详解java实现HTTP请求的三种方式

package com.powerX.httpClient;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStream;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;public class HttpClient {  public static String doGet(String httpurl) {    HttpURLConnection connection = null;    InputStream is = null;    BufferedReader br = null;    String result = null;// 返回结果字符串    try {      // 创建远程url连接对象      URL url = new URL(httpurl);      // 通过远程url连接对象打开一个连接，强转成httpURLConnection类      connection = (HttpURLConnection) url.openConnection();      // 设置连接方式：get      connection.setRequestMethod("GET");      // 设置连接主机服务器的超时时间：15000毫秒      connection.setConnectTimeout(15000);      // 设置读取远程返回的数据时间：60000毫秒      connection.setReadTimeout(60000);      // 发送请求      connection.connect();      // 通过connection连接，获取输入流      if (connection.getResponseCode() == 200) {        is = connection.getInputStream();        // 封装输入流is，并指定字符集        br = new BufferedReader(new InputStreamReader(is, "UTF-8"));        // 存放数据        StringBuffer sbf = new StringBuffer();        String temp = null;        while ((temp = br.readLine()) != null) {          sbf.append(temp);          sbf.append("/r/n");        }        result = sbf.toString();      }    } catch (MalformedURLException e) {      e.printStackTrace();    } catch (IOException e) {      e.printStackTrace();    } finally {      // 关闭资源      if (null != br) {        try {          br.close();        } catch (IOException e) {          e.printStackTrace();        }      }      if (null != is) {        try {          is.close();        } catch (IOException e) {          e.printStackTrace();        }      }      connection.disconnect();// 关闭远程连接    }    return result;  }  public static String doPost(String httpUrl, String param) {    HttpURLConnection connection = null;    InputStream is = null;    OutputStream os = null;    BufferedReader br = null;    String result = null;    try {      URL url = new URL(httpUrl);      // 通过远程url连接对象打开连接      connection = (HttpURLConnection) url.openConnection();      // 设置连接请求方式      connection.setRequestMethod("POST");      // 设置连接主机服务器超时时间：15000毫秒      connection.setConnectTimeout(15000);      // 设置读取主机服务器返回数据超时时间：60000毫秒      connection.setReadTimeout(60000);      // 默认值为：false，当向远程服务器传送数据/写数据时，需要设置为true      connection.setDoOutput(true);      // 默认值为：true，当前向远程服务读取数据时，设置为true，该参数可有可无      connection.setDoInput(true);      // 设置传入参数的格式:请求参数应该是 name1=value1&name2=value2 的形式。      connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");      // 设置鉴权信息：Authorization: Bearer da3efcbf-0845-4fe3-8aba-ee040be542c0      connection.setRequestProperty("Authorization", "Bearer da3efcbf-0845-4fe3-8aba-ee040be542c0");      // 通过连接对象获取一个输出流      os = connection.getOutputStream();      // 通过输出流对象将参数写出去/传输出去,它是通过字节数组写出的      os.write(param.getBytes());      // 通过连接对象获取一个输入流，向远程读取      if (connection.getResponseCode() == 200) {        is = connection.getInputStream();        // 对输入流对象进行包装:charset根据工作项目组的要求来设置        br = new BufferedReader(new InputStreamReader(is, "UTF-8"));        StringBuffer sbf = new StringBuffer();        String temp = null;        // 循环遍历一行一行读取数据        while ((temp = br.readLine()) != null) {          sbf.append(temp);          sbf.append("/r/n");        }        result = sbf.toString();      }    } catch (MalformedURLException e) {      e.printStackTrace();    } catch (IOException e) {      e.printStackTrace();    } finally {      // 关闭资源      if (null != br) {        try {          br.close();        } catch (IOException e) {          e.printStackTrace();        }      }      if (null != os) {        try {          os.close();        } catch (IOException e) {          e.printStackTrace();        }      }      if (null != is) {        try {          is.close();        } catch (IOException e) {          e.printStackTrace();        }      }      // 断开与远程地址url的连接      connection.disconnect();    }    return result;  }}

package com.powerX.httpClient;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.UnsupportedEncodingException;import java.util.Iterator;import java.util.Map;import java.util.Map.Entry;import java.util.Set;import org.apache.commons.httpclient.DefaultHttpMethodRetryHandler;import org.apache.commons.httpclient.HttpClient;import org.apache.commons.httpclient.HttpStatus;import org.apache.commons.httpclient.NameValuePair;import org.apache.commons.httpclient.methods.GetMethod;import org.apache.commons.httpclient.methods.PostMethod;import org.apache.commons.httpclient.params.HttpMethodParams;public class HttpClient3 {  public static String doGet(String url) {    // 输入流    InputStream is = null;    BufferedReader br = null;    String result = null;    // 创建httpClient实例    HttpClient httpClient = new HttpClient();    // 设置http连接主机服务超时时间：15000毫秒    // 先获取连接管理器对象，再获取参数对象,再进行参数的赋值    httpClient.getHttpConnectionManager().getParams().setConnectionTimeout(15000);    // 创建一个Get方法实例对象    GetMethod getMethod = new GetMethod(url);    // 设置get请求超时为60000毫秒    getMethod.getParams().setParameter(HttpMethodParams.SO_TIMEOUT, 60000);    // 设置请求重试机制，默认重试次数：3次，参数设置为true，重试机制可用，false相反    getMethod.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, new DefaultHttpMethodRetryHandler(3, true));    try {      // 执行Get方法      int statusCode = httpClient.executeMethod(getMethod);      // 判断返回码      if (statusCode != HttpStatus.SC_OK) {        // 如果状态码返回的不是ok,说明失败了,打印错误信息        System.err.println("Method faild: " + getMethod.getStatusLine());      } else {        // 通过getMethod实例，获取远程的一个输入流        is = getMethod.getResponseBodyAsStream();        // 包装输入流        br = new BufferedReader(new InputStreamReader(is, "UTF-8"));        StringBuffer sbf = new StringBuffer();        // 读取封装的输入流        String temp = null;        while ((temp = br.readLine()) != null) {          sbf.append(temp).append("/r/n");        }        result = sbf.toString();      }    } catch (IOException e) {      e.printStackTrace();    } finally {      // 关闭资源      if (null != br) {        try {          br.close();        } catch (IOException e) {          e.printStackTrace();        }      }      if (null != is) {        try {          is.close();        } catch (IOException e) {          e.printStackTrace();        }      }      // 释放连接      getMethod.releaseConnection();    }    return result;  }  public static String doPost(String url, Map<String, Object> paramMap) {    // 获取输入流    InputStream is = null;    BufferedReader br = null;    String result = null;    // 创建httpClient实例对象    HttpClient httpClient = new HttpClient();    // 设置httpClient连接主机服务器超时时间：15000毫秒    httpClient.getHttpConnectionManager().getParams().setConnectionTimeout(15000);    // 创建post请求方法实例对象    PostMethod postMethod = new PostMethod(url);    // 设置post请求超时时间    postMethod.getParams().setParameter(HttpMethodParams.SO_TIMEOUT, 60000);    NameValuePair[] nvp = null;    // 判断参数map集合paramMap是否为空    if (null != paramMap && paramMap.size() > 0) {// 不为空      // 创建键值参数对象数组，大小为参数的个数      nvp = new NameValuePair[paramMap.size()];      // 循环遍历参数集合map      Set<Entry<String, Object>> entrySet = paramMap.entrySet();      // 获取迭代器      Iterator<Entry<String, Object>> iterator = entrySet.iterator();      int index = 0;      while (iterator.hasNext()) {        Entry<String, Object> mapEntry = iterator.next();        // 从mapEntry中获取key和value创建键值对象存放到数组中        try {          nvp[index] = new NameValuePair(mapEntry.getKey(),              new String(mapEntry.getValue().toString().getBytes("UTF-8"), "UTF-8"));        } catch (UnsupportedEncodingException e) {          e.printStackTrace();        }        index++;      }    }    // 判断nvp数组是否为空    if (null != nvp && nvp.length > 0) {      // 将参数存放到requestBody对象中      postMethod.setRequestBody(nvp);    }    // 执行POST方法    try {      int statusCode = httpClient.executeMethod(postMethod);      // 判断是否成功      if (statusCode != HttpStatus.SC_OK) {        System.err.println("Method faild: " + postMethod.getStatusLine());      }      // 获取远程返回的数据      is = postMethod.getResponseBodyAsStream();      // 封装输入流      br = new BufferedReader(new InputStreamReader(is, "UTF-8"));      StringBuffer sbf = new StringBuffer();      String temp = null;      while ((temp = br.readLine()) != null) {        sbf.append(temp).append("/r/n");      }      result = sbf.toString();    } catch (IOException e) {      e.printStackTrace();    } finally {      // 关闭资源      if (null != br) {        try {          br.close();        } catch (IOException e) {          e.printStackTrace();        }      }      if (null != is) {        try {          is.close();        } catch (IOException e) {          e.printStackTrace();        }      }      // 释放连接      postMethod.releaseConnection();    }    return result;  }}

package com.powerX.httpClient;import java.io.IOException;import java.io.UnsupportedEncodingException;import java.util.ArrayList;import java.util.Iterator;import java.util.List;import java.util.Map;import java.util.Map.Entry;import java.util.Set;import org.apache.http.HttpEntity;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.impl.client.CloseableHttpClient;import org.apache.http.impl.client.HttpClients;import org.apache.http.message.BasicNameValuePair;import org.apache.http.util.EntityUtils;public class HttpClient4 {  public static String doGet(String url) {    CloseableHttpClient httpClient = null;    CloseableHttpResponse response = null;    String result = "";    try {      // 通过址默认配置创建一个httpClient实例      httpClient = HttpClients.createDefault();      // 创建httpGet远程连接实例      HttpGet httpGet = new HttpGet(url);      // 设置请求头信息，鉴权      httpGet.setHeader("Authorization", "Bearer da3efcbf-0845-4fe3-8aba-ee040be542c0");      // 设置配置请求参数      RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(35000)// 连接主机服务超时时间          .setConnectionRequestTimeout(35000)// 请求超时时间          .setSocketTimeout(60000)// 数据读取超时时间          .build();      // 为httpGet实例设置配置      httpGet.setConfig(requestConfig);      // 执行get请求得到返回对象      response = httpClient.execute(httpGet);      // 通过返回对象获取返回数据      HttpEntity entity = response.getEntity();      // 通过EntityUtils中的toString方法将结果转换为字符串      result = EntityUtils.toString(entity);    } catch (ClientProtocolException e) {      e.printStackTrace();    } catch (IOException e) {      e.printStackTrace();    } finally {      // 关闭资源      if (null != response) {        try {          response.close();        } catch (IOException e) {          e.printStackTrace();        }      }      if (null != httpClient) {        try {          httpClient.close();        } catch (IOException e) {          e.printStackTrace();        }      }    }    return result;  }  public static String doPost(String url, Map<String, Object> paramMap) {    CloseableHttpClient httpClient = null;    CloseableHttpResponse httpResponse = null;    String result = "";    // 创建httpClient实例    httpClient = HttpClients.createDefault();    // 创建httpPost远程连接实例    HttpPost httpPost = new HttpPost(url);    // 配置请求参数实例    RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(35000)// 设置连接主机服务超时时间        .setConnectionRequestTimeout(35000)// 设置连接请求超时时间        .setSocketTimeout(60000)// 设置读取数据连接超时时间        .build();    // 为httpPost实例设置配置    httpPost.setConfig(requestConfig);    // 设置请求头    httpPost.addHeader("Content-Type", "application/x-www-form-urlencoded");    // 封装post请求参数    if (null != paramMap && paramMap.size() > 0) {      List<NameValuePair> nvps = new ArrayList<NameValuePair>();      // 通过map集成entrySet方法获取entity      Set<Entry<String, Object>> entrySet = paramMap.entrySet();      // 循环遍历，获取迭代器      Iterator<Entry<String, Object>> iterator = entrySet.iterator();      while (iterator.hasNext()) {        Entry<String, Object> mapEntry = iterator.next();        nvps.add(new BasicNameValuePair(mapEntry.getKey(), mapEntry.getValue().toString()));      }      // 为httpPost设置封装好的请求参数      try {        httpPost.setEntity(new UrlEncodedFormEntity(nvps, "UTF-8"));      } catch (UnsupportedEncodingException e) {        e.printStackTrace();      }    }    try {      // httpClient对象执行post请求,并返回响应参数对象      httpResponse = httpClient.execute(httpPost);      // 从响应对象中获取响应内容      HttpEntity entity = httpResponse.getEntity();      result = EntityUtils.toString(entity);    } catch (ClientProtocolException e) {      e.printStackTrace();    } catch (IOException e) {      e.printStackTrace();    } finally {      // 关闭资源      if (null != httpResponse) {        try {          httpResponse.close();        } catch (IOException e) {          e.printStackTrace();        }      }      if (null != httpClient) {        try {          httpClient.close();        } catch (IOException e) {          e.printStackTrace();        }      }    }    return result;  }}