最近做了一个WIFI传书本地阅读功能，有所收获在这里记录下吧。
用户下载的书籍分为两种，一种是有章节格式的，比如 第一章，001章、等，这种可以用正则来直接分章节，还有绝大多数书籍是没有这种格式的，这种如果整本书来直接解析的话，对CPU要求比较大，可能会卡死闪退，所有手动分章节还是很有必要的，这种情况下我们采用按照两千字来分。
话不多说，开始吧。
1、WIFI传书把书传到APP沙盒里，这里我们采用的是 GCDWebServer ，很方便，这里就不做陈述了。
2、将沙盒里面的 .txt 文件转成 文本 ，这里的坑点也不少，我们专门写了一个 NSStringEncoding 解码的算法来转文字，可以解析多种编码方式的文本，这种算法只能适配iOS11及以上系统，其他系统只能采用系统UTF-8方法来解析，限制较多。
//转成文字 - (void)encodeWithURL:(NSString *)url result:(void (^)(NSString *content))result; - (void)encodeWithURL:(NSString *)url result:(void (^)(NSString *content))result { if (url.length == 0) { result(@""); return; } NSData *data = [NSData dataWithContentsOfFile:url options:NSDataReadingMappedIfSafe error:nil]; if (@available(iOS 11.0, *)) { NSString *content = data.mc_autoString; if (content.length == 0) { NSString *txt = data.utf8String; txt = [txt stringByReplacingOccurrencesOfString:@"\r\n" withString:@"\n"]; txt = [txt stringByReplacingOccurrencesOfString:@"\r" withString:@"\n"]; result(txt); return; } result(content); return; } NSString *txt = data.utf8String; txt = [txt stringByReplacingOccurrencesOfString:@"\r\n" withString:@"\n"]; txt = [txt stringByReplacingOccurrencesOfString:@"\r" withString:@"\n"]; result(txt); }
3、文本拿到之后开始分章节吧
//分章节 - (void)separateChapterContent:(NSString *)content result:(void (^)(NSArray *chapterArr))result; - (void)separateChapterContent:(NSString *)content result:(void (^)(NSArray *chapterArr))result { NSMutableArray *chapters = [[NSMutableArray alloc] init]; NSString *parten = @"第[0-9一二三四五六七八九十百千]*[章回].*"; NSError* error = NULL; NSRegularExpression *reg = [NSRegularExpression regularExpressionWithPattern:parten options:NSRegularExpressionCaseInsensitive error:&error]; NSArray* match = [reg matchesInString:content options:NSMatchingReportCompletion range:NSMakeRange(0, [content length])]; if (match.count >= 100) { __block NSRange lastRange = NSMakeRange(0, 0); [match enumerateObjectsUsingBlock:^(NSTextCheckingResult * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) { NSRange range = [obj range]; NSInteger local = range.location; if (idx == 0) { NSDictionary *dict = @{@"title":@"序章", @"content":[content substringWithRange:NSMakeRange(0, local)] }; [chapters addObject:dict]; } if (idx > 0 ) { NSUInteger len = local-lastRange.location; NSDictionary *dict = @{@"title":[content substringWithRange:lastRange], @"content":[content substringWithRange:NSMakeRange(lastRange.location, len)] }; [chapters addObject:dict]; } if (idx == match.count-1) { NSDictionary *dict = @{@"title":[content substringWithRange:range], @"content":[content substringWithRange:NSMakeRange(local, content.length-local)] }; [chapters addObject:dict]; } lastRange = range; }]; } else { //不能分章节的书籍按照2000字来手动分章节 NSArray *lineAry = [content componentsSeparatedByString:@"\n"]; NSMutableArray *bodyTextAry = [[NSMutableArray alloc] init]; NSInteger outLength = 0; //末尾长度 NSInteger startLength = 0; //起始长度 NSInteger textLeng = content.length; //总长度 NSLog(@"总长度:%ld",textLeng); //先把文字按2000字分出来 for (int i = 0; i < lineAry.count ; i ++) { NSString *textLine = lineAry[i]; outLength += textLine.length; if (i+1 != lineAry.count) { ++outLength; } if (outLength >= 2000) { NSRange lastRange = NSMakeRange(startLength, outLength); [bodyTextAry addObject:[content substringWithRange:lastRange]]; startLength += outLength; outLength = 0; } else if (i == lineAry.count - 1) { NSRange lastRange = NSMakeRange(startLength, outLength); [bodyTextAry addObject:[content substringWithRange:lastRange]]; } } //再构造数据传出去 [bodyTextAry enumerateObjectsUsingBlock:^(NSString *obj, NSUInteger idx, BOOL * _Nonnull stop) { NSDictionary *dict = @{@"title":[NSString stringWithFormat:@"第%lu章",(unsigned long)idx+1], @"content":obj }; [chapters addObject:dict]; }]; } result(chapters); }
4、章节分好之后就存入本地数据库，然后传入阅读器解析阅读吧。
注：补充下文本转文字的算法吧
第一种，如果文本是以utf-8来编码的
NSData+Addition.h #import <Foundation/Foundation.h> NS_ASSUME_NONNULL_BEGIN @interface NSData (Addition) #pragma mark - Encode and Decode /** UTF8编码 */ - (nullable NSString *)utf8String; /** Base64编码 */ - (nullable NSString *)base64EncodedString; /** Base64解码 @param base64EncodedString The encoded string. */ + (nullable NSData *)dataWithBase64EncodedString:(NSString *)base64EncodedString; /** Json解析 如果失败,返回 nil */ - (nullable id)jsonValueDecodedWithError:(NSError **)error; #pragma mark - Hash /** MD5编码 */ - (NSString *)md5String; @end NSData+Addition.m #import "NSData+Addition.h" #include <CommonCrypto/CommonCrypto.h> @implementation NSData (Addition) #pragma mark - Encode and Decode static const char base64EncodingTable[64] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; static const short base64DecodingTable[256] = { -2, -2, -2, -2, -2, -2, -2, -2, -2, -1, -1, -2, -1, -1, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -1, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, 62, -2, -2, -2, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -2, -2, -2, -2, -2, -2, -2, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -2, -2, -2, -2, -2, -2, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2 }; - (NSString *)utf8String { if (self.length > 0) { return [[NSString alloc] initWithData:self encoding:NSUTF8StringEncoding]; } return @""; } - (NSString *)base64EncodedString { NSUInteger length = self.length; if (length == 0) return @""; NSUInteger out_length = ((length + 2) / 3) * 4; uint8_t *output = malloc(((out_length + 2) / 3) * 4); if (output == NULL) return nil; const char *input = self.bytes; NSInteger i, value; for (i = 0; i < length; i += 3) { value = 0; for (NSInteger j = i; j < i + 3; j++) { value <<= 8; if (j < length) { value |= (0xFF & input[j]); } } NSInteger index = (i / 3) * 4; output[index + 0] = base64EncodingTable[(value >> 18) & 0x3F]; output[index + 1] = base64EncodingTable[(value >> 12) & 0x3F]; output[index + 2] = ((i + 1) < length) ? base64EncodingTable[(value >> 6) & 0x3F] : ‘=‘; output[index + 3] = ((i + 2) < length) ? base64EncodingTable[(value >> 0) & 0x3F] : ‘=‘; } NSString *base64 = [[NSString alloc] initWithBytes:output length:out_length encoding:NSASCIIStringEncoding]; free(output); return base64; } + (NSData *)dataWithBase64EncodedString:(NSString *)base64EncodedString { NSInteger length = base64EncodedString.length; const char *string = [base64EncodedString cStringUsingEncoding:NSASCIIStringEncoding]; if (string == NULL) return nil; while (length > 0 && string[length - 1] == ‘=‘) length--; NSInteger outputLength = length * 3 / 4; NSMutableData *data = [NSMutableData dataWithLength:outputLength]; if (data == nil) return nil; if (length == 0) return data; uint8_t *output = data.mutableBytes; NSInteger inputPoint = 0; NSInteger outputPoint = 0; while (inputPoint < length) { char i0 = string[inputPoint++]; char i1 = string[inputPoint++]; char i2 = inputPoint < length ? string[inputPoint++] : ‘A‘; char i3 = inputPoint < length ? string[inputPoint++] : ‘A‘; output[outputPoint++] = (base64DecodingTable[i0] << 2) | (base64DecodingTable[i1] >> 4); if (outputPoint < outputLength) { output[outputPoint++] = ((base64DecodingTable[i1] & 0xf) << 4) | (base64DecodingTable[i2] >> 2); } if (outputPoint < outputLength) { output[outputPoint++] = ((base64DecodingTable[i2] & 0x3) << 6) | base64DecodingTable[i3]; } } return data; } - (nullable id)jsonValueDecodedWithError:(NSError **)error { id value = [NSJSONSerialization JSONObjectWithData:self options:kNilOptions error:error]; return value; } #pragma mark - Hash - (NSString *)md5String { unsigned char result[CC_MD5_DIGEST_LENGTH]; CC_MD5(self.bytes, (CC_LONG)self.length, result); return [NSString stringWithFormat: @"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x", result[0], result[1], result[2], result[3], result[4], result[5], result[6], result[7], result[8], result[9], result[10], result[11], result[12], result[13], result[14], result[15] ]; } @end
第二种算法先不发了，，，，