Java编程中base64图片与文件图片的相互转化工具

        <!--Base64Encoder等工具类 -->
		<dependency>
			<groupId>commons-codec</groupId>
			<artifactId>commons-codec</artifactId>
			<version>1.10</version>
		</dependency>
		<!--/Base64Encoder等工具类 -->

2.Java编程代码:

package com.note234.common;

import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.imageio.ImageIO;

import org.apache.commons.codec.binary.Base64;

/**
 * 图片与base64编码的互转工具
 * 
 * @author note234
 *
 */
public class ImageBase64Util {

	public static void main(String[] args) {
		try {
			File image = new File("C:\\Users\\fghfghdf\\Desktop\\temp\\2.png");
			String imageStr = image2Base64(new FileInputStream(image));
			System.out.println(imageStr);
			File out = new File("C:\\Users\\fghfghdf\\Desktop\\temp\\3.png");
			base642Image(imageStr, new FileOutputStream(out));
		} catch (Exception e) {
			e.printStackTrace();
		}

	}

	/**
	 * 图片文件转换为base64编码的串
	 * 
	 * @param imageFileInputStream
	 *            图片文件输入流
	 * @return 编码后的base64串
	 * @throws IOException
	 *             可能出现IO异常
	 */
	public static String image2Base64(InputStream imageFileInputStream) throws IOException {
		byte[] data = new byte[imageFileInputStream.available()];
		imageFileInputStream.read(data);
		imageFileInputStream.close();
		Base64 base64 = new Base64();
		return base64.encodeAsString(data);
	}

	/**
	 * base64串转换为图片文件
	 * 
	 * @param base64Image
	 *            图片base64串
	 * @param outputStream
	 *            输出流
	 * @throws IOException
	 *             可能出现IO异常
	 */
	public static void base642Image(String base64Image, OutputStream outputStream) throws IOException {
		Base64 base64 = new Base64();
		// 解码
		byte[] imageArr = base64.decode(base64Image);
		InputStream sbs = new ByteArrayInputStream(imageArr);
		BufferedImage bufferImg = ImageIO.read(sbs);
		ImageIO.write(bufferImg, "PNG", outputStream);
	}

}

注意
前端传递过来的图片，一般会有一个前缀，如下
“data:image/jpeg;base64,” 
解码之前去掉,否则错误。