Java网络请求（get/post）工具类实现的两种方式

本文主要是介绍Java网络请求（get/post）工具类实现的两种方式，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

基于HttpClient实现

基本思路都是一样的，通过HttpResponse实例获得请求返回的数据体，具体数据封装在HttpEntity对象中。

/*** Created by Song on 2016/11/28.* 基于HttpClient提供网络访问工具*/
public final class NetUtil {public static CloseableHttpClient httpClient = HttpClientBuilder.create().build();/*** get请求获取String类型数据* @param url 请求链接* @return*/public static String get(String url){StringBuffer sb = new StringBuffer();HttpGet httpGet = new HttpGet(url);try {HttpResponse response = httpClient.execute(httpGet);           //1HttpEntity entity = response.getEntity();InputStreamReader reader = new InputStreamReader(entity.getContent(),"utf-8");char [] charbufer;while (0<reader.read(charbufer=new char[10])){sb.append(charbufer);}}catch (IOException e){//1e.printStackTrace();}finally {httpGet.releaseConnection();}return sb.toString();}/*** post方式请求数据* @param url 请求链接* @param data post数据体* @return*/public static String post(String url, Map<String,String> data){StringBuffer sb = new StringBuffer();HttpPost httpPost = new HttpPost(url);List<NameValuePair> valuePairs = new ArrayList<NameValuePair>();if(null != data) {for (String key : data.keySet()) {valuePairs.add(new BasicNameValuePair(key, data.get(key)));}}try {httpPost.setEntity(new UrlEncodedFormEntity(valuePairs));HttpResponse response = httpClient.execute(httpPost);HttpEntity httpEntity = response.getEntity();BufferedInputStream bis = new BufferedInputStream(httpEntity.getContent());byte [] buffer;while (0<bis.read(buffer=new byte[128])){sb.append(new String(buffer,"utf-8"));}}catch (UnsupportedEncodingException e){//数据格式有误e.printStackTrace();}catch (IOException e){//请求出错e.printStackTrace();}finally {httpPost.releaseConnection();}return sb.toString();}}

基于Java net工具包
基本思路是通过HttpURLConnection 对象设置网络连接参数，建立网络连接，与获得请求返回的网络数据输入流，并从中获得数据。对于JSON格式的数据体，可进一步封装为JSONObject。

import net.sf.json.JSONObject;import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;/*** 实现GET以及POST请求* mail:1147649695@qq.com*/
public class UrlReqUtil {public static JSONObject get(String url){HttpURLConnection http = null;InputStream is = null;try {URL urlGet = new URL(url);http = (HttpURLConnection) urlGet.openConnection();http.setRequestMethod("GET");http.setRequestProperty("Content-Type","application/x-www-form-urlencoded");http.setDoOutput(true);http.setDoInput(true);System.setProperty("sun.net.client.defaultConnectTimeout", "30000");System.setProperty("sun.net.client.defaultReadTimeout", "30000");http.connect();is =http.getInputStream();int size =is.available();byte[] jsonBytes =new byte[size];is.read(jsonBytes);String message=new String(jsonBytes,"UTF-8");return JSONObject.fromObject(message);} catch (Exception e) {return null;}finally {if(null != http) http.disconnect();try {if (null != is) is.close();}catch (IOException e){e.printStackTrace();}}}public static String post(String url,String data){HttpURLConnection http = null;PrintWriter out = null;BufferedReader reader = null;try {//创建连接URL urlPost = new URL(url);http = (HttpURLConnection) urlPost.openConnection();http.setDoOutput(true);http.setDoInput(true);http.setRequestMethod("POST");http.setUseCaches(false);http.setInstanceFollowRedirects(true);http.setRequestProperty("Content-Type","application/x-www-form-urlencoded");http.connect();//POST请求OutputStreamWriter outWriter = new OutputStreamWriter(http.getOutputStream(), "utf-8");out = new PrintWriter(outWriter);out.print(data);out.flush();out.close();out = null;//读取响应reader = new BufferedReader(new InputStreamReader(http.getInputStream()));String lines;StringBuffer sb = new StringBuffer("");while ((lines = reader.readLine()) != null) {lines = new String(lines.getBytes(), "utf-8");sb.append(lines);}reader.close();reader = null;System.out.println(sb.toString());return sb.toString();} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();return null;}finally {if(null != http) http.disconnect();if(null != out) out.close();try{if(null != reader) reader.close();}catch (IOException e){e.printStackTrace();}}}
}