HttpClient使用详解 (一)

Http协议的重要性相信不用我多说了，HttpClient相比传统JDK自带的URLConnection，增加了易用性和灵活性（具体区别，日后我们再讨论），它不仅是客户端发送Http请求变得容易，而且也方便了开发人员测试接口（基于Http协议的），即提高了开发的效率，也方便提高代码的健壮性。因此熟练掌握HttpClient是很重要的必修内容，掌握HttpClient后，相信对于Http协议的了解会更加深入。

一、简介

HttpClient是Apache Jakarta Common下的子项目，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已经应用在很多的项目中，比如Apache Jakarta上很著名的另外两个开源项目Cactus和HTMLUnit都使用了HttpClient。

下载地址: http://hc.apache.org/downloads.cgi

二、特性

1. 基于标准、纯净的Java语言。实现了Http1.0和Http1.1

2. 以可扩展的面向对象的结构实现了Http全部的方法（GET, POST, PUT, DELETE, HEAD, OPTIONS, and TRACE）。

3. 支持HTTPS协议。

4. 通过Http代理建立透明的连接。

5. 利用CONNECT方法通过Http代理建立隧道的https连接。

6. Basic, Digest, NTLMv1, NTLMv2, NTLM2 Session, SNPNEGO/Kerberos认证方案。

7. 插件式的自定义认证方案。

8. 便携可靠的套接字工厂使它更容易的使用第三方解决方案。

9. 连接管理器支持多线程应用。支持设置最大连接数，同时支持设置每个主机的最大连接数，发现并关闭过期的连接。

10. 自动处理Set-Cookie中的Cookie。

11. 插件式的自定义Cookie策略。

12. Request的输出流可以避免流中内容直接缓冲到socket服务器。

13. Response的输入流可以有效的从socket服务器直接读取相应内容。

14. 在http1.0和http1.1中利用KeepAlive保持持久连接。

15. 直接获取服务器发送的response code和 headers。

16. 设置连接超时的能力。

17. 实验性的支持http1.1 response caching。

18. 源代码基于Apache License 可免费获取。

三、使用方法

使用HttpClient发送请求、接收响应很简单，一般需要如下几步即可。

1. 创建HttpClient对象。

2. 创建请求方法的实例，并指定请求URL。如果需要发送GET请求，创建HttpGet对象；如果需要发送POST请求，创建HttpPost对象。

3. 如果需要发送请求参数，可调用HttpGet、HttpPost共同的setParams(HetpParams
params)方法来添加请求参数；对于HttpPost对象而言，也可调用setEntity(HttpEntity
entity)方法来设置请求参数。

4. 调用HttpClient对象的execute(HttpUriRequest request)发送请求，该方法返回一个HttpResponse。

5. 调用HttpResponse的getAllHeaders()、getHeaders(String

name)等方法可获取服务器的响应头；调用HttpResponse的getEntity()方法可获取HttpEntity对象，该对象包装了服务器的响应内容。程序可通过该对象获取服务器的响应内容。

6. 释放连接。无论执行方法是否成功，都必须释放连接

四、实例

package com.test;  
 
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.KeyManagementException;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.CertificateException;
import java.util.ArrayList;
import java.util.List;  
 
import javax.net.ssl.SSLContext;  
 
import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
import org.apache.http.client.ClientProtocolException;
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.SSLConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLContexts;
import org.apache.http.conn.ssl.TrustSelfSignedStrategy;
import org.apache.http.entity.ContentType;
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;
import org.junit.Test;  
 
public class HttpClientTest {  
 
    @Test
    public void jUnitTest() {
        get();
    }  
 
    /**
     * HttpClient连接SSL
     */
    public void ssl() {
        CloseableHttpClient httpclient = null;
        try {
            KeyStore trustStore = KeyStore.getInstance(KeyStore.getDefaultType());
            FileInputStream instream = new FileInputStream(new File("d:\\tomcat.keystore"));
            try {
                // 加载keyStore d:\\tomcat.keystore
                trustStore.load(instream, "123456".toCharArray());
            } catch (CertificateException e) {
                e.printStackTrace();
            } finally {
                try {
                    instream.close();
                } catch (Exception ignore) {
                }
            }
            // 相信自己的CA和所有自签名的证书
            SSLContext sslcontext = SSLContexts.custom().loadTrustMaterial(trustStore, new TrustSelfSignedStrategy()).build();
            // 只允许使用TLSv1协议
            SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslcontext, new String[] { "TLSv1" }, null,
                    SSLConnectionSocketFactory.BROWSER_COMPATIBLE_HOSTNAME_VERIFIER);
            httpclient = HttpClients.custom().setSSLSocketFactory(sslsf).build();
            // 创建http请求(get方式)
            HttpGet httpget = new HttpGet("https://localhost:8443/myDemo/Ajax/serivceJ.action");
            System.out.println("executing request" + httpget.getRequestLine());
            CloseableHttpResponse response = httpclient.execute(httpget);
            try {
                HttpEntity entity = response.getEntity();
                System.out.println("----------------------------------------");
                System.out.println(response.getStatusLine());
                if (entity != null) {
                    System.out.println("Response content length: " + entity.getContentLength());
                    System.out.println(EntityUtils.toString(entity));
                    EntityUtils.consume(entity);
                }
            } finally {
                response.close();
            }
        } catch (ParseException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (KeyManagementException e) {
            e.printStackTrace();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (KeyStoreException e) {
            e.printStackTrace();
        } finally {
            if (httpclient != null) {
                try {
                    httpclient.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }  
 
    /**
     * post方式提交表单（模拟用户登录请求）
     */
    public void postForm() {
        // 创建默认的httpClient实例.
        CloseableHttpClient httpclient = HttpClients.createDefault();
        // 创建httppost
        HttpPost httppost = new HttpPost("http://localhost:8080/myDemo/Ajax/serivceJ.action");
        // 创建参数队列
        List<NameValuePair> formparams = new ArrayList<NameValuePair>();
        formparams.add(new BasicNameValuePair("username", "admin"));
        formparams.add(new BasicNameValuePair("password", "123456"));
        UrlEncodedFormEntity uefEntity;
        try {
            uefEntity = new UrlEncodedFormEntity(formparams, "UTF-8");
            httppost.setEntity(uefEntity);
            System.out.println("executing request " + httppost.getURI());
            CloseableHttpResponse response = httpclient.execute(httppost);
            try {
                HttpEntity entity = response.getEntity();
                if (entity != null) {
                    System.out.println("--------------------------------------");
                    System.out.println("Response content: " + EntityUtils.toString(entity, "UTF-8"));
                    System.out.println("--------------------------------------");
                }
            } finally {
                response.close();
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e1) {
            e1.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // 关闭连接,释放资源
            try {
                httpclient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }  
 
    /**
     * 发送 post请求访问本地应用并根据传递参数不同返回不同结果
     */
    public void post() {
        // 创建默认的httpClient实例.
        CloseableHttpClient httpclient = HttpClients.createDefault();
        // 创建httppost
        HttpPost httppost = new HttpPost("http://localhost:8080/myDemo/Ajax/serivceJ.action");
        // 创建参数队列
        List<NameValuePair> formparams = new ArrayList<NameValuePair>();
        formparams.add(new BasicNameValuePair("type", "house"));
        UrlEncodedFormEntity uefEntity;
        try {
            uefEntity = new UrlEncodedFormEntity(formparams, "UTF-8");
            httppost.setEntity(uefEntity);
            System.out.println("executing request " + httppost.getURI());
            CloseableHttpResponse response = httpclient.execute(httppost);
            try {
                HttpEntity entity = response.getEntity();
                if (entity != null) {
                    System.out.println("--------------------------------------");
                    System.out.println("Response content: " + EntityUtils.toString(entity, "UTF-8"));
                    System.out.println("--------------------------------------");
                }
            } finally {
                response.close();
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e1) {
            e1.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // 关闭连接,释放资源
            try {
                httpclient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }  
 
    /**
     * 发送 get请求
     */
    public void get() {
        CloseableHttpClient httpclient = HttpClients.createDefault();
        try {
            // 创建httpget.
            HttpGet httpget = new HttpGet("http://www.baidu.com/");
            System.out.println("executing request " + httpget.getURI());
            // 执行get请求.
            CloseableHttpResponse response = httpclient.execute(httpget);
            try {
                // 获取响应实体
                HttpEntity entity = response.getEntity();
                System.out.println("--------------------------------------");
                // 打印响应状态
                System.out.println(response.getStatusLine());
                if (entity != null) {
                    // 打印响应内容长度
                    System.out.println("Response content length: " + entity.getContentLength());
                    // 打印响应内容
                    System.out.println("Response content: " + EntityUtils.toString(entity));
                }
                System.out.println("------------------------------------");
            } finally {
                response.close();
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (ParseException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // 关闭连接,释放资源
            try {
                httpclient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }  
 
    /**
     * 上传文件
     */
    public void upload() {
        CloseableHttpClient httpclient = HttpClients.createDefault();
        try {
            HttpPost httppost = new HttpPost("http://localhost:8080/myDemo/Ajax/serivceFile.action");  
 
            FileBody bin = new FileBody(new File("F:\\image\\sendpix0.jpg"));
            StringBody comment = new StringBody("A binary file of some kind", ContentType.TEXT_PLAIN);  
 
            HttpEntity reqEntity = MultipartEntityBuilder.create().addPart("bin", bin).addPart("comment", comment).build();  
 
            httppost.setEntity(reqEntity);  
 
            System.out.println("executing request " + httppost.getRequestLine());
            CloseableHttpResponse response = httpclient.execute(httppost);
            try {
                System.out.println("----------------------------------------");
                System.out.println(response.getStatusLine());
                HttpEntity resEntity = response.getEntity();
                if (resEntity != null) {
                    System.out.println("Response content length: " + resEntity.getContentLength());
                }
                EntityUtils.consume(resEntity);
            } finally {
                response.close();
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                httpclient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

五、实例(开发用到工具类实例)

package com.fh.util.http;
 
import java.io.File;
import java.io.IOException;
import java.net.URISyntaxException;
import java.nio.charset.Charset;
import java.security.cert.CertificateException;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
 
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLHandshakeException;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
 
import org.apache.http.HttpEntity;
import org.apache.http.HttpEntityEnclosingRequest;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.NoHttpResponseException;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpRequestRetryHandler;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.params.ClientPNames;
import org.apache.http.client.params.CookiePolicy;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.conn.params.ConnRoutePNames;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.ssl.SSLSocketFactory;
import org.apache.http.entity.StringEntity;
import org.apache.http.entity.mime.MultipartEntity;
import org.apache.http.entity.mime.content.ByteArrayBody;
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.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.params.CoreProtocolPNames;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpContext;
import org.apache.http.util.EntityUtils;
 
import net.sf.json.JSONObject;
 
/**
 * @className:HttpClientUtil.java
 * @classDescription:HttpClient工具类//待完善模拟登录，cookie,证书登录
 * @author:xiayingjie
 * @createTime:2011-8-31
 */
 
public class HttpClientUtilMy {
 
    public static String CHARSET_ENCODING = "UTF-8";
    // private static String
    // USER_AGENT="Mozilla/4.0 (compatible; MSIE 6.0; Win32)";//ie6
    public static String USER_AGENT = "Mozilla/4.0 (compatible; MSIE 7.0; Win32)";// ie7
 
    // private static String
    // USER_AGENT="Mozilla/4.0 (compatible; MSIE 8.0; Win32)";//ie8
 
    /**
     * 获取DefaultHttpClient对象
     *
     * @param charset
     *            字符编码
     * @return DefaultHttpClient对象
     */
    private static DefaultHttpClient getDefaultHttpClient(final String charset) {
        DefaultHttpClient httpclient = new DefaultHttpClient();
        // 模拟浏览器，解决一些服务器程序只允许浏览器访问的问题
        httpclient.getParams().setParameter(CoreProtocolPNames.USER_AGENT, USER_AGENT);
        httpclient.getParams().setParameter(CoreProtocolPNames.USE_EXPECT_CONTINUE, Boolean.FALSE);
        httpclient.getParams().setParameter(CoreProtocolPNames.HTTP_CONTENT_CHARSET,
                charset == null ? CHARSET_ENCODING : charset);
 
        // 浏览器兼容性
        httpclient.getParams().setParameter(ClientPNames.COOKIE_POLICY, CookiePolicy.BROWSER_COMPATIBILITY);
        // 定义重试策略
        httpclient.setHttpRequestRetryHandler(requestRetryHandler);
 
        return httpclient;
    }
 
    /**
     * 访问https的网站
     *
     * @param httpclient
     */
    private static void enableSSL(DefaultHttpClient httpclient) {
        // 调用ssl
        try {
            SSLContext sslcontext = SSLContext.getInstance("TLS");
            sslcontext.init(null, new TrustManager[] { truseAllManager }, null);
            SSLSocketFactory sf = new SSLSocketFactory(sslcontext);
            sf.setHostnameVerifier(SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);
            Scheme https = new Scheme("https", sf, 443);
            httpclient.getConnectionManager().getSchemeRegistry().register(https);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
 
    /**
     * 重写验证方法，取消检测ssl
     */
    private static TrustManager truseAllManager = new X509TrustManager() {
 
        public void checkClientTrusted(java.security.cert.X509Certificate[] arg0, String arg1)
                throws CertificateException {
            // TODO Auto-generated method stub
 
        }
 
        public void checkServerTrusted(java.security.cert.X509Certificate[] arg0, String arg1)
                throws CertificateException {
            // TODO Auto-generated method stub
 
        }
 
        public java.security.cert.X509Certificate[] getAcceptedIssuers() {
            // TODO Auto-generated method stub
            return null;
        }
 
    };
 
    /**
     * 异常自动恢复处理, 使用HttpRequestRetryHandler接口实现请求的异常恢复
     */
    private static HttpRequestRetryHandler requestRetryHandler = new HttpRequestRetryHandler() {
        // 自定义的恢复策略
        public boolean retryRequest(IOException exception, int executionCount, HttpContext context) {
            // 设置恢复策略，在发生异常时候将自动重试3次
            if (executionCount >= 3) {
                // 如果连接次数超过了最大值则停止重试
                return false;
            }
            if (exception instanceof NoHttpResponseException) {
                // 如果服务器连接失败重试
                return true;
            }
            if (exception instanceof SSLHandshakeException) {
                // 不要重试ssl连接异常
                return false;
            }
            HttpRequest request = (HttpRequest) context.getAttribute(ExecutionContext.HTTP_REQUEST);
            boolean idempotent = (request instanceof HttpEntityEnclosingRequest);
            if (!idempotent) {
                // 重试，如果请求是考虑幂等
                return true;
            }
            return false;
        }
    };
 
    /**
     * 使用ResponseHandler接口处理响应，HttpClient使用ResponseHandler会自动管理连接的释放，解决了对连接的释放管理
     */
    private static ResponseHandler<String> responseHandler = new ResponseHandler<String>() {
        // 自定义响应处理
        public String handleResponse(HttpResponse response) throws ClientProtocolException, IOException {
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                String charset = EntityUtils.getContentCharSet(entity) == null ? CHARSET_ENCODING
                        : EntityUtils.getContentCharSet(entity);
                return new String(EntityUtils.toByteArray(entity), charset);
            } else {
                return null;
            }
        }
    };
 
    /**
     * 使用post方法获取相关的数据
     *
     * @param url
     * @param paramsList
     * @return
     */
    public static String post(String url, List<NameValuePair> paramsList) {
        return httpRequest(url, paramsList, "POST", null);
    }
 
    /**
     * 使用post方法并且通过代理获取相关的数据
     *
     * @param url
     * @param paramsList
     * @param proxy
     * @return
     */
    public static String post(String url, List<NameValuePair> paramsList, HttpHost proxy) {
        return httpRequest(url, paramsList, "POST", proxy);
    }
 
    /**
     * 使用get方法获取相关的数据
     *
     * @param url
     * @param paramsList
     * @return
     */
    public static String get(String url, List<NameValuePair> paramsList) {
        return httpRequest(url, paramsList, "GET", null);
    }
 
    /**
     * 使用get方法并且通过代理获取相关的数据
     *
     * @param url
     * @param paramsList
     * @param proxy
     * @return
     */
    public static String get(String url, List<NameValuePair> paramsList, HttpHost proxy) {
        return httpRequest(url, paramsList, "GET", proxy);
    }
 
    /**
     * 提交数据到服务器
     *
     * @param url
     * @param params
     * @param authenticated
     * @throws IOException
     * @throws ClientProtocolException
     */
    public static String httpRequest(String url, List<NameValuePair> paramsList, String method, HttpHost proxy) {
        String responseStr = null;
        // 判断输入的值是是否为空
        if (null == url || "".equals(url)) {
            return null;
        }
 
        // 创建HttpClient实例
        DefaultHttpClient httpclient = getDefaultHttpClient(CHARSET_ENCODING);
 
        // 判断是否是https请求
        if (url.startsWith("https")) {
            enableSSL(httpclient);
        }
        String formatParams = null;
        // 将参数进行utf-8编码
        if (null != paramsList && paramsList.size() > 0) {
            formatParams = URLEncodedUtils.format(paramsList, CHARSET_ENCODING);
        }
        // 如果代理对象不为空则设置代理
        if (null != proxy) {
            httpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy);
        }
        try {
            // 如果方法为Get
            if ("GET".equalsIgnoreCase(method)) {
                if (formatParams != null) {
                    url = (url.indexOf("?")) < 0 ? (url + "?" + formatParams)
                            : (url.substring(0, url.indexOf("?") + 1) + formatParams);
                }
                HttpGet hg = new HttpGet(url);
                responseStr = httpclient.execute(hg, responseHandler);
 
                // 如果方法为Post
            } else if ("POST".equalsIgnoreCase(method)) {
                HttpPost hp = new HttpPost(url);
                if (formatParams != null) {
                    StringEntity entity = new StringEntity(formatParams);
                    entity.setContentType("application/x-www-form-urlencoded");
                    hp.setEntity(entity);
                }
                responseStr = httpclient.execute(hp, responseHandler);
 
            }
 
        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return responseStr;
    }
 
    /**
     * 提交数据到服务器
     *
     * @param url
     * @param params
     * @param authenticated
     * @throws IOException
     * @throws ClientProtocolException
     */
    public static String httpFileRequest(String url, Map<String, String> fileMap, Map<String, String> stringMap,
            int type, HttpHost proxy) {
        String responseStr = null;
        // 判断输入的值是是否为空
        if (null == url || "".equals(url)) {
            return null;
        }
        // 创建HttpClient实例
        DefaultHttpClient httpclient = getDefaultHttpClient(CHARSET_ENCODING);
 
        // 判断是否是https请求
        if (url.startsWith("https")) {
            enableSSL(httpclient);
        }
 
        // 如果代理对象不为空则设置代理
        if (null != proxy) {
            httpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy);
        }
        // 发送文件
        HttpPost hp = new HttpPost(url);
        MultipartEntity multiEntity = new MultipartEntity();
        try {
            // type=0是本地路径，否则是网络路径
            if (type == 0) {
                for (String key : fileMap.keySet()) {
                    multiEntity.addPart(key, new FileBody(new File(fileMap.get(key))));
                }
            } else {
                for (String key : fileMap.keySet()) {
                    multiEntity.addPart(key, new ByteArrayBody(getUrlFileBytes(fileMap.get(key)), key));
                }
            }
            // 加入相关参数 默认编码为utf-8
            for (String key : stringMap.keySet()) {
                multiEntity.addPart(key, new StringBody(stringMap.get(key), Charset.forName(CHARSET_ENCODING)));
            }
            hp.setEntity(multiEntity);
            responseStr = httpclient.execute(hp, responseHandler);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return responseStr;
    }
 
    /**
     * 将相关文件和参数提交到相关服务器
     *
     * @param url
     * @param fileMap
     * @param StringMap
     * @return
     */
    public static String postFile(String url, Map<String, String> fileMap, Map<String, String> stringMap) {
        return httpFileRequest(url, fileMap, stringMap, 0, null);
    }
 
    /**
     * 将相关文件和参数提交到相关服务器
     *
     * @param url
     * @param fileMap
     * @param StringMap
     * @return
     */
    public static String postUrlFile(String url, Map<String, String> urlMap, Map<String, String> stringMap) {
        return httpFileRequest(url, urlMap, stringMap, 1, null);
    }
 
    /**
     * 获取网络文件的字节数组
     *
     * @param url
     * @return
     * @throws IOException
     * @throws ClientProtocolException
     * @throws ClientProtocolException
     * @throws IOException
     */
    public static byte[] getUrlFileBytes(String url) throws ClientProtocolException, IOException {
 
        byte[] bytes = null;
        // 创建HttpClient实例
        CloseableHttpClient httpclient = getDefaultHttpClient(CHARSET_ENCODING);
        // 获取url里面的信息
        HttpGet hg = new HttpGet(url);
        HttpResponse hr = httpclient.execute(hg);
        bytes = EntityUtils.toByteArray(hr.getEntity());
        // 转换内容为字节
        return bytes;
    }
 
    /**
     * 获取图片的字节数组
     *
     * @createTime 2011-11-24
     * @param url
     * @return
     * @throws IOException
     * @throws ClientProtocolException
     * @throws ClientProtocolException
     * @throws IOException
     */
    public static byte[] getImg(String url) throws ClientProtocolException, IOException {
        byte[] bytes = null;
        // 创建HttpClient实例
        DefaultHttpClient httpclient = getDefaultHttpClient(CHARSET_ENCODING);
        // 获取url里面的信息
        HttpGet hg = new HttpGet(url);
        HttpResponse hr = httpclient.execute(hg);
        bytes = EntityUtils.toByteArray(hr.getEntity());
        // 转换内容为字节
        return bytes;
    }
 
    /**
     * @Description 请求微吼接口
     * @author 张洋
     * @date 2017年8月12日 上午11:19:44
     * @param method
     *            方法名 样式:{资源名}/{函数名}
     * @param params 条件参数
     * @return
     */
    public static JSONObject getVhallUrlByPost(String method, Map<String,String> param) {
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        //封装请求参数
        for (Entry<String, String> entry : param.entrySet()) {
            params.add(new BasicNameValuePair(entry.getKey(), (String) entry.getValue()));
        }
        // 访问接口地址
        Object[] parameter = new Object[4];
        parameter[0] = method;
        String url = MessageFormat.format("http://e.vhall.com/api/vhallapi/v2/{0}", parameter);
        // String url = MessageFormat.format("http:loaclhost/{0}", parameter);
        // 参数
        // List<NameValuePair> params = new ArrayList<NameValuePair>();
        // 添加公共参数
        params.add(new BasicNameValuePair("auth_type", "1"));
        params.add(new BasicNameValuePair("account", "v19462836"));
        params.add(new BasicNameValuePair("password", "12345678"));
        String str = HttpClientUtilMy.post(url, params);
        JSONObject jsonData = JSONObject.fromObject(str);
        System.out.println("code:" + jsonData.get("code"));
        System.out.println("info:" + jsonData.get("msg"));
        System.out.println(jsonData.toString());
        return jsonData;
 
    }
 
}