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Java实现Http请求

2020-11-28 15:15  猎手家园  阅读(946)  评论(0编辑  收藏  举报
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("\r\n");
                }
                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("\r\n");
                }
                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;
    }
}