jsoup教程_2 http-client 讲解

朱雀 2023-01-08 03:25 134阅读 0赞

项目源代码 https://gitee.com/fakerlove/jsoup

### 文章目录 ###

*  2. http-client 讲解
 *   *  2.1 get 请求
     *  2.2 get带请求
     *   *  工具类
         *  发送请求
     *  2.3 Post 请求
     *  2.4 Post 带参数
     *  2.5 连接池
     *  2.6 参数

# 2. http-client 讲解 #

## 2.1 get 请求 ##

请求的网址

https://www.baidu.com

java 代码

package com.ak;
    
    import org.apache.http.client.methods.CloseableHttpResponse;
    import org.apache.http.client.methods.HttpGet;
    import org.apache.http.impl.client.CloseableHttpClient;
    import org.apache.http.impl.client.HttpClients;
    import org.apache.http.util.EntityUtils;
    
    import java.io.IOException;
    
    
    //@Slf4j
    public class demo { 
    
        public static void main(String[] args) { 
            // 打开浏览器
            CloseableHttpClient aDefault = HttpClients.createDefault();
            // 输入网址 https://movie.douban.com/chart
            HttpGet httpGet=new HttpGet("https://www.baidu.com");
            CloseableHttpResponse response=null;
            try { 
                // 获取响应内容
    
               response= aDefault.execute(httpGet);
              // System.out.println(response);
                if(response.getStatusLine().getStatusCode()==200){ 
                    String content = EntityUtils.toString(response.getEntity());
                    System.out.println(content.length());
                }
            } catch (IOException e) { 
                e.printStackTrace();
            }finally { 
                // 关闭流
                if(response!=null){ 
                    try { 
                        response.close();
                    } catch (IOException e) { 
                        e.printStackTrace();
                    }
                }
            }
    
        }
    }

## 2.2 get带请求 ##

请求的网址

https://movie.douban.com/tag/#/?sort=U&range=0,10&tags=电影

### 工具类 ###

### 发送请求 ###

package com.ak;
    
    import com.ak.utils.HttpUtils;
    import org.apache.http.client.methods.CloseableHttpResponse;
    import org.apache.http.client.methods.HttpGet;
    import org.apache.http.client.utils.URIBuilder;
    import org.apache.http.impl.client.CloseableHttpClient;
    import org.apache.http.impl.client.HttpClients;
    import org.apache.http.util.EntityUtils;
    
    import java.io.IOException;
    import java.net.URISyntaxException;
    import java.util.Random;
    
    
    /** * 请求内容 * 爬取豆瓣的内容，因为豆瓣使用了爬虫所以需要一些工具类 */
    public class demo2 { 
    
        public static void main(String[] args) { 
            // 打开浏览器
            CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(HttpUtils.cm).build();
            CloseableHttpResponse response=null;
            // 设置参数
            // 分析这个
            // https://movie.douban.com/tag/#/?sort=U&range=0,10&tags=%E5%8A%A8%E4%BD%9C,%E7%94%B5%E5%BD%B1
            try { 
                URIBuilder uriBuilder = new URIBuilder("https://movie.douban.com/tag/");
                uriBuilder.setParameter("sort","U");
                uriBuilder.setParameter("range","0,10");
                uriBuilder.setParameter("tags","电影");
                // 输入网址
                HttpGet httpGet=new HttpGet(uriBuilder.build());
                httpGet.setConfig(HttpUtils.getConfig());
                int agentNum = new Random().nextInt(HttpUtils.agents.size());
                httpGet.addHeader("User-Agent", HttpUtils.agents.get(agentNum));
    
                // 获取响应内容
               response= httpClient.execute(httpGet);
                
                if(response.getStatusLine().getStatusCode()==200){ 
                    String content = EntityUtils.toString(response.getEntity());
                    System.out.println(content);
                }
            } catch (Exception e) { 
                e.printStackTrace();
            }finally { 
                // 关闭流
                if(response!=null){ 
                    try { 
                        response.close();
                    } catch (IOException e) { 
                        e.printStackTrace();
                    }
                }
            }
    
        }
    }

爬取

https://www.baidu.com/s&wd=faker

类似于想要查找faker 的信息

package com.ak;
    
    import com.ak.utils.HttpUtils;
    import org.apache.http.client.methods.CloseableHttpResponse;
    import org.apache.http.client.methods.HttpGet;
    import org.apache.http.client.utils.URIBuilder;
    import org.apache.http.impl.client.CloseableHttpClient;
    import org.apache.http.impl.client.HttpClients;
    import org.apache.http.util.EntityUtils;
    
    import java.io.IOException;
    import java.net.URISyntaxException;
    import java.util.Random;
    
    
    /** * 请求内容 * 爬取豆瓣的内容，因为豆瓣使用了爬虫所以需要一些工具类 */
    public class demo2 { 
    
        public static void main(String[] args) { 
            // 打开浏览器
            CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(HttpUtils.cm).build();
            CloseableHttpResponse response=null;
            // 设置参数
            // 分析这个
            // https://movie.douban.com/tag/#/?sort=U&range=0,10&tags=%E5%8A%A8%E4%BD%9C,%E7%94%B5%E5%BD%B1
            try { 
                // https://movie.douban.com/tag/
                URIBuilder uriBuilder = new URIBuilder("https://www.baidu.com/s");
                uriBuilder.setParameter("wd","faker");
    // uriBuilder.setParameter("range","0,10");
    // uriBuilder.setParameter("tags","电影");
                // 输入网址
                HttpGet httpGet=new HttpGet(uriBuilder.build());
                httpGet.setConfig(HttpUtils.getConfig());
                int agentNum = new Random().nextInt(HttpUtils.agents.size());
                httpGet.addHeader("User-Agent", HttpUtils.agents.get(agentNum));
    
                // 获取响应内容
               response= httpClient.execute(httpGet);
                
                if(response.getStatusLine().getStatusCode()==200){ 
                    String content = EntityUtils.toString(response.getEntity());
                    System.out.println(content);
                }
            } catch (Exception e) { 
                e.printStackTrace();
            }finally { 
                // 关闭流
                if(response!=null){ 
                    try { 
                        response.close();
                    } catch (IOException e) { 
                        e.printStackTrace();
                    }
                }
            }
    
        }
    }

## 2.3 Post 请求 ##

请求网址

https://www.baidu.com

java代码

区别在于他们之间的HttpPost和HttpGet

package com.ak;
    
    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.util.EntityUtils;
    
    import java.io.IOException;
    
    
    //@Slf4j
    public class demo3 { 
    
        public static void main(String[] args) { 
            // 打开浏览器
            CloseableHttpClient aDefault = HttpClients.createDefault();
            // 输入网址 https://movie.douban.com/chart
            HttpPost httppost=new HttpPost("https://www.baidu.com");
            CloseableHttpResponse response=null;
            try { 
                // 获取响应内容
    
               response= aDefault.execute(httppost);
              // System.out.println(response);
                if(response.getStatusLine().getStatusCode()==200){ 
                    String content = EntityUtils.toString(response.getEntity());
                    System.out.println(content);
                }
            } catch (IOException e) { 
                e.printStackTrace();
            }finally { 
                // 关闭流
                if(response!=null){ 
                    try { 
                        response.close();
                    } catch (IOException e) { 
                        e.printStackTrace();
                    }
                }
            }
    
        }
    }

## 2.4 Post 带参数 ##

爬取网址

http://yun.itheima.com/search

java 代码

package com.ak;
    
    import com.ak.utils.HttpUtils;
    import org.apache.http.NameValuePair;
    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.client.utils.URIBuilder;
    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.util.ArrayList;
    import java.util.List;
    import java.util.Random;
    
    
    //@Slf4j
    public class demo4 { 
    
        public static void main(String[] args) { 
            CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(HttpUtils.cm).build();
            CloseableHttpResponse response=null;
            // 设置参数
            // 分析这个
            // https://www.baidu.com/s
            try { 
                // 封装表单对象
                List<NameValuePair> params=new ArrayList<>();
                params.add(new BasicNameValuePair("keys","java"));
    
                // 输入网址
                HttpPost httpPost=new HttpPost("http://yun.itheima.com/search");
                UrlEncodedFormEntity formEntity=new UrlEncodedFormEntity(params,"utf-8");
                int agentNum = new Random().nextInt(HttpUtils.agents.size());
                // 设置配置
                httpPost.setConfig(HttpUtils.getConfig());
                // 设置表单内容
                httpPost.setEntity(formEntity);
                // 设置代理
                httpPost.addHeader("User-Agent", HttpUtils.agents.get(agentNum));
    
                // 获取响应内容
                response= httpClient.execute(httpPost);
                System.out.println(response);
                if(response.getStatusLine().getStatusCode()==200){ 
                    String content = EntityUtils.toString(response.getEntity());
                    System.out.println(content);
                }
            } catch (Exception e) { 
                e.printStackTrace();
            }finally { 
                // 关闭流
                if(response!=null){ 
                    try { 
                        response.close();
                    } catch (IOException e) { 
                        e.printStackTrace();
                    }
                }
            }
    
        }
    }

## 2.5 连接池 ##

package com.ak.utils;
    
    import org.apache.http.client.config.RequestConfig;
    import org.apache.http.client.methods.CloseableHttpResponse;
    import org.apache.http.client.methods.HttpGet;
    import org.apache.http.impl.client.CloseableHttpClient;
    import org.apache.http.impl.client.HttpClients;
    import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
    import org.apache.http.util.EntityUtils;
    
    import java.io.IOException;
    import java.util.ArrayList;
    import java.util.Random;
    
    public class HttpUtils { 
    
        public static PoolingHttpClientConnectionManager cm;
        public static ArrayList<String> agents;
    
        static  { 
            // 创建连接池管理器
            cm = new PoolingHttpClientConnectionManager();
            // 设置连接数
            cm.setMaxTotal(100);
            // 设置每个主机（理解为网站，如：百度10个、网易10个）的最大连接数
            cm.setDefaultMaxPerRoute(10);
    
            //初始化 User-Agent 信息
            agents = new ArrayList<String>();
            // 添加 User-Agent 信息
            agents.add("Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.95 Safari/537.36");
            agents.add("Mozilla/5.0 (Windows NT 5.1; U; en; rv:1.8.1) Gecko/20061208 Firefox/2.0.0 Opera 9.50");
            agents.add("Mozilla/5.0 (Windows NT 6.1; WOW64; rv:34.0) Gecko/20100101 Firefox/34.0");
            agents.add("Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/534.57.2 (KHTML, like Gecko) Version/5.1.7 Safari/534.57.2");
            agents.add("Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.71 Safari/537.36");
            agents.add("Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.11 (KHTML, like Gecko) Chrome/23.0.1271.64 Safari/537.11");
            agents.add("Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.133 Safari/534.16");
            agents.add("Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.101 Safari/537.36");
            agents.add("Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.71 Safari/537.1 LBBROWSER");
            agents.add("Mozilla/5.0 (Windows NT 5.1) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.84 Safari/535.11 SE 2.X MetaSr 1.0");
            agents.add("Mozilla/5.0 (Windows NT 5.1) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.84 Safari/535.11 SE 2.X MetaSr 1.0");
            agents.add("Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/38.0.2125.122 UBrowser/4.0.3214.0 Safari/537.36");
            System.out.println("<--------- HttpUtils initialization success --------->");
        }
    
    
        /** * 获取页面源代码 * * @param url 网页链接 * @return 页面源代码 */
        public String doGetHtml(String url) { 
            // 通过连接池获取 httpClient
            CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(cm).build();
    
            HttpGet httpGet = new HttpGet(url);
    
            // 伪造 User-Agent（反反爬虫）
            // 生成一个范围在 0-x（不包含x）内的任意正整数
            int agentNum = new Random().nextInt(agents.size());
    
            httpGet.addHeader("User-Agent", agents.get(agentNum));
    
            // 设置请求信息
            httpGet.setConfig(getConfig());
    
            // 定义 response，方便 finally 中关闭
            CloseableHttpResponse response = null;
            try { 
                response = httpClient.execute(httpGet);
                // 获取并判断，状态码是否正常（正常值：200）
                if (response.getStatusLine().getStatusCode() == 200) { 
                    // 判断响应体是否为空，不为空则获取内容
                    if (response.getEntity() != null) { 
                        // 获取响应体，并指定 UTF-8 编码
                        String content = EntityUtils.toString(response.getEntity(), "utf8");
    
                        return content;
                    }
                }
            } catch (IOException e) { 
                e.printStackTrace();
            } finally { 
                // 判断并关闭 response
                if (response != null) { 
                    try { 
                        response.close();
                    } catch (IOException e) { 
                        e.printStackTrace();
                    }
                }
                // 不关闭 httpClient，交给连接池管理
            }
            System.out.println("<--------- doGetHtml() ERROR --------->");
            return "";
        }
    
        public static RequestConfig getConfig() { 
    
            RequestConfig config = RequestConfig.custom()
                    // 创建连接的最长时间
                    .setConnectTimeout(1000)
                    // 获取连接最长时间
                    .setConnectionRequestTimeout(1000)
                    // 数据传输最长时间
                    .setSocketTimeout(10 * 1000)
                    .build();
            return config;
        }
    }

## 2.6 参数 ##

public static RequestConfig getConfig() { 
    
            RequestConfig config = RequestConfig.custom()
                    // 创建连接的最长时间
                    .setConnectTimeout(1000)
                    // 获取连接最长时间
                    .setConnectionRequestTimeout(1000)
                    // 数据传输最长时间
                    .setSocketTimeout(10 * 1000)
                    .build();
            return config;
    }