java io流

1.example(从程序写到本地)
String tempPath = "F:\\temp\\test\\test.txt";
//生成文件
try {
    File files = new File(tempPath);
    if(!files.exists()){
        files.createNewFile();
    }
    String content = "key = value";
    FileWriter fw = new FileWriter(files.getAbsoluteFile(),true);
    BufferedWriter bw= new BufferedWriter(fw);
    bw.write(content);
    bw.flush();
    bw.close();
    fw.close();
}catch (IOException e){
}

 

2.example2(file 转成 MultipartFile )

<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.3.3</version>
</dependency>

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;

(1) (file转成multifile)FileItemFactory factory = new DiskFileItemFactory(16, null);
String textFieldName = "textField";
int num = tempPath.lastIndexOf(".");
String extFile = tempPath.substring(num);
FileItem item = factory.createItem(textFieldName, "text/plain", true, "MyFileName");
File newfile = new File(tempPath);
int bytesRead = 0;
byte[] buffer = new byte[8192];
try {
    FileInputStream fis = new FileInputStream(newfile);
    OutputStream os = item.getOutputStream();
    while ((bytesRead = fis.read(buffer, 0, 8192)) != -1) {
        os.write(buffer, 0, bytesRead);
    }
    os.close();
    fis.close();
} catch (IOException e) {
    e.printStackTrace();
}
MultipartFile mfile = new CommonsMultipartFile(item);

(2)(file转成multifile,并上传文件到oss)ResponseBean responseBean = new ResponseBean();
String fileName = "zh_CN.js";
String tempPath = this.getClass().getResource("").getPath()+"\\zh_CN.js";
MultipartFile multipartFile = null;
//上传文件
try {
    File f = new File(tempPath);
    FileItem fileItem = new DiskFileItem(fileName, Files.probeContentType(f.toPath()), false, f.getName(), (int) f.length(), f.getParentFile());
    try (InputStream input = new FileInputStream(f); OutputStream os = fileItem.getOutputStream();) {
        IOUtils.copy(input, os);
        multipartFile  = new CommonsMultipartFile(fileItem);
    }
    if (multipartFile != null) {
        FileResult fileResult = fileUplaod.upload(multipartFile.getSize(), multipartFile.getContentType(), fileName, multipartFile.getInputStream());
        System.out.println("fileResult: "+fileResult.toString() +"   url: "+fileResult.getFileUrl()+"   key: "+fileResult.getFileKey());
        return responseBean.success(fileResult);
    }
} catch (IOException e) {
    logger.error("上传文件失败", e);
    return responseBean.failure("文件上传失败");
}

return responseBean.success("true");