解析URL字符串以获取键值的最佳方法？

81

我需要解析这样的URL字符串：

&ad_eurl=http://www.youtube.com/video/4bL4FI1Gz6s&hl=it_IT&iv_logging_level=3&ad_flags=0&endscreen_module=http://s.ytimg.com/yt/swfbin/endscreen-vfl6o3XZn.swf&cid=241&cust_gender=1&avg_rating=4.82280613104

我需要将NSString拆分为诸如cid=241和的标志部分&avg_rating=4.82280613104。我一直在用，substringWithRange:但是值以随机顺序返回，所以搞砸了。是否有任何类可以轻松解析，因此您基本上可以将其转换为NSDictionary以便能够读取键的值（例如ValueForKey：cid应该返回241）。还是有比使用NSMakeRange子字符串更简单的解析方法？

ios  objective-c  swift  parsing  cocoa-touch 
— 乔纳斯·G
source

Answers:

121

编辑（2018年6月）：这个答案更好。苹果NSURLComponents在iOS 7中添加了功能。

我将创建一个字典，获得键/值对的数组

NSMutableDictionary *queryStringDictionary = [[NSMutableDictionary alloc] init];
NSArray *urlComponents = [urlString componentsSeparatedByString:@"&"];

然后填充字典：

for (NSString *keyValuePair in urlComponents)
{
    NSArray *pairComponents = [keyValuePair componentsSeparatedByString:@"="];
    NSString *key = [[pairComponents firstObject] stringByRemovingPercentEncoding];
    NSString *value = [[pairComponents lastObject] stringByRemovingPercentEncoding];

    [queryStringDictionary setObject:value forKey:key];
}

然后，您可以查询

[queryStringDictionary objectForKey:@"ad_eurl"];

这未经测试，您可能应该再进行一些错误测试。

— 托马斯·乔林
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13
这不是URL解码组件。在执行objectAtIndex：1之前，它也没有对pairComponents数组进行边界检查（如果索引1处没有对象怎么办？）。
— Yetanotherjosh 2012年
8
使用“ componentsSeparatedByString”从查询字符串中的值中拆分键是不正确的。值中常包含“ =”（例如，base64编码的令牌）。
— donleyp
1
一点优化： NSArray *urlComponents = [urlString componentsSeparatedByString:@"&"]; NSMutableDictionary *queryStringDictionary = [[NSMutableDictionary alloc] initWithCapacity: urlComponents.count];
— adnako
3
如果任何值包含字符“ =”，它将破坏填充逻辑。您可以用NSRange range = [keyValuePair rangeOfString:@"="]; NSString *key = [keyValuePair substringToIndex:range.location]; NSString *value = [keyValuePair substringFromIndex:range.location+1];
— Renato Silva Das Neves
1
这没有得到第一项。
— 基思·阿德勒
166

我也在https://stackoverflow.com/a/26406478/215748回答了这个问题。

您可以使用 queryItems在URLComponents。

获得此属性的值时，NSURLComponents类将解析查询字符串并返回一个NSURLQueryItem对象数组，每个对象代表一个键-值对，并按照它们在原始查询字符串中出现的顺序排列。

let url = "http://example.com?param1=value1&param2=param2"
let queryItems = URLComponents(string: url)?.queryItems
let param1 = queryItems?.filter({$0.name == "param1"}).first
print(param1?.value)

另外，您可以在URL上添加扩展名，以简化操作。 

extension URL {
    var queryParameters: QueryParameters { return QueryParameters(url: self) }
}

class QueryParameters {
    let queryItems: [URLQueryItem]
    init(url: URL?) {
        queryItems = URLComponents(string: url?.absoluteString ?? "")?.queryItems ?? []
        print(queryItems)
    }
    subscript(name: String) -> String? {
        return queryItems.first(where: { $0.name == name })?.value
    }
}

然后，您可以按名称访问参数。

let url = URL(string: "http://example.com?param1=value1&param2=param2")!
print(url.queryParameters["param1"])
— 小野
source
47

我有点迟了，但是直到现在为止所提供的答案都无法按我需要的方式工作。您可以使用以下代码段：

NSMutableDictionary *queryStrings = [[NSMutableDictionary alloc] init];
for (NSString *qs in [url.query componentsSeparatedByString:@"&"]) {
    // Get the parameter name
    NSString *key = [[qs componentsSeparatedByString:@"="] objectAtIndex:0];
    // Get the parameter value
    NSString *value = [[qs componentsSeparatedByString:@"="] objectAtIndex:1];
    value = [value stringByReplacingOccurrencesOfString:@"+" withString:@" "];
    value = [value stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

    queryStrings[key] = value;
}

url您要解析的URL在哪里。您在queryStrings可变字典中具有所有转义的查询字符串。

编辑：Swift版本：

var queryStrings = [String: String]()
if let query = url.query {
    for qs in query.componentsSeparatedByString("&") {
        // Get the parameter name
        let key = qs.componentsSeparatedByString("=")[0]
        // Get the parameter value
        var value = qs.componentsSeparatedByString("=")[1]
        value = value.stringByReplacingOccurrencesOfString("+", withString: " ")
        value = value.stringByReplacingPercentEscapesUsingEncoding(NSUTF8StringEncoding)!

        queryStrings[key] = value
    }
}
— 尼科洛夫斯基
source
2
这是一个很好的答案，但不是最好的。当参数是base64编码的字符串之类的参数时，请务必小心。正如@donleyp所说，'='字符可以是正常值。例如，base64编码的字符串需要使用'='字符进行填充。
— khcpietro
如果我错了，@ Aigori会纠正我，但是在我看来，这个答案支持base64。=用于填充的符号=直到最终解码后才会显示。但是，它不支持没有值的查询参数。
— 鲍里斯（Boris）
@Boris例如，http://example.org/?base64=ZGF0YT1bMTUyLCAyNDI2LCAyMzE1XQ==使用答案代码对该URL进行解码。它将返回ZGF0YT1bMTUyLCAyNDI2LCAyMzE1XQ不能ZGF0YT1bMTUyLCAyNDI2LCAyMzE1XQ==。当然，某些base64解码器可以正确解码，但是例如NSData initWithBase64EncodedString:options:返回空字符串而不填充=。因此，使用答案代码处理base64字符串时应格外小心。
— khcpietro
@Aigori是的，您是对的，但是在这种情况下url不会是http://example.org/?base64=ZGF0YT1bMTUyLCAyNDI2LCAyMzE1XQ==，http://example.org/?base64=ZGF0YT1bMTUyLCAyNDI2LCAyMzE1XQ%3D%3D因为值应该是url编码
— Boris
10

对于iOS8及更高版本，请使用NSURLComponents：

+(NSDictionary<NSString *, NSString *> *)queryParametersFromURL:(NSURL *)url {
    NSURLComponents *urlComponents = [NSURLComponents componentsWithURL:url resolvingAgainstBaseURL:NO];
    NSMutableDictionary<NSString *, NSString *> *queryParams = [NSMutableDictionary<NSString *, NSString *> new];
    for (NSURLQueryItem *queryItem in [urlComponents queryItems]) {
        if (queryItem.value == nil) {
            continue;
        }
        [queryParams setObject:queryItem.value forKey:queryItem.name];
    }
    return queryParams;
}

对于以下iOS 8：

+(NSDictionary<NSString *, NSString *> *)queryParametersFromURL:(NSURL *)url    
    NSMutableDictionary<NSString *, NSString *> * parameters = [NSMutableDictionary<NSString *, NSString *> new];
    [self enumerateKeyValuePairsFromQueryString:url.query completionblock:^(NSString *key, NSString *value) {
        parameters[key] = value;
    }];
    return parameters.copy;
}

- (void)enumerateKeyValuePairsFromQueryString:(NSString *)queryString completionBlock:(void (^) (NSString *key, NSString *value))block {
    if (queryString.length == 0) {
        return;
    }
    NSArray *keyValuePairs = [queryString componentsSeparatedByString:@"&"];
    for (NSString *pair in keyValuePairs) {
        NSRange range = [pair rangeOfString:@"="];
        NSString *key = nil;
        NSString *value = nil;

        if (range.location == NSNotFound) {
            key = pair;
            value = @"";
        }
        else {
            key = [pair substringToIndex:range.location];
            value = [pair substringFromIndex:(range.location + range.length)];
        }

        key = [self decodedStringFromString:key];
        key = key ?: @"";

        value = [self decodedStringFromString:value];
        value = value ?: @"";

        block(key, value);
    }
}

+ (NSString *)decodedStringFromString:(NSString *)string {
    NSString *input = shouldDecodePlusSymbols ? [string stringByReplacingOccurrencesOfString:@"+" withString:@" " options:NSLiteralSearch range:NSMakeRange(0, string.length)] : string;
    return [input stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
}
— Yatheesha BL
source
6

如果您想迅速做同样的事情，可以使用扩展名。

extension NSURL {
    func queryDictionary() -> [String:String] {
        let components = self.query?.componentsSeparatedByString("&")
        var dictionary = [String:String]()

        for pairs in components ?? [] {
            let pair = pairs.componentsSeparatedByString("=")
            if pair.count == 2 {
                dictionary[pair[0]] = pair[1]
            }
        }

        return dictionary
    }
}
— 阿波奇
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4

如果您使用NSURLComponents以下简明扩展名，也可以做到这一点：

extension NSURLComponents {

    func getQueryStringParameter(name: String) -> String? {
        return (self.queryItems? as [NSURLQueryItem])
            .filter({ (item) in item.name == name }).first?
            .value()
    }

}
— 吉尔斯·德梅（Gilles De Mey）
source
1
在Swift 2中， func getQueryStringParameter(name: String) -> String? { return self.queryItems?.filter({ (item) in item.name == name }).first?.value }
— Jedidja
4

由于iOS 8的就可以直接使用属性name和value上NSURLQueryItem。

例如，如何解析URL并获取解析对中键的特定值。

NSURLComponents *urlComponents = [NSURLComponents componentsWithURL:@"someURL" resolvingAgainstBaseURL:false];
NSArray *queryItems = urlComponents.queryItems;
NSMutableArray *someIDs = [NSMutableArray new];
for (NSURLQueryItem *item in queryItems) {
    if ([item.name isEqualToString:@"someKey"]) {
        [someIDs addObject:item.value];
    }
}
NSLog(@"%@", someIDs);
— 雅库布·特鲁拉
source
4

迅捷5

extension URL {
    func queryParams() -> [String:String] {
        let queryItems = URLComponents(url: self, resolvingAgainstBaseURL: false)?.queryItems
        let queryTuples: [(String, String)] = queryItems?.compactMap{
            guard let value = $0.value else { return nil }
            return ($0.name, value)
        } ?? []
        return Dictionary(uniqueKeysWithValues: queryTuples)
    }
}
— 五条
source
3

该代码在三种情况下均有效

1. http://www.youtube.com/watch?v=VWsl7C-y7EI&feature=youtu.be 2. http://youtu.be/lOvcFqQyaDY
3. http://www.youtube.com/watch?v= VWsl7C-y7EI

NSArray *arr = [youtubeurl componentsSeparatedByString:@"v="];
 NSString *youtubeID;
if([arr count]>0)
{
    if([arr count]==1){
        youtubeID= [[youtubeurl componentsSeparatedByString:@"/"] lastObject];

    }
    else{
        NSArray *urlComponents = [[arr objectAtIndex:1] componentsSeparatedByString:@"&"];
        youtubeID=[urlComponents objectAtIndex:0];
    }
}
— 仁珠Ja那
source
1
我特别在寻找一种提取YouTube ID的解决方案，但我忘记考虑到有效的YouTube URL有多种变体这一事实。+1谢谢！
— 2015年
3 
-(NSArray *)getDataOfQueryString:(NSString *)url{
    NSArray *strURLParse = [url componentsSeparatedByString:@"?"];
    NSMutableArray *arrQueryStringData = [[NSMutableArray alloc] init];
    if ([strURLParse count] < 2) {
        return arrQueryStringData;
    }
    NSArray *arrQueryString = [[strURLParse objectAtIndex:1] componentsSeparatedByString:@"&"];

    for (int i=0; i < [arrQueryString count]; i++) {
        NSMutableDictionary *dicQueryStringElement = [[NSMutableDictionary alloc]init];
        NSArray *arrElement = [[arrQueryString objectAtIndex:i] componentsSeparatedByString:@"="];
        if ([arrElement count] == 2) {
            [dicQueryStringElement setObject:[arrElement objectAtIndex:1] forKey:[arrElement objectAtIndex:0]];
        }
        [arrQueryStringData addObject:dicQueryStringElement];
    }

    return arrQueryStringData; 
}

您此函数只是传递URL，您将获得querystring的所有元素。

— 疯狂的开发人员
source
3

通过URL上的Swift 3扩展的形式来解决此问题

extension URL {

  func value(for paramater: String) -> String? {

    let queryItems = URLComponents(string: self.absoluteString)?.queryItems
    let queryItem = queryItems?.filter({$0.name == paramater}).first
    let value = queryItem?.value

    return value
  }

}

要旨

— 达摩
source
2

作为完整功能：

+ (NSString *)getQueryComponentWithName:(NSString *)name  fromURL:(NSURL *)url{

NSString *component = nil;
if (url) {
    NSString *query = url.query;

    NSMutableDictionary *queryStringDictionary = [NSMutableDictionary dictionary];
    NSArray *urlComponents = [query componentsSeparatedByString:@"&"];

    for (NSString *keyValuePair in urlComponents){

        NSArray *pairComponents = [keyValuePair componentsSeparatedByString:@"="];
        NSString *key = [[pairComponents firstObject] stringByRemovingPercentEncoding];
        NSString *value = [[pairComponents lastObject] stringByRemovingPercentEncoding];

        [queryStringDictionary setObject:value forKey:key];
    }

    component = [queryStringDictionary objectForKey:name];
}

return component;
}
[self getQueryComponentWithName:@"example" fromURL:[NSURL URLWithString:@"https://google.es/?example=test"]];
— 93sauu
source
你必须在那里例如小错字-在括号worngly放置
— Vaiden
2

要将查询参数作为字典：

extension URL {
    var parameters: [String: String] {
        var parameters = [String: String]()
        if let urlComponents = URLComponents(url: self, resolvingAgainstBaseURL: false),
            let queryItems = urlComponents.queryItems {
            for queryItem in queryItems where queryItem.value != nil {
                parameters[queryItem.name] = queryItem.value
            }
        }
        return parameters
    }
}

或返回Optional（如果这样更方便）。

— 奥列克桑德·布拉夫廖夫（Oleksandr Buravlyov）
source
0

NSURL中的Query属性将提供查询字符串。然后，您可以使用componentsSeparatedByString解析查询字符串

    NSArray *parameters = [[url query] componentsSeparatedByString:@"&"];

    NSMutableDictionary *keyValuePairs = [NSMutableDictionary dictionary];

    for (NSString *eachParam in parameters)
    {
        NSArray *QryParts = [eachParam componentsSeparatedByString:@"="];
        if ( [QryParts count] == 2 )
        {
            keyValuePairs[QryParts[0]] = QryParts[1];
        }
        else
        {
            keyValuePairs[QryParts[0]] = QryParts[0];
        }
    }

NSString * name = [keyValuePairs valueForKey:@"name"];
NSString * username = [keyValuePairs valueForKey:@"username"];
— 乔·M
source
0 
- (NSString *)getLoginTokenFromUrl:(NSString *)urlString {
    NSURL *url = [NSURL URLWithString:urlString];
    NSArray *queryStrings = [url.query componentsSeparatedByString:@"&"];

    NSMutableDictionary *queryParams = [[NSMutableDictionary alloc] init];
    for (NSString *qs in queryStrings) {
        // Get the parameter name
        NSArray *components = [qs componentsSeparatedByString:@"="];
        NSString *key = [components objectAtIndex:0];

        // Get the parameter value
        NSString *value;
        if (components.count > 1) {
            value = [components objectAtIndex:1];
        }
        else {
            value = @"";
        }
        value = [value stringByReplacingOccurrencesOfString:@"+" withString:@" "];
        value = [value stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

        queryParams[key] = value;
    }

    return [queryParams objectForKey:@"login_token"];
}
— Yogesh Maheshwari
source
0

Swift 2方法：

extension NSURL {

  var queryDictionary: [String: String] {
    var queryDictionary = [String: String]()
    guard let components = NSURLComponents(URL: self, resolvingAgainstBaseURL: false), queryItems = components.queryItems else { return queryDictionary }
    queryItems.forEach { queryDictionary[$0.name] = $0.value }
    return queryDictionary
  }

}

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— 斯科特·加德纳
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