通过java代码HttpRequestUtil（服务器端）发送HTTP请求并解析

Posted 2021-02-15 sunseeker

关键代码：String jsonStr = HttpRequestUtil.sendGet(config.getAddress() + config.getPorts() + config.getFind(), "");

jsonStr 获取的是一个json字符串

1.HttpRequestUtil工具类源码：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;

public class HttpRequestUtil {

    public static void main(String[] args) {
        // 发送 GET 请求
        String s = HttpRequestUtil.sendGet("http://v.qq.com/x/cover/kvehb7okfxqstmc.html?vid=e01957zem6o", "");
        System.out.println(s);
    }

    /**
     * 向指定URL发送GET方法的请求
     *
     * @param url   发送请求的URL
     * @param param 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @return URL 所代表远程资源的响应结果
     */
    public static String sendGet(String url, String param) {
        String result = "";
        BufferedReader in = null;
        try {
            String urlNameString = url + "?" + param;
            URL realUrl = new URL(urlNameString);
            // 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(), "UTF-8"));
            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;
    }

    /**
     * 向指定 URL 发送POST方法的请求
     *
     * @param url   发送请求的 URL
     * @param param 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @return 所代表远程资源的响应结果
     */
    public static String sendPost(String url, String param) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {
            URL realUrl = new URL(url);
            // 打开和URL之间的连接
            URLConnection conn = realUrl.openConnection();
            // 设置通用的请求属性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            out = new PrintWriter(conn.getOutputStream());
            // 发送请求参数
            out.print(param);
            // flush输出流的缓冲
            out.flush();
            // 定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader(
                    new InputStreamReader(conn.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("发送 POST 请求出现异常！" + e);
            e.printStackTrace();
        }
        //使用finally块来关闭输出流、输入流
        finally {
            try {
                if (out != null) {
                    out.close();
                }
                if (in != null) {
                    in.close();
                }
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
        return result;
    }
}

2.1config 的读取配置文件类源码：

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

@Component
@ConfigurationProperties(prefix = "api")
public class AddressApiConfig {

    /**
     * 网址
     */
    private String address;

    /**
     * 端口
     */
    private String ports;

    /**
     * 获取所有ys科目
     */
    private String find;

    /**
     * 获取变动值
     */
    private String getBalance;

    /**
     * 获取所有的部门
     */
    private String departmentAll;

    /**
     * 获取指定部门
     */
    private String getDepartment;

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getPorts() {
        return ports;
    }

    public void setPorts(String ports) {
        this.ports = ports;
    }

    public String getFind() {
        return find;
    }

    public void setFind(String find) {
        this.find = find;
    }

    public String getGetBalance() {
        return getBalance;
    }

    public void setGetBalance(String getBalance) {
        this.getBalance = getBalance;
    }

    public String getDepartmentAll() {
        return departmentAll;
    }

    public void setDepartmentAll(String departmentAll) {
        this.departmentAll = departmentAll;
    }

    public String getGetDepartment() {
        return getDepartment;
    }

    public void setGetDepartment(String getDepartment) {
        this.getDepartment = getDepartment;
    }
}

2.2 配置文件properties：

知识延伸：@ConfigurationProperties和@Value区别

https://blog.csdn.net/wangmx1993328/article/details/81002901