Java HttpClient用法的示例详解
作者：怪 咖@
Java开发语言中实现HTTP请求的方法主要有两种：一种是JAVA的标准类HttpUrlConnection；另一种是第三方开源框架HTTPClient。本文就将详细讲讲Java中HttpClient的使用，需要的可以参考一下
1、导入依赖
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.3</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.58</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpmime</artifactId>
<version>4.5.3</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
<version>4.4.13</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.7</version>
</dependency>
2、使用工具类
该工具类将get请求和post请求当中几种传参方式都写了，其中有get地址栏传参、get的params传参、post的params传参、post的json传参。
import com.alibaba.fastjson.JSONObject;
import org.apache.http.Consts;
import org.apache.http.HttpEntity;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
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.client.utils.URIBuilder;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.entity.mime.HttpMultipartMode;
import org.apache.http.entity.mime.MultipartEntityBuilder;
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 org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.*;
import java.net.URI;
import java.net.URISyntaxException;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
public class HttpClientUtil {
private static Logger logger = LoggerFactory.getLogger(HttpClientUtil.class);
private static final int DEFULT_TIMEOUT = 30 * 1000;//默认超时时间20秒
/**
* 可以访问 http://localhost:9005/yzhwsj/addPersonal/1/2 这样的接口
* @param url
* @param headers
* @param urlParam
* @param timeout
* @return
*/
private static String doUrlGet(String url, Map<String, String> headers, List<String> urlParam, Integer timeout) {
//创建httpClient对象
CloseableHttpClient httpClient = HttpClients.createDefault();
String resultString = null;
CloseableHttpResponse response = null;
try {
//创建uri
if (urlParam != null){
for (String param : urlParam) {
url = url + "/" + param;
}
}
//创建hTTP get请求
HttpGet httpGet = new HttpGet(url);
//设置超时时间
int timeoutTmp = DEFULT_TIMEOUT;
if (timeout != null) {
timeoutTmp = timeout;
}
RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(timeoutTmp)
.setConnectionRequestTimeout(timeoutTmp).setSocketTimeout(timeoutTmp).build();
httpGet.setConfig(requestConfig);
//设置头信息
if (null != headers) {
for (String key : headers.keySet()) {
httpGet.setHeader(key, headers.get(key));
}
}
//执行请求
response = httpClient.execute(httpGet);
if (HttpStatus.SC_OK == response.getStatusLine().getStatusCode()) {
resultString = EntityUtils.toString(response.getEntity(), Consts.UTF_8);
}
} catch (IOException e) {
logger.error("http调用异常" + e.toString(), e);
} finally {
try {
if (null != response) {
response.close();
}
} catch (IOException e) {
logger.error("response关闭异常" + e.toString(), e);
}
try {
if (null != httpClient) {
httpClient.close();
}
} catch (IOException e) {
logger.error("httpClient关闭异常" + e.toString(), e);
}
}
return resultString;
}
/**
* @param url
* @param headers
* @param params
* @param timeout
* @return
*/
private static String doGet(String url, Map<String, String> headers, Map<String, Object> params, Integer timeout) {
//创建httpClient对象
CloseableHttpClient httpClient = HttpClients.createDefault();
String resultString = null;
CloseableHttpResponse response = null;
try {
// 1.创建uri
URIBuilder builder = new URIBuilder(url);
if (params != null) {
//uri添加参数
for (String key : params.keySet()) {
builder.addParameter(key, String.valueOf(params.get(key)));
}
}
URI uri = builder.build();
// 2.创建hTTP get请求
HttpGet httpGet = new HttpGet(uri);
// 3.设置超时时间
int timeoutTmp = DEFULT_TIMEOUT;
if (timeout != null) {
timeoutTmp = timeout;
}
RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(timeoutTmp)
.setConnectionRequestTimeout(timeoutTmp).setSocketTimeout(timeoutTmp).build();
httpGet.setConfig(requestConfig);
// 4.设置头信息
if (null != headers) {
for (String key : headers.keySet()) {
httpGet.setHeader(key, headers.get(key));
}
}
// 5.执行请求
response = httpClient.execute(httpGet);
if (HttpStatus.SC_OK == response.getStatusLine().getStatusCode()) {
resultString = EntityUtils.toString(response.getEntity(), Consts.UTF_8);
}
} catch (URISyntaxException e) {
logger.error("http调用异常" + e.toString(), e);
} catch (IOException e) {
logger.error("http调用异常" + e.toString(), e);
} finally {
try {
if (null != response) {
response.close();
}
} catch (IOException e) {
logger.error("response关闭异常" + e.toString(), e);
}
try {
if (null != httpClient) {
httpClient.close();
}
} catch (IOException e) {
logger.error("httpClient关闭异常" + e.toString(), e);
}
}
return resultString;
}
/**
* 调用http post请求（json数据）
*
* @param url
* @param headers
* @param json
* @return
*/
public static String doJsonPost(String url, Map<String, String> headers, JSONObject json, Integer timeout) {
CloseableHttpClient httpClient = HttpClients.createDefault();
CloseableHttpResponse response = null;
String resultString = "";
try {
// 1.创建http post请求
HttpPost httpPost = new HttpPost(url);
// 2.设置超时时间
int timeoutTmp = DEFULT_TIMEOUT;
if (timeout != null) {
timeoutTmp = timeout;
}
RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(timeoutTmp)
.setConnectionRequestTimeout(timeoutTmp).setSocketTimeout(timeoutTmp).build();
httpPost.setConfig(requestConfig);
// 3.设置参数信息
StringEntity s = new StringEntity(json.toString(), Consts.UTF_8);
// 发送json数据需要设置的contentType
s.setContentType("application/json");
httpPost.setEntity(s);
// 4.设置头信息
if (headers != null) {
for (String key : headers.keySet()) {
httpPost.setHeader(key, headers.get(key));
}
}
// 5.执行http请求
response = httpClient.execute(httpPost);
if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
resultString = EntityUtils.toString(response.getEntity(), Consts.UTF_8);
}
} catch (UnsupportedEncodingException e) {
logger.error("调用http异常" + e.toString(), e);
} catch (ClientProtocolException e) {
logger.error("调用http异常" + e.toString(), e);
} catch (IOException e) {
logger.error("调用http异常" + e.toString(), e);
} finally {
try {
if (null != response) {
response.close();
}
} catch (IOException e) {
logger.error("关闭response异常" + e.toString(), e);
}
try {
if (null != httpClient) {
httpClient.close();
}
} catch (IOException e) {
logger.error("关闭httpClient异常" + e.toString(), e);
}
}
return resultString;
}
/**
* 调用http post请求 基础方法
*
* @param url 请求的url
* @param headers 请求头
* @param params 参数
* @param timeout 超时时间
* @return
*/
public static String doPost(String url, Map<String, String> headers, Map<String, Object> params, Integer timeout) {
CloseableHttpClient httpClient = HttpClients.createDefault();
CloseableHttpResponse response = null;
String resultString = "";
try {
// 1.创建http post请求
HttpPost httpPost = new HttpPost(url);
// 2.设置超时时间
int timeoutTmp = DEFULT_TIMEOUT;
if (timeout != null) {
timeoutTmp = timeout;
}
RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(timeoutTmp)
.setConnectionRequestTimeout(timeoutTmp).setSocketTimeout(timeoutTmp).build();
httpPost.setConfig(requestConfig);
// 3.设置参数信息
if (params != null) {
List<NameValuePair> paramList = new ArrayList<>();
for (String key : params.keySet()) {
paramList.add(new BasicNameValuePair(key, String.valueOf(params.get(key))));
}
// 模拟表单
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList, Consts.UTF_8);
httpPost.setEntity(entity);
}
// 4.设置头信息
if (headers != null) {
for (String key : headers.keySet()) {
httpPost.setHeader(key, headers.get(key));
}
}
// 5.执行http请求
response = httpClient.execute(httpPost);
if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
resultString = EntityUtils.toString(response.getEntity(), Consts.UTF_8);
}
} catch (UnsupportedEncodingException e) {
logger.error("调用http异常" + e.toString(), e);
} catch (ClientProtocolException e) {
logger.error("调用http异常" + e.toString(), e);
} catch (IOException e) {
logger.error("调用http异常" + e.toString(), e);
} finally {
try {
if (null != response) {
response.close();
}
} catch (IOException e) {
logger.error("关闭response异常" + e.toString(), e);
}
try {
if (null != httpClient) {
httpClient.close();
}
} catch (IOException e) {
logger.error("关闭httpClient异常" + e.toString(), e);
}
}
return resultString;
}
/**
* 通过httpClient上传文件
*
* @param url 请求的URL
* @param headers 请求头参数
* @param path 文件路径
* @param fileName 文件名称
* @param timeout 超时时间
* @return
*/
public static String UploadFileByHttpClient(String url, Map<String, String> headers, String path, String fileName, Integer timeout) {
String resultString = "";
CloseableHttpClient httpClient = HttpClients.createDefault();
CloseableHttpResponse response = null;
InputStream content = null;
BufferedReader in = null;
try {
// 1.创建http post请求
HttpPost httpPost = new HttpPost(url);
// 2.设置超时时间
int timeoutTmp = DEFULT_TIMEOUT;
if (timeout != null) {
timeoutTmp = timeout;
}
RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(timeoutTmp)
.setConnectionRequestTimeout(timeoutTmp).setSocketTimeout(timeoutTmp).build();
httpPost.setConfig(requestConfig);
// 3.设置参数信息
// HttpMultipartMode.RFC6532参数的设定是为避免文件名为中文时乱码
MultipartEntityBuilder builder = MultipartEntityBuilder.create().setMode(HttpMultipartMode.RFC6532);
// 上传文件的路径
File file = new File(path + File.separator + fileName);
builder.setCharset(Charset.forName("UTF-8"));
builder.addBinaryBody("file", file, ContentType.MULTIPART_FORM_DATA, fileName);
HttpEntity entity = builder.build();
httpPost.setEntity(entity);
// 4.设置头信息
if (headers != null) {
for (String key : headers.keySet()) {
httpPost.setHeader(key, headers.get(key));
}
}
// 5.执行http请求
response = httpClient.execute(httpPost);
if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
resultString = EntityUtils.toString(response.getEntity(), Consts.UTF_8);
}
} catch (Exception e) {
logger.error("上传文件失败：", e);
} finally {
try {
if (null != httpClient) {
httpClient.close();
}
} catch (IOException e) {
logger.error("关闭httpClient异常" + e.toString(), e);
}
try {
if (null != content) {
content.close();
}
} catch (IOException e) {
logger.error("关闭content异常" + e.toString(), e);
}
try {
if (null != in) {
in.close();
}
} catch (IOException e) {
logger.error("关闭in异常" + e.toString(), e);
}
}
return resultString;
}
}
/**
* 通过httpClient批量上传文件
*
* @param url 请求的URL
* @param headers 请求头参数
* @param params 参数
* @param paths 文件路径(key文件名称，value路径)
* @param timeout 超时时间
* @return
*/
public static String UploadFilesByHttpClient(String url, Map<String, String> headers, Map<String, String> params, Map<String, String> paths, Integer timeout) {
String resultString = "";
CloseableHttpClient httpClient = HttpClients.createDefault();
CloseableHttpResponse response = null;
InputStream content = null;
BufferedReader in = null;
try {
// 1.创建http post请求
HttpPost httpPost = new HttpPost(url);
// 2.设置超时时间
int timeoutTmp = DEFULT_TIMEOUT;
if (timeout != null) {
timeoutTmp = timeout;
}
RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(timeoutTmp)
.setConnectionRequestTimeout(timeoutTmp).setSocketTimeout(timeoutTmp).build();
httpPost.setConfig(requestConfig);
// 3.设置文件信息
// HttpMultipartMode.RFC6532参数的设定是为避免文件名为中文时乱码
MultipartEntityBuilder builder = MultipartEntityBuilder.create().setMode(HttpMultipartMode.RFC6532);
builder.setCharset(Charset.forName("UTF-8"));
// 上传文件的路径
for (Map.Entry<String, String> m : paths.entrySet()) {
File file = new File(m.getValue() + File.separator + m.getKey());
builder.addBinaryBody("files", file, ContentType.MULTIPART_FORM_DATA, m.getKey());
}
// 4.设置参数信息
ContentType contentType = ContentType.create("text/plain", Charset.forName("UTF-8"));
for (Map.Entry<String, String> param : params.entrySet()) {
builder.addTextBody(param.getKey(), param.getValue(), contentType);
}
HttpEntity entity = builder.build();
httpPost.setEntity(entity);
// 5.设置头信息
if (headers != null) {
for (String key : headers.keySet()) {
httpPost.setHeader(key, headers.get(key));
}
}
// 6.执行http请求
response = httpClient.execute(httpPost);
if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
resultString = EntityUtils.toString(response.getEntity(), Consts.UTF_8);
}
} catch (Exception e) {
logger.error("上传文件失败：", e);
} finally {
try {
if (null != httpClient) {
httpClient.close();
}
} catch (IOException e) {
logger.error("关闭httpClient异常" + e.toString(), e);
}
try {
if (null != content) {
content.close();
}
} catch (IOException e) {
logger.error("关闭content异常" + e.toString(), e);
}
try {
if (null != in) {
in.close();
}
} catch (IOException e) {
logger.error("关闭in异常" + e.toString(), e);
}
}
return resultString;
}
3、扩展
上面的工具类，方法都携带了token和超时时间，假如接口用不到可以做接口拓展。例如：
/**
* 调用http get请求
*
* @param url
* @param params
* @return
*/
public static String doGet(String url, Map<String, Object> params) {
return doGet(url, null, params, null);
}
如果涉及到put请求和delete请求，跟上面都差不多，只不过创建请求的时候改为:
HttpDelete httpDelete = new HttpDelete(); HttpPut httpPut = new HttpPut();
到此这篇关于Java HttpClient用法的示例详解的文章就介绍到这了,更多相关Java HttpClient内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家！