HttpClient先post登陆,在get数据

深碍√TFBOYSˉ_ 2021-11-09 02:54 194阅读 0赞

我用的是httpclient-4.5.1.jar,如果httpclient版本太低的话,此方法可能用不了,需要用手工设置cookie.那种方法,暂不讨论,主要思路就是通过登陆时获取返回的cookie,再讲coolie的值填到新的请求头中,不过这种方法一般不怎么遇到,基本上对面接口都会直接返回给你一个token,你下次访问直接将这个token作为参数传过去就能获取自己想要的数据.

package test;
    
    import java.util.Date;
    import java.util.HashMap;
    import java.util.Map;
    
    import org.apache.http.HttpEntity;
    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.entity.StringEntity;
    import org.apache.http.impl.client.CloseableHttpClient;
    import org.apache.http.impl.client.HttpClients;
    import org.apache.http.util.EntityUtils;
    
    import com.alibaba.fastjson.JSONArray;
    
    public class JKTest03 {
    
    
    	public static void main(String[] args) throws Exception {
    		long st=new Date().getTime();
    		CloseableHttpClient http = HttpClients.createDefault();
    		try {
    			String url = "post";
    			HashMap<String, String> map = new HashMap<String, String>();
    			map.put("username", "admin");
    			map.put("password", "pass");
    			getlogin(http, map, url);//登陆验证
    			String url2 = "get";
    			String list = Get(http, url2);//获取数据
    			System.out.println(list);
    		} finally {
    			http.close();
    		}
    		long et=new Date().getTime();
    		System.out.println("共费时:"+(et-st));
    		// System.out.println("结束");
    	}
    
    	public static String getlogin(CloseableHttpClient client, Map<String, String> map, String url) throws Exception {
    		String body = "";
    		String encoding = "utf-8";
    		// 创建post方式请求对象
    		HttpPost httpPost = new HttpPost(url);
    		// 装填参数,常规格式
    		/*
    		 * List<NameValuePair> nvps = new ArrayList<NameValuePair>(); if (map != null) {
    		 * for (Entry<String, String> entry : map.entrySet()) {
    		 * //System.out.println(entry.getKey()+"=="+ entry.getValue()); nvps.add(new
    		 * BasicNameValuePair(entry.getKey(), entry.getValue())); } } // 设置参数到请求对象中
    		 * httpPost.setEntity(new UrlEncodedFormEntity(nvps, encoding));
    		 * // 设置参数到请求对象中
    		  httpPost.setEntity(new UrlEncodedFormEntity(nvps, encoding));
    		 */
    		
    		//参数是json格式
    		httpPost.setEntity(new StringEntity(JSONArray.toJSONString(map)));
    		// 设置header信息
    		// 指定报文头【Content-type】、【User-Agent】
    		//参数是json的需要将Content-type设为application/json
    		httpPost.setHeader("Content-type", "application/json");//默认是:application/x-www-form-urlencoded
    		httpPost.setHeader("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
    		
    		// 执行请求操作，并拿到结果（同步阻塞）
    		CloseableHttpResponse response = client.execute(httpPost);
    		// response.
    
    		// 获取结果实体
    		HttpEntity entity = response.getEntity();
    		if (entity != null) {
    			// 按指定编码转换结果实体为String类型
    			body = EntityUtils.toString(entity, encoding);
    		}
    		
    		// 释放链接
    		response.close();
    		return body;
    	}
    	public static String Get(CloseableHttpClient http, String url) throws Exception {
    		HttpGet httpget = new HttpGet(url);
    
    		String body = "";
    		CloseableHttpResponse response = http.execute(httpget);
    		// response.
    
    		// 获取结果实体
    		HttpEntity entity = response.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");
    		}
    		// 释放链接
    		response.close();
    		return body;
    	}
    }