Java代码  

1. /** 
2.     1:Documents：应用中用户数据可以放在这里，iTunes备份和恢复的时候会包括此目录 
3.     2:tmp：存放临时文件，iTunes不会备份和恢复此目录，此目录下文件可能会在应用退出后删除 
4.     3:Library/Caches：存放缓存文件，iTunes不会备份此目录，此目录下文件不会在应用退出删除 
5.      */  
6.     NSArray *paths1=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory  
7.                                                        , NSUserDomainMask  
8.                                                        , YES);  
9.       
10.       
11.     NSString *documentsDirect=[paths1 objectAtIndex:0];  
12.     assert(1 == paths1.count);  
13.     NSLog(@">>documentsDirect=%@",documentsDirect);  
14.    
15.     NSArray *Librarypaths =  NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory, NSDocumentDirectory, YES);  
16.     NSString* libraryDirectory  = [Librarypaths objectAtIndex:0];  
17.     NSLog(@">>Librarypaths.length =%d",[Librarypaths count]);  
18.      assert(1 < Librarypaths.count);  
19.        
20.     NSLog(@"libraryDirectory=%@",libraryDirectory);  
21.       
22.     //如果要指定其他文件目录，比如Caches目录，需要更换目录工厂常量，上面代码其他的可不变  
23.     NSArray *pathcaches=NSSearchPathForDirectoriesInDomains(NSCachesDirectory  
24.                                                        , NSUserDomainMask  
25.                                                        , YES);  
26.     NSString* cacheDirectory  = [pathcaches objectAtIndex:0];  
27.     NSLog(@"cacheDirectory=%@",cacheDirectory);  
28.     /** 
29.      使用NSSearchPathForDirectoriesInDomains只能定位Caches目录和Documents目录。 
30.       
31.      tmp目录，不能按照上面的做法获得目录了，有个函数可以获得应用的根目录 
32.      */  
33.     NSString *tempDir1=NSHomeDirectory() ;  
34.     NSString *tempDir2=NSTemporaryDirectory();  
35.     NSLog(@"tempDir1=%@",tempDir1);  
36.     NSLog(@"tempDir2=%@",tempDir2);  

/**    1:Documents：应用中用户数据可以放在这里，iTunes备份和恢复的时候会包括此目录    2:tmp：存放临时文件，iTunes不会备份和恢复此目录，此目录下文件可能会在应用退出后删除    3:Library/Caches：存放缓存文件，iTunes不会备份此目录，此目录下文件不会在应用退出删除     */    NSArray *paths1=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory                                                       , NSUserDomainMask                                                       , YES);            NSString *documentsDirect=[paths1 objectAtIndex:0];    assert(1 == paths1.count);    NSLog(@">>documentsDirect=%@",documentsDirect);     NSArray *Librarypaths =  NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory, NSDocumentDirectory, YES);    NSString* libraryDirectory  = [Librarypaths objectAtIndex:0];    NSLog(@">>Librarypaths.length =%d",[Librarypaths count]);     assert(1 < Librarypaths.count);         NSLog(@"libraryDirectory=%@",libraryDirectory);        //如果要指定其他文件目录，比如Caches目录，需要更换目录工厂常量，上面代码其他的可不变    NSArray *pathcaches=NSSearchPathForDirectoriesInDomains(NSCachesDirectory                                                       , NSUserDomainMask                                                       , YES);    NSString* cacheDirectory  = [pathcaches objectAtIndex:0];    NSLog(@"cacheDirectory=%@",cacheDirectory);    /**     使用NSSearchPathForDirectoriesInDomains只能定位Caches目录和Documents目录。          tmp目录，不能按照上面的做法获得目录了，有个函数可以获得应用的根目录     */    NSString *tempDir1=NSHomeDirectory() ;    NSString *tempDir2=NSTemporaryDirectory();    NSLog(@"tempDir1=%@",tempDir1);    NSLog(@"tempDir2=%@",tempDir2);

  归档 普通自定义对象和字节流之间的转换

 序列化 某些特定类型（NSDictionary, NSArray, NSString, NSDate, NSNumber，NSData）的数据和字节流之间(通常将其保存为plist文件)的转换

 2.1 归档

 如果我们需要将自定义的一个对象保存到文件，应该如何做呢？ 

这里引入两个东西：一个是NSCoding协议 ；另一个是NSKeyedArchiver，NSKeyedArchiver其实继承于NSCoder，可以以键值对的方式将对象的属性进行序列化和反序列化。 
具体的过程可以这样描述 通过NSKeyedArchiver 可以将实现了NSCoding协议的对象 和 字节流 相互转换 。

像一些框架中的数据类型如NSDictionary,NSArray,NSString... 都已经实现了NSCoding协议，所以可以直接对他们进行归档操作。

  这里来一个比较完整的例子，一个Address类，一个User类，User类下有个Address类型的属性

Java代码  

1. #import <Foundation/Foundation.h>  
2.   
3. @interface Address : NSObject<NSCoding>  
4. {  
5.     NSString *country;  
6.     NSString *city;  
7. }  
8. @property(nonatomic,copy) NSString *country;  
9. @property(nonatomic,copy) NSString *city;   
10. @end  

#import <Foundation/Foundation.h>@interface Address : NSObject<NSCoding>{    NSString *country;    NSString *city;}@property(nonatomic,copy) NSString *country;@property(nonatomic,copy) NSString *city; @end

Java代码  

1. #import "Address.h"  
2.   
3. @implementation Address  
4. @synthesize country;  
5. @synthesize city;  
6. - (void)encodeWithCoder:(NSCoder *)aCoder{  
7.     [aCoder encodeObject:country forKey:@"country"];  
8.     [aCoder encodeObject:city forKey:@"city"];  
9. }  
10. - (id)initWithCoder:(NSCoder *)aDecoder{  
11.     if (self = [super init]) {  
12.         [self setCountry:[aDecoder decodeObjectForKey:@"country"]];  
13.         [self setCity:[aDecoder decodeObjectForKey:@"city"]];  
14.     } return self;  
15. }  
16. @end  

#import "Address.h"@implementation Address@synthesize country;@synthesize city;- (void)encodeWithCoder:(NSCoder *)aCoder{    [aCoder encodeObject:country forKey:@"country"];    [aCoder encodeObject:city forKey:@"city"];}- (id)initWithCoder:(NSCoder *)aDecoder{    if (self = [super init]) {        [self setCountry:[aDecoder decodeObjectForKey:@"country"]];        [self setCity:[aDecoder decodeObjectForKey:@"city"]];    } return self;}@end

Java代码  

1. #import <Foundation/Foundation.h>  
2. #import "Address.h"  
3. @interface User : NSObject<NSCoding>{  
4.     NSString *_name;  
5.     NSString *_password;  
6.     Address *_address;  
7. }  
8. @property(nonatomic,copy) NSString *name;  
9. @property(nonatomic,copy) NSString *password;  
10. @property(nonatomic,retain) Address *address;  
11.   
12. @end  

#import <Foundation/Foundation.h>#import "Address.h"@interface User : NSObject<NSCoding>{    NSString *_name;    NSString *_password;    Address *_address;}@property(nonatomic,copy) NSString *name;@property(nonatomic,copy) NSString *password;@property(nonatomic,retain) Address *address;@end

Java代码  

1. #import "User.h"  
2.   
3.   
4. @implementation User  
5. @synthesize name = _name;  
6. @synthesize password = _password;  
7. @synthesize address = _address;  
8.   
9. - (void)encodeWithCoder:(NSCoder *)aCoder{  
10.     [aCoder encodeObject:_name forKey:@"name"];  
11.     [aCoder encodeObject:_password forKey:@"password"];  
12.     [aCoder encodeObject:_address forKey:@"address"];  
13. }  
14. - (id)initWithCoder:(NSCoder *)aDecoder{  
15.     if (self = [super init]) {  
16.         [self setName:[aDecoder decodeObjectForKey:@"name"]];  
17.         [self setPassword:[aDecoder decodeObjectForKey:@"password"]];  
18.         [self setAddress:[aDecoder decodeObjectForKey:@"address"]];  
19.     }  
20.     return self;  
21. }  
22.   
23. @end  

#import "User.h"@implementation User@synthesize name = _name;@synthesize password = _password;@synthesize address = _address;- (void)encodeWithCoder:(NSCoder *)aCoder{    [aCoder encodeObject:_name forKey:@"name"];    [aCoder encodeObject:_password forKey:@"password"];    [aCoder encodeObject:_address forKey:@"address"];}- (id)initWithCoder:(NSCoder *)aDecoder{    if (self = [super init]) {        [self setName:[aDecoder decodeObjectForKey:@"name"]];        [self setPassword:[aDecoder decodeObjectForKey:@"password"]];        [self setAddress:[aDecoder decodeObjectForKey:@"address"]];    }    return self;}@end

 操作应用

Java代码  

1. NSString *tempDir2=NSTemporaryDirectory();      
2.      
3.      
4. // Do any additional setup after loading the view, typically from a nib.  
5.    Address *myAddress = [[Address alloc] init] ;  
6.    myAddress.country = @"中国";  
7.    myAddress.city = @"杭州";  
8.    User *user = [[User alloc] init] ;  
9.      
10.    user.name = @"卢克";  
11.    user.password = @"lukejin";  
12.    user.address = myAddress;  
13.    //归档  保存的是plist的二进制数据格式  
14.    NSString *path = [tempDir2 stringByAppendingPathComponent:@"user"];  
15.    [NSKeyedArchiver archiveRootObject:user toFile:path];  
16.      
17.      
18.    //从文档中读取  
19.    User *object = [NSKeyedUnarchiver unarchiveObjectWithFile:path];  
20.    NSLog(@"object.name : %@",object.name);  

 NSString *tempDir2=NSTemporaryDirectory();            	// Do any additional setup after loading the view, typically from a nib.    Address *myAddress = [[Address alloc] init] ;    myAddress.country = @"中国";    myAddress.city = @"杭州";    User *user = [[User alloc] init] ;        user.name = @"卢克";    user.password = @"lukejin";    user.address = myAddress;    //归档  保存的是plist的二进制数据格式    NSString *path = [tempDir2 stringByAppendingPathComponent:@"user"];    [NSKeyedArchiver archiveRootObject:user toFile:path];            //从文档中读取    User *object = [NSKeyedUnarchiver unarchiveObjectWithFile:path];    NSLog(@"object.name : %@",object.name);

使用数据对象自带的方法，如字典类写文件：

数据：

Java代码  

1. NSMutableDictionary *dataDictionary = [[NSMutableDictionary alloc] init] ;  
2.   [dataDictionary setValue:[NSNumber numberWithInt:222] forKey:@"intNumber"];  
3.   [dataDictionary setValue:[NSArray arrayWithObjects:@"1",@"2", nil] forKey:@"testArray"];  

  NSMutableDictionary *dataDictionary = [[NSMutableDictionary alloc] init] ;    [dataDictionary setValue:[NSNumber numberWithInt:222] forKey:@"intNumber"];    [dataDictionary setValue:[NSArray arrayWithObjects:@"1",@"2", nil] forKey:@"testArray"];

 写文件

Java代码  

1. [dataDictionary writeToFile:@"/Users/zhoumoban/Desktop/test.plist" atomically:YES];  

[dataDictionary writeToFile:@"/Users/zhoumoban/Desktop/test.plist" atomically:YES];

 读文件：

Java代码  

1. NSDictionary *dictionaryFromFile = [NSDictionary dictionaryWithContentsOfFile:@"/Users/zhoumoban/Desktop/test.plist"];  
2.    NSLog(@"%@",[dictionaryFromFile objectForKey:@"intNumber"]);  

 NSDictionary *dictionaryFromFile = [NSDictionary dictionaryWithContentsOfFile:@"/Users/zhoumoban/Desktop/test.plist"];    NSLog(@"%@",[dictionaryFromFile objectForKey:@"intNumber"]);

 另外：使用NSPropertyListSerialization类。通过NSPropertyListSerialization类可以将数据对象直接转成NSData或者直接写到文件或者流中去

Java代码  

1. NSString *error;  
2.       
3.     NSData *xmlData = [NSPropertyListSerialization dataFromPropertyList:dataDictionary format:NSPropertyListXMLFormat_v1_0 errorDescription:&error];  
4.       
5.     if(xmlData) {  
6.         NSLog(@"No error creating XML data.");  
7.         [xmlData writeToFile:@"/Users/zhoumoban/Desktop/test2.plist" atomically:YES];  
8.     } else {  
9.         if (error) {  
10.             NSLog(@"error:%@", error);  
11.            // [error release];  
12.         }  
13.     }  
14.      //读取  
15.     NSDictionary *dictionaryFromFile2 = (NSDictionary *)[NSPropertyListSerialization propertyListWithData:[NSData dataWithContentsOfFile:@"/Users/zhoumoban/Desktop/test2.plist"] options:0 format:NULL error:&error];  
16.     NSLog(@"＝＝＝%@",[dictionaryFromFile2 objectForKey:@"intNumber"]);  

iOS 各种系统文件目录 临时，缓存，document,lib,归档，序列化