如何漂亮打印 json 来自 API 在调试器中调用的响应？

Question

试图弄清楚如何在调试时漂亮地打印来自 API 我的响应的 json 值：

let session = URLSession(configuration: .default)
let task = session.dataTask(with: urlRequest) { data, response, error in
    completion(data, response, error)
}

在调试器中，如果我执行 po 数据，这就是我得到的结果：

如何打印出数据对象中的实际 json 结构？希望看到这样的东西：

{ "firstName" : "John", "lastName" : "Doe", ... }

po debugPrint(data) 在这种情况下不输出任何内容。

Answer 1

试试 JSONSerialization，像这样：

let url = URL(string: "http://date.jsontest.com")
var request : URLRequest = URLRequest(url: url!)
request.httpMethod = "GET"

let dataTask = URLSession.shared.dataTask(with: request) {
    data,response,error in
    do {
        if let jsonResult = try JSONSerialization.jsonObject(with: data!, options: []) as? NSDictionary {
            print(jsonResult)
        }
    } catch let error {
        print(error.localizedDescription)
    }
}
dataTask.resume()

其中 jsonResult 将打印出以下内容：

{
    date = "02-19-2018";
    "milliseconds_since_epoch" = 1519078643223;
    time = "10:17:23 PM";
}

Answer 2

// given raw JSON, return a usable Foundation object
private func convertDataWithCompletionHandler(_ data: Data, completionHandlerForConvertData: (_ result: AnyObject?, _ error: NSError?) -> Void) {
    
    var parsedResult: AnyObject! = nil
    do {
        parsedResult = try JSONSerialization.jsonObject(with: data, options: .allowFragments) as AnyObject
    } catch {
        let userInfo = [NSLocalizedDescriptionKey : "Could not parse the data as JSON: '\(data)'"]
        completionHandlerForConvertData(nil, NSError(domain: "convertDataWithCompletionHandler", code: 1, userInfo: userInfo))
    }
    completionHandlerForConvertData(parsedResult, nil)
}

Answer 3

e print(String(data: JSONSerialization.data(withJSONObject: JSONSerialization.jsonObject(with: data, options: []), options: .prettyPrinted), encoding: .utf8)!)

Answer 4

这是给你的 objective-c 代码。

NSString+PrettyPrint.h

@interface NSString (PrettyPrint)

+ (NSString * _Nonnull)prettifiedJsonStringFromData:(nullable NSData *)data;
+ (NSString * _Nonnull)prettifiedStringFromDictionary:(nullable NSDictionary *)dictionary;

@end

NSString+PrettyPrint.m

#import "NSString+PrettyPrint.h"

@implementation NSString (Prettified)

- (NSString *)trimForCount:(NSUInteger)count {
    return self.length > count ? [self substringWithRange:NSMakeRange(0, count)] : self;
}

+ (NSString *)prettifiedStringFromDictionary:(nullable NSDictionary *)dictionary {
    
    if (dictionary == nil) { return @"nil"; }
    
    NSMutableString *returnStr = [NSMutableString stringWithString:@"[ \n"];
    
    for (NSString *key in dictionary) {
        [returnStr appendFormat:@"  %@: %@,\n", key, [dictionary valueForKey:key]];
    }
    
    [returnStr appendFormat:@"]"];
    
    return returnStr;
}

+ (NSString *)prettifiedJsonStringFromData:(nullable NSData *)data {
    
    if (data == nil) { return @"nil"; }
    
    
    NSData *jsonData;
    NSError *error = nil;
    
    NSString *jsonStr = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    jsonData = [jsonStr dataUsingEncoding:NSUTF8StringEncoding];
    id jsonObject;
    @try {
        jsonObject = [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingAllowFragments error:&error];
    } @catch(id anException) {
        return anException ? [NSString stringWithFormat:@"Json Parse Exception: %@", anException] : jsonStr ? jsonStr : @"json parse exception";
    }
    if (jsonObject == nil) {
        return jsonStr ? jsonStr : @"nil (json object from data)";
    } else {
        BOOL isValidJsonObject = [NSJSONSerialization isValidJSONObject:jsonObject];
        if (isValidJsonObject) {
            NSData *finalData = [NSJSONSerialization dataWithJSONObject:jsonObject options:NSJSONWritingPrettyPrinted error:&error];
            //TODO: error description
            NSString *prettyJson = [[NSString alloc] initWithData:finalData encoding:NSUTF8StringEncoding];
            return prettyJson;
        } else {
            return [NSString stringWithFormat:@"%@\n%@", jsonStr, @" (⚠️ Invalid json object ⚠️)\n"];
        }
    }
}

@end

然后调用方法，

ex1。打印正文、响应等的 NSData

NSLog(@"body: %@", [NSString prettifiedJsonStringFromData:[request HTTPBody]]);

ex2。打印 NSDictionary

NSLog(@"headers: %@", [NSString prettifiedStringFromDictionary:[request allHTTPHeaderFields]]);

您可能会在日志中得到这些结果。

编辑日志：

编辑于220112，防止异常

如何漂亮打印 json 来自 API 在调试器中调用的响应？

How to prettyPrint json response from API call in debugger?

debugging

xcode

swift

xcode9