数据库实体类：package com.easy.kotlin.picturecrawler.entity import java.util.* import javax.persistence.* @Entity @Table(indexes = arrayOf( Index(name = "idx_url", unique = true, columnList = "url"), Index(name = "idx_category", unique = false, columnList = "category"))) class Image { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) var id: Long = -1 @Version var version: Int = 0 @Column(length = 255, unique = true, nullable = false) var category: String = "" var isFavorite: Int = 0 @Column(length = 255, unique = true, nullable = false) var url: String = "" var gmtCreated: Date = Date() var gmtModified: Date = Date() var isDeleted: Int = 0 //1 Yes 0 No var deletedDate: Date = Date() @Lob var imageBlob: ByteArray = byteArrayOf() /* 0-Baidu 1-Gank */ var sourceType: Int = 0 override fun toString(): String { return "Image(id=$id, version=$version, category='$category', isFavorite=$isFavorite, url='$url', gmtCreated=$gmtCreated, gmtModified=$gmtModified, isDeleted=$isDeleted, deletedDate=$deletedDate)" } }其中的 @Lob var imageBlob: ByteArray = byteArrayOf() 这个字段存储图片的 Base64内容。

存库代码val Image = Image() Image.category = "干货集中营福利" Image.url = url Image.sourceType = 1 Image.imageBlob = getByteArray(url) logger.info("Image = ${Image}") imageRepository.save(Image)

其中的getByteArray(url) 函数：private fun getByteArray(url: String): ByteArray { val urlObj = URL(url) return urlObj.readBytes() }

前端 html 展示图片代码：{ title: '图片', field: 'imageBlob', align: 'center', valign: 'middle', formatter: function (value, row, index) { // var html = "" var html = '' return html } }

点击下载 js ：function downloadImage(src) { var $a = $("").attr("href", src).attr("download", "sotu.png"); $a[0].click(); } function downBase64Image(url) { var blob = base64Img2Blob(url); url = window.URL.createObjectURL(blob); var $a = $("").attr("href", url).attr("download", "sotu.png"); $a[0].click(); } function base64Img2Blob(code) { var parts = code.split(';base64,'); var contentType = parts[0].split(':')[1]; var raw = window.atob(parts[1]); var rawLength = raw.length; var uInt8Array = new Uint8Array(rawLength); for (var i = 0; i < rawLength; ++i) { uInt8Array[i] = raw.charCodeAt(i); } return new Blob([uInt8Array], {type: contentType}); }

或者：function downloadFile(fileName, content) { var aLink = document.createElement('a'); var blob = base64Img2Blob(content); //new Blob([content]); var evt = document.createEvent("HTMLEvents"); evt.initEvent("click", false, false);//initEvent 不加后两个参数在FF下会报错 aLink.download = fileName; aLink.href = URL.createObjectURL(blob); aLink.dispatchEvent(evt); }