• Java实现Http请求


    import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.io.OutputStream;
    import java.net.HttpURLConnection;
    import java.net.URL;
    import java.nio.charset.StandardCharsets;
    
    /**
     * @title: HttpClient类实现Get、Post方法
     * @author: 猎手部落
     * @date: 2020年11月18日 16:00
     * @description: 备忘
     */
    public class HttpClient {
    
        //GET方法
        public static String doGet(String httpurl) {
    
            HttpURLConnection connection = null;
            InputStream is = null;
            BufferedReader br = null;
            String result = null; //返回结果字符串
    
            try {
                //创建远程url连接对象
                URL url = new URL(httpurl);
    
                //通过远程url连接对象打开一个连接,强转成httpURLConnection类
                connection = (HttpURLConnection) url.openConnection();
    
                //设置连接方式:get
                connection.setRequestMethod("GET");
    
                //设置连接主机服务器的超时时间:15000毫秒
                connection.setConnectTimeout(15000);
    
                //设置读取远程返回的数据时间:60000毫秒
                connection.setReadTimeout(60000);
    
                //发送请求
                connection.connect();
    
                //通过connection连接,获取输入流
                if (connection.getResponseCode() == 200) {
    
                    is = connection.getInputStream();
    
                    //封装输入流is,并指定字符集
                    br = new BufferedReader(new InputStreamReader(is, StandardCharsets.UTF_8));
    
                    //存放数据
                    StringBuilder sb = new StringBuilder();
                    String line;
    
                    while ((line = br.readLine()) != null) {
                        sb.append(line);
                        sb.append("
    ");
                    }
                    result = sb.toString();
                }
    
            } catch (IOException e) {
                e.printStackTrace();
    
            } finally {
    
                //关闭资源
                if (null != br) {
                    try {
                        br.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
    
                if (null != is) {
                    try {
                        is.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
    
                assert connection != null;
                connection.disconnect(); //关闭远程连接
            }
    
            return result;
        }
    
        //POST方法
        public static String doPost(String httpUrl, String param) {
    
            HttpURLConnection connection = null;
            InputStream is = null;
            OutputStream os = null;
            BufferedReader br = null;
            String result = null;
    
            try {
                URL url = new URL(httpUrl);
    
                //通过远程url连接对象打开连接
                connection = (HttpURLConnection) url.openConnection();
    
                //设置连接请求方式
                connection.setRequestMethod("POST");
    
                //设置连接主机服务器超时时间:15000毫秒
                connection.setConnectTimeout(15000);
    
                //设置读取主机服务器返回数据超时时间:60000毫秒
                connection.setReadTimeout(60000);
    
                //默认值为:false,当向远程服务器传送数据/写数据时,需要设置为true
                connection.setDoOutput(true);
    
                //默认值为:true,当前向远程服务读取数据时,设置为true,该参数可有可无
                connection.setDoInput(true);
    
                //设置传入参数的格式:请求参数应该是 name1=value1&name2=value2 的形式。
                connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
    
                //设置鉴权信息:Authorization: Bearer da3efcbf-0845-4fe3-8aba-ee040be542c0
                connection.setRequestProperty("Authorization", "Bearer da3efcbf-0845-4fe3-8aba-ee040be542c0");
    
                //通过连接对象获取一个输出流
                os = connection.getOutputStream();
    
                //通过输出流对象将参数写出去/传输出去,它是通过字节数组写出的
                os.write(param.getBytes());
    
                //通过连接对象获取一个输入流,向远程读取
                if (connection.getResponseCode() == 200) {
    
                    is = connection.getInputStream();
    
                    //对输入流对象进行包装:charset根据工作项目组的要求来设置
                    br = new BufferedReader(new InputStreamReader(is, StandardCharsets.UTF_8));
    
                    StringBuilder sb = new StringBuilder();
                    String line;
    
                    //循环遍历一行一行读取数据
                    while ((line = br.readLine()) != null) {
                        sb.append(line);
                        sb.append("
    ");
                    }
                    result = sb.toString();
                }
    
            } catch (IOException e) {
                e.printStackTrace();
    
            } finally {
    
                //关闭资源
                if (null != br) {
                    try {
                        br.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
    
                if (null != os) {
                    try {
                        os.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
    
                if (null != is) {
                    try {
                        is.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
    
                //断开与远程地址url的连接
                assert connection != null;
                connection.disconnect();
            }
    
            return result;
        }
    }
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  • 原文地址:https://www.cnblogs.com/hunttown/p/14052696.html
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