android 前提是引入base64encode,base64decode六个开源类

package com.example.testapp;

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

import android.app.Activity;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.os.Environment;

public class MainActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		System.out.println("path---->"+Environment.getExternalStorageDirectory().getPath());
		File file = new File(Environment.getExternalStorageDirectory().getPath()+"//qq.jpg");
		InputStream in = null;
		byte[] data = null;
		// 读取图片字节数组
		try {
			in = new FileInputStream(file);
			data = new byte[in.available()];
			in.read(data);
			in.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
		// 对字节数组Base64编码
		BASE64Encoder encoder = new BASE64Encoder();
		System.out.println("drf--------"+encoder.encode(data));// 返回Base64编码过的字节数组字符串
	}



	private InputStream Bitmap2Bytes(Bitmap bmp) {
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		// 得到输出流
		bmp.compress(Bitmap.CompressFormat.JPEG, 100, baos);
		// 转输入流
		InputStream isBm = new ByteArrayInputStream(baos.toByteArray());
		return isBm;
	}

}

server

package com.dong.test.binaryimage;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

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

public class TestLUcky {
	public static void main(String[] args) {
		String strImg = GetImageStr();
		System.out.println(strImg);
		GenerateImage(strImg);
	}

	public static String GetImageStr() {// 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
		String imgFile = "c:\\qq.jpg";// 待处理的图片
		InputStream in = null;
		byte[] data = null;
		// 读取图片字节数组
		try {
			in = new FileInputStream(imgFile);
			data = new byte[in.available()];
			in.read(data);
			in.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
		// 对字节数组Base64编码
		BASE64Encoder encoder = new BASE64Encoder();
		return encoder.encode(data);// 返回Base64编码过的字节数组字符串
	}

	public static boolean GenerateImage(String imgStr) {// 对字节数组字符串进行Base64解码并生成图片
		if (imgStr == null) // 图像数据为空
			return false;
		BASE64Decoder decoder = new BASE64Decoder();
		try {
			// Base64解码
			byte[] b = decoder.decodeBuffer(imgStr);
			for (int i = 0; i < b.length; ++i) {
				if (b[i] < 0) {// 调整异常数据
					b[i] += 256;
				}
			}
			// 生成jpeg图片
			String imgFilePath = "c:\\qq.bak.jpg";// 新生成的图片
			OutputStream out = new FileOutputStream(imgFilePath);
			out.write(b);
			out.flush();
			out.close();
			return true;
		} catch (Exception e) {
			return false;
		}
	}

}