Java发送get,post请求

淡淡的烟草味﹌ 2022-06-12 13:50 268阅读 0赞

import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.net.URL;
    import java.net.URLConnection;
    import java.util.ArrayList;
    import java.util.List;
    import java.util.Map;
    import java.util.Map.Entry;
    import org.apache.http.HttpEntity;
    import org.apache.http.NameValuePair;
    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.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 HttpRequestUtils {
    	/** 
    	 * 发送post请求
    	 * @param url  请求路径
    	 * @param headers 请求参数(需封装成Map<String, String>, 无参数为null)
    	 * @return
    	 */
    	public static String executePost(String url, Map<String, String> headers) {
    		String body = "";
    		// 创建httpclient对象
    		CloseableHttpClient closeableHttpClient = HttpClients.createDefault();
    		// 创建post方式请求对象
    		HttpPost httpPost = new HttpPost(url);
    		// 超时设置
    		RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(2000).setConnectTimeout(2000).build();
    		httpPost.setConfig(requestConfig);
    		// 装填参数
    		List<NameValuePair> nvps = new ArrayList<NameValuePair>();
    		if (headers != null) {
    			for (Entry<String, String> entry : headers.entrySet()) {
    				nvps.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
    			}
    		}
    
    		CloseableHttpResponse httpResponse = null;
    		try {
    			// 设置参数到请求对象中
    			httpPost.setEntity(new UrlEncodedFormEntity(nvps, "utf-8"));
    
    			// 设置header信息
    			// 指定报文头
    			httpPost.setHeader("x-access-token", "52D9C7AE-626F-405C-AB4C-8762E7C32184");
    
    			// 执行请求操作，并拿到结果（同步阻塞）
    			httpResponse = closeableHttpClient.execute(httpPost);
    			// 获取结果实体
    			HttpEntity entity = httpResponse.getEntity();
    			if (entity != null) {
    				// 按指定编码转换结果实体为String类型
    				body = EntityUtils.toString(entity, "utf-8");
    			}
    			EntityUtils.consume(entity);
    		} catch (IOException e) {
    			e.printStackTrace();
    		} finally {
    			try {
    				httpResponse.close();
    			} catch (IOException e) {
    				e.printStackTrace();
    			}
    		}
    		try {
    			closeableHttpClient.close(); // 关闭连接、释放资源
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    		return body;
    	}
    
    	/**
    	 * 发送get请求
    	 * @param url  请求路径
    	 * @param param 请求参数
    	 * @return
    	 */
    	public static String sendGet(String url, String param) {
    		String urlName = url + "?" + param;
    		return sendGet(urlName);
    	}
    
    	/**
    	 * 发送get请求
    	 * @param url 请求路径
    	 * @return
    	 */
    	public static String sendGet(String url) {
            String result = "";
            BufferedReader in = null;
            try {
                URL realUrl = new URL(url);
                // 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;
        }
    }