本博客遷移來自：http://www.jianshu.com/users/465865c268ed/latest_articles
使用JSPatch這麼久了，一直都是使用http://jspatch.com/平臺集成SDK來實現js文件下發和版本控制，簡單便捷。事實卻是如此，使用它我們可以不用爲了下發js文件再去搭建服務器，也避免了在解決文件加密時的麻煩（在項目中我一直是這麼用的）。但今天閒着沒事，決定自己實現文件下發。
1：新建工程，從github下載JSPatch sdk集成到工程
2：沒有服務器來存放js文件？那麼就使用雲服務吧，最便捷的當屬七牛了（七牛的忠實用戶)，js內容如下:
require('UILabel');
defineClass('ViewController', {
testFunction: function() {
console.log('我是voidxin')
self.contentLabel().setText('我是voidxin, 我來自JSpatch');
},
});目的是替換native的testFunction方法
3：怎麼解決js文件的加密問題？那就用AES256加密js文件內容吧，讀取的時候再用AES256解密。加密代碼如下（加密祕鑰是ab12）：
新建NSData+AES256分類：
// NSData+AES256.h
// VXHotFix
//
// Created by voidxin on 16/12/7.
// Copyright © 2016年 wugumofang. All rights reserved.
//
#import <Foundation/Foundation.h>
#import <CommonCrypto/CommonDigest.h>
#import <CommonCrypto/CommonCryptor.h>
@interface NSData (AES256)
-(NSData *) aes256_encrypt:(NSString *)key;
-(NSData *) aes256_decrypt:(NSString *)key;
@end
//
// NSData+AES256.m
// VXHotFix
//
// Created by voidxin on 16/12/7.
// Copyright © 2016年 wugumofang. All rights reserved.
//
#import "NSData+AES256.h"
@implementation NSData (AES256)
//加密
- (NSData *)aes256_encrypt:(NSString *)key
{
char keyPtr[kCCKeySizeAES256+1];
bzero(keyPtr, sizeof(keyPtr));
[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
NSUInteger dataLength = [self length];
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);
size_t numBytesEncrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128,
kCCOptionPKCS7Padding | kCCOptionECBMode,
keyPtr, kCCBlockSizeAES128,
NULL,
[self bytes], dataLength,
buffer, bufferSize,
&numBytesEncrypted);
if (cryptStatus == kCCSuccess) {
return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
}
free(buffer);
return nil;
}
//解密
- (NSData *)aes256_decrypt:(NSString *)key
{
char keyPtr[kCCKeySizeAES256+1];
bzero(keyPtr, sizeof(keyPtr));
[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
NSUInteger dataLength = [self length];
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);
size_t numBytesDecrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128,
kCCOptionPKCS7Padding | kCCOptionECBMode,
keyPtr, kCCBlockSizeAES128,
NULL,
[self bytes], dataLength,
buffer, bufferSize,
&numBytesDecrypted);
if (cryptStatus == kCCSuccess) {
return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
}
free(buffer);
return nil;
}
@end新建NSString+AES256分類如下：
//
// NSString+AES256.h
// VXHotFix
//
// Created by voidxin on 16/12/7.
// Copyright © 2016年 wugumofang. All rights reserved.
//
#import <Foundation/Foundation.h>
#import <CommonCrypto/CommonDigest.h>
#import <CommonCrypto/CommonCryptor.h>
#import "NSData+AES256.h"
@interface NSString (AES256)
-(NSString *) aes256_encrypt:(NSString *)key;
-(NSString *) aes256_decrypt:(NSString *)key;
@end//
// NSString+AES256.m
// VXHotFix
//
// Created by voidxin on 16/12/7.
// Copyright © 2016年 wugumofang. All rights reserved.
//
#import "NSString+AES256.h"
@implementation NSString (AES256)
-(NSString *) aes256_encrypt:(NSString *)key
{
NSData *data = [self dataUsingEncoding:NSUTF8StringEncoding];
NSData *result = [data aes256_encrypt:key];
if (result && result.length > 0) {
Byte *datas = (Byte*)[result bytes];
NSMutableString *output = [NSMutableString stringWithCapacity:result.length * 2];
for(int i = 0; i < result.length; i++){
[output appendFormat:@"%02x", datas[i]];
}
return output;
}
return nil;
}
-(NSString *) aes256_decrypt:(NSString *)key
{
NSMutableData *data = [NSMutableData dataWithCapacity:self.length / 2];
unsigned char whole_byte;
char byte_chars[3] = {'\0','\0','\0'};
int i;
for (i=0; i < [self length] / 2; i++) {
byte_chars[0] = [self characterAtIndex:i*2];
byte_chars[1] = [self characterAtIndex:i*2+1];
whole_byte = strtol(byte_chars, NULL, 16);
[data appendBytes:&whole_byte length:1];
}
NSData* result = [data aes256_decrypt:key];
if (result && result.length > 0) {
return [[NSString alloc] initWithData:result encoding:NSUTF8StringEncoding];
}
return nil;
}
@end
注意：以上方法可在google搜到，我只是搬運工，但特別注意的是，在NSString+AES256中要去掉
const char *cstr = [self cStringUsingEncoding:NSUTF8StringEncoding]; NSData *data = [NSData dataWithBytes:cstr length:self.length];改成：
NSData *data = [self dataUsingEncoding:NSUTF8StringEncoding];不然加密後解密時會丟失字段。
加密後的js文件內容是：(文件名是“hotfix2.js”，把加密後的文件放到七牛上)
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：怎麼解決版本控制問題？新建appversion.txt文件，裏面保存要修復目標版本的app版本號，然後存在七牛雲，每次啓動app時，讀取appverson.txt文件中的內容，和app當前版本對比，版本號相同時則執行JS文件修復。
版本控制代碼如下：
+ (void)checkVersion{
//獲取服務器端控制的版本號和本地版本號對比
NSString *path = kVersion_URL;
NSString *content = [NSString stringWithContentsOfURL:[NSURL URLWithString:path] encoding:NSUTF8StringEncoding error:nil];
[content isEqualToString:[self _getterAppVersion]] ? ({
//版本號一致執行js代碼
@try {
NSString *path = kFilePath_URL;
NSString *content = [NSString stringWithContentsOfURL:[NSURL URLWithString:path] encoding:NSUTF8StringEncoding error:nil];
//AES256解密
content = [content aes256_decrypt:kEnKey];
NSLog(@"解密後是:%@",content);
[JPEngine startEngine];
[JPEngine evaluateScript:content];
} @catch (NSException *exception) {
NSLog(@"加載jspatch文件出錯");
} @finally {
}
}) : ({
//版本號不一致不執行js代碼
});
}
+ (NSString *)_getterAppVersion{
//獲取當前app版本號
NSDictionary *infoDic = [NSBundle mainBundle].infoDictionary;
NSString *app_version = [infoDic objectForKey:@"CFBundleShortVersionString"];
NSLog(@"app version:%@",app_version);
return app_version;
}
由此即可實現js文件的下發和版本控制並保證js文件的安全性
本文demo下載請跳轉至：https://github.com/voidxin/VXHotFix