Android 使用 Base64 编码 _Android

归志宁无五亩园，读书本意在元元。这篇文章主要讲述Android 使用 Base64 编码相关的知识，希望能为你提供帮助。

//1. android Base64 编码 String base64 = android.util.Base64.encodeToString(maps.replace(" " " , maps).getBytes(), android.util.Base64.DEFAULT); //2. org.apache.commons.codec.binary.Base64 编码 String base64Apache= Base64.encodeBase64String(gson.toJson(map).getBytes()); //3. Base64Utils return Base64Utils.encode(gson.toJson(map));

【Android 使用 Base64 编码】推荐使用方案3 Android和java后台都使用相同的 Base64Utils :

import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.ByteArrayOutputStream; import java.io.CharArrayWriter; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.Reader; import java.io.Writer; public class Base64Utils { private static Base64Utils utils = null; public Base64Utils() { } /** * 机能概要:单利，懒汉模式 * @return */ public static Base64Utils getInstance(){ if(utils == null){ synchronized (Base64Utils.class) { if(utils == null ){ utils = new Base64Utils(); } } } return utils; } /** * 功能：编码字符串 * @param data *源字符串 * @return String */ public static String encode(String data) { return new String(encode(data.getBytes())); }/** * 功能：解码字符串 * * @author jiangshuai * @date 2016年10月03日 * @param data *源字符串 * @return String */ public static String decode(String data) { return new String(decode(data.toCharArray())); }/** * 功能：编码byte[] * @param data *源 * @return char[] */ public static char[] encode(byte[] data) { char[] out = new char[((data.length + 2) / 3) * 4]; for (int i = 0, index = 0; i < data.length; i += 3, index += 4) { boolean quad = false; boolean trip = false; int val = (0xFF & (int) data[i]); val < < = 8; if ((i + 1) < data.length) { val |= (0xFF & (int) data[i + 1]); trip = true; } val < < = 8; if ((i + 2) < data.length) { val |= (0xFF & (int) data[i + 2]); quad = true; } out[index + 3] = alphabet[(quad ? (val & 0x3F) : 64)]; val > > = 6; out[index + 2] = alphabet[(trip ? (val & 0x3F) : 64)]; val > > = 6; out[index + 1] = alphabet[val & 0x3F]; val > > = 6; out[index + 0] = alphabet[val & 0x3F]; } return out; }/** * 功能：解码 * @param data *编码后的字符数组 * @return byte[] */ public static byte[] decode(char[] data) {int tempLen = data.length; for (int ix = 0; ix < data.length; ix++) { if ((data[ix] > 255) || codes[data[ix]] < 0) { --tempLen; // ignore non-valid chars and padding } } // calculate required length: // -- 3 bytes for every 4 valid base64 chars // -- plus 2 bytes if there are 3 extra base64 chars, // or plus 1 byte if there are 2 extra.int len = (tempLen / 4) * 3; if ((tempLen % 4) == 3) { len += 2; } if ((tempLen % 4) == 2) { len += 1; } byte[] out = new byte[len]; int shift = 0; // # of excess bits stored in accum int accum = 0; // excess bits int index = 0; // we now go through the entire array (NOT using the ' tempLen' value) for (int ix = 0; ix < data.length; ix++) { int value = https://www.songbingjia.com/android/(data[ix] > 255) ? -1 : codes[data[ix]]; if (value > = 0) { // skip over non-code accum < < = 6; // bits shift up by 6 each time thru shift += 6; // loop, with new bits being put in accum |= value; // at the bottom. if (shift > = 8) { // whenever there are 8 or more shifted in, shift -= 8; // write them out (from the top, leaving any out[index++] = // excess at the bottom for next iteration. (byte) ((accum > > shift) & 0xff); } } }// if there is STILL something wrong we just have to throw up now! if (index != out.length) { throw new Error(" Miscalculated data length (wrote " + index + " instead of " + out.length + " )" ); } return out; }/** * 功能：编码文件 * * @param file *源文件 */ public static void encode(File file) throws IOException { if (!file.exists()) { System.exit(0); }else { byte[] decoded = readBytes(file); char[] encoded = encode(decoded); writeChars(file, encoded); } file = null; }/** * 功能：解码文件。 * * @param file *源文件 * @throws IOException */ public static void decode(File file) throws IOException { if (!file.exists()) { System.exit(0); } else { char[] encoded = readChars(file); byte[] decoded = decode(encoded); writeBytes(file, decoded); } file = null; }// // code characters for values 0..63 // private static char[] alphabet = " ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=" .toCharArray(); // // lookup table for converting base64 characters to value in range 0..63 // private static byte[] codes = new byte[256]; static { for (int i = 0; i < 256; i++) { codes[i] = -1; // LoggerUtil.debug(i + " & " + codes[i] + " " ); } for (int i = ' A' ; i < = ' Z' ; i++) { codes[i] = (byte) (i - ' A' ); // LoggerUtil.debug(i + " & " + codes[i] + " " ); }for (int i = ' a' ; i < = ' z' ; i++) { codes[i] = (byte) (26 + i - ' a' ); // LoggerUtil.debug(i + " & " + codes[i] + " " ); } for (int i = ' 0' ; i < = ' 9' ; i++) { codes[i] = (byte) (52 + i - ' 0' ); // LoggerUtil.debug(i + " & " + codes[i] + " " ); } codes[' +' ] = 62; codes[' /' ] = 63; }private static byte[] readBytes(File file) throws IOException { ByteArrayOutputStream baos = new ByteArrayOutputStream(); byte[] b = null; InputStream fis = null; InputStream is = null; try { fis = new FileInputStream(file); is = new BufferedInputStream(fis); int count = 0; byte[] buf = new byte[16384]; while ((count = is.read(buf)) != -1) { if (count > 0) { baos.write(buf, 0, count); } } b = baos.toByteArray(); } finally { try { if (fis != null) fis.close(); if (is != null) is.close(); if (baos != null) baos.close(); } catch (Exception e) { System.out.println(e); } }return b; }private static char[] readChars(File file) throws IOException { CharArrayWriter caw = new CharArrayWriter(); Reader fr = null; Reader in = null; try { fr = new FileReader(file); in = new BufferedReader(fr); int count = 0; char[] buf = new char[16384]; while ((count = in.read(buf)) != -1) { if (count > 0) { caw.write(buf, 0, count); } }} finally { try { if (caw != null) caw.close(); if (in != null) in.close(); if (fr != null) fr.close(); } catch (Exception e) { System.out.println(e); } }return caw.toCharArray(); }private static void writeBytes(File file, byte[] data) throws IOException { OutputStream fos = null; OutputStream os = null; try { fos = new FileOutputStream(file); os = new BufferedOutputStream(fos); os.write(data); } finally { try { if (os != null) os.close(); if (fos != null) fos.close(); } catch (Exception e) { System.out.println(e); } } }private static void writeChars(File file, char[] data) throws IOException { Writer fos = null; Writer os = null; try { fos = new FileWriter(file); os = new BufferedWriter(fos); os.write(data); } finally { try { if (os != null) os.close(); if (fos != null) fos.close(); } catch (Exception e) { e.printStackTrace(); } } } }