Java通过HttpClient发送HTTP请求办法

Java|java教程 本篇文章主要介绍了JAVA通过HttpClient发送HTTP请求的方法示例，详细的介绍了HttpClient使用，具有一定的参考价值，有兴趣的可以了解一下HttpClient介绍HttpClient 不是一个浏览器。它是一个客户端的 HTTP 通信实现库。HttpClient的目标是发 送和接收HTTP 报文。HttpClient不会去缓存内容，执行 嵌入在 HTML 页面中的javascript 代码，猜测内容类型，重新格式化请求/重定向URI，或者其它和 HTTP 运输无关的功能。HttpClient使用

使用需要引入jar包，maven项目引入如下：

      org.apache.httpcomponents      httpclient      4.5              org.apache.httpcomponents      httpcore      4.4.4              org.apache.httpcomponents      httpmime      4.5    

使用方法，代码如下：　

package com.test;import java.io.File;import java.io.IOException;import java.security.KeyManagementException;import java.security.KeyStoreException;import java.security.NoSuchAlgorithmException;import java.util.Iterator;import java.util.List;import java.util.Map;import org.apache.http.HttpEntity;import org.apache.http.HttpStatus;import org.apache.http.client.config.RequestConfig;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.config.Registry;import org.apache.http.config.RegistryBuilder;import org.apache.http.conn.socket.ConnectionSocketFactory;import org.apache.http.conn.socket.PlainConnectionSocketFactory;import org.apache.http.conn.ssl.SSLConnectionSocketFactory;import org.apache.http.conn.ssl.SSLContextBuilder;import org.apache.http.conn.ssl.TrustSelfSignedStrategy;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.DefaultHttpRequestRetryHandler;import org.apache.http.impl.client.HttpClients;import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;import org.apache.http.util.EntityUtils;/** *  * @author H__D * @date 2016年10月19日 上午11:27:25 * */public class HttpClientUtil {  // utf-8字符编码  public static final String CHARSET_UTF_8 = "utf-8";  // HTTP内容类型。  public static final String CONTENT_TYPE_TEXT_HTML = "text/xml";  // HTTP内容类型。相当于form表单的形式，提交数据  public static final String CONTENT_TYPE_FORM_URL = "application/x-www-form-urlencoded";  // HTTP内容类型。相当于form表单的形式，提交数据  public static final String CONTENT_TYPE_JSON_URL = "application/json;charset=utf-8";    // 连接管理器  private static PoolingHttpClientConnectionManager pool;  // 请求配置  private static RequestConfig requestConfig;  static {        try {      //System.out.println("初始化HttpClientTest~~~开始");      SSLContextBuilder builder = new SSLContextBuilder();      builder.loadTrustMaterial(null, new TrustSelfSignedStrategy());      SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(          builder.build());      // 配置同时支持 HTTP 和 HTPPS      Registry socketFactoryRegistry = RegistryBuilder. create().register(          "http", PlainConnectionSocketFactory.getSocketFactory()).register(          "https", sslsf).build();      // 初始化连接管理器      pool = new PoolingHttpClientConnectionManager(          socketFactoryRegistry);      // 将最大连接数增加到200，实际项目最好从配置文件中读取这个值      pool.setMaxTotal(200);      // 设置最大路由      pool.setDefaultMaxPerRoute(2);      // 根据默认超时限制初始化requestConfig      int socketTimeout = 10000;      int connectTimeout = 10000;      int connectionRequestTimeout = 10000;      requestConfig = RequestConfig.custom().setConnectionRequestTimeout(          connectionRequestTimeout).setSocketTimeout(socketTimeout).setConnectTimeout(          connectTimeout).build();      //System.out.println("初始化HttpClientTest~~~结束");    } catch (NoSuchAlgorithmException e) {      e.printStackTrace();    } catch (KeyStoreException e) {      e.printStackTrace();    } catch (KeyManagementException e) {      e.printStackTrace();    }        // 设置请求超时时间    requestConfig = RequestConfig.custom().setSocketTimeout(50000).setConnectTimeout(50000)        .setConnectionRequestTimeout(50000).build();  }  public static CloseableHttpClient getHttpClient() {        CloseableHttpClient httpClient = HttpClients.custom()        // 设置连接池管理        .setConnectionManager(pool)        // 设置请求配置        .setDefaultRequestConfig(requestConfig)        // 设置重试次数        .setRetryHandler(new DefaultHttpRequestRetryHandler(0, false))        .build();        return httpClient;  }  /**   * 发送Post请求   *    * @param httpPost   * @return   */  private static String sendHttpPost(HttpPost httpPost) {    CloseableHttpClient httpClient = null;    CloseableHttpResponse response = null;    // 响应内容    String responseContent = null;    try {      // 创建默认的httpClient实例.      httpClient = getHttpClient();      // 配置请求信息      httpPost.setConfig(requestConfig);      // 执行请求      response = httpClient.execute(httpPost);      // 得到响应实例      HttpEntity entity = response.getEntity();      // 可以获得响应头      // Header[] headers = response.getHeaders(HttpHeaders.CONTENT_TYPE);      // for (Header header : headers) {      // System.out.println(header.getName());      // }      // 得到响应类型      // System.out.println(ContentType.getOrDefault(response.getEntity()).getMimeType());      // 判断响应状态      if (response.getStatusLine().getStatusCode() >= 300) {        throw new Exception(            "HTTP Request is not success, Response code is " + response.getStatusLine().getStatusCode());      }      if (HttpStatus.SC_OK == response.getStatusLine().getStatusCode()) {        responseContent = EntityUtils.toString(entity, CHARSET_UTF_8);        EntityUtils.consume(entity);      }    } catch (Exception e) {      e.printStackTrace();    } finally {      try {        // 释放资源        if (response != null) {          response.close();        }      } catch (IOException e) {        e.printStackTrace();      }    }    return responseContent;  }  /**   * 发送Get请求   *    * @param httpGet   * @return   */  private static String sendHttpGet(HttpGet httpGet) {    CloseableHttpClient httpClient = null;    CloseableHttpResponse response = null;    // 响应内容    String responseContent = null;    try {      // 创建默认的httpClient实例.      httpClient = getHttpClient();      // 配置请求信息      httpGet.setConfig(requestConfig);      // 执行请求      response = httpClient.execute(httpGet);      // 得到响应实例      HttpEntity entity = response.getEntity();      // 可以获得响应头      // Header[] headers = response.getHeaders(HttpHeaders.CONTENT_TYPE);      // for (Header header : headers) {      // System.out.println(header.getName());      // }      // 得到响应类型      // System.out.println(ContentType.getOrDefault(response.getEntity()).getMimeType());      // 判断响应状态      if (response.getStatusLine().getStatusCode() >= 300) {        throw new Exception(            "HTTP Request is not success, Response code is " + response.getStatusLine().getStatusCode());      }      if (HttpStatus.SC_OK == response.getStatusLine().getStatusCode()) {        responseContent = EntityUtils.toString(entity, CHARSET_UTF_8);        EntityUtils.consume(entity);      }    } catch (Exception e) {      e.printStackTrace();    } finally {      try {        // 释放资源        if (response != null) {          response.close();        }      } catch (IOException e) {        e.printStackTrace();      }    }    return responseContent;  }        /**   * 发送 post请求   *    * @param httpUrl   *      地址   */  public static String sendHttpPost(String httpUrl) {    // 创建httpPost    HttpPost httpPost = new HttpPost(httpUrl);    return sendHttpPost(httpPost);  }  /**   * 发送 get请求   *    * @param httpUrl   */  public static String sendHttpGet(String httpUrl) {    // 创建get请求    HttpGet httpGet = new HttpGet(httpUrl);    return sendHttpGet(httpGet);  }      /**   * 发送 post请求（带文件）   *    * @param httpUrl   *      地址   * @param maps   *      参数   * @param fileLists   *      附件   */  public static String sendHttpPost(String httpUrl, Map maps, List fileLists) {    HttpPost httpPost = new HttpPost(httpUrl);// 创建httpPost    MultipartEntityBuilder meBuilder = MultipartEntityBuilder.create();    if (maps != null) {      for (String key : maps.keySet()) {        meBuilder.addPart(key, new StringBody(maps.get(key), ContentType.TEXT_PLAIN));      }    }    if (fileLists != null) {      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 httpUrl   *      地址   * @param params   *      参数(格式:key1=value1&key2=value2)   *    */  public static String sendHttpPost(String httpUrl, String params) {    HttpPost httpPost = new HttpPost(httpUrl);// 创建httpPost    try {      // 设置参数      if (params != null && params.trim().length() > 0) {        StringEntity stringEntity = new StringEntity(params, "UTF-8");        stringEntity.setContentType(CONTENT_TYPE_FORM_URL);        httpPost.setEntity(stringEntity);      }    } catch (Exception e) {      e.printStackTrace();    }    return sendHttpPost(httpPost);  }  /**   * 发送 post请求   *    * @param maps   *      参数   */  public static String sendHttpPost(String httpUrl, Map maps) {    String parem = convertStringParamter(maps);    return sendHttpPost(httpUrl, parem);  }        /**   * 发送 post请求 发送json数据   *    * @param httpUrl   *      地址   * @param paramsJson   *      参数(格式 json)   *    */  public static String sendHttpPostJson(String httpUrl, String paramsJson) {    HttpPost httpPost = new HttpPost(httpUrl);// 创建httpPost    try {      // 设置参数      if (paramsJson != null && paramsJson.trim().length() > 0) {        StringEntity stringEntity = new StringEntity(paramsJson, "UTF-8");        stringEntity.setContentType(CONTENT_TYPE_JSON_URL);        httpPost.setEntity(stringEntity);      }    } catch (Exception e) {      e.printStackTrace();    }    return sendHttpPost(httpPost);  }    /**   * 发送 post请求 发送xml数据   *    * @param httpUrl  地址   * @param paramsXml 参数(格式 Xml)   *    */  public static String sendHttpPostXml(String httpUrl, String paramsXml) {    HttpPost httpPost = new HttpPost(httpUrl);// 创建httpPost    try {      // 设置参数      if (paramsXml != null && paramsXml.trim().length() > 0) {        StringEntity stringEntity = new StringEntity(paramsXml, "UTF-8");        stringEntity.setContentType(CONTENT_TYPE_TEXT_HTML);        httpPost.setEntity(stringEntity);      }    } catch (Exception e) {      e.printStackTrace();    }    return sendHttpPost(httpPost);  }    /**   * 将map集合的键值对转化成：key1=value1&key2=value2 的形式   *    * @param parameterMap   *      需要转化的键值对集合   * @return 字符串   */  public static String convertStringParamter(Map parameterMap) {    StringBuffer parameterBuffer = new StringBuffer();    if (parameterMap != null) {      Iterator iterator = parameterMap.keySet().iterator();      String key = null;      String value = null;      while (iterator.hasNext()) {        key = (String) iterator.next();        if (parameterMap.get(key) != null) {          value = (String) parameterMap.get(key);        } else {          value = "";        }        parameterBuffer.append(key).append("=").append(value);        if (iterator.hasNext()) {          parameterBuffer.append("&");        }      }    }    return parameterBuffer.toString();  }  public static void main(String[] args) throws Exception {        System.out.println(sendHttpGet("http://www.baidu.com"));    }}