- URL编码默认使用的字符集是US-ASCII.对于非ASCII字符, 需要使用ASCII字符集的超级进行编码.
- URL中只允许包含4种字符:
英文字符 : a-zA-Z
数字: 0-9
-_.~ 4个特殊字符.
保留字符: ! * ' ( ) ; : @ & = + $ , / ? # [ ]
URL编码使用%其后跟随两位(中文是三位)的十六进制数来替换非ASCII字符,
不能在URL中包含任何非ASCII字符, 如中文字符等.
基本的NSURL
NSString *urlString = @"https://www.baidu.com";
NSURL *url = [NSURL URLWithString:urlString];
但是, 若urlString中含有中文等非URL允许的字符时, 创建的NSURL对象为nil.
iOS 7之后: stringByAddingPercentEncodingWithAllowedCharacters
NSString *latestUrl = @"https://www.baidu.com?name=小明&age=20";
latestUrl = [[latestUrl copy] stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];
///https://www.baidu.com?name=%E5%B0%8F%E6%98%8E&age=20
NSString *originUrlString = @"https://www.baidu.com/百度?name=小明&age=20";
NSString *encode_fragment = [[originUrlString copy] stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];
NSCharacterSet *encode_fragment_invertedSet = [NSCharacterSet URLQueryAllowedCharacterSet].invertedSet;
NSString *encode_fragment_invertedString = [[originUrlString copy] stringByAddingPercentEncodingWithAllowedCharacters:encode_fragment_invertedSet];
/**
encode_fragment:
https://www.baidu.com/%E7%99%BE%E5%BA%A6?name=%E5%B0%8F%E6%98%8E&age=20
encode_fragment_invertedString
%68%74%74%70%73%3A%2F%2F%77%77%77%2E%62%61%69%64%75%2E%63%6F%6D%2F%E7%99%BE%E5%BA%A6%3F%6E%61%6D%65%3D%E5%B0%8F%E6%98%8E%26%61%67%65%3D%32%30
*/
/**
URLFragmentAllowedCharacterSet "#%<>[\]^`{|}
URLHostAllowedCharacterSet "#%/<>?@\^`{|}
URLPasswordAllowedCharacterSet "#%/:<>?@[\]^`{|}
URLPathAllowedCharacterSet "#%;<>?[\]^`{|}
URLQueryAllowedCharacterSet "#%<>[\]^`{|}
URLUserAllowedCharacterSet "#%/:<>?@[\]^`
*/
///自定义的字符集. 如(带空格): [NSCharacterSet characterSetWithCharactersInString:@"#%/!*'\"();:@&=+$,[]? "]
NSString *latestUrl_2 = @"https://www.baidu.com?name=小明&age=20";
NSCharacterSet *defaultCharacterSet = [NSCharacterSet characterSetWithCharactersInString:@"?&=/ "];
if (defaultCharacterSet) {
NSString *latestUrl_2_defaultAllow = [[latestUrl_2 copy] stringByAddingPercentEncodingWithAllowedCharacters:defaultCharacterSet];
/**
%68%74%74%70%73%3A//%77%77%77%2E%62%61%69%64%75%2E%63%6F%6D?%6E%61%6D%65=%E5%B0%8F%E6%98%8E&%61%67%65=%32%30
可以看出除了?&=/ ,其他字符都被编码了.
*/
//invertSet
NSCharacterSet *invertCharacterSet = defaultCharacterSet.invertedSet;
latestUrl_2 = [[latestUrl_2 copy] stringByAddingPercentEncodingWithAllowedCharacters:invertCharacterSet];
/**
https:%2F%2Fwww.baidu.com%3Fname%3D%E5%B0%8F%E6%98%8E%26age%3D20
*/
}
/// 服务端会对请求进行UTF-8解码一次，请确保请求中的字符只进行一次UTF-8编码。
URL中含有中文并且拼接额外参数
NSString *originUrlString = @"https://www.baidu.com?name=小明&age=20";
//需要拼接的参数:转为通过&拼接
NSMutableDictionary *urlParamsDic = [NSMutableDictionary dictionary];
[urlParamsDic setValue:@"22" forKey:@"sex"];
[urlParamsDic setValue:@"one" forKey:@"class"];
__block NSMutableString *joinStr = [NSMutableString string];
if (urlParamsDic && [urlParamsDic isKindOfClass:[NSDictionary class]] && urlParamsDic.count) {
[urlParamsDic enumerateKeysAndObjectsUsingBlock:^(id _Nonnull key, id _Nonnull obj, BOOL * _Nonnull stop) {
if (key && obj) {
[joinStr appendFormat:@"%@=%@&",key,obj];
}
}];
if ([joinStr hasSuffix:@"&"]) {
[joinStr deleteCharactersInRange:NSMakeRange(joinStr.length-1, 1)];
}
}
///joinStr = sex=22&class=one
/**
*url中含有中文,先对其encode生成NSURL
* 拼接后再decode,最后再对拼接后的encode
*/
//1.encode生成NSURL
NSURL *originUrl = [NSURL URLWithString:[originUrlString stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]]];
///originUrl = https://www.baidu.com?name=%E5%B0%8F%E6%98%8E&age=20
//2.在url后拼接参数
NSString *latestURLString = @"";
BOOL cointainQuery = NO;
if (joinStr.length == 0 || [originUrl.query rangeOfString:joinStr].location != NSNotFound) {
//其中,若joinStr = 0则表示默认包含该空字符串
cointainQuery = YES;///
}
if (cointainQuery) {
latestURLString = originUrl.absoluteString;
}else{
///originUrl.query: name=%E5%B0%8F%E6%98%8E&age=20
if (originUrl.query.length>0) {
latestURLString = [NSString stringWithFormat:@"%@&%@", originUrl.absoluteString,joinStr];
///https://www.baidu.com?name=%E5%B0%8F%E6%98%8E&age=20&sex=22&class=one
}else{
BOOL hasSuffix = [originUrl.absoluteString hasSuffix:@"?"];
latestURLString = [NSString stringWithFormat:@"%@%@%@",originUrl.absoluteString, hasSuffix ? @"":@"?", joinStr];
}
}
///
//3.拼接后decode
latestURLString = [latestURLString stringByRemovingPercentEncoding];
///latestURLString = https://www.baidu.com?name=小明&age=20&sex=22&class=one
///
//4.最后对对接后的encode
latestURLString = [latestURLString stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];
///latestURLString =https://www.baidu.com?name=%E5%B0%8F%E6%98%8E&age=20&sex=22&class=one
NSLog(@"%@",latestURLString);
