java如何写接口给别人调用 - Go语言中文社区

java如何写接口给别人调用


计算机语言分类有很多,如C、C++、C#、Java、Php、Python等等,她们有各自的特性及擅长的领域,但她们各自又不是全能的。在一个稍微大型一点的项目都会用到多种语言共同完成,那么这些编程语言如何进行通信呢。什么意思呢,就是比如说我Java写的一个方法,其他编程语言要怎么去调用呢?这就是本文要探讨的问题了。

一般来说,方法层面的编程语言通信用的是网络接口形式,只暴露出形参和结果供别人调用。接口一般分为接口定义者和接口调用者,定义者可以规定接收参数的类型及返回形式,而接口定义者则只能完全按照接口定义者规定的参数进行访问。就叫是我们所说的webService(网络服务)。

以前的做法是利用XML作接口格式定义,然后通过Http做通讯和请求,如大名鼎鼎的SOAP,其实现在也是的,只不过现在流行RestFul风格的Rest接口形式,但用的还是XML+HTTP,那这两者有啥区别呢?最大的区别就是SOAP返回的主要是XML格式,有时还需要附带一些辅助文件,而Rest则还可以返回JSON类型的字符串,减少了很多繁乱的XML标签。本文就以Java为例,用她写一个接口,并让其他人去调用,以此来简单展示接口调用是怎么样一个过程。

步骤:

1、本机装有Java JDK运行环境及编程IDE(如Myeclipse)

2、建立一个maven项目,用以下载jar包,项目结构如下:



3 pom.xml文件内容如下:

<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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>ws</groupId>
  <artifactId>restful</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>restful-server</name>
  <url>http://maven.apache.org</url>
  <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <jersey.version>2.6</jersey.version>
        <jersey-spring.version>2.23.1</jersey-spring.version>
        <spring.version>4.2.7.RELEASE</spring.version>
        <servlet-api-version>3.1.0</servlet-api-version>
        <logback.version>1.1.1</logback.version>
        <jcloverslf4j.version>1.7.6</jcloverslf4j.version>
    </properties>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    
    <dependency>
            <groupId>org.glassfish.jersey.ext</groupId>
            <artifactId>jersey-spring3</artifactId>
            <version>${jersey-spring.version}</version>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-core</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-web</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring-beans</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>org.glassfish.jersey.containers</groupId>
            <artifactId>jersey-container-servlet</artifactId>
            <version>${jersey-spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.containers</groupId>
            <artifactId>jersey-container-servlet-core</artifactId>
            <version>${jersey-spring.version}</version>
        </dependency>

         <dependency>
            <groupId>org.glassfish.jersey.media</groupId>
            <artifactId>jersey-media-json-jackson</artifactId>
            <version>${jersey.version}</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.media</groupId>
            <artifactId>jersey-media-multipart</artifactId>
            <version>${jersey.version}</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.ext</groupId>
            <artifactId>jersey-entity-filtering</artifactId>
            <version>${jersey.version}</version>
        </dependency>

        <!-- Spring4.2 dependencies -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>

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

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>${servlet-api-version}</version>
            <scope>provided</scope>
        </dependency>

        <!-- Logback dependencies -->
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>${logback.version}</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jcl-over-slf4j</artifactId>
            <version>${jcloverslf4j.version}</version>
        </dependency>
    
  </dependencies>
  <build>
    <finalName>restful</finalName>
  </build>
</project>

4 applicationContext.xml内容如下:

<?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"
       xmlns:tx="http://www.springframework.org/schema/tx"
       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-4.1.xsd">

    <context:component-scan base-package="com.kendy.*"></context:component-scan>
</beans>

5 web.xml则主要配置采用的容器、日志管理及拦截器,拦截器可以实现到达请求郑涛之前进行身份认证,踢除没有访问资格的请求,而rest项目一般是用Jersey容器。配置如下:(kendy只是我的英文名,你们可以自己定义路径)

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:javaee="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <display-name></display-name>
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:applicationContext.xml</param-value>
  </context-param>
  <listener>
    <listener-class>
            org.springframework.web.context.ContextLoaderListener
        </listener-class>
  </listener>
  <servlet>
    <servlet-name>jersey-serlvet</servlet-name>
    <servlet-class>
            org.glassfish.jersey.servlet.ServletContainer
        </servlet-class>
    <init-param>
      <param-name>javax.ws.rs.Application</param-name>
      <param-value>com.kendy.filter.RestJaxRsApplication</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>jersey-serlvet</servlet-name>
    <url-pattern>/*</url-pattern>
  </servlet-mapping>
</web-app>


6 拦截器如下:

import java.io.IOException;
import java.io.InputStream;
import java.util.List;
import java.util.Map.Entry;

import javax.ws.rs.WebApplicationException;
import javax.ws.rs.container.ContainerRequestContext;
import javax.ws.rs.container.ContainerRequestFilter;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.Response.Status;
import javax.ws.rs.ext.Provider;

/**
 * 拦截请求
 */
@Provider
public class MyFilter implements ContainerRequestFilter {

  @Override
  public void filter(ContainerRequestContext context) throws IOException {
    
    //打印出所有请求头
    MultivaluedMap<String, String> map =  context.getHeaders();
    for(Entry<String, List<String>> entry : map.entrySet()){
    	String key = entry.getKey();
    	List<String> valueList = entry.getValue();
    	String values = valueList.toString();
    	System.out.println(key + ":"+values.substring(1,values.length()-1));
    }

7 注册Jersey容器所要管理的类

import org.codehaus.jackson.jaxrs.JacksonJsonProvider;
import org.glassfish.jersey.server.ResourceConfig;

import com.kendy.restful.AccountManager;
import com.kendy.restful.AuthorityManager;
import com.kendy.restful.CardManager;
import com.kendy.restful.DeviceManager;
import com.kendy.restful.UserResource;

/**
 * ${DESCRIPTION}
 */
public class RestJaxRsApplication extends ResourceConfig {

    /**
     * Register JAX-RS application components.
     */
    public RestJaxRsApplication() {

        //服务类所在的包路径
        packages("com.kendy.*");
        
        // register application resources
        this.register(YouClass.class);
     
        // register filters
        this.register(MyFilter.class);
        //this.register(RequestContextFilter.class);
        
        register(JacksonJsonProvider.class);
        //register(MultiPartFeature.class);
    }
}

8 接口定义(Restful风格)

package com.kendy.restful;

import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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

import org.springframework.stereotype.Component;

@Component
@Path("/CardManager")
public class CardManager {
	
    private SimpleDateFormat sdf =new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

    @POST
    @Path("size")
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public Map<String,Object> size(){
    	Map<String,Object> map = new HashMap<>();
    	//do something here
    	map.put("Size", 1024);
    	return map;
    }
    
    @POST
    @Path("getDetail")
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public Map<String,List<Map<String,Object>>> getDetail(){
    	Map<String,List<Map<String,Object>>> map = new HashMap<>();
    	//do something here
    	List<Map<String,Object>> list = new ArrayList<>();
    	Map<String,Object> subMap = new HashMap<>();
    	subMap.put("UUID", 10086);
    	subMap.put("CardID", 10081);
    	subMap.put("StartTime", sdf.format(new Date()));
    	subMap.put("EndTime", sdf.format(new Date()));
    	list.add(subMap);
    	map.put("Card", list);
    	
    	return map;
    }
}

9 调用接口,有多种方式,本文用HttpClient

/**
     * 发送 post请求webService接口
     * @param url 访问的接口地址
     * @param account 用户名
     * @param code 密码
     * @param param 查询参数
     * @return HttpResponse 该类包含请求方法的态码及返回的数据
     */  
    public static HttpResponse post(String url,String account,String code,Map<String,Object> param) {  
        //创建HttpClient实例及Post方法
    	HttpClient httpclient = new DefaultHttpClient();  
        HttpPost httppost = new HttpPost(url); 
        //对用户密码MD5加密
		code = getMD5(code);
		//添加相关请求头,依情况而定
		httppost.setHeader("Authorization","WSSE profile="UsernameToken"");  
		httppost.setHeader("X-WSSE","UsernameToken Username=""+account+"",PasswordDigest=""+code+""");  
		httppost.addHeader("Content-type","application/json; charset=utf-8");  
		httppost.setHeader("Accept", "application/json");  
		httppost.setHeader("Connection","keep-alive");  
		httppost.setHeader("Accept-Encoding","gzip");  
		httppost.setHeader("Accept-Language", "zh-CN,en,*");  
		httppost.setHeader("User-Agent","Mozilla/5.0"); 
		//传递请求参数
		String paramJsonStr = JSON.toJSONString(param);
		if(param != null)
			httppost.setEntity(new StringEntity(paramJsonStr, Charset.forName("UTF-8")));  
		HttpResponse response = null;
		try {  
			//执行post请求
            response = httpclient.execute(httppost);  
        } catch (Exception e) {  
            e.printStackTrace();  
        } 
        return response;
    }  

10 返回接口



11 最后通过Map、List和Json工具对返回来的字面量进行各种处理。

	/**
	 * 将从接口返回的JSON数据转换为实体集合等待插入数据表
	 * 实体 IgmAccessControlChannelModel --> IGM_ACCESSCONTROL_CHANNEL
	 * 	   IgmStationDoorModel --> IGM_STATION_DOOR
	 */
	@SuppressWarnings({ "unchecked", "rawtypes" })
	private Map<String,Object> getDeviceEntityList(String data){
		Map<String,Object> totalMap = new HashMap<>();
		//把以下三个结果放到totalMap里返回
		List<IgmAccessControlChannelModel> accessControlList = new ArrayList<>();
		List<IgmStationDoorModel> doorList = new ArrayList<>();
		List<String> deviceIds = new ArrayList<>();
		
		IgmAccessControlChannelModel accessControlModel = null;
		IgmStationDoorModel stationDoorModel = null;
		
		Map map = JSON.parseObject(data, Map.class);
		map = (Map<String,List<Map<String,Object>>>)map;
		List<Map<String,Object>> deviceList = (List<Map<String, Object>>) map.get("Device");
		
		for(Map<String,Object> deviceMap : deviceList){
			String deviceId = (String)(deviceMap.get("DeviceID")+"");
			Object channels = deviceMap.get("Channels");
			List<Map<String,Object>> channelList = (List<Map<String,Object>>)channels;
			
			String id = ""; //用于设置igmaccessControlchannel表和igmstationDoor表的stationDoorid
			//判断该门禁设备ID在本平台是否匹配
			boolean isMatched = isDeviceIdMatched(deviceId);
			
			if(isMatched){
				for(Map<String,Object> chnnelMap : channelList){
					accessControlModel = new IgmAccessControlChannelModel();
					stationDoorModel = new IgmStationDoorModel();
					for(Map.Entry<String, Object> entry : chnnelMap.entrySet()){
						String key =  entry.getKey().trim();
						String value = "";
						if(key.equals("Channel")){
							value =(Integer)entry.getValue()+"";
						}else{
							value = (String)entry.getValue();
						}
						
						switch(key){
						case "Channel":
							accessControlModel.setCommandCode(Integer.parseInt(value));
							accessControlModel.setControlChannelName("控制通道"+value);
							stationDoorModel.setDoorCode(value);
							break;
						case "Description":
							stationDoorModel.setStationDoorName(value);
							break;
						default: break;
						}
					}
					id = UUID.randomUUID().toString();
					
					accessControlModel.setAccessControlChannelId(UUID.randomUUID().toString());
					accessControlModel.setDeviceId(deviceId);
					accessControlModel.setStationDoorId(id);
					
					stationDoorModel.setStationDoorId(id);
					stationDoorModel.setDeviceId(deviceId);
					stationDoorModel.setRemark("指纹门禁");
					
					accessControlList.add(accessControlModel);
					doorList.add(stationDoorModel);
				}
				deviceIds.add(deviceId);
			}else{
				//deviceId不匹配的跳过
			}
		}





版权声明:本文来源CSDN,感谢博主原创文章,遵循 CC 4.0 by-sa 版权协议,转载请附上原文出处链接和本声明。
原文链接:https://blog.csdn.net/greatkendy123/article/details/52818466
站方申明:本站部分内容来自社区用户分享,若涉及侵权,请联系站方删除。
  • 发表于 2020-03-08 16:37:37
  • 阅读 ( 769 )
  • 分类:

0 条评论

请先 登录 后评论

官方社群

GO教程

猜你喜欢