httpcore/httpclient简单实例

时间 2021-07-13 标签 java小程序 httpcore httpclient

项目摘要：

项目具体实施：

httpcore实例

新建一个maven项目，引入如下jar包：

<groupId>org.apache.httpcomponents</groupId>

<artifactId>httpcore</artifactId>

</dependency>

<!-- <dependency>

<groupId>org.apache.httpcomponents</groupId>

<artifactId>httpcore-nio</artifactId>

</dependency> -->

</dependency>

</dependency>

进入http://hc.apache.org/httpcomponents-core-4.4.x/examples.html网站，选择Synchronous HTTP file server ，将其代码复制进自己新建的一个类，比如该项目里的Application.java,修改代码如下：

package com;

import java.io.IOException;

import java.util.concurrent.TimeUnit;

import org.apache.http.ExceptionLogger;

import org.apache.http.config.SocketConfig;

import org.apache.http.impl.bootstrap.HttpServer;

import org.apache.http.impl.bootstrap.ServerBootstrap;

import com.handle.HttpAdminHandler;

import com.handle.HttpUserHandler;

/**

* 实例：http://hc.apache.org/httpcomponents-core-4.4.x/examples.html

public class Application {

public static void main(final String[] args) throws Exception {

try {

int port = 8080;

SocketConfig socketConfig = SocketConfig.custom()

.setSoTimeout(15000)

.setTcpNoDelay(true)

.build();

final HttpServer server = ServerBootstrap.bootstrap()

.setListenerPort(port) //端口号

.setServerInfo("Test/1.1") //

.setSocketConfig(socketConfig)

.setExceptionLogger(ExceptionLogger.STD_ERR)

// 注册httpHandler

//.registerHandler("/user*", new HttpUserHandler())

//.registerHandler("/admin*", new HttpAdminHandler())

.create();

server.start();

System.out.println("启动成功！");

server.awaitTermination(Long.MAX_VALUE, TimeUnit.DAYS);

Runtime.getRuntime().addShutdownHook(new Thread() {

@Override

public void run() {

server.shutdown(5, TimeUnit.SECONDS);

}

});

} catch (IOException e) {

e.printStackTrace();

} catch (InterruptedException e) {

e.printStackTrace();

}

上述代码实现了自己的两个业务类，分别是

//.registerHandler("/user*", new HttpUserHandler())

//.registerHandler("/admin*", new HttpAdminHandler())

由于这两个业务类涉及到一个实体类（Admin中未实现其业务）和一个业务类，该项目数据为模拟数据，并没有从数据库保存数据。

其中，实体类User.java为：

package com.entity;

import java.io.Serializable;

public class User implements Serializable{

private static final long serialVersionUID = 1L;

private int id;

private String name;

private int age;

private String job;

public User() {

super();

}

public User(int id, String name, int age, String job) {

super();

this.id = id;

this.name = name;

this.age = age;

this.job = job;

}

/*********get / set************/

}

业务类UserService.java为：

接口类：

package com.service;

import java.util.List;

import com.entity.User;

public interface IUserSevice {

List<User> getAllUser();

User getUserById(int id);

void deleteUserById(int id);

void addUser(User user);

}

实现类

package com.service;

import java.util.ArrayList;

import java.util.Iterator;

import java.util.List;

import com.entity.User;

public class UserService implements IUserSevice{

private List<User> users=new ArrayList<User>();

public UserService() {

users.add(new User(1, "Tom", 12, "java开发"));

users.add(new User(2, "Jack", 12, "java测试"));

users.add(new User(3, "David", 12, "Python开发"));

users.add(new User(4, "Mary", 12, "前端开发"));

users.add(new User(5, "Smith", 12, "java大数据开发"));

}

public List<User> getAllUser() {

return users;

}

public User getUserById(int id) {

for (User user : users) {

if (user.getId()==id) {

return user;

}

return null;

}

public void deleteUserById(int id) {

Iterator<User> it=users.iterator();

while (it.hasNext()) {

User user = (User) it.next();

if (user.getId()==id) {

it.remove();

}

public void addUser(User user) {

user.getId();

users.add(user);

}

HttpUserHandler注册类：

package com.handle;

import java.io.IOException;

import java.util.List;

import java.util.Locale;

import org.apache.http.HttpException;

import org.apache.http.HttpRequest;

import org.apache.http.HttpResponse;

import org.apache.http.MethodNotSupportedException;

import org.apache.http.entity.ContentType;

import org.apache.http.entity.StringEntity;

import org.apache.http.protocol.HttpContext;

import org.apache.http.protocol.HttpRequestHandler;

import com.entity.User;

import com.service.UserService;

import net.sf.json.JSONArray;

import net.sf.json.JSONObject;

public class HttpUserHandler implements HttpRequestHandler {

public void handle(HttpRequest request, HttpResponse response, HttpContext context)

throws HttpException, IOException {

String method = request.getRequestLine().getMethod().toUpperCase(Locale.ENGLISH);

if (!method.equals("GET") && !method.equals("HEAD") && !method.equals("POST")) {

throw new MethodNotSupportedException(method + "方法不被支持");

}

String target = request.getRequestLine().getUri();

System.out.println("前端发来的请求:" + target);

UserService userService=new UserService();

if (target.equals("/user")&&method.equals("GET")) {

List<User> users = userService.getAllUser();

JSONArray json = JSONArray.fromObject(users);

StringEntity entity = new StringEntity(json.toString(), ContentType.create("application/json", "UTF-8"));

response.setEntity(entity);

}else if(target.equals("/user/1")&&method.equals("GET")){

User user = userService.getUserById(1);

JSONObject json = JSONObject.fromObject(user);

StringEntity entity = new StringEntity(json.toString(), ContentType.create("application/json", "UTF-8"));

response.setEntity(entity);

}

else {

response.setEntity(new StringEntity("没有这个服务", ContentType.create("text/html", "UTF-8")));

}

HttpAdminHandler注册类

package com.handle;

/****import****/

public class HttpAdminHandler implements HttpRequestHandler {

public void handle(HttpRequest request, HttpResponse response, HttpContext context)

throws HttpException, IOException {

System.out.println("admin:"+request.getRequestLine().getUri());

StringEntity entity = new StringEntity("管理员模块", ContentType.create("application/json", "UTF-8"));

response.setEntity(entity);

}

运行Application.java类，浏览器输入localhost:8080/user,则输出所有用户信息。上述代码其他模块还未实现，可以作为练习而完成。

httpclient实例

新建一个客户端项目，引入相关jar包：

<groupId>org.apache.httpcomponents</groupId>

<artifactId>httpclient</artifactId>

</dependency>

新建HttpClientGetDemo.java类，由于官网没有权限进入示例代码，所以参考网络资源后，编写如下代码

package com.request.demo;

import java.io.IOException;

import org.apache.http.HttpEntity;

import org.apache.http.HttpResponse;

import org.apache.http.client.ClientProtocolException;

import org.apache.http.client.ResponseHandler;

import org.apache.http.client.methods.HttpGet;

import org.apache.http.impl.client.CloseableHttpClient;

import org.apache.http.impl.client.HttpClients;

import org.apache.http.util.EntityUtils;

/**

* 参考: https://www.cnblogs.com/yoci/p/10232171.html

public class HttpClientGetDemo {

/**

* httpClient Get请求

public static void main(String[] args) throws IOException {

try (CloseableHttpClient httpclient = HttpClients.createDefault()) {

// 第一步配置 get 请求 url

HttpGet httpget = new HttpGet("http://localhost:8080/user");

// 第二步创建一个自定义的 response handler

ResponseHandler<String> responseHandler = new ResponseHandler<String>() {

@Override

public String handleResponse(HttpResponse response) throws IOException {

int status = response.getStatusLine().getStatusCode();

System.out.println("status:" + status);

if (status >= 200 && status < 300) {

HttpEntity entity = response.getEntity();

return entity != null ? EntityUtils.toString(entity) : null;

} else {

throw new ClientProtocolException("Unexpected response status: " + status);

}

};

// 第三步执行请求

String responseBody = httpclient.execute(httpget, responseHandler);

System.out.println(responseBody);

}

启动服务端，然后运行客户端，输出所有用户信息。这里有一点，服务端会出现客户断已断开的错误，暂时还没有得到解决。该示例同样很多业务是没有实现的，可以作为练习添加其他模块。

本文相关资源（文档和代码同本文一致，无需下载）：https://download.csdn.net/download/qq_25337221/12445221

参考链接：

1. apache httpcore:

http://hc.apache.org/httpcomponents-core-4.4.x/examples.html

2. httpclient实例: https://www.cnblogs.com/yoci/p/10232171.html

本内容由安康学院“雨季”原创。