提交图片到服务器，如果图片太大的话，会导致内存溢出。所以我们需要对图片进行压缩 并且转化成base64编码进行提交

1.传入图片的url   压缩图片并转化成base64

/*** 传入url 先压缩 后转为base64* @param srcPath* @return*/
private String getimage(String srcPath) {BitmapFactory.Options newOpts = new BitmapFactory.Options();//开始读入图片，此时把options.inJustDecodeBounds 设回true了newOpts.inJustDecodeBounds = true;Bitmap bitmap = BitmapFactory.decodeFile(srcPath,newOpts);//此时返回bm为空newOpts.inJustDecodeBounds = false;int w = newOpts.outWidth;int h = newOpts.outHeight;//现在主流手机比较多是800*480分辨率，所以高和宽我们设置为float hh = 1280f;//这里设置高度为800ffloat ww = 720f;//这里设置宽度为480f//缩放比。由于是固定比例缩放，只用高或者宽其中一个数据进行计算即可int be = 1;//be=1表示不缩放if (w > h && w > ww) {//如果宽度大的话根据宽度固定大小缩放be = (int) (newOpts.outWidth / ww);} else if (w < h && h > hh) {//如果高度高的话根据宽度固定大小缩放be = (int) (newOpts.outHeight / hh);}if (be <= 0)be = 1;newOpts.inSampleSize = be;//设置缩放比例//重新读入图片，注意此时已经把options.inJustDecodeBounds 设回false了bitmap = BitmapFactory.decodeFile(srcPath, newOpts);return compressImageToBase64(bitmap);//压缩好比例大小后再进行质量压缩
}private String compressImageToBase64(Bitmap image) {ByteArrayOutputStream baos = new ByteArrayOutputStream();image.compress(Bitmap.CompressFormat.JPEG, 100, baos);//质量压缩方法，这里100表示不压缩，把压缩后的数据存放到baos中int options = 100;while ( baos.toByteArray().length / 1024>100) {  //循环判断如果压缩后图片是否大于100kb,大于继续压缩baos.reset();//重置baos即清空baosimage.compress(Bitmap.CompressFormat.JPEG, options, baos);//这里压缩options%，把压缩后的数据存放到baos中options -= 10;//每次都减少10}byte[] bytes = baos.toByteArray();Log.e("preencode", new String(bytes));String url = new String(Base64Coder.encode(bytes));return  url;}

2.Base64Coder

package com.ifonyo.door.utils;
/*** 下面这些注释是下载这个类的时候本来就有的，本来要删除的，但看了下竟然是license，吼吼，* 好东西，留在注释里，以备不时之用，大家有需要加license的可以到下面的网址找哦*///EPL, Eclipse Public License, V1.0 or later, http://www.eclipse.org/legal
//LGPL, GNU Lesser General Public License, V2.1 or later, http://www.gnu.org/licenses/lgpl.html
//GPL, GNU General Public License, V2 or later, http://www.gnu.org/licenses/gpl.html
//AL, Apache License, V2.0 or later, http://www.apache.org/licenses
//BSD, BSD License, http://www.opensource.org/licenses/bsd-license.php
/*** A Base64 encoder/decoder.** <p>* This class is used to encode and decode data in Base64 format as described in RFC 1521.** <p>* Project home page: <a href="http://www.source-code.biz/base64coder/java/">www.source-code.biz/base64coder/java</a>* Author: Christian d'Heureuse, Inventec Informatik AG, Zurich, Switzerland* Multi-licensed: EPL / LGPL / GPL / AL / BSD.*//*** 这个类在上面注释的网址中有，大家可以自行下载下，也可以直接用这个，* 公开的Base64Coder类（不用深究它是怎么实现的，* 还是那句话，有轮子直接用轮子），好用的要死人了...* 小马也很无耻的引用了这个网址下的东东，吼吼...* @Title: Base64Coder.java* @Package com.xiaoma.piccut.demo* @Description: TODO* @author XiaoMa*/public class Base64Coder {//The line separator string of the operating system.private static final String systemLineSeparator = System.getProperty("line.separator");//Mapping table from 6-bit nibbles to Base64 characters.private static char[]    map1 = new char[64];static {int i=0;for (char c='A'; c<='Z'; c++) map1[i++] = c;for (char c='a'; c<='z'; c++) map1[i++] = c;for (char c='0'; c<='9'; c++) map1[i++] = c;map1[i++] = '+'; map1[i++] = '/'; }//Mapping table from Base64 characters to 6-bit nibbles.private static byte[]    map2 = new byte[128];static {for (int i=0; i<map2.length; i++) map2[i] = -1;for (int i=0; i<64; i++) map2[map1[i]] = (byte)i; }/*** Encodes a string into Base64 format.* No blanks or line breaks are inserted.* @param s  A String to be encoded.* @return   A String containing the Base64 encoded data.*/public static String encodeString (String s) {return new String(encode(s.getBytes())); }/*** Encodes a byte array into Base 64 format and breaks the output into lines of 76 characters.* This method is compatible with <code>sun.misc.BASE64Encoder.encodeBuffer(byte[])</code>.* @param in  An array containing the data bytes to be encoded.* @return    A String containing the Base64 encoded data, broken into lines.*/public static String encodeLines (byte[] in) {return encodeLines(in, 0, in.length, 76, systemLineSeparator); }/*** Encodes a byte array into Base 64 format and breaks the output into lines.* @param in            An array containing the data bytes to be encoded.* @param iOff          Offset of the first byte in <code>in</code> to be processed.* @param iLen          Number of bytes to be processed in <code>in</code>, starting at <code>iOff</code>.* @param lineLen       Line length for the output data. Should be a multiple of 4.* @param lineSeparator The line separator to be used to separate the output lines.* @return              A String containing the Base64 encoded data, broken into lines.*/public static String encodeLines (byte[] in, int iOff, int iLen, int lineLen, String lineSeparator) {int blockLen = (lineLen*3) / 4;if (blockLen <= 0) throw new IllegalArgumentException();int lines = (iLen+blockLen-1) / blockLen;int bufLen = ((iLen+2)/3)*4 + lines*lineSeparator.length();StringBuilder buf = new StringBuilder(bufLen);int ip = 0;while (ip < iLen) {int l = Math.min(iLen-ip, blockLen);buf.append (encode(in, iOff+ip, l));buf.append (lineSeparator);ip += l; }return buf.toString(); }/*** Encodes a byte array into Base64 format.* No blanks or line breaks are inserted in the output.* @param in  An array containing the data bytes to be encoded.* @return    A character array containing the Base64 encoded data.*/public static char[] encode (byte[] in) {return encode(in, 0, in.length); }/*** Encodes a byte array into Base64 format.* No blanks or line breaks are inserted in the output.* @param in    An array containing the data bytes to be encoded.* @param iLen  Number of bytes to process in <code>in</code>.* @return      A character array containing the Base64 encoded data.*/public static char[] encode (byte[] in, int iLen) {return encode(in, 0, iLen); }/*** Encodes a byte array into Base64 format.* No blanks or line breaks are inserted in the output.* @param in    An array containing the data bytes to be encoded.* @param iOff  Offset of the first byte in <code>in</code> to be processed.* @param iLen  Number of bytes to process in <code>in</code>, starting at <code>iOff</code>.* @return      A character array containing the Base64 encoded data.*/public static char[] encode (byte[] in, int iOff, int iLen) {int oDataLen = (iLen*4+2)/3;       // output length without paddingint oLen = ((iLen+2)/3)*4;         // output length including paddingchar[] out = new char[oLen];int ip = iOff;int iEnd = iOff + iLen;int op = 0;while (ip < iEnd) {int i0 = in[ip++] & 0xff;int i1 = ip < iEnd ? in[ip++] & 0xff : 0;int i2 = ip < iEnd ? in[ip++] & 0xff : 0;int o0 = i0 >>> 2;int o1 = ((i0 &   3) << 4) | (i1 >>> 4);int o2 = ((i1 & 0xf) << 2) | (i2 >>> 6);int o3 = i2 & 0x3F;out[op++] = map1[o0];out[op++] = map1[o1];out[op] = op < oDataLen ? map1[o2] : '='; op++;out[op] = op < oDataLen ? map1[o3] : '='; op++; }return out; }/*** Decodes a string from Base64 format.* No blanks or line breaks are allowed within the Base64 encoded input data.* @param s  A Base64 String to be decoded.* @return   A String containing the decoded data.* @throws   IllegalArgumentException If the input is not valid Base64 encoded data.*/public static String decodeString (String s) {return new String(decode(s)); }/*** Decodes a byte array from Base64 format and ignores line separators, tabs and blanks.* CR, LF, Tab and Space characters are ignored in the input data.* This method is compatible with <code>sun.misc.BASE64Decoder.decodeBuffer(String)</code>.* @param s  A Base64 String to be decoded.* @return   An array containing the decoded data bytes.* @throws   IllegalArgumentException If the input is not valid Base64 encoded data.*/public static byte[] decodeLines (String s) {char[] buf = new char[s.length()+3];int p = 0;for (int ip = 0; ip < s.length(); ip++) {char c = s.charAt(ip);if (c != ' ' && c != '\r' && c != '\n' && c != '\t')buf[p++] = c; }while ((p % 4) != 0)buf[p++] = '0';return decode(buf, 0, p); }/*** Decodes a byte array from Base64 format.* No blanks or line breaks are allowed within the Base64 encoded input data.* @param s  A Base64 String to be decoded.* @return   An array containing the decoded data bytes.* @throws   IllegalArgumentException If the input is not valid Base64 encoded data.*/public static byte[] decode (String s) {return decode(s.toCharArray()); }/*** Decodes a byte array from Base64 format.* No blanks or line breaks are allowed within the Base64 encoded input data.* @param in  A character array containing the Base64 encoded data.* @return    An array containing the decoded data bytes.* @throws    IllegalArgumentException If the input is not valid Base64 encoded data.*/public static byte[] decode (char[] in) {return decode(in, 0, in.length); }/*** Decodes a byte array from Base64 format.* No blanks or line breaks are allowed within the Base64 encoded input data.* @param in    A character array containing the Base64 encoded data.* @param iOff  Offset of the first character in <code>in</code> to be processed.* @param iLen  Number of characters to process in <code>in</code>, starting at <code>iOff</code>.* @return      An array containing the decoded data bytes.* @throws      IllegalArgumentException If the input is not valid Base64 encoded data.*/public static byte[] decode (char[] in, int iOff, int iLen) {if (iLen%4 != 0) throw new IllegalArgumentException ("Length of Base64 encoded input string is not a multiple of 4.");while (iLen > 0 && in[iOff+iLen-1] == '=') iLen--;int oLen = (iLen*3) / 4;byte[] out = new byte[oLen];int ip = iOff;int iEnd = iOff + iLen;int op = 0;while (ip < iEnd) {int i0 = in[ip++];int i1 = in[ip++];int i2 = ip < iEnd ? in[ip++] : 'A';int i3 = ip < iEnd ? in[ip++] : 'A';if (i0 > 127 || i1 > 127 || i2 > 127 || i3 > 127)throw new IllegalArgumentException ("Illegal character in Base64 encoded data.");int b0 = map2[i0];int b1 = map2[i1];int b2 = map2[i2];int b3 = map2[i3];if (b0 < 0 || b1 < 0 || b2 < 0 || b3 < 0)throw new IllegalArgumentException ("Illegal character in Base64 encoded data.");int o0 = ( b0       <<2) | (b1>>>4);int o1 = ((b1 & 0xf)<<4) | (b2>>>2);int o2 = ((b2 &   3)<<6) |  b3;out[op++] = (byte)o0;if (op<oLen) out[op++] = (byte)o1;if (op<oLen) out[op++] = (byte)o2; }return out; }//Dummy constructor.private Base64Coder() {}} // end class Base64Coder