springboot文件上传java文件中转工具类[笔记]

╰+哭是因爲堅強的太久メ 2022-10-18 11:24 82阅读 0赞

# java文件上传中转工具类 #

## springboot项目，版本2.2.6 ##

<parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.2.6.RELEASE</version>
        </parent>

## 依赖jar ##

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

## 工具类 ##

import org.apache.http.HttpEntity;
    import org.apache.http.HttpResponse;
    import org.apache.http.client.methods.HttpPost;
    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 org.springframework.web.multipart.MultipartFile;
    
    import java.io.File;
    import java.io.FileInputStream;
    import java.nio.charset.StandardCharsets;
    import java.util.*;
    
    /** * @author vick * @version 1.0 * <span>create at 2021/6/5 10:40</span> */
    public class FileUtils { 
    
        /** * 单文件中转上传 * @param file 文件 * @param remoteUrl 请求完整url * @param params 额外参数,可为空 */
        public static String uploadMultipartFile(MultipartFile file, String remoteUrl, Map<String, Object> params) { 
            List<MultipartFile> files = new ArrayList<>();
            files.add(file);
            return uploadMultipartFile(files, remoteUrl, params);
        }
    
        /** * 多文件中转请求 * <p>特别注意files,接受控制层用files参数名接收</p> * @param files 文件 * @param remoteUrl 请求完整url * @param params 额外参数,可为空 */
        public static String uploadMultipartFile(List<MultipartFile> files, String remoteUrl, Map<String, Object> params) { 
            try (CloseableHttpClient httpClient = HttpClients.createDefault()) { 
                HttpPost httpPost = new HttpPost(remoteUrl);
                MultipartEntityBuilder builder = MultipartEntityBuilder.create();
                builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
    
                for (MultipartFile file : files) { 
                    String fileName = file.getOriginalFilename();
                    builder.addBinaryBody("files", file.getInputStream(), ContentType.MULTIPART_FORM_DATA, fileName);
                    builder.addTextBody("fileName", fileName);
                }
    
                buildExtParams(params, builder);
    
                HttpEntity entity = builder.build();
                httpPost.setEntity(entity);
                HttpResponse response = httpClient.execute(httpPost);
                HttpEntity responseEntity = response.getEntity();
                return EntityUtils.toString(responseEntity, StandardCharsets.UTF_8);
            } catch (Exception e) { 
                throw new RuntimeException("upload file has error " + e.getMessage());
            }
        }
    
        /** * 单个中转文件请求 * @param file 文件 * @param remoteUrl 请求完整url * @param params 额外参数,可为空 */
        public static String uploadFile(File file, String remoteUrl, Map<String, Object> params) { 
            List<File> files = new ArrayList<>();
            files.add(file);
            return uploadFile(files, remoteUrl, params);
        }
    
        /** * 中转文件请求 * @param files 文件 * @param remoteUrl 请求完整url * @param params 额外参数,可为空 */
        public static String uploadFile(List<File> files, String remoteUrl, Map<String, Object> params) { 
            try (CloseableHttpClient httpClient = HttpClients.createDefault()) { 
                HttpPost httpPost = new HttpPost(remoteUrl);
                MultipartEntityBuilder builder = MultipartEntityBuilder.create();
                builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
                for (File file : files) { 
                    builder.addBinaryBody("files", new FileInputStream(file), ContentType.MULTIPART_FORM_DATA, file.getName());
                    builder.addTextBody("fileName", file.getName());
                }
    
                buildExtParams(params, builder);
    
                HttpEntity entity = builder.build();
                httpPost.setEntity(entity);
                HttpResponse response = httpClient.execute(httpPost);
                HttpEntity responseEntity = response.getEntity();
                return EntityUtils.toString(responseEntity, StandardCharsets.UTF_8);
            } catch (Exception e) { 
                throw new RuntimeException("upload file has error " + e.getMessage());
            }
        }
    
        /** * 构建额外的参数，例如除了文件外，添加其他参数，用户ID（userId）等 * @param params 参数 * @param builder 文件上传实体构建器 */
        private static void buildExtParams(Map<String, Object> params, MultipartEntityBuilder builder) { 
            if (CollectionUtils.notEmpty(params)) { 
                params.forEach((k, v) -> { 
                    builder.addTextBody(k, Objects.isNull(v) ? null : String.valueOf(v));
                });
            }
        }
    }