Question

Java中的httpclient4.5应该怎么使用

Answer 1

一、所需要的jar包
httpclient-4.5.jar
httpcore-4.4.1.jar
httpmime-4.5.jar
二、实例
Java代码
package cn.tzz.apache.httpclient;

import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import org.apache.http.HttpEntity;
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.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.conn.ssl.DefaultHostnameVerifier;
import org.apache.http.conn.util.PublicSuffixMatcher;
import org.apache.http.conn.util.PublicSuffixMatcherLoader;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.entity.mime.content.StringBody;
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;

public class HttpClientUtil {
private RequestConfig requestConfig = RequestConfig.custom()
.setSocketTimeout(15000)
.setConnectTimeout(15000)
.setConnectionRequestTimeout(15000)
.build();

private static HttpClientUtil instance = null;
private HttpClientUtil(){}
public static HttpClientUtil getInstance(){
if (instance == null) {
instance = new HttpClientUtil();
}
return instance;
}

/**
* 发送 post请求
* @param httpUrl 地址
*/
public String sendHttpPost(String httpUrl) {
HttpPost httpPost = new HttpPost(httpUrl);// 创建httpPost
return sendHttpPost(httpPost);
}

/**
* 发送 post请求
* @param httpUrl 地址
* @param params 参数(格式:key1=value1&key2=value2)
*/
public String sendHttpPost(String httpUrl, String params) {
HttpPost httpPost = new HttpPost(httpUrl);// 创建httpPost
try {
//设置参数
StringEntity stringEntity = new StringEntity(params, "UTF-8");
stringEntity.setContentType("application/x-www-form-urlencoded");
httpPost.setEntity(stringEntity);
} catch (Exception e) {
e.printStackTrace();
}
return sendHttpPost(httpPost);
}

/**
* 发送 post请求
* @param httpUrl 地址
* @param maps 参数
*/
public String sendHttpPost(String httpUrl, Map<String, String> maps) {
HttpPost httpPost = new HttpPost(httpUrl);// 创建httpPost
// 创建参数队列
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
for (String key : maps.keySet()) {
nameValuePairs.add(new BasicNameValuePair(key, maps.get(key)));
}
try {
httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs, "UTF-8"));
} catch (Exception e) {
e.printStackTrace();
}
return sendHttpPost(httpPost);
}

/**
* 发送 post请求（带文件）
* @param httpUrl 地址
* @param maps 参数
* @param fileLists 附件
*/
public String sendHttpPost(String httpUrl, Map<String, String> maps, List<File> fileLists) {
HttpPost httpPost = new HttpPost(httpUrl);// 创建httpPost
MultipartEntityBuilder meBuilder = MultipartEntityBuilder.create();
for (String key : maps.keySet()) {
meBuilder.addPart(key, new StringBody(maps.get(key), ContentType.TEXT_PLAIN));
}
for(File file : fileLists) {
FileBody fileBody = new FileBody(file);
meBuilder.addPart("files", fileBody);
}
HttpEntity reqEntity = meBuilder.build();
httpPost.setEntity(reqEntity);
return sendHttpPost(httpPost);
}

/**
* 发送Post请求
* @param httpPost
* @return
*/
private String sendHttpPost(HttpPost httpPost) {
CloseableHttpClient httpClient = null;
CloseableHttpResponse response = null;
HttpEntity entity = null;
String responseContent = null;
try {
// 创建默认的httpClient实例.
httpClient = HttpClients.createDefault();
httpPost.setConfig(requestConfig);
// 执行请求
response = httpClient.execute(httpPost);
entity = response.getEntity();
responseContent = EntityUtils.toString(entity, "UTF-8");
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
// 关闭连接,释放资源
if (response != null) {
response.close();
}
if (httpClient != null) {
httpClient.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return responseContent;
}

/**
* 发送 get请求
* @param httpUrl
*/
public String sendHttpGet(String httpUrl) {
HttpGet httpGet = new HttpGet(httpUrl);// 创建get请求
return sendHttpGet(httpGet);
}

/**
* 发送 get请求Https
* @param httpUrl
*/
public String sendHttpsGet(String httpUrl) {
HttpGet httpGet = new HttpGet(httpUrl);// 创建get请求
return sendHttpsGet(httpGet);
}

/**
* 发送Get请求
* @param httpPost
* @return
*/
private String sendHttpGet(HttpGet httpGet) {
CloseableHttpClient httpClient = null;
CloseableHttpResponse response = null;
HttpEntity entity = null;
String responseContent = null;
try {
// 创建默认的httpClient实例.
httpClient = HttpClients.createDefault();
httpGet.setConfig(requestConfig);
// 执行请求
response = httpClient.execute(httpGet);
entity = response.getEntity();
responseContent = EntityUtils.toString(entity, "UTF-8");
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
// 关闭连接,释放资源
if (response != null) {
response.close();
}
if (httpClient != null) {
httpClient.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return responseContent;
}

/**
* 发送Get请求Https
* @param httpPost
* @return
*/
private String sendHttpsGet(HttpGet httpGet) {
CloseableHttpClient httpClient = null;
CloseableHttpResponse response = null;
HttpEntity entity = null;
String responseContent = null;
try {
// 创建默认的httpClient实例.
PublicSuffixMatcher publicSuffixMatcher = PublicSuffixMatcherLoader.load(new URL(httpGet.getURI().toString()));
DefaultHostnameVerifier hostnameVerifier = new DefaultHostnameVerifier(publicSuffixMatcher);
httpClient = HttpClients.custom().setSSLHostnameVerifier(hostnameVerifier).build();
httpGet.setConfig(requestConfig);
// 执行请求
response = httpClient.execute(httpGet);
entity = response.getEntity();
responseContent = EntityUtils.toString(entity, "UTF-8");
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
// 关闭连接,释放资源
if (response != null) {
response.close();
}
if (httpClient != null) {
httpClient.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return responseContent;
}
}

Answer 2

这个问题你应该看api而不是来这儿问