JAVA发送http get/post请求，调用http接口、方法

水深无声 2022-05-10 11:24 539阅读 0赞

原文链接：[https://blog.csdn.net/capmiachael/article/details/51833531][https_blog.csdn.net_capmiachael_article_details_51833531]

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）][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][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";
                }
            }
        }

[https_blog.csdn.net_capmiachael_article_details_51833531]: https://blog.csdn.net/capmiachael/article/details/51833531
[http_download.csdn.net_download_capmiachael_9760550]: http://download.csdn.net/download/capmiachael/9760550%EF%BC%89
[http_www.oschina.net_code_snippet_2266157_45252]: http://www.oschina.net/code/snippet_2266157_45252