java直接使用url和参数调用第三方接口

Bertha 。 2023-06-29 05:51 27阅读 0赞

**前言**  
我们调用接口，通常都是在微服务中，可以直接使用client，通过feign调用别的服务的接口，  
还有一种原始的方法。如下：

### 1.核心工具类 ###

import org.springframework.stereotype.Component;
    
    import java.io.BufferedReader;
    import java.io.InputStreamReader;
    import java.io.PrintWriter;
    import java.net.HttpURLConnection;
    import java.net.URL;
    import java.net.URLConnection;
    import java.util.Map;
    
    /** * Http请求工具类 * @author weihong.zhu */
    @Component
    public class HttpUtil { 
    
        /** * 设置连接超时时间,20000,消除魔术数字 */
        private static final int TWOTHOUSAND = 20000;
    
        /** * 发送post请求 * * @param url 请求路径 * @param header 请求头 * @param body 请求体 * @return String */
        public String doPost(String url, Map<String, String> header, String body) { 
            String result = "";
            BufferedReader in = null;
            PrintWriter out = null;
            try { 
                // 设置 url
                URL realUrl = new URL(url);
                HttpURLConnection connection = (HttpURLConnection) realUrl.openConnection();
                // 设置 header
                for (String key : header.keySet()) { 
                    connection.setRequestProperty(key, header.get(key));
                }
                // 设置请求 body
                connection.setDoOutput(true);
                connection.setDoInput(true);
    
                //设置连接超时和读取超时时间
                connection.setConnectTimeout(TWOTHOUSAND);
                connection.setReadTimeout(TWOTHOUSAND);
                try { 
                    out = new PrintWriter(connection.getOutputStream());
                    // 保存body
                    out.print(body);
                    // 发送body
                    out.flush();
                } catch (Exception e) { 
                    e.printStackTrace();
                }
                try { 
                    // 获取响应body
                    in = new BufferedReader(new InputStreamReader(connection.getInputStream(), "UTF-8"));
                    String line;
                    while ((line = in.readLine()) != null) { 
                        result += line;
                    }
                } catch (Exception e) { 
                    e.printStackTrace();
                }
            } catch (Exception e) { 
                e.printStackTrace();
                //return null;
            }
            return result;
        }
    
        /** * 发送get请求 * * @param url 请求路径 * @param header 请求头 * @return String */
        public String doGet(String url, Map<String, String> header) { 
            String result = "";
            BufferedReader in = null;
            try { 
                // 设置 url
                URL realUrl = new URL(url);
                URLConnection connection = realUrl.openConnection();
                // 设置 header
                for (String key : header.keySet()) { 
                    connection.setRequestProperty(key, header.get(key));
                }
                // 设置请求 body
                in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
                String line;
                while ((line = in.readLine()) != null) { 
                    result += line;
                }
            } catch (Exception e) { 
                return null;
            }
            return result;
        }
    }

### 2.使用 ###

Map<String, String> map = new HashMap<>(); // 所有的参数，通过map形式放入header中
    	String jsonStr = httpUtil.doGet(url, map); //返回jsonstring 形式的结果