JAVA 接口文件传参 & 接收文件；接口接收文件流（主打的就是无脑）

「爱情、让人受尽委屈。」 2023-09-30 21:30 6阅读 0赞

有这么一个业务场景： **系统A** 把文件传送到 **系统B**。 **系统B**对文件进行处理（加水印or保存...）系**系统B** 把处理完的文件返回给**系统A** 。 **系统A**进行保存备份。

编写了两个类 sendFile（系统A） ReceiveFileController（系统B）采用 httpClient 进行接口调用 ，系统B 把回传的文件写在 response的流里。话不多说，上代码

**系统A：**

1.POM文件

<dependency>
                <groupId>org.apache.httpcomponents</groupId>
                <artifactId>httpmime</artifactId>
                <version>4.5</version>
            </dependency>
            <dependency>
                <groupId>org.apache.httpcomponents</groupId>
                <artifactId>httpclient</artifactId>
                <version>4.5</version>
            </dependency>

2. 调用接口 发送文件 接收返回的文件流保存文件

package com.example.File;
    
    import org.apache.http.Consts;
    import org.apache.http.HttpEntity;
    import org.apache.http.client.config.RequestConfig;
    import org.apache.http.client.methods.CloseableHttpResponse;
    import org.apache.http.client.methods.HttpPost;
    import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
    import org.apache.http.entity.ContentType;
    import org.apache.http.entity.mime.HttpMultipartMode;
    import org.apache.http.entity.mime.MultipartEntityBuilder;
    import org.apache.http.impl.client.CloseableHttpClient;
    import org.apache.http.impl.client.HttpClients;
    import org.apache.http.util.EntityUtils;
    
    import javax.net.ssl.SSLContext;
    import javax.net.ssl.TrustManager;
    import javax.net.ssl.X509TrustManager;
    import java.io.*;
    import java.nio.file.Files;
    import java.security.KeyManagementException;
    import java.security.NoSuchAlgorithmException;
    import java.security.cert.CertificateException;
    import java.security.cert.X509Certificate;
    
    /**
     * @Cimpany yuJ.wang
     * @ClassName： sendFile
     * @Description： 发送文件
     * @Date： 2023/3/30 16:24
     * @Author： 老王头
     */
    public class sendFile {
    
    
        public static void main(String[] args) {
            doPostFile2("https://.../receiveFile/test","userid",new File("D:\\1.jpg"),"D:\\2.jpg");
        }
    
        /**
        * @Description:   httpClient调用接口传送文件  接收文件流保存本地
        * * @Param url:  接口地址
         * @Param param: 参数值
         * @Param file: 文件
         * @Param downloadPath: 保存地址
        * @return: void
        * @Author: laoWangTou
        * @Date: 2023/3/30
        */
        public static void doPostFile2(String url, String param, File file,String downloadPath) {
            CloseableHttpClient httpClient = HttpClients.createDefault();
            // https   需要SSL
            if (url.startsWith("https://")) {
                httpClient = sslClient();
            }
            String resultString = "";
            CloseableHttpResponse response = null;
            HttpPost httppost = new HttpPost(url);
            //返回的字节流
            byte[] bytes = null;
            try {
                // HttpMultipartMode.RFC6532    避免文件名为中文时乱码
                MultipartEntityBuilder builder = MultipartEntityBuilder.create().setMode(HttpMultipartMode.RFC6532);
                builder.setCharset(Consts.UTF_8);
                builder.setContentType(ContentType.MULTIPART_FORM_DATA);
                //或者使用字节流也行,根据具体需要使用
                builder.addBinaryBody("file", Files.readAllBytes(file.toPath()),ContentType.APPLICATION_OCTET_STREAM,file.getName());
                // 添加参数 addTextBody的key可以自定义和被调接口的入参保持一直    可多个addTextBody     key不一样即可  需在接收方接收
                builder.addTextBody("param", param);
                //builder.addTextBody("key1", param);
                //可以设置 请求头
                //httppost.addHeader("token", param.get("token"));
                HttpEntity reqEntity = builder.build();
                httppost.setEntity(reqEntity);
                // 设置超时时间
                httppost.setConfig(getConfig());
                response = httpClient.execute(httppost);
                //我这里  调用接口返的字节流  所以获取字节数组
                //resultString = EntityUtils.toString(response.getEntity(), "UTF-8");
                HttpEntity entity = response.getEntity();
                //输出流 字节数组
                bytes = EntityUtils.toByteArray(entity);
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                try {
                    response.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
    
            InputStream inputStream = new ByteArrayInputStream(bytes);
            OutputStream outputStream = null;
            try {
                // todo下载的目录不存在需要创建
                byte[] bs = new byte[1024];
                int len;
                outputStream = new FileOutputStream(downloadPath);
                while ((len = inputStream.read(bs)) != -1) {
                    outputStream.write(bs, 0, len);
                }
            } catch (Exception e) {
                throw new RuntimeException("照片处理失败：" + e);
            } finally {
                try {
                    outputStream.close();
                    inputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
    
        }
    
    
        //超时时间;
        private static RequestConfig getConfig() {
            return RequestConfig.custom().setConnectionRequestTimeout(50000).setSocketTimeout(150000)
                    .setConnectTimeout(50000).build();
        }
    
        /**
         * HTTPS   设置SSL请求处理
         */
        private static CloseableHttpClient sslClient() {
            try {
                SSLContext ctx = SSLContext.getInstance("TLS");
                X509TrustManager tm = new X509TrustManager() {
                    @Override
                    public void checkClientTrusted(java.security.cert.X509Certificate[] arg0, String arg1)
                            throws CertificateException {}
    
                    @Override
                    public void checkServerTrusted(java.security.cert.X509Certificate[] arg0, String arg1)
                            throws CertificateException {}
    
                    @Override
                    public X509Certificate[] getAcceptedIssuers() {
                        return null;
                    }
    
                };
                ctx.init(null, new TrustManager[] { tm }, null);
                SSLConnectionSocketFactory sslConnectionSocketFactory = SSLConnectionSocketFactory.getSocketFactory();
                return HttpClients.custom().setSSLSocketFactory(sslConnectionSocketFactory).build();
            } catch (NoSuchAlgorithmException e) {
                throw new RuntimeException(e);
            } catch (KeyManagementException e) {
                throw new RuntimeException(e);
            }
        }
    
    }

**系统B**

package com.example.File;
    
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.RestController;
    import org.springframework.web.multipart.MultipartFile;
    
    import javax.servlet.http.HttpServletResponse;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    
    /**
     * @Cimpany yuJ.wang
     * @ClassName： receiveFile
     * @Description： 接收文件
     * @Date： 2023/3/30 16:24
     * @Author： 老王头
     */
    @RestController
    @RequestMapping(value = "/receiveFile")
    public class ReceiveFileController {
    
        @PostMapping("/test")
        public void receiveFile(@RequestParam("file")MultipartFile file, @RequestParam("param")String param, HttpServletResponse response){
            try {
                //拿到文件流
                InputStream inputStream = file.getInputStream();
                //todo开始处理业务
    
                //处理完的文件放在 response中
                OutputStream outputStream = response.getOutputStream();
                //todo 把处理的东西写在  outputStream即可
    
    
            } catch (IOException e) {
                e.printStackTrace();
            }
    
        }
    
    }