【Java】Java网络编程封装方式例子

一、再Java系统开发中，网络编程是绕不开的技能之一，也就是发送请求和接收请求的处理。最常用的就是我们经常说的post请求，get请求这些东西。系统在调用别的系统的接口时无一不是通过网络。各种do get  do post。

再spring框架中我们常用的fegin就是一种网络编程的封装。

有时我们也可以自己封装自己的网络请求工具类

例如：

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.InetAddress;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.net.UnknownHostException;
import java.util.Map;

import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
import org.springframework.util.StringUtils;
import org.springframework.web.client.RestTemplate;

import cn.hutool.core.collection.CollectionUtil;
import lombok.extern.slf4j.Slf4j;

/**
 * http请求
 */
@Slf4j
public class HttpUtils {
    
    public static String doGet(String url) {
        return doGet(url, null);
    }

    public static String doGet(String url, Map<String, String> map) {

        String resultString = "";
        RestTemplate client = new RestTemplate();
        HttpHeaders headers = new HttpHeaders();
        // 参数设置
        MultiValueMap<String, String> params = new LinkedMultiValueMap<String, String>();
        if (CollectionUtil.isNotEmpty(map)) {
            for (String key : map.keySet()) {
                params.add(key, map.get(key));
            }
        }

        try {

            // 设置表单提交
            headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
            HttpEntity<MultiValueMap<String, String>> requestEntity = new HttpEntity<MultiValueMap<String, String>>(
                    params, headers);
            // 执行HTTP请求
            ResponseEntity<String> response = client.exchange(url, HttpMethod.GET, requestEntity, String.class);
            resultString = response.getBody();
        } catch (Exception e) {
            log.error(e.getMessage(), e);
        }

        return resultString;

    }

    public static String doPost(String url) {
        return doPost(url, null);
    }

    public static String doPost(String url, Map<String, String> map) {

        String resultString = "";
        ResponseEntity<String> response = null;
        RestTemplate client = new RestTemplate();
        HttpHeaders headers = new HttpHeaders();
        // 参数设置
        MultiValueMap<String, String> params = new LinkedMultiValueMap<String, String>();
        if (CollectionUtil.isNotEmpty(map)) {
            for (String key : map.keySet()) {
                params.add(key, map.get(key));
            }
        }

        try {

            // 请勿轻易改变此提交方式，大部分的情况下，提交方式都是表单提交
            headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
            HttpEntity<MultiValueMap<String, String>> requestEntity = new HttpEntity<MultiValueMap<String, String>>(
                    params, headers);
            // 执行HTTP请求
            response = client.exchange(url, HttpMethod.POST, requestEntity, String.class);
            resultString = response.getBody();
        } catch (Exception e) {
            log.error(e.getMessage(), e);
        }
        return resultString;

    }

    public static String doPostJson(String url, String json) {

        String resultString = "";
        RestTemplate client = new RestTemplate();
        ResponseEntity<String> response = null;
        // 提交方式设置
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);
        HttpEntity<String> requestEntity = new HttpEntity<String>(json, headers);
        try {
            // 执行HTTP请求
            response = client.exchange(url, HttpMethod.POST, requestEntity, String.class);
            resultString = response.getBody();

        } catch (Exception e) {
            log.error(e.getMessage(), e);
        } finally {
            try {

            } catch (Exception e) {
                // TODO Auto-generated catch block
                log.error(e.getMessage(), e);
            }
        }
        return resultString;

    }
    
    
    /**
     * 创建http请求头
     * @param url
     * @return
     * @throws Exception
     */
    public static URLConnection FactoryCreatURLConnection(String url) throws Exception {
        URL realUrl;
        URLConnection conn = null;
        try {
            // 打开和URL之间的连接
            realUrl = new URL(url);
            conn = realUrl.openConnection();
            conn.setRequestProperty("accept", "text/plain;charset=utf-8");
            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded; charset=utf-8");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
        } catch (MalformedURLException e1) {
            e1.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return conn;
    }

        if (StringUtils.isEmpty(url)) {
            return false;
        }
        HttpURLConnection connection = null;
        try {
            connection = (HttpURLConnection) new URL(url).openConnection();
            // 设置超时时间
            connection.setConnectTimeout(timeout);
            connection.setReadTimeout(timeout);
            if (connection.getResponseCode() >= HttpURLConnection.HTTP_OK
                    && connection.getResponseCode() <= HttpURLConnection.HTTP_VERSION) {
                return true;
            }
        } catch (Exception e) {
            log.error(" HttpURLConnection exception happend!");
            return false;
        } finally {
            if (connection != null) {
                connection.disconnect();
            }
        }
        return false;
    }

    /**
     * 判断ip是否能ping通
     */
    public static boolean checkIp(String ipAddr) {
        try {
            boolean status = false;
            if (!StringUtils.isEmpty(ipAddr)) {
                int timeOut = 3000; // 超时 3秒
                status = InetAddress.getByName(ipAddr).isReachable(timeOut);
                return status;
            }
            return status;
        } catch (UnknownHostException e) {
            e.printStackTrace();
            return false;
        } catch (IOException e) {
            e.printStackTrace();
            return false;
        }
    }

}

package cn.ctg.common.util;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.InetAddress;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.net.UnknownHostException;
import java.util.Map;

import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
import org.springframework.util.StringUtils;
import org.springframework.web.client.RestTemplate;

import cn.hutool.core.collection.CollectionUtil;
import lombok.extern.slf4j.Slf4j;

/**
 * http请求
 */
@Slf4j
public class HttpUtils {
	
	public static String doGet(String url) {
		return doGet(url, null);
	}

	public static String doGet(String url, Map<String, String> map) {

		String resultString = "";
		RestTemplate client = new RestTemplate();
		HttpHeaders headers = new HttpHeaders();
		// 参数设置
		MultiValueMap<String, String> params = new LinkedMultiValueMap<String, String>();
		if (CollectionUtil.isNotEmpty(map)) {
			for (String key : map.keySet()) {
				params.add(key, map.get(key));
			}
		}

		try {

			// 设置表单提交
			headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
			HttpEntity<MultiValueMap<String, String>> requestEntity = new HttpEntity<MultiValueMap<String, String>>(
					params, headers);
			// 执行HTTP请求
			ResponseEntity<String> response = client.exchange(url, HttpMethod.GET, requestEntity, String.class);
			resultString = response.getBody();
		} catch (Exception e) {
			log.error(e.getMessage(), e);
		}

		return resultString;

	}

	public static String doPost(String url) {
		return doPost(url, null);
	}

	public static String doPost(String url, Map<String, String> map) {

		String resultString = "";
		ResponseEntity<String> response = null;
		RestTemplate client = new RestTemplate();
		HttpHeaders headers = new HttpHeaders();
		// 参数设置
		MultiValueMap<String, String> params = new LinkedMultiValueMap<String, String>();
		if (CollectionUtil.isNotEmpty(map)) {
			for (String key : map.keySet()) {
				params.add(key, map.get(key));
			}
		}

		try {

			// 请勿轻易改变此提交方式，大部分的情况下，提交方式都是表单提交
			headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
			HttpEntity<MultiValueMap<String, String>> requestEntity = new HttpEntity<MultiValueMap<String, String>>(
					params, headers);
			// 执行HTTP请求
			response = client.exchange(url, HttpMethod.POST, requestEntity, String.class);
			resultString = response.getBody();
		} catch (Exception e) {
			log.error(e.getMessage(), e);
		}
		return resultString;

	}

	public static String doPostJson(String url, String json) {

		String resultString = "";
		RestTemplate client = new RestTemplate();
		ResponseEntity<String> response = null;
		// 提交方式设置
		HttpHeaders headers = new HttpHeaders();
		headers.setContentType(MediaType.APPLICATION_JSON);
		HttpEntity<String> requestEntity = new HttpEntity<String>(json, headers);
		try {
			// 执行HTTP请求
			response = client.exchange(url, HttpMethod.POST, requestEntity, String.class);
			resultString = response.getBody();

		} catch (Exception e) {
			log.error(e.getMessage(), e);
		} finally {
			try {

			} catch (Exception e) {
				// TODO Auto-generated catch block
				log.error(e.getMessage(), e);
			}
		}
		return resultString;

	}
	
	
	/**
	 * 创建http请求头
	 * @param url
	 * @return
	 * @throws Exception
	 */
	public static URLConnection FactoryCreatURLConnection(String url) throws Exception {
		URL realUrl;
		URLConnection conn = null;
		try {
			// 打开和URL之间的连接
			realUrl = new URL(url);
			conn = realUrl.openConnection();
			conn.setRequestProperty("accept", "text/plain;charset=utf-8");
			conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded; charset=utf-8");
			conn.setRequestProperty("connection", "Keep-Alive");
			conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
		} catch (MalformedURLException e1) {
			e1.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return conn;
	}

	/**
	 * 判断连接是否可用
	 * 
	 * @param url http请求地址
	 * @return
	 */
	public static boolean isRearchUrl(String url) {
		return isRearchUrl(url, 3000);
	}

	/**
	 * 判断连接是否可用
	 * 
	 * @param url http请求地址
	 * @return
	 */
	public static boolean isRearchUrl(String url, int timeout) {

		if (StringUtils.isEmpty(url)) {
			return false;
		}
		HttpURLConnection connection = null;
		try {
			connection = (HttpURLConnection) new URL(url).openConnection();
			// 设置超时时间
			connection.setConnectTimeout(timeout);
			connection.setReadTimeout(timeout);
			if (connection.getResponseCode() >= HttpURLConnection.HTTP_OK
					&& connection.getResponseCode() <= HttpURLConnection.HTTP_VERSION) {
				return true;
			}
		} catch (Exception e) {
			log.error(" HttpURLConnection exception happend!");
			return false;
		} finally {
			if (connection != null) {
				connection.disconnect();
			}
		}
		return false;
	}

	/**
	 * 判断ip是否能ping通
	 */
	public static boolean checkIp(String ipAddr) {
		try {
			boolean status = false;
			if (!StringUtils.isEmpty(ipAddr)) {
				int timeOut = 3000; // 超时 3秒
				status = InetAddress.getByName(ipAddr).isReachable(timeOut);
				return status;
			}
			return status;
		} catch (UnknownHostException e) {
			e.printStackTrace();
			return false;
		} catch (IOException e) {
			e.printStackTrace();
			return false;
		}
	}


}