artifactId>resteasy-jaxrs</artifactId><version>3.0.19.Final</version><!--<scope>provided</scope>--></dependency><dependency><groupId>org.jboss.resteasy</groupId><artifactId>resteasy-client</artifactId><version>3.0.19.Final</version></dependency><dependency><groupId>org.jboss.resteasy</groupId><artifactId>resteasy-multipart-provider</artifactId><version>3.0.19.Final</version><scope>provided</scope></dependency><dependency><groupId>org.jboss.resteasy</groupId><artifactId>resteasy-jackson2-provider</artifactId><version>3.0.19.Final</version></dependency><dependency><groupId>org.jboss.resteasy</groupId><artifactId>resteasy-servlet-initializer</artifactId><version>3.0.19.Final</version></dependency>

2）实现API接口 TestRest

思路
图片url是：“http://pic38.nipic.com/” +id+"/"+pic_name
得到一张图片
将图片另存到本地，并得到以时间戳命名的名称
返回fin = pic + id

代码：

package Rest;import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;/*** 用来处理请求的API* @author bobo**/
@Path("/path1")
public class TestRest {@GET@Produces("application/json")@Path("subpath/{id}/{pic_name}")public String get(@PathParam("id") String id , @PathParam("pic_name") String pic_name) throws IOException{//String result = "接收参数： " + id +"  " + pic_name;URL url1 = new URL("http://pic38.nipic.com/" +id+"/"+pic_name);URLConnection uc = url1.openConnection();InputStream inputStream = uc.getInputStream();String path = "D:\\image\\"+System.currentTimeMillis()+".jpg";FileOutputStream out = new FileOutputStream(path);int j = 0;while ((j = inputStream.read()) != -1) {out.write(j);}inputStream.close();//得到picString pic = path.substring(9, path.length()-4);String fin = pic + " " + id;System.out.println(pic + " " + id);return fin;}
}

测试：
运行程序，tomcat启动
输入url http://localhost:8080/api_test_1/path1/subpath/20140225/2531170_214014788000_2.jpg
返回：

3） web.xml配置

<!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><display-name>Archetype Created Web Application</display-name><context-param><param-name>resteasy.resources</param-name><param-value>Rest.TestRest</param-value></context-param><listener><listener-class>org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap</listener-class></listener><servlet><servlet-name>Resteasy</servlet-name><servlet-class>org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher</servlet-class></servlet><servlet-mapping><servlet-name>Resteasy</servlet-name><url-pattern>/*</url-pattern></servlet-mapping>
</web-app>

4）测试API接口 TestRestAPI

代码：

package Rest;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;public class TestRestAPI{  public static final String USER_API =   "http://localhost:8080/api_2/path1/subpath/20140225/2531170_214014788000_2.jpg";  public static String getPic() throws IOException{//列出原始数据StringBuilder json = new StringBuilder();   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);  BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream(),"UTF-8")); String inputLine = null; while ( (inputLine = in.readLine()) != null){ json.append(inputLine); } String Strjson=json.toString();return Strjson.toString().split(" ")[0];}public static String getUid() throws IOException{//列出原始数据StringBuilder json = new StringBuilder();   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);  BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream(),"UTF-8")); String inputLine = null; while ( (inputLine = in.readLine()) != null){ json.append(inputLine); } String Strjson=json.toString();return Strjson.toString().split(" ")[1];}public static void main(String[] args) throws IOException {//列出原始数据StringBuilder json = new StringBuilder();   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);  BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream(),"UTF-8")); String inputLine = null; while ( (inputLine = in.readLine()) != null){ json.append(inputLine); } String Strjson=json.toString();String[] str = Strjson.toString().split(" ");String pic_name = str[0];String id = str[1];int user_id = Integer.parseInt(id);System.out.println("pic_name:");System.out.println(pic_name); System.out.println("id:"); System.out.println(user_id);}
}

测试：
运行程序，tomcat启动
给定url
http://localhost:8080/api_test_1/path1/subpath/20140225/2531170_214014788000_2.jpg
两个方法：
getPic() 得到：1571794041366
getUid() 得到：20140225
主函数得到：
pic_name:
1571794041366
id:
20140225