一个可以将图片转成base64编码的工具类
/** * Copyright (c) 2011-2017, 玛雅牛 (myaniu AT gmail dot com). * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.jfinal.kit; import java.awt.image.BufferedImage; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.IOException; import javax.imageio.ImageIO; public class ImageKit { private ImageKit() { } /** * 生成形如data:image/jpeg;base64,iVBORw0KGgoA……的字符串,将图片文件Data URI化 * * @param imageFilePath 图片文件路径 * @return 形如data:image/jpeg;base64,iVBORw0KGgoA……的字符串 * @throws IOException */ public static String encodeDataUri(String imageFilePath) throws IOException{ return encodeDataUri(new File(imageFilePath)); } /** * 生成形如data:image/jpeg;base64,iVBORw0KGgoA……的字符串,将图片文件Data URI化 * * @param imageFile 图片文件对象 * @return 形如data:image/jpeg;base64,iVBORw0KGgoA……的字符串 * @throws IOException */ public static String encodeDataUri(File imageFile) throws IOException{ String type = FileKit.getFileExtension(imageFile).toLowerCase(); if("jpg".equals(type)) { type = "jpeg"; } return "data:image/"+type+";base64," + encodeBase64(imageFile); } /** * 将文件编码成base64格式 * * @param imageFilePath 图片文件路径 * @return base64编码格式的字符串 * @throws IOException */ public static String encodeBase64(String imageFilePath) throws IOException{ return encodeBase64(new File(imageFilePath)); } /** * 将文件编码成base64格式 * * @param imageFile 图片文件对象 * @return base64编码格式的字符串 * @throws IOException */ public static String encodeBase64(File imageFile) throws IOException{ BufferedImage bi = ImageIO.read(imageFile); String type = FileKit.getFileExtension(imageFile).toLowerCase(); ByteArrayOutputStream baos = new ByteArrayOutputStream(); ImageIO.write(bi,type, baos); return Base64Kit.encode(baos.toByteArray()); } }