仅需6步，教你轻易撕掉app开发框架的神秘面纱（6）：各种公共方法及工具类的封装

为什么要封装公共方法

封装公共方法有2方面的原因：
一是功能方面的原因：有些方法很多地方都会用，而且它输入输出明确，并且跟业务逻辑无关。比如检查用户是否登录，检查某串数字是否为合法的手机号。像这种方法就应该封装起来，供各个模块调用，避免重复造轮子。

二是防止出错：每一个合格的程序员就是从一个个错误中走出来的，任何一个架构包括android/iOS都有一些容易犯的错，我们可以把这些容易犯错的地方封装一下，每次用统一的，规定好的处理方式，这样就不会出错了。

防止重复：这个词在框架构造中提到的次数最多。这也是编写高可用代码的最重要的因素之一。

封装哪些内容及依据

下面就是一个最基本的应用需要封装的方法：

1. 时间相关：获取本地时间，获取服务器时间，获取时间格式化等等。
2. log和toast：log和toast的封装是为了做开关。应用正式版本中大多数调试log都应关闭。
3. 异常上传：把客户端错误上传至服务器，就可以从服务端查看客户端哪里问题最严重，有的放矢。对于android来说，获取未捕获异常也很重要，请 查看此文 ，向下滚动至第三点：异常类捕获。
4. 常见错误规避：如类型转换，subString这些容易引发异常的地方。
5. 一些工具方法：如dp转px，px转dp，md5，判断手机号邮箱是否合法，获取设备信息等等。

代码:
贴这些代码的目的是分辨出哪些代码可以放在utils中，并且要养成往utils中提取代码的习惯。

更充分一点儿说：只要有2个地方使用的类似代码，就需要考虑是否可以提取成公共方法了。

时间相关函数：

//android: TimeUtils.java
public class TimeUtils {private static long timeOffset = Long.MAX_VALUE;//同服务器的时间差public static long getLocalTime(){//获取本地时间，单位：sreturn (long)(getLocalTimeMs() / 1000.0);}public static long getCurrTime(){//获取服务器时间，单位：sreturn getCurrTimeInner(getLocalTime(), 1);}private static long getCurrTimeInner(long base, long factor){if(timeOffset != Long.MAX_VALUE && timeOffset != 0){return base + timeOffset * factor;}return base;}public static long getLocalTimeMs(){//获取本地时间，单位：msreturn System.currentTimeMillis();}public static long getCurrTimeMs(){//获取服务器时间，单位：msreturn getCurrTimeInner(getLocalTimeMs(), 1000);}public static void adjustTimeOff(long serverTimeStamp){//调整时间差，需要在调用服务器接口时获取到服务器时间后调用timeOffset = serverTimeStamp - getLocalTime();}
}

//iOS: TimeUtils.h#import <Foundation/Foundation.h>@interface TimeUtils : NSObject+(double)getLocalTimeWithSec;//获取本地时间，单位：s
+(double)getLocalTimeWithMSec;//获取本地时间，单位：ms
+(double)getCurrentTimeWithSec;//获取服务器时间，单位：s
+(double)getCurrentTimeWithMSec;//获取服务器时间，单位：ms
+(void)setTimeOffsetWithServer:(double) serverTime;调整时间差，需要在调用服务器接口时获取到服务器时间后调用@end

//iOS: TimeUtils.m#import "TimeUtils.h"static double sTimeOffWithServer = 0;@implementation TimeUtils+(double)getLocalTimeWithSec{return [[NSDate date]timeIntervalSince1970];
}+(double)getLocalTimeWithMSec{return [self getCurrentTimeWithSec] * 1000;
}+(void)setTimeOffsetWithServer:(double) serverTime{sTimeOffWithServer = serverTime - [self getLocalTimeWithSec];
}+(double)getCurrentTimeWithSec{return [self getLocalTimeWithSec] + sTimeOffWithServer;
}+(double)getCurrentTimeWithMSec{return [self getLocalTimeWithMSec] + sTimeOffWithServer;
}@end

log及toast封装

关联章节：网络模块封装

//android LogUtils.java
public class LogUtils {public static boolean isOpen = true;//所有非错误log必须使用此方法打印public static void d(String tag, String msg){if (isOpen){Log.d(tag, msg);}}//所有不带有异常的错误必须使用此方法打印public static void e(String tag, String msg){if (isOpen){Log.e(tag, msg);}else{uploadErrorLog(Utils.getClientInfo(), msg);}}public static String[] exceptionToString(Throwable e){StackTraceElement[] eles = e.getStackTrace();String []ret = new String[eles.length + 1];ret[0] = e.toString();for (int i = 0; i < eles.length; i++) {ret[i + 1] = "  at " + eles[i].toString();}return ret;}//所有带有异常的错误必须使用此方法打印public static void e(String tag, Throwable tr){if(isOpen){String exarr[] = exceptionToString(tr);for (int i = 0; i < exarr.length; i++){e(tag, exarr[i]);}}else{String exarr[] = exceptionToString(tr);StringBuilder sb = new StringBuilder();for (String s: exarr){sb.append(s);}//注：ClientInfo中包含：设备信息，应用信息，设备号等信息。uploadErrorLog(Utils.getClientInfo(), sb.toString());}}//上传错误至服务器private static void uploadErrorLog(String clientInfo, String errorString){//TODO：向特定服务器上传//此处为伪代码，具体代码请联系本系列的第四章，统一编写。Server.post("{\"clientInfo\":" + clientInfo + ",\"errorString\":" + errorString);}//提示用toastpublic static void toastTip(Context context,@NonNull String msg) {showToast(context, msg);}//调试用toastpublic static void toastDebug(Context context,@NonNull String msg) {if (isOpen) {showToast(context, msg);}}private static void showToast(Context context,@NonNull String msg) {Toast.makeText(context, msg, Toast.LENGTH_SHORT).show();}
}

//iOS: LogUtils.h//debug log的宏定义：所有非错误log必须使用此宏打印
#if defined(DEBUG) && DEBUG == 1
#define DebugLog(...) NSLog(__VA_ARGS__)
#else
#define DebugLog(...)
#endif//error log 的宏定义：所有错误log必须使用此宏打印
#if defined(DEBUG) && DEBUG == 1
#define ErrorLog(...) DebugLog(__VA_ARGS__)
#else
#define ErrorLog(...)                                                                         \
do{                                                                                           \NSString *errorString = [NSString stringWithFormat: __VA_ARGS__];                         \NSLog(errorString);                                                                       \[LogUtils uploadErrorLogWithClientInfo:[Utils getClientInfo] andErrorString:errorString]; \
}while(0);
#endif//tip toast宏定义：所有提示用户所用的宏定义必须使用此宏打印
#define TipToast(msg, duration, viewCtl) [LogUtils toastWithMessage: msg andDuration: duration andViewController:viewCtl]//debug toast宏定义：所有debug用的宏定义必须使用此宏打印
#if defined(DEBUG) && DEBUG == 1
#define DebugToast(msg, duration, viewCtl) TipToast(msg, duration, viewCtl)
#else
#define DebugToast(msg, duration, viewCtl)
#endif@interface LogUtils : NSObject
//上传错误数据至服务器。
+(void) uploadErrorLogWithClientInfo:(NSString *)clientInfo andErrorString:(NSString*) errorString;
//为某个页面显示toast，模拟android
+(void) toastWithMessage:(NSString *)msg andDuration:(NSInteger) duration andViewCotroller:(UIViewController *)viewCtl;
@end

//iOS: LogUtils.m
#import "LogUtils.h"
@implements LogUtils
+(void)uploadErrorLogWithClientInfo:(NSString *)clientInfo andErrorString:(NSString*) errorString{//TODO：向特定服务器上传//此处为伪代码，具体代码请联系本系列的第四章：[网络模块封装](http://blog.csdn.net/hard_man/article/details/50699346)，统一编写。[Server postWithString: "{\"clientInfo\":" + clientInfo + ",\"errorString\":" + errorString];
}
+(void) toastWithMessage:(NSString *)msg andDuration:(NSInteger) duration andViewCotroller:(UIViewController *)viewCtl{UIView *baseView = [[UIView alloc] init];[viewCtl.view addSubview:baseView];baseView.userInteractionEnabled = NO;//此处使用Masory来指定View的大小和位置[baseView makeConstraints:^(MASConstraintMaker *make) {make.edges.equalTo(viewCtl.view);}];UIView *toastBg = [[UIView alloc] init];//背景色toastBg.backgroundColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:0.8];//设置圆角toastBg.layer.cornerRadius = 3;toastBg.layer.masksToBounds = YES;//关闭点击toastBg.userInteractionEnabled = NO;[baseView addSubview:toastBg];[toastBg makeConstraints:^(MASConstraintMaker *make) {make.width.lessThanOrEqualTo(viewCtl.view.bounds.size.width - 30);make.centerX.equalTo(baseView);make.centerY.equalTo(baseView).offset(0);}];//文字UILabel *label = [[UILabel alloc] init];label.text = msg;label.textColor = [Color whiteColor];label.textAlign = NSTextAlignmentLeft;label.font = [UIFont systemFontOfSize: 15];label.numberOfLines = 3;label.userInteractionEnabled = NO;[toastBg addSubview:label];[label makeConstraints:^(MASConstraintMaker *make) {make.edges.equalTo(toastBg).insets(UIEdgeInsetsMake(5, 10, 5, 10));}];[baseView layoutIfNeeded];[UIView animateWithDuration:0.3 delay:duration options:UIViewAnimationOptionCurveLinear animations:^{toastBg.alpha = 0;} completion:^(BOOL finished) {[baseView removeFromSuperview];}];
}
@end

//android: Utils.java
//下面是我项目中使用的，查看更多可[点击此处](http://www.cnblogs.com/cr330326/p/4422507.html)。
public class Utils{//获取app信息public static String getClientInfo(){StringBuilder ret = new StringBuilder();//系统版本ret.append("os:android");//系统版本号：ret.append(",osVersion:" + android.os.Build.VERSION.RELEASE);//手机型号：ret.append(",phoneBrand:" + android.os.Build.BRAND);ret.append(",phoneModel:" + android.os.Build.MODEL);//      ret.append(",phoneDevice:" + android.os.Build.DEVICE);
//      ret.append(",phoneID:" + android.os.Build.ID);
//      ret.append(",phoneBootLoader:" + android.os.Build.BOOTLOADER);
//      ret.append(",phoneBoard:" + android.os.Build.BOARD);
//      ret.append(",phoneCpuAbi:" + android.os.Build.CPU_ABI);
//      ret.append(",phoneCpuAbi2:" + android.os.Build.CPU_ABI2);
//      ret.append(",phoneDisplay:" + android.os.Build.DISPLAY);
//      ret.append(",phoneFingerPrint:" + android.os.Build.FINGERPRINT);
//      ret.append(",phoneHardware:" + android.os.Build.HARDWARE);
//      ret.append(",phoneHost:" + android.os.Build.HOST);
//      ret.append(",phoneManufacturer:" + android.os.Build.MANUFACTURER);
//      ret.append(",phoneProduct:" + android.os.Build.PRODUCT);
//      ret.append(",phoneRadio:" + android.os.Build.RADIO);
//      ret.append(",phoneSerial:" + android.os.Build.SERIAL);
//      ret.append(",phoneTags:" + android.os.Build.TAGS);
//      ret.append(",phoneTime:" + android.os.Build.TIME);
//      ret.append(",phoneType:" + android.os.Build.TYPE);
//      ret.append(",phoneUser:" + android.os.Build.USER);
//      ret.append(",phoneGetRadioVersion:" + android.os.Build.getRadioVersion());//app 版本号try {PackageInfo pkgInfo = Constants.GLOBAL_CONTEXT.getPackageManager().getPackageInfo(Constants.GLOBAL_CONTEXT.getPackageName(), 0);ret.append(",appVersionName:" + pkgInfo.versionName);ret.append(",appVersionCode:" + pkgInfo.versionCode);} catch (NameNotFoundException e) {}//uuidTelephonyManager telephonyManager = (TelephonyManager) Constants.GLOBAL_CONTEXT.getSystemService(Context.TELEPHONY_SERVICE);ret.append(",uuid:" + telephonyManager.getDeviceId());return ret.toString();}//避免出错的substringpublic static String subString(String src, int start, int to){if(src != null){int len = src.length;int wantLen = to - start + 1;if(wantLen < len){to = len - 1;wantLen = to - start + 1;}if(to >= start){return src.substring(start, wantLen);}else{return null;}}return null;}public static int getStatusBarHeight() {Class<?> c = null;Object obj = null;Field field = null;int x = 0, sbar = 0;try {c = Class.forName("com.android.internal.R$dimen");obj = c.newInstance();field = c.getField("status_bar_height");x = Integer.parseInt(field.get(obj).toString());sbar = context.getResources().getDimensionPixelSize(x);} catch (Exception e1) {e1.printStackTrace();}if (sbar == 0) {sbar = Util.dp(20);}return sbar;}//获取屏幕高度public static int getScreenHeight() {return context.getResources().getDisplayMetrics().heightPixels;}public static int getScreenWidth() {return context.getResources().getDisplayMetrics().widthPixels;}//dp sp px 之间转换public static int px2dp(int px) {return (int) (1.0f * px / context.getResources().getDisplayMetrics().density + 0.5f);}public static int dp2px(int dp) {return (int) (1.0f * dp * context.getResources().getDisplayMetrics().density + 0.5f);}public static int sp2px(int sp) {return (int) (1.0f * sp * context.getResources().getDisplayMetrics().scaledDensity + 0.5f);}public static int px2sp(int px) {return (int) (1.0f * px / context.getResources().getDisplayMetrics().scaledDensity + 0.5f);}public static int sp2dp(int sp) {return px2dp(sp2px(sp));}public static int dp2sp(int dp) {return px2sp(dp2px(dp));}public static int dp(int dp) {return dp2px(dp);}public static int sp(int sp) {return sp2px(sp);}//读取asstes图片public static Bitmap getImageFromAssetsFile(String fileName, Context context) {Bitmap image = null;AssetManager am = context.getResources().getAssets();try {InputStream is = am.open(fileName);image = BitmapFactory.decodeStream(is);is.close();} catch (IOException e) {e.printStackTrace();}return image;}//验证邮箱格式public static boolean isEmail(String email) {String str = "^([\\w-\\.]+)@((\\[[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.)|(([\\w-]+\\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\\]?)$";Pattern p = Pattern.compile(str);Matcher m = p.matcher(email);return m.matches();}//验证手机号码格式public static boolean isMobileNO(String mobiles) {Pattern p = Pattern.compile("^1(3[0-9]|4[57]|5[0-35-9]|8[025-9]|7[0-9])\\d{8}$");Matcher m = p.matcher(mobiles);return m.matches();}
}

//iOS: Utils.h
@interface Utils:NSObject//下面是一系列回调函数block
typedef void (^VoidIntCallback) (NSUInteger);
typedef void (^VoidCallback) ();
typedef void (^VoidStringCallback) (NSString *);
typedef void (^VoidBoolCallback) (BOOL);
typedef void (^VoidIdCallback) (id);//获取当前设备名称
+ (NSString *)getDeviceName;
//获取设备信息
+(NSString *)getClientInfo;
+(int)getRandomNumber:(int)from to:(int)to;
//获取文件夹的大小
+(float) folderSizeAtPath:(NSString*) folderPath;
+(long long) fileSizeAtPath:(NSString*) filePath;
//清除缓存
+(NSString *)clearCache;
//判断输入是否合法
+(BOOL) isValidPhone:(NSString *)num;
+(BOOL) isValidEmail:(NSString *)email;//一个页面中局部view显示／隐藏时所用的动画。默认采取渐显／渐隐的方式
+(void) createShowAnimForViewTypeChangeWithOneView:(UIView *) view andComplete:(VoidCallback) completeCb;
+(void) createHideAnimForViewTypeChangeWithOneView:(UIView *) view andComplete:(VoidCallback) completeCb;
+(void) createAnimForViewTypeChangeWithFromView:(UIView *) fromView toView:(UIView *)toView andComplete:(VoidCallback) completeCb;
@end

//iOS: Utils.m
#import "Utils.h"
#import <ADSupport/ASIdentifierManager.h>
@implements Utils//这个函数是从网上找的代码，不是很准确，使用的方法也奇怪，这里只是表示一个意思，可令getClientInfo调用。
//想要更正确的代码，请自行查找。
+ (NSString *)getDeviceName{CGRect rect = [[UIScreen mainScreen] bounds];CGFloat width = rect.size.width;CGFloat height = rect.size.height;//get current interface OrientationUIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];//unknownif (UIInterfaceOrientationUnknown == orientation) {return @"unknown";}//    portrait  width * height//    iPhone4:320*480//    iPhone5:320*568//    iPhone6:375*667//    iPhone6Plus:414*736//portraitif (UIInterfaceOrientationPortrait == orientation) {if (width ==  320.0f) {if (height == 480.0f) {return @"iphone4/iPhone4s";//iphone4} else {return @"iPhone5/iPhone5s";}} else if (width == 375.0f) {return @"iPhone6/iPhone6s";} else if (width == 414.0f) {return @"iPhone6plus/iPhone6sPlus";}} else if (UIInterfaceOrientationLandscapeLeft == orientation || UIInterfaceOrientationLandscapeRight == orientation) {//landscapeif (height == 320.0) {if (width == 480.0f) {return @"iphone4/iPhone4s";} else {return @"iPhone5/iPhone5s";}} else if (height == 375.0f) {return @"iPhone6/iPhone6s";} else if (height == 414.0f) {return @"iPhone6plus/iPhone6sPlus";}}return -1;
}
//获取设备信息
+(NSString *)getClientInfo{NSMutableString *ret = [[NSMutableString alloc]init];[ret appendString:@"os:iphone"];[ret appendFormat:@",osVersion:%f", [[[UIDevice currentDevice] systemVersion] floatValue]];[ret appendString:@",phoneBrand:iphone"];[ret appendFormat:@",phoneModel:%@", [self getDeviceName]];[ret appendFormat:@",appVersionName:%@", [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleShortVersionString"]];[ret appendFormat:@",appVersionCode:%@", [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleVersion"]];NSString * adId = [[[ASIdentifierManager sharedManager] advertisingIdentifier] UUIDString];NSString * deviceId = [[UIDevice currentDevice].identifierForVendor UUIDString];[ret appendFormat:@",deviceId:%@", deviceId];NSString *identifier = nil;if(!adId){identifier = deviceId;}else{identifier = adId;[ret appendFormat:@",adId:%@", adId];}[ret appendFormat:@",uuid:%@", identifier];return ret;
}+ (long long) fileSizeAtPath:(NSString*) filePath{NSFileManager* manager = [NSFileManager defaultManager];if ([manager fileExistsAtPath:filePath]){return [[manager attributesOfItemAtPath:filePath error:nil] fileSize];}return 0;
}+(int)getRandomNumber:(int)from to:(int)to{return (int)(from + (arc4random() % (to - from + 1)));
}//遍历文件夹获得文件夹大小，返回多少M
+ (float ) folderSizeAtPath:(NSString*) folderPath{NSFileManager* manager = [NSFileManager defaultManager];if (![manager fileExistsAtPath:folderPath]) return 0;NSEnumerator *childFilesEnumerator = [[manager subpathsAtPath:folderPath] objectEnumerator];NSString* fileName;long long folderSize = 0;while ((fileName = [childFilesEnumerator nextObject]) != nil){NSString* fileAbsolutePath = [folderPath stringByAppendingPathComponent:fileName];folderSize += [self fileSizeAtPath:fileAbsolutePath];}return folderSize/(1024.0*1024.0);
}+ (NSString *)clearCache
{//清除缓存目录NSArray *searchPaths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);NSString *searchPath = [searchPaths lastObject];NSString *str = [NSString stringWithFormat:@"缓存已清除%.1fM", [self folderSizeAtPath:searchPath]];NSLog(@"%@",str);NSArray *files = [[NSFileManager defaultManager] subpathsAtPath:searchPath];for (NSString *p in files) {NSError *error;NSString *currPath = [searchPath stringByAppendingPathComponent:p];if ([[NSFileManager defaultManager] fileExistsAtPath:currPath]) {BOOL ret = [[NSFileManager defaultManager] removeItemAtPath:currPath error:&error];YYLog(@"移除文件 %@ ret= %d", currPath, ret);}else{YYLog(@"文件不存在 %@", currPath);}}return str;
}
+(BOOL) isValidNum:(NSString *)num{const char *cvalue = [num UTF8String];int len = (int)strlen(cvalue);for (int i = 0; i < len; i++) {if(cvalue[i] < '0' || cvalue[i] > '9'){return NO;}}return YES;
}
+(BOOL) isValidPhone:(NSString *)num{if (!num) {return NO;}const char *cvalue = [num UTF8String];int len = (int)strlen(cvalue);if (len != 11) {return NO;}if (![Util isValidNum:num]){return NO;}NSString *preString = [[NSString stringWithFormat:@"%@",num] substringToIndex:2];if ([preString isEqualToString:@"13"] ||[preString isEqualToString: @"15"] ||[preString isEqualToString: @"18"] ||[preString isEqualToString: @"17"]){return YES;}else{return NO;}return YES;
}+ (BOOL) isValidEmail:(NSString *)e
{if (!e) {return NO;}NSArray *array = [e componentsSeparatedByString:@"."];if ([array count] >= 4) {return NO;}NSString *emailRegex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}";NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegex];return [emailTest evaluateWithObject:e];
}@end

代码清单：

    //android: LogUtils.javaTimeUtils.javaUtils.java

    //iOS:LogUtils.hLogUtils.mTimeUtils.hTimeUtils.mUtils.hUtils.m

至此框架基本搭建完毕，可以快乐地写页面去啦。
当然在项目进行的过程中，也需要慢慢给这个还瘦弱的框架添枝加叶。
让它慢慢壮大，更加完整。
等经过一个或2个项目的洗礼，就会成为一个完整的，不错的框架了。