JavaVersion.h

#import <Foundation/Foundation.h>
 
@interface JavaVersion : NSObject
 
@property (nonatomic, readonly) NSInteger familyNumber;
@property (nonatomic, readonly) NSInteger updateNumber;
 
+ (BOOL)isValid:(NSString *)version;
+ (id)parse:(NSString *)str;
 
- (NSComparisonResult)compare:(JavaVersion *)otherVersion;
- (BOOL)lessThan:(JavaVersion *)otherVersion;
- (BOOL)greaterThan:(JavaVersion *)otherVersion;
 
@end

JavaVersion.m

#import "JavaVersion.h"
 
@implementation JavaVersion
 
+ (BOOL)isValid:(NSString *)version
{
    @try {
        [JavaVersion parse:version];
    }
    @catch (NSException *exception) {
        if ([exception.name isEqualToString:@"JVParseException"]) {
            return NO;
        } else {
            [exception raise];
        }
    }
    return YES;
}
 
+ (id)parse:(NSString *)version
{
    NSScanner *scanner = [NSScanner scannerWithString:version];
    // VERSION FORMAT 'JDK7u40'
    [scanner scanString:@"JDK" intoString:NULL];
    int familyNumber, updateNumber;
    [scanner scanInt:&familyNumber];
    [scanner scanString:@"u" intoString:NULL];
    [scanner scanInt:&updateNumber];
    // 正しくスキャンできれば version lenght と scanLocation は等しい
    if ([version length] != [scanner scanLocation]) {
        [NSException raise:@"JVParseException" format:@"Format is invalid"];
    }
    JavaVersion *v = [[JavaVersion alloc] initWithFamilyNumber:familyNumber updateNumber:updateNumber];
    return v;
}
 
- (id)initWithFamilyNumber:(NSInteger)familyNumber updateNumber:(NSInteger)updateNumber
{
    self = [super init];
    if (self) {
        _familyNumber = familyNumber;
        _updateNumber = updateNumber;
    }
    return self;
}
 
- (NSComparisonResult)compare:(JavaVersion *)otherVersion
{
    // ファミリーナンバーを比較
    if (self.familyNumber > otherVersion.familyNumber) {
        return NSOrderedDescending;
    }
    if (self.familyNumber < otherVersion.familyNumber) {
        return NSOrderedAscending;
    }
    
    // ファミリーナンバーが等しいときはアップデートナンバーを比較
    if (self.updateNumber > otherVersion.updateNumber) {
        return NSOrderedDescending;
    }
    if (self.updateNumber < otherVersion.updateNumber) {
        return NSOrderedAscending;
    }
    
    return NSOrderedSame;
}
 
- (BOOL)lessThan:(JavaVersion *)otherVersion
{
    return [self compare:otherVersion] == NSOrderedAscending;
}
 
- (BOOL)greaterThan:(JavaVersion *)otherVersion
{
    return [self compare:otherVersion] == NSOrderedDescending;
}
 
@end

JavaVersionSpec.m

#import <Kiwi/Kiwi.h>
#import "JavaVersion.h"

SPEC_BEGIN(hoge)

describe(@"JavaVersion", ^{
    it(@"isValidはJDK7u40のときture", ^{
        [[@([JavaVersion isValid:@"JDK7u40"]) should] beYes];
    });
    
    it(@"JDK7u40以外はfalse", ^{
        [[@([JavaVersion isValid:@"hoge"]) should] beNo];
    });
    
    it(@"isValidはJDK7u9xのときfalse", ^{
        [[@([JavaVersion isValid:@"JDK7u9x"]) should] beNo];
    });
    
    it(@"インスタンスのfamilyNumberメソッドはファミリーナンバーを返す", ^{
        JavaVersion *v = [JavaVersion parse:@"JDK7u40"];
        [[@([v familyNumber]) should] equal:@7];
    });
    
    it(@"インスタンスのupdateNumberメソッドはアップデートナンバーを返す", ^{
        JavaVersion *v = [JavaVersion parse:@"JDK7u40"];
        [[@([v updateNumber]) should] equal:@40];
    });
    
    it(@"パースできないときは例外を投げる", ^{
        [[theBlock(^{
            [JavaVersion parse:@"Hohogheohoheoge"];
        }) should]  raiseWithName:@"JVParseException"];
    });
    
    describe(@"compare", ^{
        __block JavaVersion *a, *b, *c, *d;
        beforeAll(^{
            a = [JavaVersion parse:@"JDK7u51"];
            b = [JavaVersion parse:@"JDK7u40"];
            c = [JavaVersion parse:@"JDK8u0"];
            d = [JavaVersion parse:@"JDK7u51"];
        });
        
        it(@"a は b より大きい", ^{
            [[@([a compare:b]) should] equal:@(NSOrderedDescending)];
            [[@([a greaterThan:b]) should] beTrue];
        });
        
        it(@"a は c より小さい", ^{
            [[@([a compare:c]) should] equal:@(NSOrderedAscending)];
            [[@([a lessThan:c]) should] beTrue];
        });
        it(@"a は d と等しい", ^{
            [[@([a compare:d]) should] equal:@(NSOrderedSame)];
        });
        
    });
});

SPEC_END