HttpClient的基本使用
概述
HttpClient 是Apache Jakarta Common 下的子项目，可以用来提供高效的、最新的、功能丰富的支持 HTTP 协议的客户端编程工具包，并且它支持 HTTP 协议最新的版本和建议。
HttpClient相比JDK自带的URLConnection，增加了易用性和灵活性，使客户端发送Http请求变得更加容易，而且也方便开发测试接口，大大提高开发的效率。
常用HTTP协议客户端包括有：httpclient、restTemplate、okHttp
官网：https://hc.apache.org/index.html
添加依赖
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.13</version>
</dependency>
Get请求
1.无参数的GET请求
@Test
public void get() throws IOException {
// 创建HttpClient对象
CloseableHttpClient httpClient = HttpClients.createDefault();
// 创建HttpGet请求
HttpGet httpGet = new HttpGet("https://www.baidu.com");
// 响应对象
CloseableHttpResponse response = null;
try {
// 使用HttpClient发起请求
response = httpClient.execute(httpGet);
// 判断响应状态码是否为200
if (response.getStatusLine().getStatusCode() == 200) {
// 获取返回数据
HttpEntity httpEntity = response.getEntity();
String content = EntityUtils.toString(httpEntity, "UTF-8");
// 打印数据长度
log.info("content:{}", content);
}
} finally {
// 释放连接
if (response != null) {
response.close();
}
httpClient.close();
}
}
2.带参数的GET请求
HttpGet httpGet = new HttpGet("https://www.baidu.com/s?wd=java");
POST请求
1.无参数的POST请求
@Test
public void post() throws IOException {
// 创建HttpClient对象
CloseableHttpClient httpClient = HttpClients.createDefault();
// 创建HttpGet请求
HttpPost httpPost = new HttpPost("http://www.baidu.com");
// 响应对象
CloseableHttpResponse response = null;
try {
// 使用HttpClient发起请求
response = httpClient.execute(httpPost);
// 判断响应状态码是否为200
if (response.getStatusLine().getStatusCode() == 200) {
// 获取返回数据
HttpEntity httpEntity = response.getEntity();
String content = EntityUtils.toString(httpEntity, "UTF-8");
// 打印数据长度
log.info("content:{}", content);
}
} finally {
// 释放连接
if (response != null) {
response.close();
}
httpClient.close();
}
}
2.带参数的POST请求
public static void main(String[] args) throws Exception {
// 创建HttpClient对象
CloseableHttpClient httpClient = HttpClients.createDefault();
// 创建HttpPost对象，设置url访问地址
HttpPost httpPost = new HttpPost("https://fanyi.baidu.com/langdetect");
// 声明List集合，封装表单中的参数
List<NameValuePair> params = new ArrayList<NameValuePair>();
// 实际请求地址：https://fanyi.baidu.com/langdetect?query=Java
params.add(new BasicNameValuePair("query", "Java"));
// 创建表单的Entity对象,第一个参数是封装好的表单数据，第二个参数是编码
UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(params, "utf8");
//设置表单的Entity对象到Post请求中
httpPost.setEntity(formEntity);
CloseableHttpResponse response = null;
try {
// 使用HttpClient发起请求，获取response
response = httpClient.execute(httpPost);
// 解析响应
if (response.getStatusLine().getStatusCode() == 200) {
String content = EntityUtils.toString(response.getEntity(), "utf8");
log.info("content={}", content);
}
} finally {
// 关闭资源
response.close();
httpClient.close();
}
}
连接池
每次请求都要创建HttpClient，会有频繁创建和销毁的问题，可以使用连接池来解决这个问题。
public class HttpClientPool {
public static PoolingHttpClientConnectionManager getHttpClientPool(){
// 创建连接池管理器
PoolingHttpClientConnectionManager poolingHttpClientConnectionManager = new PoolingHttpClientConnectionManager();
// 设置最大连接数
poolingHttpClientConnectionManager.setMaxTotal(100);
// 设置每个主机的最大连接数
poolingHttpClientConnectionManager.setDefaultMaxPerRoute(10);
return poolingHttpClientConnectionManager;
}
public static void main(String[] args) {
// 使用连接池管理器发起请求
PoolingHttpClientConnectionManager httpClientPool = HttpClientPool.getHttpClientPool();
// 从连接池中获取HttpClient对象
CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(httpClientPool).build();
}
}
请求参数配置
对请求进行参数配置，如cookie设置，代理设置，以及常用的请求超时时间设置。
public class HttpClientPool {
public static PoolingHttpClientConnectionManager getHttpClientPool() {
// 创建连接池管理器
PoolingHttpClientConnectionManager poolingHttpClientConnectionManager = new PoolingHttpClientConnectionManager();
// 设置最大连接数
poolingHttpClientConnectionManager.setMaxTotal(100);
// 设置每个主机的最大连接数
poolingHttpClientConnectionManager.setDefaultMaxPerRoute(10);
return poolingHttpClientConnectionManager;
}
public static void main(String[] args) throws IOException {
// 使用连接池管理器发起请求
PoolingHttpClientConnectionManager httpClientPool = HttpClientPool.getHttpClientPool();
// 从连接池中获取HttpClient对象
CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(httpClientPool).build();
HttpGet httpGet = new HttpGet("http://www.baidu.com");
// 配置请求信息
RequestConfig config = RequestConfig.custom()
// 创建连接的最长时间，单位是毫秒
.setConnectTimeout(1000)
// 设置获取连接的最长时间，单位是毫秒
.setConnectionRequestTimeout(500)
// 设置数据传输的最长时间，单位是毫秒
.setSocketTimeout(10 * 1000)
.build();
// 给请求设置请求信息
httpGet.setConfig(config);
// 使用HttpClient发起请求，获取response
CloseableHttpResponse execute = httpClient.execute(httpGet);
}
}
工具类封装
HttpClientResult
/**
* Description: 封装httpClient响应结果
*/
@Data
@AllArgsConstructor
@NoArgsConstructor
public class HttpClientResult implements Serializable {
/**
* 响应状态码
*/
private int code;
/**
* 响应数据
*/
private String content;
}
HttpClientUtils
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.*;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.*;
/**
* Description: httpClient工具类
*/
public class HttpClientUtils {
// 编码格式。发送编码格式统一用UTF-8
private static final String ENCODING = "UTF-8";
// 设置连接超时时间，单位毫秒。
private static final int CONNECT_TIMEOUT = 6000;
// 请求获取数据的超时时间(即响应时间)，单位毫秒。
private static final int SOCKET_TIMEOUT = 6000;
/**
* 发送get请求；不带请求头和请求参数
*
* @param url 请求地址
*/
public static HttpClientResult doGet(String url) throws Exception {
return doGet(url, null, null);
}
/**
* 发送get请求；带请求参数
*
* @param url 请求地址
* @param params 请求参数集合
*/
public static HttpClientResult doGet(String url, Map<String, String> params) throws Exception {
return doGet(url, null, params);
}
/**
* 发送get请求；带请求头和请求参数
*
* @param url 请求地址
* @param headers 请求头集合
* @param params 请求参数集合
*/
public static HttpClientResult doGet(String url, Map<String, String> headers, Map<String, String> params) throws Exception {
// 创建httpClient对象
CloseableHttpClient httpClient = HttpClients.createDefault();
// 创建访问的地址
URIBuilder uriBuilder = new URIBuilder(url);
if (params != null) {
Set<Map.Entry<String, String>> entrySet = params.entrySet();
for (Map.Entry<String, String> entry : entrySet) {
uriBuilder.setParameter(entry.getKey(), entry.getValue());
}
}
// 创建http对象
HttpGet httpGet = new HttpGet(uriBuilder.build());
/**
* setConnectTimeout：设置连接超时时间，单位毫秒。
* setConnectionRequestTimeout：设置从connect Manager(连接池)获取Connection
* 超时时间，单位毫秒。这个属性是新加的属性，因为目前版本是可以共享连接池的。
* setSocketTimeout：请求获取数据的超时时间(即响应时间)，单位毫秒。 如果访问一个接口，多少时间内无法返回数据，就直接放弃此次调用。
*/
RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(CONNECT_TIMEOUT).setSocketTimeout(SOCKET_TIMEOUT).build();
httpGet.setConfig(requestConfig);
// 设置请求头
packageHeader(headers, httpGet);
try {
// 执行请求并获得响应结果
return getHttpClientResult(httpClient, httpGet);
} finally {
// 释放资源
close(httpClient);
}
}
/**
* 发送post请求；不带请求头和请求参数
*
* @param url 请求地址
*/
public static HttpClientResult doPost(String url) throws Exception {
return doPost(url, null, null);
}
/**
* 发送post请求；带请求参数
*
* @param url 请求地址
* @param params 参数集合
*/
public static HttpClientResult doPost(String url, Map<String, String> params) throws Exception {
return doPost(url, null, params);
}
/**
* 发送post请求；带请求头和请求参数
*
* @param url 请求地址
* @param headers 请求头集合
* @param params 请求参数集合
*/
public static HttpClientResult doPost(String url, Map<String, String> headers, Map<String, String> params) throws Exception {
// 创建httpClient对象
CloseableHttpClient httpClient = HttpClients.createDefault();
// 创建http对象
HttpPost httpPost = new HttpPost(url);
/**
* setConnectTimeout：设置连接超时时间，单位毫秒。
* setConnectionRequestTimeout：设置从connect Manager(连接池)获取Connection
* 超时时间，单位毫秒。这个属性是新加的属性，因为目前版本是可以共享连接池的。
* setSocketTimeout：请求获取数据的超时时间(即响应时间)，单位毫秒。 如果访问一个接口，多少时间内无法返回数据，就直接放弃此次调用。
*/
RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(CONNECT_TIMEOUT).setSocketTimeout(SOCKET_TIMEOUT).build();
httpPost.setConfig(requestConfig);
// 设置请求头
/*httpPost.setHeader("Cookie", "");
httpPost.setHeader("Accept", "application/json");
httpPost.setHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36");*/
packageHeader(headers, httpPost);
// 封装请求参数
packageParam(params, httpPost);
try {
// 执行请求并获得响应结果
return getHttpClientResult(httpClient, httpPost);
} finally {
// 释放资源
close(httpClient);
}
}
/**
* 发送put请求；不带请求参数
*
* @param url 请求地址
*/
public static HttpClientResult doPut(String url) throws Exception {
return doPut(url, null);
}
/**
* 发送put请求；带请求参数
*
* @param url 请求地址
* @param params 参数集合
*/
public static HttpClientResult doPut(String url, Map<String, String> params) throws Exception {
CloseableHttpClient httpClient = HttpClients.createDefault();
HttpPut httpPut = new HttpPut(url);
RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(CONNECT_TIMEOUT).setSocketTimeout(SOCKET_TIMEOUT).build();
httpPut.setConfig(requestConfig);
packageParam(params, httpPut);
try {
return getHttpClientResult(httpClient, httpPut);
} finally {
close(httpClient);
}
}
/**
* 发送delete请求；不带请求参数
*
* @param url 请求地址
*/
public static HttpClientResult doDelete(String url) throws Exception {
CloseableHttpClient httpClient = HttpClients.createDefault();
HttpDelete httpDelete = new HttpDelete(url);
RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(CONNECT_TIMEOUT).setSocketTimeout(SOCKET_TIMEOUT).build();
httpDelete.setConfig(requestConfig);
try {
return getHttpClientResult(httpClient, httpDelete);
} finally {
close(httpClient);
}
}
/**
* 发送delete请求；带请求参数
*
* @param url 请求地址
* @param params 参数集合
*/
public static HttpClientResult doDelete(String url, Map<String, String> params) throws Exception {
if (params == null) {
params = new HashMap<>();
}
params.put("_method", "delete");
return doPost(url, params);
}
/**
* Description: 封装请求头
*/
public static void packageHeader(Map<String, String> params, HttpRequestBase httpMethod) {
// 封装请求头
if (params != null) {
Set<Map.Entry<String, String>> entrySet = params.entrySet();
for (Map.Entry<String, String> entry : entrySet) {
// 设置到请求头到HttpRequestBase对象中
httpMethod.setHeader(entry.getKey(), entry.getValue());
}
}
}
/**
* Description: 封装请求参数
*/
public static void packageParam(Map<String, String> params, HttpEntityEnclosingRequestBase httpMethod)
throws UnsupportedEncodingException {
// 封装请求参数
if (params != null) {
List<NameValuePair> nvps = new ArrayList<>();
Set<Map.Entry<String, String>> entrySet = params.entrySet();
for (Map.Entry<String, String> entry : entrySet) {
nvps.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
}
// 设置到请求的http对象中
httpMethod.setEntity(new UrlEncodedFormEntity(nvps, ENCODING));
}
}
/**
* Description: 获得响应结果
*/
public static HttpClientResult getHttpClientResult(CloseableHttpClient httpClient, HttpRequestBase httpMethod) throws IOException {
try (CloseableHttpResponse httpResponse = httpClient.execute(httpMethod)) {
// 获取返回结果
if (httpResponse != null && httpResponse.getStatusLine() != null) {
String content = "";
if (httpResponse.getEntity() != null) {
content = EntityUtils.toString(httpResponse.getEntity(), ENCODING);
}
return new HttpClientResult(httpResponse.getStatusLine().getStatusCode(), content);
}
}
return new HttpClientResult(HttpStatus.SC_INTERNAL_SERVER_ERROR, null);
}
/**
* Description: 释放资源
*/
public static void close(CloseableHttpClient httpClient) throws IOException {
if (httpClient != null) {
httpClient.close();
}
}
}
测试
public class HttpClientUtilsTest {
/**
* Description: 测试get无参请求
*/
@Test
public void testGet() throws Exception {
HttpClientResult result = HttpClientUtils.doGet("https://www.baidu.com");
System.out.println(result);
}
/**
* Description: 测试get带参请求
*/
@Test
public void testGetWithParam() throws Exception {
Map<String, String> params = new HashMap<String, String>();
params.put("word", "java");
HttpClientResult result = HttpClientUtils.doGet("url", params);
System.out.println(result);
}
/**
* Description: 测试post带请求头不带请求参数
*/
@Test
public void testPost() throws Exception {
Map<String, String> headers = new HashMap<String, String>();
headers.put("Cookie", "cokie");
headers.put("Accept", "application/json");
headers.put("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36");
HttpClientResult result = HttpClientUtils.doPost("url", headers, null);
System.out.println(result);
}
/**
* Description: 测试post带参请求
*/
@Test
public void testPostWithParam() throws Exception {
Map<String, String> params = new HashMap<String, String>();
params.put("word", "java");
HttpClientResult result = HttpClientUtils.doPost("url", params);
System.out.println(result);
}
}
