base64编码及JNI实现，base64编码非原创，只做JNI端处理

直接上代码:

#include <stdlib.h>
#include <stdio.h>
#include <getopt.h>
#include <string.h>
#include "base64.h"
extern "C" {
//Base64 编码
int Base64Encode(unsigned char *OrgString, unsigned char *Base64String, int OrgStringLen) {

int Base64StringLen = 0;
static unsigned char Base64Encode[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789.@";

while (OrgStringLen > 0) {
*Base64String++ = Base64Encode[(OrgString[0] >> 2) & 0x3f];
if (OrgStringLen > 2) {
*Base64String++ = Base64Encode[((OrgString[0] & 3) << 4)
| (OrgString[1] >> 4)];
*Base64String++ = Base64Encode[((OrgString[1] & 0xF) << 2)
| (OrgString[2] >> 6)];
*Base64String++ = Base64Encode[OrgString[2] & 0x3F];
} else {
switch (OrgStringLen) {
case 1:
*Base64String++ = Base64Encode[(OrgString[0] & 3) << 4];
*Base64String++ = '_';
*Base64String++ = '_';
break;
case 2:
*Base64String++ = Base64Encode[((OrgString[0] & 3) << 4)
| (OrgString[1] >> 4)];
*Base64String++ = Base64Encode[((OrgString[1] & 0x0F) << 2)
| (OrgString[2] >> 6)];
*Base64String++ = '_';
break;
}
}

OrgString += 3;
OrgStringLen -= 3;
Base64StringLen += 4;
}

*Base64String = '\0';
return Base64StringLen;
}
//Base64 解码
char GetBase64Value(unsigned char ch) //得到编码值
{
if ((ch >= 'A') && (ch <= 'Z')) // A ~ Z
return ch - 'A';
if ((ch >= 'a') && (ch <= 'z')) // a ~ z
return ch - 'a' + 26;
if ((ch >= '0') && (ch <= '9')) // 0 ~ 9
return ch - '0' + 52;
switch (ch) // 其它字符
{
case '.':
return 62;
case '@':
return 63;
case '_': //Base64 填充字符
return 0;
default:
return 0;
}
}
// 解码函数
int Base64Decode(unsigned char *OrgString, unsigned char *Base64String, int Base64StringLen,bool bForceDecode) //解码函数
{
if (Base64StringLen % 4 && !bForceDecode) //如果不是 4 的倍数,则 Base64 编码有问题
{
OrgString[0] = '\0';
return -1;
}
unsigned char Base64Encode[4];
int OrgStringLen = 0;

while (Base64StringLen > 2) //当待解码个数不足3个时,将忽略它(强制解码时有效)
{
Base64Encode[0] = GetBase64Value(Base64String[0]);
Base64Encode[1] = GetBase64Value(Base64String[1]);
Base64Encode[2] = GetBase64Value(Base64String[2]);
Base64Encode[3] = GetBase64Value(Base64String[3]);

*OrgString++ = (Base64Encode[0] << 2) | (Base64Encode[1] >> 4);
*OrgString++ = (Base64Encode[1] << 4) | (Base64Encode[2] >> 2);
*OrgString++ = (Base64Encode[2] << 6) | (Base64Encode[3]);

Base64String += 4;
Base64StringLen -= 4;
OrgStringLen += 3;
}

return OrgStringLen;
}
//Base64 函数完毕
}

Jni交互代码

/*
* Class: com_encrypt_EncryptActivity
* Method: base64Encrypt
* Signature: (Ljava/lang/String;)Ljava/lang/String;
*/
JNIEXPORT jstring JNICALL Java_com_encrypt_EncryptActivity_base64Encrypt(
JNIEnv *env, jobject, jstring str) {
//接收java端传过来的字符串变量,需要编码的字符串
const char *string;
//base64加密后字符串指针
unsigned char *base64String;
//接收java端字符串
string = env->GetStringUTFChars(str, 0);
//计算出字符串的长度
int len = strlen(string) + 1;
//为字符串分配空间，通常为4个字节一组，且加密后长度小于2倍的长度加4
base64String = new unsigned char[len * 2 + 4];
//进行base64编码
Base64Encode((unsigned char *) string, base64String, len);

__android_log_print(ANDROID_LOG_INFO, "[INFO][Base64Encyrpt]",
"hello, base64 encode \n%s", (char *) base64String);
//释放出从java端接收的字符串
env->ReleaseStringUTFChars(str, string);
//返回加密的字符串到java端
return env->NewStringUTF((char *) base64String);
}

/*
* Class: com_encrypt_EncryptActivity
* Method: base64Decrypt
* Signature: (Ljava/lang/String;)Ljava/lang/String;
*/
JNIEXPORT jstring JNICALL Java_com_encrypt_EncryptActivity_base64Decrypt(
JNIEnv *env, jobject, jstring str) {
//base64解码后字符串指针
unsigned char *decodeStr;
//接收java端传过来的字符串变量
const char *datestring;
//接收java端字符串
datestring = env->GetStringUTFChars(str, 0);
//字符串的长度
int len = strlen(datestring) + 1;
//为字符串分配空间
decodeStr = new unsigned char[len];
//base64解码
Base64Decode(decodeStr, (unsigned char *) datestring, len, true);

__android_log_print(ANDROID_LOG_INFO, "[INFO][Base64Decyrpt]",
"hello, base64 decode \n%s!", decodeStr);
//释放出从java端接收的字符串
env->ReleaseStringUTFChars(str, datestring);
//返回解码的字符串到java端
return env->NewStringUTF((char *) decodeStr);
}

java端声明:

public native String base64Encrypt(String str);

public native String base64Decrypt(String str);

载入库:

static {
System.loadLibrary("生成的库名称");
}

文件下载
base64编码及JNI实现
http://192.210.60.138/dz/forum.php?mod=viewthread&tid=15&fromuid=1
(出处: IStudy)