byte数组、Blob、inputStream、outputStream、MultipartFile之间的转换

• byte数组=>inputStream

byte[] b=new byte[1024];
ByteArrayInputStream inputStream=new ByteArrayInputStream(b);

• inputstream=>byte数组

public static final byte[] input2byte(InputStream inStream)  
            throws IOException {
       
        ByteArrayOutputStream swapStream = new ByteArrayOutputStream();  
        byte[] buff = new byte[1024];  
        int rc = 0;  
        while ((rc = inStream.read(buff, 0, 1024)) > 0) {
       
            swapStream.write(buff, 0, rc);  
        }  
        byte[] in2b = swapStream.toByteArray();  
        return in2b;  
    }  

• outputStream=>byte数组

ByteArrayOutputStream outputStream=new ByteArrayOutputStream();
byte[] b=outputStream.toByteArray()

• inputStream=>file

//Files是来自java.nio包
Files.copy(inputstream,Paths.get(”文件的路径“))

• MultipartFile=>byte数组

byte[] imgBytes = multipartFile.getBytes();

• byte数组=>MultipartFile

byte[] testFile = new byte[1024];
InputStream inputStream = new ByteArrayInputStream(testFile);
MultipartFile file = new MockMultipartFile(ContentType.APPLICATION_OCTET_STREAM.toString(), inputStream);

• inputStream => Blob

//Blob是java.sql.Blob
可通过Hibernate提供的API：Hibernate.createBlob(new FileInputStream(" 可以为图片/文件等路径 "))

• Blob => InputStream

//Blob是java.sql.Blob
InputStream inputStream=blob.getBinaryStream()