前言
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。下面是具体代码示例
package ink.mmao.mmaoink_wx.utils;
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.entity.StringEntity;
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;
import javax.net.ssl.SSLContext;
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;
/**
* @author laomao
* @version 1.0
* @description: TODO
* @date 2020/9/26 上午8:58
*/
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;
}
/**
* HTTP Post 重载 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, String params, String charset)
throws IOException {
if (StringUtils.isBlank(url)) {
return null;
}
HttpPost httpPost = new HttpPost(url);
if (params != null && params instanceof String) {
httpPost.setEntity(new StringEntity(params,"UTF-8"));
}
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();
}
}
原文链接：https://blog.csdn.net/qq_28165595/article/details/78885775