字符串,数组,json,字典之间的相互转化1

将NSData转化为NSString

+ (NSString *)jsonDataToString:(NSData *)jsonData
{
    NSString *jsonString = @"";
    if(jsonData != nil)
    {
        jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
    }
    return jsonString;
}

将字典或者数组转化为JSON Data

+ (NSData *)toJSONData:(id)theData
{
    NSError *error = nil;
    NSData *jsonData = nil;
    if ([NSJSONSerialization isValidJSONObject:theData]) {
        jsonData = [NSJSONSerialization dataWithJSONObject:theData
                                                   options:NSJSONWritingPrettyPrinted
                                                     error:&error];
    }
    if ([jsonData length] > 0 && error == nil){
        return jsonData;
    } else {
        return nil;
    }
}

将Data转化为jSON

+ (id)jsonDataToObj:(NSData *)data
{
    id obj = nil;
    
    if (data) {
        obj = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil];
    }
    return obj;
}

#pragma mark - json String to Object
+ (id)jsonStringToObj:(NSString *)jsonString
{
    id obj = nil;
    if (jsonString) {
        NSData *data = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
        if (data) {
            obj = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil];
        }
    }
    return obj;
}

+ (NSDictionary *)dictionaryWithJsonString:(NSString *)jsonString
{
    if (jsonString && [jsonString isKindOfClass:[NSDictionary class]])
    {
        return [(NSDictionary*)jsonString copy];
    }
    else if (jsonString && [jsonString isKindOfClass:[NSString class]] && jsonString.length > 0)
    {
        NSData *jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
        NSError *err;
        return [NSJSONSerialization JSONObjectWithData:jsonData
                                                            options:NSJSONReadingMutableContainers
                                                              error:&err];
    }
    else
    {
        return nil;
    }
}

+ (NSArray *)arrayWithJsonString:(NSString *)jsonString
{

    if (jsonString == nil || ![jsonString isKindOfClass:[NSString class]] || jsonString.length <= 0) {
        return nil;
    }
    
    NSData *jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
    NSError *err;
    
    NSArray *arr = [NSJSONSerialization JSONObjectWithData:jsonData
                                                        options:NSJSONReadingMutableContainers
                                                          error:&err];
    if(err) {
        NSLog(@"json解析失败：%@",err);
        return nil;
    }
    return arr;
}