前台传入base64图片，java后台转为MultipartFile文件

MultipartFile是spring框架中的接口，主要的实现类都不太适用于base64的上传文件，这里需要自己写一个实现类。代码如下：

public class BASE64DecodedMultipartFile implements MultipartFile {

private final byte[] imgContent;
private final String header;

public BASE64DecodedMultipartFile(byte[] imgContent, String header) {
this.imgContent = imgContent;
this.header = header.split(";")[0];
}

@Override
public String getName() {
// TODO - implementation depends on your requirements
return System.currentTimeMillis() + Math.random() + "." + header.split("/")[1];
}

@Override
public String getOriginalFilename() {
// TODO - implementation depends on your requirements
return System.currentTimeMillis() + (int)Math.random() * 10000 + "." + header.split("/")[1];
}

@Override
public String getContentType() {
// TODO - implementation depends on your requirements
return header.split(":")[1];
}

@Override
public boolean isEmpty() {
return imgContent == null || imgContent.length == 0;
}

@Override
public long getSize() {
return imgContent.length;
}

@Override
public byte[] getBytes() throws IOException {
return imgContent;
}

@Override
public InputStream getInputStream() throws IOException {
return new ByteArrayInputStream(imgContent);
}

 

 

 

然后再写个工具类：

public static MultipartFile base64ToMultipart(String base64) {
try {
String[] baseStrs = base64.split(",");

BASE64Decoder decoder = new BASE64Decoder();
byte[] b = new byte[0];
b = decoder.decodeBuffer(baseStrs[1]);

for(int i = 0; i < b.length; ++i) {
if (b[i] < 0) {
b[i] += 256;
}
}

return new BASE64DecodedMultipartFile(b, baseStrs[0]);
} catch (IOException e) {
e.printStackTrace();
return null;
}
}

然后在代码中调用工具类就可以啦