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：
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1. <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
2. xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
3. <modelVersion>4.0.0</modelVersion>
4. <groupId>ws</groupId>
5. <artifactId>restful</artifactId>
6. <packaging>war</packaging>
7. <version>0.0.1-SNAPSHOT</version>
8. <name>restful-server</name>
9. <url>http://maven.apache.org</url>
10. <properties>
11. <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
12. <jersey.version>2.6</jersey.version>
13. <jersey-spring.version>2.23.1</jersey-spring.version>
14. <spring.version>4.2.7.RELEASE</spring.version>
15. <servlet-api-version>3.1.0</servlet-api-version>
16. <logback.version>1.1.1</logback.version>
17. <jcloverslf4j.version>1.7.6</jcloverslf4j.version>
18. </properties>
19. <dependencies>
20. <dependency>
21. <groupId>junit</groupId>
22. <artifactId>junit</artifactId>
23. <version>3.8.1</version>
24. <scope>test</scope>
25. </dependency>
26.
27. <dependency>
28. <groupId>org.glassfish.jersey.ext</groupId>
29. <artifactId>jersey-spring3</artifactId>
30. <version>${jersey-spring.version}</version>
31. <exclusions>
32. <exclusion>
33. <groupId>org.springframework</groupId>
34. <artifactId>spring-core</artifactId>
35. </exclusion>
36. <exclusion>
37. <groupId>org.springframework</groupId>
38. <artifactId>spring-web</artifactId>
39. </exclusion>
40. <exclusion>
41. <groupId>org.springframework</groupId>
42. <artifactId>spring-beans</artifactId>
43. </exclusion>
44. </exclusions>
45. </dependency>
46.
47. <dependency>
48. <groupId>org.glassfish.jersey.containers</groupId>
49. <artifactId>jersey-container-servlet</artifactId>
50. <version>${jersey-spring.version}</version>
51. </dependency>
52. <dependency>
53. <groupId>org.glassfish.jersey.containers</groupId>
54. <artifactId>jersey-container-servlet-core</artifactId>
55. <version>${jersey-spring.version}</version>
56. </dependency>
57.
58. <dependency>
59. <groupId>org.glassfish.jersey.media</groupId>
60. <artifactId>jersey-media-json-jackson</artifactId>
61. <version>${jersey.version}</version>
62. </dependency>
63. <dependency>
64. <groupId>org.glassfish.jersey.media</groupId>
65. <artifactId>jersey-media-multipart</artifactId>
66. <version>${jersey.version}</version>
67. </dependency>
68. <dependency>
69. <groupId>org.glassfish.jersey.ext</groupId>
70. <artifactId>jersey-entity-filtering</artifactId>
71. <version>${jersey.version}</version>
72. </dependency>
73.
74. <!-- Spring4.2 dependencies -->
75. <dependency>
76. <groupId>org.springframework</groupId>
77. <artifactId>spring-core</artifactId>
78. <version>${spring.version}</version>
79. </dependency>
80.
81. <dependency>
82. <groupId>org.springframework</groupId>
83. <artifactId>spring-context</artifactId>
84. <version>${spring.version}</version>
85. </dependency>
86.
87. <dependency>
88. <groupId>org.springframework</groupId>
89. <artifactId>spring-web</artifactId>
90. <version>${spring.version}</version>
91. </dependency>
92.
93. <dependency>
94. <groupId>org.springframework</groupId>
95. <artifactId>spring-jdbc</artifactId>
96. <version>${spring.version}</version>
97. </dependency>
98.
99. <dependency>
100. <groupId>org.springframework</groupId>
101. <artifactId>spring-tx</artifactId>
102. <version>${spring.version}</version>
103. </dependency>
104. <dependency>
105. <groupId>org.springframework</groupId>
106. <artifactId>spring-test</artifactId>
107. <version>${spring.version}</version>
108. <scope>test</scope>
109. </dependency>
110.
111. <dependency>
112. <groupId>javax.servlet</groupId>
113. <artifactId>javax.servlet-api</artifactId>
114. <version>${servlet-api-version}</version>
115. <scope>provided</scope>
116. </dependency>
117.
118. <!-- Logback dependencies -->
119. <dependency>
120. <groupId>ch.qos.logback</groupId>
121. <artifactId>logback-classic</artifactId>
122. <version>${logback.version}</version>
123. </dependency>
124. <dependency>
125. <groupId>org.slf4j</groupId>
126. <artifactId>jcl-over-slf4j</artifactId>
127. <version>${jcloverslf4j.version}</version>
128. </dependency>
129.
130. </dependencies>
131. <build>
132. <finalName>restful</finalName>
133. </build>
134. </project>
4 applicationContext.xml内容如下：
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1. <?xml version="1.0" encoding="UTF-8"?>
2. <beans xmlns="http://www.springframework.org/schema/beans"
3. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4. xmlns:context="http://www.springframework.org/schema/context"
5. xmlns:tx="http://www.springframework.org/schema/tx"
6. xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
7. >
8.
9. <context:component-scan base-package="com.kendy.*"></context:component-scan>
10. </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）
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1. <?xml version="1.0" encoding="UTF-8"?>
2. <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">
3. <display-name></display-name>
4. <context-param>
5. <param-name>contextConfigLocation</param-name>
6. <param-value>classpath:applicationContext.xml</param-value>
7. </context-param>
8. <listener>
9. <listener-class>
10. org.springframework.web.context.ContextLoaderListener
11. </listener-class>
12. </listener>
13. <servlet>
14. <servlet-name>jersey-serlvet</servlet-name>
15. <servlet-class>
16. org.glassfish.jersey.servlet.ServletContainer
17. </servlet-class>
18. <init-param>
19. <param-name>javax.ws.rs.Application</param-name>
20. <param-value>com.kendy.filter.RestJaxRsApplication</param-value>
21. </init-param>
22. <load-on-startup>1</load-on-startup>
23. </servlet>
24. <servlet-mapping>
25. <servlet-name>jersey-serlvet</servlet-name>
26. <url-pattern>/*</url-pattern>
27. </servlet-mapping>
28. </web-app>6 拦截器如下：
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1. import java.io.IOException;
2. import java.io.InputStream;
3. import java.util.List;
4. import java.util.Map.Entry;
5.
6. import javax.ws.rs.WebApplicationException;
7. import javax.ws.rs.container.ContainerRequestContext;
8. import javax.ws.rs.container.ContainerRequestFilter;
9. import javax.ws.rs.core.MultivaluedMap;
10. import javax.ws.rs.core.Response.Status;
11. import javax.ws.rs.ext.Provider;
12.
13. /**
14. * 拦截请求
15. */
16. @Provider
17. public class MyFilter implements ContainerRequestFilter {
18.
19. @Override
20. public void filter(ContainerRequestContext context) throws IOException {
21.
22. //打印出所有请求头
23. MultivaluedMap<String, String> map = context.getHeaders();
24. for(Entry<String, List<String>> entry : map.entrySet()){
25. String key = entry.getKey();
26. List<String> valueList = entry.getValue();
27. String values = valueList.toString();
28. ":"+values.substring(1,values.length()-1));
29. }
7 注册Jersey容器所要管理的类
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1. import org.codehaus.jackson.jaxrs.JacksonJsonProvider;
2. import org.glassfish.jersey.server.ResourceConfig;
3.
4. import com.kendy.restful.AccountManager;
5. import com.kendy.restful.AuthorityManager;
6. import com.kendy.restful.CardManager;
7. import com.kendy.restful.DeviceManager;
8. import com.kendy.restful.UserResource;
9.
10. /**
11. * ${DESCRIPTION}
12. */
13. public class RestJaxRsApplication extends ResourceConfig {
14.
15. /**
16. * Register JAX-RS application components.
17. */
18. public RestJaxRsApplication() {
19.
20. //服务类所在的包路径
21. "com.kendy.*");
22.
23. // register application resources
24. this.register(YouClass.class);
25.
26. // register filters
27. this.register(MyFilter.class);
28. //this.register(RequestContextFilter.class);
29.
30. class);
31. //register(MultiPartFeature.class);
32. }
33. }8 接口定义（Restful风格）
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1. package com.kendy.restful;
2.
3. import java.text.SimpleDateFormat;
4. import java.util.ArrayList;
5. import java.util.Date;
6. import java.util.HashMap;
7. import java.util.List;
8. import java.util.Map;
9.
10. import javax.ws.rs.Consumes;
11. import javax.ws.rs.POST;
12. import javax.ws.rs.Path;
13. import javax.ws.rs.Produces;
14. import javax.ws.rs.core.MediaType;
15.
16. import org.springframework.stereotype.Component;
17.
18. @Component
19. @Path("/CardManager")
20. public class CardManager {
21.
22. private SimpleDateFormat sdf =new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
23.
24. @POST
25. @Path("size")
26. @Consumes(MediaType.APPLICATION_JSON)
27. @Produces(MediaType.APPLICATION_JSON)
28. public Map<String,Object> size(){
29. new HashMap<>();
30. //do something here
31. "Size", 1024);
32. return map;
33. }
34.
35. @POST
36. @Path("getDetail")
37. @Consumes(MediaType.APPLICATION_JSON)
38. @Produces(MediaType.APPLICATION_JSON)
39. public Map<String,List<Map<String,Object>>> getDetail(){
40. new HashMap<>();
41. //do something here
42. new ArrayList<>();
43. new HashMap<>();
44. "UUID", 10086);
45. "CardID", 10081);
46. "StartTime", sdf.format(new Date()));
47. "EndTime", sdf.format(new Date()));
48. list.add(subMap);
49. "Card", list);
50.
51. return map;
52. }
53. }
9 调用接口，有多种方式，本文用HttpClient
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1. /**
2. * 发送 post请求webService接口
3. * @param url 访问的接口地址
4. * @param account 用户名
5. * @param code 密码
6. * @param param 查询参数
7. * @return HttpResponse 该类包含请求方法的态码及返回的数据
8. */
9. public static HttpResponse post(String url,String account,String code,Map<String,Object> param) {
10. //创建HttpClient实例及Post方法
11. new DefaultHttpClient();
12. new HttpPost(url);
13. //对用户密码MD5加密
14. code = getMD5(code);
15. //添加相关请求头，依情况而定
16. "Authorization","WSSE profile=\"UsernameToken\"");
17. "X-WSSE","UsernameToken Username=\""+account+"\",PasswordDigest=\""+code+"\"");
18. "Content-type","application/json; charset=utf-8");
19. "Accept", "application/json");
20. "Connection","keep-alive");
21. "Accept-Encoding","gzip");
22. "Accept-Language", "zh-CN,en,*");
23. "User-Agent","Mozilla/5.0");
24. //传递请求参数
25. String paramJsonStr = JSON.toJSONString(param);
26. if(param != null)
27. new StringEntity(paramJsonStr, Charset.forName("UTF-8")));
28. null;
29. try {
30. //执行post请求
31. response = httpclient.execute(httppost);
32. catch (Exception e) {
33. e.printStackTrace();
34. }
35. return response;
36. }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。
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1. /**
2. * 将从接口返回的JSON数据转换为实体集合等待插入数据表
3. * 实体 IgmAccessControlChannelModel --> IGM_ACCESSCONTROL_CHANNEL
4. * IgmStationDoorModel --> IGM_STATION_DOOR
5. */
6. @SuppressWarnings({ "unchecked", "rawtypes" })
7. private Map<String,Object> getDeviceEntityList(String data){
8. new HashMap<>();
9. //把以下三个结果放到totalMap里返回
10. new ArrayList<>();
11. new ArrayList<>();
12. new ArrayList<>();
13.
14. null;
15. null;
16.
17. class);
18. map = (Map<String,List<Map<String,Object>>>)map;
19. "Device");
20.
21. for(Map<String,Object> deviceMap : deviceList){
22. "DeviceID")+"");
23. "Channels");
24. List<Map<String,Object>> channelList = (List<Map<String,Object>>)channels;
25.
26. ""; //用于设置igmaccessControlchannel表和igmstationDoor表的stationDoorid
27. //判断该门禁设备ID在本平台是否匹配
28. boolean isMatched = isDeviceIdMatched(deviceId);
29.
30. if(isMatched){
31. for(Map<String,Object> chnnelMap : channelList){
32. new IgmAccessControlChannelModel();
33. new IgmStationDoorModel();
34. for(Map.Entry<String, Object> entry : chnnelMap.entrySet()){
35. String key = entry.getKey().trim();
36. "";
37. if(key.equals("Channel")){
38. "";
39. else{
40. value = (String)entry.getValue();
41. }
42.
43. switch(key){
44. case "Channel":
45. accessControlModel.setCommandCode(Integer.parseInt(value));
46. "控制通道"+value);
47. stationDoorModel.setDoorCode(value);
48. break;
49. case "Description":
50. stationDoorModel.setStationDoorName(value);
51. break;
52. default: break;
53. }
54. }
55. id = UUID.randomUUID().toString();
56.
57. accessControlModel.setAccessControlChannelId(UUID.randomUUID().toString());
58. accessControlModel.setDeviceId(deviceId);
59. accessControlModel.setStationDoorId(id);
60.
61. stationDoorModel.setStationDoorId(id);
62. stationDoorModel.setDeviceId(deviceId);
63. "指纹门禁");
64.
65. accessControlList.add(accessControlModel);
66. doorList.add(stationDoorModel);
67. }
68. deviceIds.add(deviceId);
69. else{
70. //deviceId不匹配的跳过
71. }
72. }本文章为转载内容，我们尊重原作者对文章享有的著作权。如有内容错误或侵权问题，欢迎原作者联系我们进行内容更正或删除文章。
