Java 图片 二进制转换

 1 import java.awt.image.BufferedImage;
 2 import java.io.ByteArrayInputStream;
 3 import java.io.ByteArrayOutputStream;
 4 import java.io.File;
 5 import java.io.IOException;
 6
 7 import javax.imageio.ImageIO;
 8
 9 import sun.misc.BASE64Decoder;
10 import sun.misc.BASE64Encoder;
11
12 public class TestImageBinary {
13     static BASE64Encoder encoder = new sun.misc.BASE64Encoder();
14     static BASE64Decoder decoder = new sun.misc.BASE64Decoder();
15
16     public static void main(String[] args) {
17         System.out.println(getImageBinary());
18
19         base64StringToImage(getImageBinary());
20     }
21
22     static String getImageBinary(){
23         File f = new File("c://20090709442.jpg");
24         BufferedImage bi;
25         try {
26             bi = ImageIO.read(f);
27             ByteArrayOutputStream baos = new ByteArrayOutputStream();
28             ImageIO.write(bi, "jpg", baos);
29             byte[] bytes = baos.toByteArray();
30
31             return encoder.encodeBuffer(bytes).trim();
32         } catch (IOException e) {
33             e.printStackTrace();
34         }
35         return null;
36     }
37
38     static void base64StringToImage(String base64String){
39         try {
40             byte[] bytes1 = decoder.decodeBuffer(base64String);
41
42             ByteArrayInputStream bais = new ByteArrayInputStream(bytes1);
43             BufferedImage bi1 =ImageIO.read(bais);
44             File w2 = new File("c://QQ.bmp");//可以是jpg,png,gif格式
45             ImageIO.write(bi1, "jpg", w2);//不管输出什么格式图片，此处不需改动
46         } catch (IOException e) {
47             e.printStackTrace();
48         }
49     }
50
51 }

问题是：转换后的图片颜色不对

其他人代码：

 1 package cn.com;
 2
 3 import java.io.FileInputStream;
 4 import java.io.FileOutputStream;
 5 import java.io.IOException;
 6 import java.io.InputStream;
 7 import java.io.OutputStream;
 8
 9 import sun.misc.BASE64Decoder;
10 import sun.misc.BASE64Encoder;
11
12 public class Base64Test
13 {
14     public static void main(String[] args)
15     {
16         String strImg = GetImageStr();
17         System.out.println(strImg);
18         GenerateImage(strImg);
19     }
20     //图片转化成base64字符串
21     public static String GetImageStr()
22     {//将图片文件转化为字节数组字符串，并对其进行Base64编码处理
23         String imgFile = "d://test.jpg";//待处理的图片
24         InputStream in = null;
25         byte[] data = null;
26         //读取图片字节数组
27         try
28         {
29             in = new FileInputStream(imgFile);
30             data = new byte[in.available()];
31             in.read(data);
32             in.close();
33         }
34         catch (IOException e)
35         {
36             e.printStackTrace();
37         }
38         //对字节数组Base64编码
39         BASE64Encoder encoder = new BASE64Encoder();
40         return encoder.encode(data);//返回Base64编码过的字节数组字符串
41     }
42
43     //base64字符串转化成图片
44     public static boolean GenerateImage(String imgStr)
45     {   //对字节数组字符串进行Base64解码并生成图片
46         if (imgStr == null) //图像数据为空
47             return false;
48         BASE64Decoder decoder = new BASE64Decoder();
49         try
50         {
51             //Base64解码
52             byte[] b = decoder.decodeBuffer(imgStr);
53             for(int i=0;i<b.length;++i)
54             {
55                 if(b[i]<0)
56                 {//调整异常数据
57                     b[i]+=256;
58                 }
59             }
60             //生成jpeg图片
61             String imgFilePath = "d://222.jpg";//新生成的图片
62             OutputStream out = new FileOutputStream(imgFilePath);
63             out.write(b);
64             out.flush();
65             out.close();
66             return true;
67         }
68         catch (Exception e)
69         {
70             return false;
71         }
72     }
73 }