Objective-C 语法之 NSURL

有时我们需要获取请求地址的相关信息，这时我们就可以用 NSURL 的一些方法操作来获取它。

需要注意的一点是：请求地址里可能存在特殊字符或中文，为了正确获取信息，建议使用 stringByAddingPercentEscapesUsingEncoding: 对字符串进行编码，然后对应的使用 stringByReplacingPercentEscapesUsingEncoding: 对字符串进行解码。

main.m

#import <Foundation/Foundation.h>

void testURL(NSString *strUrl) {
strUrl = [strUrl stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]; //对字符串进行编码

NSURL *url = [NSURL URLWithString:strUrl];
NSMutableString *mStrInfo = [[NSMutableString alloc] initWithString:@"URL相关信息如下：\n"];
[mStrInfo appendFormat:@"absoluteString: %@\n", [url absoluteString]];
[mStrInfo appendFormat:@"relativeString: %@\n", [url relativeString]];
[mStrInfo appendFormat:@"baseURL: %@\n", [url baseURL]];
[mStrInfo appendFormat:@"absoluteURL: %@\n", [url absoluteURL]];
[mStrInfo appendFormat:@"scheme: %@\n", [url scheme]];
[mStrInfo appendFormat:@"resourceSpecifier: %@\n", [url resourceSpecifier]];
[mStrInfo appendFormat:@"host: %@\n", [url host]];
[mStrInfo appendFormat:@"port: %@\n", [url port]];
[mStrInfo appendFormat:@"user: %@\n", [url user]];
[mStrInfo appendFormat:@"password: %@\n", [url password]];
[mStrInfo appendFormat:@"path: %@\n", [url path]];
[mStrInfo appendFormat:@"fragment: %@\n", [url fragment]]; //编码后的字符串，获取到的值为null，而不是正常情况的a=1；最终a=1被作为query的值内容了
[mStrInfo appendFormat:@"parameterString: %@\n", [url parameterString]];
[mStrInfo appendFormat:@"query: %@\n", [url query]];
[mStrInfo appendFormat:@"relativePath: %@\n", [url relativePath]]; //如果baseURL是nil，relativePath就跟path一样
[mStrInfo appendFormat:@"pathComponents: %@\n", [url pathComponents]];

NSLog(@"%@", [mStrInfo stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding]); //对字符串进行解码
}

int main(int argc, const char * argv[]) {
@autoreleasepool {
NSString *strUrl = @"http://www.cnblogs.com:80/huangjianwu/archive/2015/06.html?author=KenmuHuang黄&page=1#a=1";
testURL(strUrl);
}
return 0;
}

结果：

2015-06-19 23:17:29.496 OCNSURL[768:34254] URL相关信息如下：
absoluteString: http://www.cnblogs.com:80/huangjianwu/archive/2015/06.html?author=KenmuHuang黄&page=1#a=1 relativeString: http://www.cnblogs.com:80/huangjianwu/archive/2015/06.html?author=KenmuHuang黄&page=1#a=1 baseURL: (null)
absoluteURL: http://www.cnblogs.com:80/huangjianwu/archive/2015/06.html?author=KenmuHuang黄&page=1#a=1 scheme: http
resourceSpecifier: //www.cnblogs.com:80/huangjianwu/archive/2015/06.html?author=KenmuHuang黄&page=1#a=1
host: www.cnblogs.com
port: 80
user: (null)
password: (null)
path: /huangjianwu/archive/2015/06.html
fragment: (null)
parameterString: (null)
query: author=KenmuHuang黄&page=1#a=1
relativePath: /huangjianwu/archive/2015/06.html
pathComponents: (
"/",
huangjianwu,
archive,
2015,
"06.html"
)