【加/解密】base64工具类

import java.io.ByteArrayInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

/**
 * Base64工具类
 * 
 */
public class Base64Util {

    public static String fileToBase64(String filepath, String filename) throws IOException {
        String fileName = filepath + filename; // 源文件
        String strBase64 = null;
        InputStream in = null;
        try {
            in = new FileInputStream(fileName);
            // in.available()返回文件的字节长度
            byte[] bytes = new byte[in.available()];
            // 将文件中的内容读入到数组中
            in.read(bytes);
            // strBase64 = new BASE64Encoder().encode(bytes); // 将字节流数组转换为字符串
            strBase64 = encode(bytes); // 将字节流数组转换为字符串
        } catch (FileNotFoundException fe) {
            fe.printStackTrace();
        } catch (IOException ioe) {
            ioe.printStackTrace();
        }finally{
            if(in!=null)
                in.close();     
        }
        return strBase64;
    }

    public static String fileToBase64(String filepathame) throws IOException {
        String fileName = filepathame; // 源文件
        String strBase64 = null;
        try {
            InputStream in = new FileInputStream(fileName);
            // in.available()返回文件的字节长度
            byte[] bytes = new byte[in.available()];
            // 将文件中的内容读入到数组中
            in.read(bytes);
            // strBase64 = new BASE64Encoder().encode(bytes); // 将字节流数组转换为字符串
            strBase64 = encode(bytes); // 将字节流数组转换为字符串
            in.close();
        } catch (FileNotFoundException fe) {
            fe.printStackTrace();
        } catch (IOException ioe) {
            ioe.printStackTrace();
        }
        return strBase64;
    }

    public static String base64ToFile(String strBase64, String filepath, String filename) throws IOException {
        String string = strBase64;
        FileUtils.createNewFileDirectory(filepath);
        String fileName = filepath + filename;// 生成的新文件
        ByteArrayInputStream in = null;
        FileOutputStream out = null;
        try {
            // 解码，然后将字节转换为文件
            // byte[] bytes = new BASE64Decoder().decodeBuffer(string);
            // byte[] bytes = decode(string.trim().replaceAll(" ", ""));
            byte[] bytes = decode(string.trim());
            // 将字符串转换为byte数组
            in = new ByteArrayInputStream(bytes);
            byte[] buffer = new byte[1024];
            out = new FileOutputStream(fileName);
            int bytesum = 0;
            int byteread = 0;
            while ((byteread = in.read(buffer)) != -1) {
                bytesum += byteread;
                out.write(buffer, 0, byteread); // 文件写操作
            }
        } catch (IOException ioe) {
            ioe.printStackTrace();
        }finally{
            if(out!=null)
                out.close();
            if(in!=null)
                in.close();
        }
        return fileName;
    }

    /**
     * 编码
     * 
     * @param bstr
     * @return String
     */
    public static String encode(byte[] bstr) {
        return new BASE64Encoder().encode(bstr);
    }

    /**
     * 解码
     * 
     * @param str
     * @return string
     */
    public static byte[] decode(String str) {
        byte[] bt = null;
        try {
            BASE64Decoder decoder = new BASE64Decoder();
            bt = decoder.decodeBuffer(str);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return bt;
    }


    public static void main(String[] args) {
        try {
            //将文件流化
            System.out.println(fileToBase64("E:\\", "2.pdf"));
            //将流化文件重新生成文件
            base64ToFile(fileToBase64("E:\\", "2.pdf"), "E:\\", "zhu.pdf");
        } catch (IOException e1) {
            // TODO Auto-generated catch block
            System.out.println("error");
            e1.printStackTrace();
        }
    }
}