Java发起HTTP请求：使用Apache的HttpClient
许多小伙伴都喜欢用apache的HttpComponts里的HttpClient来向远程发起HTTP请求
从HttpComponents官网的features说明来看，当前版本(HttpClient4.5)仅支持到HTTP/1.1。 但是HttpCore.5.1BETA将支持HTTP/2，可惜还在BETA阶段。
使用方式：
项目中引入对应的maven依赖：
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.13</version>
</dependency>参考了别人的代码,简单使用：
/**
* 使用apache的HttpClient发起HTTP以及HTTPS请求
* 注意：当前的apache的HttpClient4.5只支持到HTTP/1.1
* 参考：https://zhuanlan.zhihu.com/p/69285935
* 参考：https://blog.csdn.net/happylee6688/article/details/47148227
*/
public class HttpClientUtil {
private static PoolingHttpClientConnectionManager connMgr;
private static RequestConfig requestConfig;
private static final int MAX_TIMEOUT = 7000;
static {
// 设置连接池
connMgr = new PoolingHttpClientConnectionManager();
// 设置连接池大小
connMgr.setMaxTotal(100);
connMgr.setDefaultMaxPerRoute(connMgr.getMaxTotal());
RequestConfig.Builder configBuilder = RequestConfig.custom();
// 设置连接超时
configBuilder.setConnectTimeout(MAX_TIMEOUT);
// 设置读取超时
configBuilder.setSocketTimeout(MAX_TIMEOUT);
// 设置从连接池获取连接实例的超时
configBuilder.setConnectionRequestTimeout(MAX_TIMEOUT);
// 在提交请求之前 测试连接是否可用
configBuilder.setStaleConnectionCheckEnabled(true);
requestConfig = configBuilder.build();
}
/**
* 发送 GET 请求（HTTP），K-V形式
*
* @param url
* @param params
* @return
*/
public static String doGet(String url, Map<String, Object> params) {
String result = null;
try {
//url上拼接参数
if (params != null) {
StringBuffer param = new StringBuffer();
int i = 0;
for (String key : params.keySet()) {
param.append(i == 0 ? "?" : "&");
param.append(key).append("=").append(params.get(key));
i++;
}
url += param;
}
// 通过址默认配置创建一个httpClient实例
@Cleanup CloseableHttpClient httpClient = HttpClients.createDefault();
// 创建httpGet远程连接实例
HttpGet httpGet = new HttpGet(url);
// 设置请求头信息示例（不需要可注释掉）：鉴权
httpGet.setHeader("Authorization", "Bearer da3efcbf-0845-4fe3-8aba-ee040be542c0");
// 设置配置请求参数
/*RequestConfig requestConfig = RequestConfig.custom()
// 连接主机服务超时时间
.setConnectTimeout(35000)
// 请求超时时间
.setConnectionRequestTimeout(35000)
// 数据读取超时时间
.setSocketTimeout(60000)
.build();*/
// 为httpGet实例设置配置
httpGet.setConfig(requestConfig);
// 执行get请求得到返回对象
HttpResponse response = httpClient.execute(httpGet);
int statusCode = response.getStatusLine().getStatusCode();
//System.out.println("执行状态码 : " + statusCode);
// 通过返回对象获取返回数据
HttpEntity entity = response.getEntity();
// 通过EntityUtils中的toString方法将结果转换为字符串
result = EntityUtils.toString(entity);
if (response != null) {
EntityUtils.consume(response.getEntity());
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return result;
}
/**
* 发送 GET 请求（HTTP），不带输入数据
*
* @param url
* @return
*/
public static String doGet(String url) {
return doGet(url, null);
}
/**
* 发送 POST 请求（HTTP），K-V形式
*
* @param apiUrl API接口URL
* @param params 参数map
* @return
*/
public static String doPost(String url, Map<String, Object> params) {
String result = "";
try {
// 创建httpClient实例
@Cleanup CloseableHttpClient httpClient = HttpClients.createDefault();
// 创建httpPost远程连接实例
HttpPost httpPost = new HttpPost(url);
// 配置请求参数实例
/*RequestConfig requestConfig = RequestConfig.custom()
// 设置连接主机服务超时时间
.setConnectTimeout(35000)
// 设置连接请求超时时间
.setConnectionRequestTimeout(35000)
// 设置读取数据连接超时时间
.setSocketTimeout(60000)
.build();*/
// 为httpPost实例设置配置
httpPost.setConfig(requestConfig);
// 设置请求头示例（不需要可注释掉）
httpPost.setHeader("Content-Type", "application/x-www-form-urlencoded");
httpPost.setHeader("Cookie", "id=123;token=234");
// 封装post请求参数
//将传入post参数，转换为HttpClient可以接受的形式
if (params != null && params.size() > 0) {
List<NameValuePair> pairList = new ArrayList<>(params.size());
for (Map.Entry<String, Object> entry : params.entrySet()) {
NameValuePair pair = new BasicNameValuePair(entry.getKey(), entry
.getValue().toString());
pairList.add(pair);
}
// 为httpPost设置封装好的请求参数
httpPost.setEntity(new UrlEncodedFormEntity(pairList, StandardCharsets.UTF_8));
}
// httpClient对象执行post请求,并返回响应参数对象
HttpResponse httpResponse = httpClient.execute(httpPost);
// 从响应对象中获取响应内容
HttpEntity entity = httpResponse.getEntity();
if (entity != null) {
result = EntityUtils.toString(entity);
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return result;
}
/**
* 发送 POST 请求（HTTP），JSON形式
*
* @param apiUrl
* @param json json对象
* @return
*/
public static String doPost(String apiUrl, String jsonStr) {
CloseableHttpClient httpClient = HttpClients.createDefault();
String httpStr = null;
HttpPost httpPost = new HttpPost(apiUrl);
CloseableHttpResponse response = null;
try {
httpPost.setConfig(requestConfig);
//解决中文乱码问题
StringEntity stringEntity = new StringEntity(jsonStr, StandardCharsets.UTF_8);
stringEntity.setContentEncoding("UTF-8");
stringEntity.setContentType("application/json");
httpPost.setEntity(stringEntity);
response = httpClient.execute(httpPost);
HttpEntity entity = response.getEntity();
//System.out.println(response.getStatusLine().getStatusCode());
httpStr = EntityUtils.toString(entity);
if (response != null) {
EntityUtils.consume(response.getEntity());
}
} catch (IOException e) {
e.printStackTrace();
}
return httpStr;
}
/**
* 发送 POST 请求（HTTP），不带输入数据
*
* @param apiUrl
* @return
*/
public static String doPost(String apiUrl) {
return doPost(apiUrl, (Map<String, Object>) null);
}
/**
* 发送 SSL POST 请求（HTTPS），K-V形式
*
* @param apiUrl API接口URL
* @param params 参数map
* @return
*/
public static String doPostSSL(String apiUrl, Map<String, Object> params) {
CloseableHttpClient httpClient =
HttpClients.custom().setSSLSocketFactory(createSSLConnSocketFactory()).setConnectionManager(connMgr).setDefaultRequestConfig(requestConfig).build();
HttpPost httpPost = new HttpPost(apiUrl);
CloseableHttpResponse response = null;
String httpStr = null;
try {
httpPost.setConfig(requestConfig);
List<NameValuePair> pairList = new ArrayList<NameValuePair>(params.size());
for (Map.Entry<String, Object> entry : params.entrySet()) {
NameValuePair pair = new BasicNameValuePair(entry.getKey(), entry
.getValue().toString());
pairList.add(pair);
}
httpPost.setEntity(new UrlEncodedFormEntity(pairList, StandardCharsets.UTF_8));
response = httpClient.execute(httpPost);
int statusCode = response.getStatusLine().getStatusCode();
if (statusCode != HttpStatus.SC_OK) {
return null;
}
HttpEntity entity = response.getEntity();
if (entity == null) {
return null;
}
httpStr = EntityUtils.toString(entity, "utf-8");
if (response != null) {
EntityUtils.consume(response.getEntity());
}
} catch (Exception e) {
e.printStackTrace();
}
return httpStr;
}
/**
* 发送 SSL POST 请求（HTTPS），JSON形式
*
* @param apiUrl API接口URL
* @param json JSON对象
* @return
*/
public static String doPostSSL(String apiUrl, Object json) {
CloseableHttpClient httpClient =
HttpClients.custom().setSSLSocketFactory(createSSLConnSocketFactory()).setConnectionManager(connMgr).setDefaultRequestConfig(requestConfig).build();
HttpPost httpPost = new HttpPost(apiUrl);
CloseableHttpResponse response = null;
String httpStr = null;
try {
httpPost.setConfig(requestConfig);
//解决中文乱码问题
StringEntity stringEntity = new StringEntity(json.toString(), "UTF-8");
stringEntity.setContentEncoding("UTF-8");
stringEntity.setContentType("application/json");
httpPost.setEntity(stringEntity);
response = httpClient.execute(httpPost);
int statusCode = response.getStatusLine().getStatusCode();
if (statusCode != HttpStatus.SC_OK) {
return null;
}
HttpEntity entity = response.getEntity();
if (entity == null) {
return null;
}
httpStr = EntityUtils.toString(entity, "utf-8");
if (response != null) {
EntityUtils.consume(response.getEntity());
}
} catch (Exception e) {
e.printStackTrace();
}
return httpStr;
}
/**
* 创建SSL安全连接
*
* @return
*/
private static SSLConnectionSocketFactory createSSLConnSocketFactory() {
SSLConnectionSocketFactory sslsf = null;
try {
SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(null, new TrustStrategy() {
@Override
public boolean isTrusted(X509Certificate[] chain, String authType) throws CertificateException {
return true;
}
}).build();
sslsf = new SSLConnectionSocketFactory(sslContext, new HostnameVerifier() {
@Override
public boolean verify(String host, SSLSession session) {
return true;
}
});
} catch (GeneralSecurityException e) {
e.printStackTrace();
}
return sslsf;
}
}测试：
class HttpClientUtilTest {
@Test
void doGet() {
System.out.println("Test doGet(): ");
String url = "https://httpbin.org/anything";
String res = HttpClientUtil.doGet(url);
System.out.println(res);
res = HttpClientUtil.doGet(url + "?key1=value1&key2=value2");
System.out.println(res);
Map<String, Object> params = new HashMap<>(8);
params.put("key1", "value1");
params.put("key2", "value2");
res = HttpClientUtil.doGet(url, params);
System.out.println(res);
}
@Test
void doPost() {
System.out.println("Test doPost(): ");
String url = "https://httpbin.org/anything";
String res = HttpClientUtil.doPost(url);
System.out.println(res);
Map<String, Object> params = new HashMap<>(8);
params.put("key1", "value1");
params.put("key2", "value2");
res = HttpClientUtil.doPost(url, params);
System.out.println(res);
JsonMapper mapper = new JsonMapper();
ObjectNode node = mapper.createObjectNode();
node.put("key1", "value1");
node.put("key2", "value2");
String jsonStr = node.toString();
res = HttpClientUtil.doPost(url, jsonStr);
System.out.println(res);
}
@Test
void doPostSSL() {
System.out.println("Test doPostSSL(): ");
String url = "https://httpbin.org/anything";
Map<String, Object> params = new HashMap<>(8);
params.put("key1", "value1");
params.put("key2", "value2");
String res = HttpClientUtil.doPostSSL(url, params);
System.out.println(res);
JsonMapper mapper = new JsonMapper();
ObjectNode node = mapper.createObjectNode();
node.put("key1", "value1");
node.put("key2", "value2");
String jsonStr = node.toString();
res = HttpClientUtil.doPostSSL(url, jsonStr);
System.out.println(res);
}
}
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