Question

Java中的httpclient4.5应该怎么使用？

Answer 1

• 代码如下：

1. package org.apache.http.examples.client;
   import java.net.URI;
   import java.util.List;
   import org.apache.http.HttpEntity;
   import org.apache.http.client.methods.CloseableHttpResponse;
   import org.apache.http.client.methods.HttpGet;
   import org.apache.http.client.methods.HttpUriRequest;
   import org.apache.http.client.methods.RequestBuilder;
   import org.apache.http.cookie.Cookie;
   import org.apache.http.impl.client.BasicCookieStore;
   import org.apache.http.impl.client.CloseableHttpClient;
   import org.apache.http.impl.client.HttpClients;
   import org.apache.http.util.EntityUtils;
   

   /**
   * A example that demonstrates how HttpClient APIs can be used to perform
   * form-based logon.
   */
   

2. public class ClientFormLogin { public static void main(String[] args) throws Exception {       BasicCookieStore cookieStore = new BasicCookieStore();
   CloseableHttpClient httpclient = HttpClients.custom()
   .setDefaultCookieStore(cookieStore)
   .build();
   try {
   

3. HttpGet httpget = new HttpGet("https://someportal/");
   CloseableHttpResponse response1 = httpclient.execute(httpget);
   try {HttpEntity entity = response1.getEntity();
   System.out.println("Login form get: " + response1.getStatusLine());
   EntityUtils.consume(entity);
   System.out.println("Initial set of cookies:");
   

4. List<Cookie> cookies = cookieStore.getCookies();
   if (cookies.isEmpty()) {System.out.println("None");} else {for (int i = 0; i < cookies.size(); i++) { System.out.println("- " + cookies.get(i).toString()); }}           } finally {response1.close();}
   

5. HttpUriRequest login = RequestBuilder.post()
   .setUri(new URI("https://someportal/"))
   .addParameter("IDToken1", "username")
   addParameter("IDToken2", "password")
   .build();CloseableHttpResponse response2 = httpclient.execute(login);

6. try {HttpEntity entity = response2.getEntity();

   System.out.println("Login form get: " + response2.getStatusLine()); EntityUtils.consume(entity);

   System.out.println("Post logon cookies:")

   List<Cookie> cookies = cookieStore.getCookies(); for (int i = 0; i < cookies.size();

   i++) {}finally { response2.close();

7. finally}

• JAVA

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Answer 2

Java中的httpclient4.5使用：

HttpClient client = new HttpClient();
GetMethod get = new GetMethod(Url);
client.executeMethod(get);
if (get.getStatusCode() != HttpStatus.SC_OK) {
System.out.println("无返回或返回不正确");
}
String repMsg = get.getResponseBodyAsString();

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;
}  
}