apache HttpClient和HttpURLConnection发送get请求和post请求

Myth丶恋晨 2022-06-02 12:21 195阅读 0赞

# apache HttpClient和HttpURLConnection发送get请求和post请求 #

本文主要介绍如题的两种方式下，如何发送http的get和post请求。

apache  HttpClient

package com.xueyou.http;
    
    import org.apache.http.HttpEntity;
    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.impl.client.CloseableHttpClient;
    import org.apache.http.impl.client.HttpClients;
    import org.apache.http.message.BasicNameValuePair;
    import org.apache.http.util.EntityUtils;
    
    import java.io.IOException;
    import java.io.UnsupportedEncodingException;
    import java.util.ArrayList;
    import java.util.List;
    
    public class HttpClient {
        public static final String GET_URL = "http://www.baidu.com";
        public static final String POST_URL = "http://www.baidu.com";
    
        public static void main(String[] args) throws Exception {
            getRequest();
            postRequest();
        }
    
        /**
         * post方式提交json代码
         *
         * @throws Exception
         */
        public static void getRequest() throws Exception {
            CloseableHttpClient httpclient = HttpClients.createDefault();
            try {
                // 创建httpget.
                HttpGet httpget = new HttpGet(GET_URL);
                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();
                }
            }
        }
    
        /**
         * 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 static void postRequest() {
            // 创建默认的httpClient实例.
            CloseableHttpClient httpclient = HttpClients.createDefault();
            // 创建httppost
            HttpPost httppost = new HttpPost(POST_URL);
            // 创建参数队列
            List formparams = new ArrayList();
            formparams.add(new BasicNameValuePair("name", "xiaoming"));
            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();
                }
            }
        }
    
    }

HttpURLConnection方式

package com.xueyou.http;
    
    import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.io.OutputStreamWriter;
    import java.net.HttpURLConnection;
    import java.net.URL;
    import java.util.HashMap;
    
    public class URLConnectionClient {
        private final static String HTTP_URL_GET = "http://www.baidu.com";
        private final static String HTTP_URL_POST =  "http://www.baidu.com";
        private static HashMap<String, String> mData = new HashMap<String, String>();
    
        public static void main(String[] args) throws Exception {
            mData.put("name", "HongBin");
            mData.put("sex", "male");
    
            System.out.println("GetResult:" + startGet(HTTP_URL_GET));
            System.out.println("PostResult:" + startPost(HTTP_URL_POST));
        }
    
        private static String startGet(String path) {
            BufferedReader in = null;
            StringBuilder result = new StringBuilder();
            try {
                //GET请求直接在链接后面拼上请求参数
                String mPath = path + "?";
                for (String key : mData.keySet()) {
                    mPath += key + "=" + mData.get(key) + "&";
                }
                mPath = mPath.substring(0, mPath.length() - 1);
                URL url = new URL(mPath);
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                conn.setRequestMethod("GET");
                //Get请求不需要DoOutPut
                conn.setDoOutput(false);
                conn.setDoInput(true);
                //设置连接超时时间和读取超时时间
                conn.setConnectTimeout(10000);
                conn.setReadTimeout(10000);
    //            String routeCode = conn.getRequestProperty("routeCode");
                conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
                //连接服务器
                conn.connect();
                // 取得输入流，并使用Reader读取
                in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
                String line;
                while ((line = in.readLine()) != null) {
                    result.append(line);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            //关闭输入流
            finally {
                try {
                    if (in != null) {
                        in.close();
                    }
                } catch (IOException ex) {
                    ex.printStackTrace();
                }
            }
            return result.toString();
        }
    
        private static String startPost(String path) {
            OutputStreamWriter out = null;
            BufferedReader in = null;
            StringBuilder result = new StringBuilder();
            try {
                URL url = new URL(path);
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                conn.setRequestMethod("POST");
                // 发送POST请求必须设置为true
                conn.setDoOutput(true);
                conn.setDoInput(true);
                //设置连接超时时间和读取超时时间
                conn.setConnectTimeout(10000);
                conn.setReadTimeout(10000);
                conn.setRequestProperty("Content-Type", "x-www-form-urlencoded");
    
                out = new OutputStreamWriter(conn.getOutputStream());
                // POST的请求参数写在正文中
                for (String key : mData.keySet()) {
                    out.write(key + "=" + mData.get(key) + "&");
                }
                out.flush();
                out.close();
                // 取得输入流，并使用Reader读取
                in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
                String line;
                while ((line = in.readLine()) != null) {
                    result.append(line);
                }
    
            } catch (Exception e) {
                e.printStackTrace();
            }
            //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.toString();
        }
    
    }