JAVA发送http get/post请求，调用http接口、方法

三个例子 —JAVA发送http get/post请求，调用http接口、方法

例1：使用 HttpClient （commons-httpclient-3.0.jar
jar下载地址：http://download.csdn.net/download/capmiachael/9760550）

import java.io.ByteArrayInputStream;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.io.InputStream;import org.apache.commons.httpclient.HttpClient;import org.apache.commons.httpclient.methods.InputStreamRequestEntity;import org.apache.commons.httpclient.methods.PostMethod;import org.apache.commons.httpclient.methods.RequestEntity;public class HttpTool {    /**     * 发送post请求     *      * @author Michael -----CSDN: http://blog.csdn.net/capmiachael     * @param params     *            参数     * @param requestUrl     *            请求地址     * @param authorization     *            授权书     * @return 返回结果     * @throws IOException     */    public static String sendPost(String params, String requestUrl,            String authorization) throws IOException {        byte[] requestBytes = params.getBytes("utf-8"); // 将参数转为二进制流        HttpClient httpClient = new HttpClient();// 客户端实例化        PostMethod postMethod = new PostMethod(requestUrl);        //设置请求头Authorization        postMethod.setRequestHeader("Authorization", "Basic " + authorization);        // 设置请求头  Content-Type        postMethod.setRequestHeader("Content-Type", "application/json");        InputStream inputStream = new ByteArrayInputStream(requestBytes, 0,                requestBytes.length);        RequestEntity requestEntity = new InputStreamRequestEntity(inputStream,                requestBytes.length, "application/json; charset=utf-8"); // 请求体        postMethod.setRequestEntity(requestEntity);        httpClient.executeMethod(postMethod);// 执行请求        InputStream soapResponseStream = postMethod.getResponseBodyAsStream();// 获取返回的流        byte[] datas = null;        try {            datas = readInputStream(soapResponseStream);// 从输入流中读取数据        } catch (Exception e) {            e.printStackTrace();        }        String result = new String(datas, "UTF-8");// 将二进制流转为String        // 打印返回结果        // System.out.println(result);        return result;    }    /**     * 从输入流中读取数据     *      * @param inStream     * @return     * @throws Exception     */    public static byte[] readInputStream(InputStream inStream) throws Exception {        ByteArrayOutputStream outStream = new ByteArrayOutputStream();        byte[] buffer = new byte[1024];        int len = 0;        while ((len = inStream.read(buffer)) != -1) {            outStream.write(buffer, 0, len);        }        byte[] data = outStream.toByteArray();        outStream.close();        inStream.close();        return data;    }}

例2： 来源：开源中国 teardream http://www.oschina.net/code/snippet_2266157_45252

import java.io.BufferedReader;  import java.io.IOException;import java.io.InputStream;  import java.io.InputStreamReader;  import java.io.OutputStreamWriter;import java.io.UnsupportedEncodingException;  import java.net.HttpURLConnection;  import java.net.InetSocketAddress;import java.net.Proxy;import java.net.URL; import java.net.URLConnection;import java.util.List;import java.util.Map;/**  * Http请求工具类  * @author snowfigure  * @since 2014-8-24 13:30:56  * @version v1.0.1  */public class HttpRequestUtil {    static boolean proxySet = false;    static String proxyHost = "127.0.0.1";    static int proxyPort = 8087;    /**      * 编码      * @param source      * @return      */     public static String urlEncode(String source,String encode) {          String result = source;          try {              result = java.net.URLEncoder.encode(source,encode);          } catch (UnsupportedEncodingException e) {              e.printStackTrace();              return "0";          }          return result;      }    public static String urlEncodeGBK(String source) {          String result = source;          try {              result = java.net.URLEncoder.encode(source,"GBK");          } catch (UnsupportedEncodingException e) {              e.printStackTrace();              return "0";          }          return result;      }    /**      * 发起http请求获取返回结果      * @param req_url 请求地址      * @return      */     public static String httpRequest(String req_url) {        StringBuffer buffer = new StringBuffer();          try {              URL url = new URL(req_url);              HttpURLConnection httpUrlConn = (HttpURLConnection) url.openConnection();              httpUrlConn.setDoOutput(false);              httpUrlConn.setDoInput(true);              httpUrlConn.setUseCaches(false);              httpUrlConn.setRequestMethod("GET");              httpUrlConn.connect();              // 将返回的输入流转换成字符串              InputStream inputStream = httpUrlConn.getInputStream();              InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "utf-8");              BufferedReader bufferedReader = new BufferedReader(inputStreamReader);              String str = null;              while ((str = bufferedReader.readLine()) != null) {                  buffer.append(str);              }              bufferedReader.close();              inputStreamReader.close();              // 释放资源              inputStream.close();              inputStream = null;              httpUrlConn.disconnect();          } catch (Exception e) {              System.out.println(e.getStackTrace());          }          return buffer.toString();      }      /**      * 发送http请求取得返回的输入流      * @param requestUrl 请求地址      * @return InputStream      */     public static InputStream httpRequestIO(String requestUrl) {          InputStream inputStream = null;          try {              URL url = new URL(requestUrl);              HttpURLConnection httpUrlConn = (HttpURLConnection) url.openConnection();              httpUrlConn.setDoInput(true);              httpUrlConn.setRequestMethod("GET");              httpUrlConn.connect();              // 获得返回的输入流              inputStream = httpUrlConn.getInputStream();          } catch (Exception e) {              e.printStackTrace();          }          return inputStream;      }    /**     * 向指定URL发送GET方法的请求     *      * @param url     *            发送请求的URL     * @param param     *            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。     * @return URL 所代表远程资源的响应结果     */    public static String sendGet(String url, String param) {        String result = "";        BufferedReader in = null;        try {            String urlNameString = url + "?" + param;            URL realUrl = new URL(urlNameString);            // 打开和URL之间的连接            URLConnection connection = realUrl.openConnection();            // 设置通用的请求属性            connection.setRequestProperty("accept", "*/*");            connection.setRequestProperty("connection", "Keep-Alive");            connection.setRequestProperty("user-agent",                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");            // 建立实际的连接            connection.connect();            // 获取所有响应头字段            Map<String, List<String>> map = connection.getHeaderFields();            // 遍历所有的响应头字段            for (String key : map.keySet()) {                System.out.println(key + "--->" + map.get(key));            }            // 定义 BufferedReader输入流来读取URL的响应            in = new BufferedReader(new InputStreamReader(                    connection.getInputStream()));            String line;            while ((line = in.readLine()) != null) {                result += line;            }        } catch (Exception e) {            System.out.println("发送GET请求出现异常！" + e);            e.printStackTrace();        }        // 使用finally块来关闭输入流        finally {            try {                if (in != null) {                    in.close();                }            } catch (Exception e2) {                e2.printStackTrace();            }        }        return result;    }    /**     * 向指定 URL 发送POST方法的请求     *      * @param url     *            发送请求的 URL     * @param param     *            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。     * @param isproxy     *               是否使用代理模式     * @return 所代表远程资源的响应结果     */    public static String sendPost(String url, String param,boolean isproxy) {        OutputStreamWriter out = null;        BufferedReader in = null;        String result = "";        try {            URL realUrl = new URL(url);            HttpURLConnection conn = null;            if(isproxy){//使用代理模式                @SuppressWarnings("static-access")                Proxy proxy = new Proxy(Proxy.Type.DIRECT.HTTP, new InetSocketAddress(proxyHost, proxyPort));                conn = (HttpURLConnection) realUrl.openConnection(proxy);            }else{                conn = (HttpURLConnection) realUrl.openConnection();            }            // 打开和URL之间的连接            // 发送POST请求必须设置如下两行            conn.setDoOutput(true);            conn.setDoInput(true);            conn.setRequestMethod("POST");    // POST方法            // 设置通用的请求属性            conn.setRequestProperty("accept", "*/*");            conn.setRequestProperty("connection", "Keep-Alive");            conn.setRequestProperty("user-agent",                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");            conn.connect();            // 获取URLConnection对象对应的输出流            out = new OutputStreamWriter(conn.getOutputStream(), "UTF-8");            // 发送请求参数            out.write(param);            // flush输出流的缓冲            out.flush();            // 定义BufferedReader输入流来读取URL的响应            in = new BufferedReader(                    new InputStreamReader(conn.getInputStream()));            String line;            while ((line = in.readLine()) != null) {                result += line;            }        } catch (Exception e) {            System.out.println("发送 POST 请求出现异常！"+e);            e.printStackTrace();        }        //使用finally块来关闭输出流、输入流        finally{            try{                if(out!=null){                    out.close();                }                if(in!=null){                    in.close();                }            }            catch(IOException ex){                ex.printStackTrace();            }        }        return result;    }        public static void main(String[] args) {        //demo:代理访问        String url = "http://api.adf.ly/api.php";        String para = "key=youkeyid&youuid=uid&advert_type=int&domain=adf.ly&url=http://somewebsite.com";        String sr=HttpRequestUtil.sendPost(url,para,true);        System.out.println(sr);    }}

例3

/**     * 发送Http post请求     *      * @param xmlInfo     *            json转化成的字符串     * @param URL     *            请求url     * @return 返回信息     */    public static String doHttpPost(String xmlInfo, String URL) {        System.out.println("发起的数据:" + xmlInfo);        byte[] xmlData = xmlInfo.getBytes();        InputStream instr = null;        java.io.ByteArrayOutputStream out = null;        try {            URL url = new URL(URL);            URLConnection urlCon = url.openConnection();            urlCon.setDoOutput(true);            urlCon.setDoInput(true);            urlCon.setUseCaches(false);            urlCon.setRequestProperty("content-Type", "application/json");            urlCon.setRequestProperty("charset", "utf-8");            urlCon.setRequestProperty("Content-length",                    String.valueOf(xmlData.length));            System.out.println(String.valueOf(xmlData.length));            DataOutputStream printout = new DataOutputStream(                    urlCon.getOutputStream());            printout.write(xmlData);            printout.flush();            printout.close();            instr = urlCon.getInputStream();            byte[] bis = IOUtils.toByteArray(instr);            String ResponseString = new String(bis, "UTF-8");            if ((ResponseString == null) || ("".equals(ResponseString.trim()))) {                System.out.println("返回空");            }            System.out.println("返回数据为:" + ResponseString);            return ResponseString;        } catch (Exception e) {            e.printStackTrace();            return "0";        } finally {            try {                out.close();                instr.close();            } catch (Exception ex) {                return "0";            }        }    }