应用数据plist存储方法

应用数据plist存储方法

        OSX或IOS应用数据存储的常用方式:

  1. Plist归档
  2.  Preference(偏好设置)存储
  3. NSKeyedArchiver归档
  4. SQLite3
  5. Core Data

        其中,Preference存储，即是NSUserDefault存储，其实也就是存储成Plist文件。

        本文主要探讨plist存储，自己coding实现存储的过程。基本的方法就是增、删、改、查吧。
        基本功能大概如下：

  1. 添加的方法，使用键值对key-value形式存储.
  2. 取值方法，通过key来获取value.
  3. 删除方法，通过key来删除value.
  4. 修改方法，通过key来修改value.

        主要提供了一些思路，希望能够起到抛砖引玉的作用。最后附上大致的代码：

@interface DataStorage : NSObject

@property (nonatomic,copy) NSString *savePath;

+(DataStorage *)sharedInstance;

//key-value存储
- (void)setItemValue: (id)value
             forKey : (NSString *)key;
//通过key获取value
- (id)itemValueForKey : (NSString *)key;
//通过key删除value
- (void)removeItemValueForKey: (NSString *)key;
//通过一组key删除一组value
- (void)removeItemValueForKeys:(NSArray *)keyArray;
//通过key修改value
- (void)replaceItemValue:(NSString *)newValue forKey:(NSString *)key;
//删除所有的value
- (void)removeAllItemValues;
//获取所存值的个数
- (NSInteger)getItemValueCount;

@end

@implementation DataStorage

@synthesize savePath;

+ (DataStorage *)sharedInstance {
    static DataStorage *_sharedManager = nil;
    static dispatch_once_t oncePredicate;
    dispatch_once(&oncePredicate, ^{
        _sharedManager = [[self alloc] init];
    });
    return _sharedManager;
}

- (id)init {
    self = [super init];
    if (self) {
        NSString *plistPath = [[self documentPath] stringByAppendingString:@"appData.plist"];
        self.savePath = plistPath;
        [self initPlist];
    }
    return self;
}

- (void)setSaveFolderPath:(NSString *)saveFolderPath {
    self.savePath = saveFolderPath;
}

- (void)setItemValue:(id)value
              forKey:(NSString *)key {
    NSMutableDictionary *plistDictionary  = [[NSMutableDictionary alloc]init];
    if ([self isPlistFileExists]) {
        NSMutableDictionary *plistExistDictionary = [self readPlist];
        if (plistExistDictionary != nil) {
            [plistDictionary setDictionary:plistExistDictionary];
        }
    }
    [plistDictionary setValue:value forKey:key];
    [self writeToPlist:plistDictionary];
}

- (id)itemValueForKey:(NSString *)key {
    NSMutableDictionary *dataDictionary = [self readPlist];
    return [dataDictionary objectForKey:key];
}

- (void)removeItemValueForKey:(NSString *)key {
    NSMutableDictionary *dataDictionary = [self readPlist];
    [dataDictionary removeObjectForKey:key];
    [self writeToPlist:dataDictionary];

}

- (void)removeItemValueForKeys:(NSArray *)keyArray {
   NSMutableDictionary *dataDictionary = [self readPlist];
   [dataDictionary removeObjectsForKeys:keyArray];
   [self writeToPlist:dataDictionary];
}

- (void)removeAllItemValues {
    NSMutableDictionary *dataDictionary = [self readPlist];
    [dataDictionary removeAllObjects];
    [self writeToPlist:dataDictionary];
}

- (NSString *)getPlistPath {
    if (self.savePath == nil) {
        NSString *plistPath = [[self documentPath] stringByAppendingString:@"appData.plist"];
        self.savePath = plistPath;
    }
    return  self.savePath;
}

- (BOOL)isPlistFileExists {
    NSString *plistPath =[self getPlistPath];
    NSFileManager *fileManager = [NSFileManager defaultManager];
    if( [fileManager fileExistsAtPath:plistPath]== NO ) {
        NSLog(@"not exist");
        return NO;
    }else{
        NSLog(@"exist");
        return YES;
    }
}

- (void)initPlist {
    NSString *plistPath = [self getPlistPath];
    if (![self isPlistFileExists]) {
        NSFileManager *fileManager = [NSFileManager defaultManager];
        [fileManager createFileAtPath:plistPath contents:nil attributes:nil];
    }
}

-(BOOL)isItemValueExistsForKey:(NSString *)key {
    NSMutableDictionary *dataDictionary = [self readPlist];
    if ([dataDictionary objectForKey:key]) {
        NSLog(@"value not exist");
        return YES;
    }else{
        NSLog(@"value  exist");
        return NO;
    }
}

- (void)deletePlist {
    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSString *plistPath = [self getPlistPath];
    [fileManager removeItemAtPath:plistPath error:nil];
}


- (NSMutableDictionary *)readPlist {
    NSString *plistPath = [self getPlistPath];
    NSData *plistData = [[NSFileManager defaultManager] contentsAtPath:plistPath];
    NSMutableDictionary *resultDictionary = (NSMutableDictionary *)
    [NSPropertyListSerialization propertyListWithData:plistData
                                              options:0
                                               format:nil
                                                error:nil];
    return [resultDictionary mutableCopy];
}

- (void)replaceItemValue:(NSString *)newValue forKey:(NSString *)key {
    NSMutableDictionary *plistDictionary  = [[NSMutableDictionary alloc]init];
    if ([self isPlistFileExists]) {
        NSMutableDictionary *plistExistDictionary = [self readPlist];
        if (plistExistDictionary != nil) {
            [plistExistDictionary removeObjectForKey:key];
            [plistDictionary setDictionary:plistExistDictionary];
        }
    }
    [plistDictionary setValue:newValue forKey:key];
    [self writeToPlist:plistDictionary];
}

- (NSInteger)getItemValueCount {
    NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init];
    dictionary = [self readPlist];
    return [dictionary count];
}

- (void)writeToPlist:(NSMutableDictionary *)plistDictionary {
    if (plistDictionary != nil) {
        NSString *plistPath = [self getPlistPath];
        NSError *error = nil;
        NSData *plistData = [NSPropertyListSerialization
            dataWithPropertyList:plistDictionary
                          format:NSPropertyListBinaryFormat_v1_0
                         options:0
                           error:&error];
        if ([plistData writeToFile:plistPath atomically:YES]) {
            NSLog(@"write ok!");
        } else {
            NSLog(@"write error!");
        }
    }
}

- (void)generatePlist:dictionary {
    [self writeToPlist:dictionary];
}

 - (NSString *)documentPath{

    NSString *budleIdentifier =[NSString stringWithFormat:@"/%@/",[[NSBundle mainBundle] bundleIdentifier]];

    NSString *path = [NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, YES)[0] stringByAppendingString:budleIdentifier];

    NSError *err = nil;

    if (![[NSFileManager defaultManager] fileExistsAtPath:path]) {

        [[NSFileManager defaultManager] createDirectoryAtPath:path withIntermediateDirectories:YES attributes:nil error:&err];

        if (err) {
            NSLog(@"file err:%@",err);
        }
    }

    return path;
}
@end

        

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