前记：上传图片文件，我要求的方式是前端使用最简单的multipart/form-data,后台使用的是MultipartFile[]的方式接收，但是前端小哥用MUI一直发送失败，改用base64的方式发送。后端接收base64字符串后，装换成MultipartFile的方式，然后用Thumbnails对图片进行修改。
1.直接上代码吧！
解析Base64
package com.itkim.util;
import org.springframework.web.multipart.MultipartFile;
import sun.misc.BASE64Decoder;
import java.io.IOException;
/**
* @description: 传入图片的base64
* @author: KimJun
* @date: 18/11/13 00:25
*/
public class base64ToMultipart {
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;
}
}
//测试
public static void main(String[] args) {
MultipartFile multipartFiles[] = new MultipartFile[2];
multipartFiles[0] = base64ToMultipart.base64ToMultipart("");
System.out.println(multipartFiles[0].getSize());
}
}
package com.itkim.util;
import org.springframework.web.multipart.MultipartFile;
import java.io.*;
/**
* @description: TODO
* @author: KimJun
* @date: 18/11/12 23:37
*/
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);
}
@Override
public void transferTo(File dest) throws IOException, IllegalStateException {
new FileOutputStream(dest).write(imgContent);
}I
}
2.图片的实体类(补上实体类)
package com.itkim.entity;
/**
* @description: TODO
* @author: KimJun
* @date: 18/11/12 22:20
*/
public class Pic {
//图片的id 第几张。
private String picNum;
//图片的Base64编码
private String picString;
public String getPicNum() {
return picNum;
}
public String getPicString() {
return picString;
}
@Override
public String toString() {
return "Pic{" +
"picNum='" + picNum + '\'' +
", picString='" + picString + '\'' +
'}';
}
}
3.前端测试代码（需要jQuery）
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="./jquery-3.3.1.min.js"></script>
</head>
<body>
请输入图片的Base64码 1--<input name="data1" style="width: 400px"><br>
请输入图片的Base64码 2--<input name="data2" style="width: 400px"><br>
<button id="submit" onclick="btnAction()">点击发送请求</button>
<script type="text/javascript">
function btnAction() {
var pictureFiles=[];
var data1={"picNum":"0","picString": $("*[name='data1']").val()};
var data2={"picNum":"1","picString": $("*[name='data2']").val()};
pictureFiles.push(data1);
pictureFiles.push(data2);
$.ajax({
type:"POST",
url:"http://localhost:8080/user/additem",
dataType:"json",
contentType:"application/json",
data:JSON.stringify(pictureFiles),
success:function(data){
console.log("成功上传。。。。");
}
});
};
</script>
</body>
</html>
4.Controller接收
@RequestMapping(value = "additem", method = RequestMethod.POST)
@ResponseBody
public Msg multipartFileUpload(@RequestBody List<Pic> pictureFiles) throws IOException {
System.out.println(pictureFiles.toString());
System.out.println(pictureFiles.size());
//如果图片的长度、大于8则抛异常
if (pictureFiles.size() > 8) {
return Msg.fail("上传失败，图片的张数大于8");
} else {
//新建一个数组接收保存
MultipartFile[] pictureFile = new MultipartFile[pictureFiles.size()];
for (int i = 0; i < pictureFiles.size(); i++) {
String ImgBase = pictureFiles.get(i).getPicString();
System.out.println(ImgBase);
if (!ImgBase.equals(null)) {
pictureFile[i] = base64ToMultipart.base64ToMultipart(ImgBase);
} else {
break;
}
}
}
