HttpClient封装工具类
在日常开发中，我们经常需要通过http协议去调用网络内容，虽然java自身提供了net相关工具包，但是其灵活性和功能总是不如人意，于是有人专门搞出一个httpclient类库，来方便进行Http操作。对于httpcore的源码研究，我们可能并没有达到这种层次，在日常开发中也只是需要的时候，在网上百度一下，然后进行调用就行。在项目中对于这个工具类库也许没有进行很好的封装。在哪里使用就写在哪些，很多地方用到，就在多个地方写。反正是复制粘贴，很方便，但是这样就会导致项目中代码冗余。所以这里简单的对httpcient的简单操作封装成一个工具类，统一放在项目的工具包中，在使用的时候直接从工具包中调用，不需要写冗余代码。
httpclient操作实例
首先需要在注意的一点是，这是基于httpclient4.5版本的，我们在使用的时候需要引入具体对应jar。下面是具体代码示：
import java.io.IOException; import java.security.KeyManagementException; import java.security.KeyStoreException; import java.security.NoSuchAlgorithmException; import java.security.cert.CertificateException; import java.security.cert.X509Certificate; import java.util.ArrayList; import java.util.List; import java.util.Map; import javax.net.ssl.SSLContext; import org.apache.commons.lang3.StringUtils; import org.apache.http.HttpEntity; import org.apache.http.NameValuePair; import org.apache.http.ParseException; import org.apache.http.client.config.RequestConfig; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.CloseableHttpResponse; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.conn.ssl.SSLConnectionSocketFactory; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClientBuilder; import org.apache.http.impl.client.HttpClients; import org.apache.http.message.BasicNameValuePair; import org.apache.http.ssl.SSLContextBuilder; import org.apache.http.ssl.TrustStrategy; import org.apache.http.util.EntityUtils; /** * 基于 httpclient 4.5版本的 http工具类 * * @author 47Gamer * */ public class HttpClientTool { private static final CloseableHttpClient httpClient; public static final String CHARSET = "UTF-8"; // 采用静态代码块，初始化超时时间配置，再根据配置生成默认httpClient对象 static { RequestConfig config = RequestConfig.custom().setConnectTimeout(60000).setSocketTimeout(15000).build(); httpClient = HttpClientBuilder.create().setDefaultRequestConfig(config).build(); } public static String doGet(String url, Map<String, String> params) { return doGet(url, params, CHARSET); } public static String doGetSSL(String url, Map<String, String> params) { return doGetSSL(url, params, CHARSET); } public static String doPost(String url, Map<String, String> params) throws IOException { return doPost(url, params, CHARSET); } /** * HTTP Get 获取内容 * @param url 请求的url地址 ?之前的地址 * @param params 请求的参数 * @param charset 编码格式 * @return 页面内容 */ public static String doGet(String url, Map<String, String> params, String charset) { if (StringUtils.isBlank(url)) { return null; } try { if (params != null && !params.isEmpty()) { List<NameValuePair> pairs = new ArrayList<NameValuePair>(params.size()); for (Map.Entry<String, String> entry : params.entrySet()) { String value = entry.getValue(); if (value != null) { pairs.add(new BasicNameValuePair(entry.getKey(), value)); } } // 将请求参数和url进行拼接 url += "?" + EntityUtils.toString(new UrlEncodedFormEntity(pairs, charset)); } HttpGet httpGet = new HttpGet(url); CloseableHttpResponse response = httpClient.execute(httpGet); int statusCode = response.getStatusLine().getStatusCode(); if (statusCode != 200) { httpGet.abort(); throw new RuntimeException("HttpClient,error status code :" + statusCode); } HttpEntity entity = response.getEntity(); String result = null; if (entity != null) { result = EntityUtils.toString(entity, "utf-8"); } EntityUtils.consume(entity); response.close(); return result; } catch (Exception e) { e.printStackTrace(); } return null; } /** * HTTP Post 获取内容 * @param url 请求的url地址 ?之前的地址 * @param params 请求的参数 * @param charset 编码格式 * @return 页面内容 * @throws IOException */ public static String doPost(String url, Map<String, String> params, String charset) throws IOException { if (StringUtils.isBlank(url)) { return null; } List<NameValuePair> pairs = null; if (params != null && !params.isEmpty()) { pairs = new ArrayList<NameValuePair>(params.size()); for (Map.Entry<String, String> entry : params.entrySet()) { String value = entry.getValue(); if (value != null) { pairs.add(new BasicNameValuePair(entry.getKey(), value)); } } } HttpPost httpPost = new HttpPost(url); if (pairs != null && pairs.size() > 0) { httpPost.setEntity(new UrlEncodedFormEntity(pairs, CHARSET)); } CloseableHttpResponse response = null; try { response = httpClient.execute(httpPost); int statusCode = response.getStatusLine().getStatusCode(); if (statusCode != 200) { httpPost.abort(); throw new RuntimeException("HttpClient,error status code :" + statusCode); } HttpEntity entity = response.getEntity(); String result = null; if (entity != null) { result = EntityUtils.toString(entity, "utf-8"); } EntityUtils.consume(entity); return result; } catch (ParseException e) { e.printStackTrace(); } finally { if (response != null) response.close(); } return null; } /** * HTTPS Get 获取内容 * @param url 请求的url地址 ?之前的地址 * @param params 请求的参数 * @param charset 编码格式 * @return 页面内容 */ public static String doGetSSL(String url, Map<String, String> params, String charset) { if (StringUtils.isBlank(url)) { return null; } try { if (params != null && !params.isEmpty()) { List<NameValuePair> pairs = new ArrayList<NameValuePair>(params.size()); for (Map.Entry<String, String> entry : params.entrySet()) { String value = entry.getValue(); if (value != null) { pairs.add(new BasicNameValuePair(entry.getKey(), value)); } } url += "?" + EntityUtils.toString(new UrlEncodedFormEntity(pairs, charset)); } HttpGet httpGet = new HttpGet(url); // https 注意这里获取https内容，使用了忽略证书的方式，当然还有其他的方式来获取https内容 CloseableHttpClient httpsClient = HttpClientTool.createSSLClientDefault(); CloseableHttpResponse response = httpsClient.execute(httpGet); int statusCode = response.getStatusLine().getStatusCode(); if (statusCode != 200) { httpGet.abort(); throw new RuntimeException("HttpClient,error status code :" + statusCode); } HttpEntity entity = response.getEntity(); String result = null; if (entity != null) { result = EntityUtils.toString(entity, "utf-8"); } EntityUtils.consume(entity); response.close(); return result; } catch (Exception e) { e.printStackTrace(); } return null; } /** * 这里创建了忽略整数验证的CloseableHttpClient对象 * @return */ public static CloseableHttpClient createSSLClientDefault() { try { SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(null, new TrustStrategy() { // 信任所有 public boolean isTrusted(X509Certificate[] chain, String authType) throws CertificateException { return true; } }).build(); SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslContext); return HttpClients.custom().setSSLSocketFactory(sslsf).build(); } catch (KeyManagementException e) { e.printStackTrace(); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } catch (KeyStoreException e) { e.printStackTrace(); } return HttpClients.createDefault(); } }
总结
上面就是对于httpclient的简单工具类，对于httpclient，还有很多知识点需要仔细研究，后面再和大家一起来总结学习！
