图形文件和二进制文件的相互转换

一 背景
   项目中掌机上传图片到web服务器并且在页面上展示，由于之前已采用webservice接口作为数据交互，所以必须把图片文件转换为二进制文件作为字符串随xml报文上传到主站，web服务器接收后解析。
   注意点：开发语言不通（java和.net），因此图片二进制文件需要base64转换（进过转换就变成utf-8字符集），否则生成图片异常。下面无论哪种方式都可以解析
   in = new ByteArrayInputStream(org.apache.axis.encoding.Base64.decode(imgStr));
   in = new ByteArrayInputStream(org.apache.commons.codec.binary.Base64.decodeBase64(imgStr.getBytes("UTF-8")));

二 代码

package picture;

import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

import cn.hexing.ami.util.Coder;

/** 
 * @Description  xxxxx
 * @author  xxx
 * @Copyright 2014 hexing Inc. All rights reserved
 * @time：2014-7-10
 * @version 1.0 
 */
public class Server {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		saveToImgByBytes(new File("D:\\proccess1.png"), "d:\\pic.data");
		String imgStr = imgToString("d:\\pic.data");
		saveToImgByStr(imgStr, "d:\\pic.png");
	}
	
	/**
	 * 图形转换成二进制文件
	 * @param imgFile 图形文件
	 * @param sfile 二进制文件
	 * @return 
	 */
    public static int saveToImgByBytes(File imgFile, String sfile){
        int stateInt = 1;
        FileOutputStream fos = null;
        FileInputStream fis = null;
        	
        try{
            fos = new FileOutputStream(new File(sfile));
            fis = new FileInputStream(imgFile);
               
            byte[] b = new byte[1024];
            int nRead =0;
            while((nRead = fis.read(b)) != -1) {
                fos.write(b,0, nRead);
            }
            fos.flush();
         
 
        } catch(Exception e) {
            stateInt =0;
            e.printStackTrace();
        } finally {
        	try {
            	if(null != fos) 
            		fos.close();
            	if(null != fis) 
            		fis.close();
			} catch (IOException e) {
				e.printStackTrace();
			}        	
        }

        return stateInt;
    }

	/**
	 * 读取二进制并生成字符串
	 * @param byteFile
	 * @return
	 */
	public static String imgToString(String byteFile) {
		ByteArrayOutputStream bos = null;
		BufferedInputStream bis = null;
		
		try{
			bos = new ByteArrayOutputStream();
			bis = new BufferedInputStream(new FileInputStream(byteFile));
			byte[] b = new byte[1024];
            int nRead = 0;
            while((nRead = bis.read(b)) != -1) {
            	bos.write(b, 0, nRead);
            }
            return Coder.encryptBASE64(bos.toByteArray());
		} catch(Exception e) {
			
		} finally {
			try {
            	if(null != bis) 
            		bis.close();
            	if(null != bos) 
            		bos.close();
			} catch (IOException e) {
				e.printStackTrace();
			}      
		}
		
		return null;
	}
    
    /**
     * 生成图形
     * @param imgStr 二进制字符串
     * @param imgFile 图形文件
     * @return
     */
    public static int saveToImgByStr(String imgStr, String imgFile) {
        int stateInt = 1;
        InputStream in = null;
        FileOutputStream fos = null;
        
        try{
            in = new ByteArrayInputStream(Coder.decryptBASE64(imgStr));
            fos = new FileOutputStream(new File(imgFile));
               
            byte[] b =new byte[1024];
            int iRead =0;
            while((iRead = in.read(b)) != -1) {
                fos.write(b, 0, iRead);
            }
            
            fos.flush();
        } catch(Exception e) {
            stateInt =0;
            e.printStackTrace();
        } finally {
            try {
            	if(null != in) 
            		in.close();
            	if(null != fos) 
            		fos.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
        }
        
        return stateInt;
  	 }    
    	
	//----------------------------------------------------------------------------------------
	public static byte[] imgByte(String txtFile) {
		try{
			ByteArrayOutputStream bos = new ByteArrayOutputStream();
			BufferedInputStream bis = new BufferedInputStream(new FileInputStream(txtFile));
			byte[] b = new byte[1024];
            int nRead =0;
            while((nRead = bis.read(b)) != -1) {
            	bos.write(b, 0, nRead);
            }
            return bos.toByteArray();
		} catch(Exception e){
			
		}
		return null;
	}

    //二进制文件转换成字符串
    public static int saveToImgByStr(byte[] imgStr, String imgFile) {
         int stateInt =1;
         
             try{
                 InputStream in = new ByteArrayInputStream(imgStr);
                 File file = new File(imgFile);
                 FileOutputStream fos = new FileOutputStream(file);
                    
                 byte[] b =new byte[1024];
                 int nRead =0;
                 while((nRead = in.read(b)) != -1) {
                     fos.write(b,0, nRead);
                 }
                 
                 fos.flush();
                 fos.close();
                 in.close();
      
             }catch(Exception e) {
                 stateInt =0;
                 e.printStackTrace();
             }finally{
             }
         
         return stateInt;
   	 }

    // 字符串转二进制
    public static byte[] hex2byte(String str) {
        if(str ==null)
            return null;
        str = str.trim();
        int len = str.length();
        if(len ==0|| len %2==1)
            return null;
        
        byte[] b =new byte[len /2];
        try{
            for(int i =0; i < str.length(); i +=2) {
                b[i /2] = (byte) Integer
                        .decode("0X"+ str.substring(i, i +2)).intValue();
            }
            return b;
        }catch(Exception e) {
            return null;
        }
    }
    
    // 二进制转字符串
    public static String byte2hex(byte[] b) {
        StringBuffer sb = new StringBuffer();
        String stmp ="";
        for(int n = 0; n < b.length; n++) {
            stmp = Integer.toHexString(b[n] &0XFF);
            if(stmp.length() ==1) {
                sb.append("0"+ stmp);
            }else{
                sb.append(stmp);
            }
        }
        return sb.toString();
    }    
}

package cn.hexing.ami.util;
import java.security.MessageDigest;

import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;

import org.apache.axis.encoding.Base64;

/**
 * @Description xx
 * @author xx
 * @Copyright 2014 hexing Inc. All rights reserved
 * @time 2014-07-10
 * @version 1.0
 */
public abstract class Coder {
	public static final String KEY_SHA = "SHA";
	public static final String KEY_MD5 = "MD5";

	/**
	 * MAC算法可选以下多种算法
	 * HmacMD5 
	 * HmacSHA1 
	 * HmacSHA256 
	 * HmacSHA384 
	 * HmacSHA512
	 */
	public static final String KEY_MAC = "HmacMD5";

	/**
	 * BASE64解密
	 * @param key
	 * @return
	 * @throws Exception
	 */
	public static byte[] decryptBASE64(String key) throws Exception {
		return Base64.decode(key);
	}

	/**
	 * BASE64加密
	 * @param key
	 * @return
	 * @throws Exception
	 */
	public static String encryptBASE64(byte[] key) throws Exception {
		return Base64.encode(key);
	}

	/**
	 * MD5加密
	 * @param data
	 * @return
	 * @throws Exception
	 */
	public static byte[] encryptMD5(byte[] data) throws Exception {

		MessageDigest md5 = MessageDigest.getInstance(KEY_MD5);
		md5.update(data);

		return md5.digest();

	}

	/**
	 * SHA加密
	 * @param data
	 * @return
	 * @throws Exception
	 */
	public static byte[] encryptSHA(byte[] data) throws Exception {

		MessageDigest sha = MessageDigest.getInstance(KEY_SHA);
		sha.update(data);

		return sha.digest();

	}

	/**
	 * 初始化HMAC密钥
	 * @return
	 * @throws Exception
	 */
	public static String initMacKey() throws Exception {
		KeyGenerator keyGenerator = KeyGenerator.getInstance(KEY_MAC);

		SecretKey secretKey = keyGenerator.generateKey();
		return encryptBASE64(secretKey.getEncoded());
	}
}

三 web服务器端实现
   方式1保存文件到数据库，一般文件不多图片很小可以用此种方式；方式2保存文件到服务器上，取文件相对路径保存到表中，推荐用第二种