Java重構示例
1.儘可能簡潔
1.1重構前
if ( flag == 1 ){
return true;
}
else{
return false;
}
1.2重構後
return flag == 1;
2.使用三位運算符
2.1重構前
if ( "Male".equals(gender) ) {
return "Mr.";
}
else{
return "Mrs.";
}
2.2重構後
return "Male".equals(gender) ? "Mr." : "Mrs.";
3.使用常量替換硬編碼
3.1重構前
for (int i = 0; i < 12; i++) {
this.getDays(i);
//skip...
}
3.2重構後
int YEAR_MONTHS = 12;
for (int month = 0; month < Month.YEAR_MONTHS; month++) {
this.getDays(month);
//skip...
}
4.使用方法替換反覆出現的表達式
4.1重構前
public boolean isStartAfter(Date date) {
Calendar calendar = BusinessCalendar.getCalendar();
calendar.setTime(date);
int hour = calendar.get(Calendar.HOUR_OF_DAY);
int minute = calendar.get(Calendar.MINUTE);
return ((hour<fromHour) || ((hour==fromHour) && (minute<=fromMinute)));
}
public boolean includes(Date date) {
Calendar calendar = BusinessCalendar.getCalendar();
calendar.setTime(date);
int hour = calendar.get(Calendar.HOUR_OF_DAY);
int minute = calendar.get(Calendar.MINUTE);
return (((fromHour<hour) || ((fromHour==hour) && (fromMinute<=minute))) && ( (hour<toHour) || ( (hour==toHour) && (minute<=toMinute))));
}
4.2重構後
private boolean tailGreatHead(int headHour, int headMinute, int tailHour, int tailMinute, boolean includeEqual) {
boolean tailGreatHeadHour = (headHour < tailHour);
boolean tailEqualHeadHour = (headHour == tailHour);
boolean tailGreatHeadMinute = (headMinute < tailMinute);
boolean tailEqualHeadMinute = (headMinute == tailMinute);
boolean tailGreatEqualHeadMinute = tailGreatHeadMinute || includeEqual && tailEqualHeadMinute;
return (tailGreatHeadHour || (tailEqualHeadHour && tailGreatEqualHeadMinute));
}
private boolean tailGreatHead(int headHour, int headMinute, int tailHour, int tailMinute) {
return tailGreatHead(headHour, headMinute, tailHour, tailMinute, false);
}
private boolean tailGreatEqualHead(int headHour, int headMinute, int tailHour, int tailMinute) {
return tailGreatHead(headHour, headMinute, tailHour, tailMinute, true);
}
public boolean isStartAfter(Date date) {
Calendar calendar = BusinessCalendar.getCalendar();
calendar.setTime(date);
int hour = calendar.get(Calendar.HOUR_OF_DAY);
int minute = calendar.get(Calendar.MINUTE);
return this.tailGreatEqualHead(hour, minute, fromHour, fromMinute);
}
public boolean includes(Date date) {
Calendar calendar = BusinessCalendar.getCalendar();
calendar.setTime(date);
int hour = calendar.get(Calendar.HOUR_OF_DAY);
int minute = calendar.get(Calendar.MINUTE);
return this.tailGreatEqualHead(fromHour, fromMinute, hour, minute) && this.tailGreatEqualHead(hour, minute, toHour, toMinute);
}
5.及早結束非正常邏輯
5.1重構前
int count = 0;
if(taskList != null && !taskList.isEmpty()){
//skip...
return count;
} else {
return count;
}
5.2重構後
int count = 0;
if(taskList == null || taskList.isEmpty()){
return 0;
}
//skip...
return count;
6.知足條件當即跳出循環
6.1重構前
public boolean contain(int year, Month month, int day) {
boolean found = false;
for (IPolyDate date : dateList) {
if (date.same(year, month.getMonth(), day)) {
found = true;
break;
}
}
return found;
}
6.2重構後
public boolean contain(int year, Month month, int day) {
for (IPolyDate date : dateList) {
if (date.same(year, month.getMonth(), day)) {
return true;
}
}
return false;
}
7.使用表結構分離公共邏輯，避免重複（堅持DRY原則）
7.1重構前
public void testGetIntPart() throws Exception {
assertEquals("0", digitTransform.getIntPart("0.01");
assertEquals("1", digitTransform.getIntPart("1.2");
assertEquals("1234", digitTransform.getIntPart("1234");
assertEquals("1", digitTransform.getIntPart("1.01");
assertEquals("0", digitTransform.getIntPart("0.01");
assertEquals("11111", digitTransform.getIntPart("11111");
assertEquals("1000", digitTransform.getIntPart("1000.11");
}
7.2重構後
public void testGetIntPart() throws Exception {
String[][] cases = new String[][] {{"0.01","0"},{"1.2","1"},
{"1234","1234"},{"1.01","1"},{"0","0"},
{"11111","11111"},{"1000.11","1000"}};
for (int i = 0, len = cases.length; i < len; i++) {
assertEquals(cases[i][1], digitTransform.getIntPart(cases[i][0]));
}
}
8.分離變化參數，使用格式化方法
8.1重構前
public class ExceedMaxWeekIndexOfMonthException extends
IndexOutOfBoundsException {
private static final long serialVersionUID = 1L;
public ExceedMaxWeekIndexOfMonthException(String message) {
super(message);
}
}
8.2重構後
public class ExceedMaxWeekIndexOfMonthException extends
IndexOutOfBoundsException {
private static final long serialVersionUID = 1L;
public ExceedMaxWeekIndexOfMonthException(int index, int maxCountOfWeekDay,
Month month) {
super(formatMessage(index, maxCountOfWeekDay, month));
}
private static String formatMessage(int index, int maxCountOfWeekDay,
Month month) {
return "Arguement index[" + index + "] exceeds max week index["
+ maxCountOfWeekDay + "] of month[" + month.toString() + "].";
}
}
9.使用方法抽取公共邏輯
9.1重構前
public int getYear() {
Calendar date = this.getCalendarDate();
return date.get(Calendar.YEAR);
}
public int getMonth() {
Calendar date = this.getCalendarDate();
return date.get(Calendar.MONTH);
}
public int getDay() {
Calendar date = this.getCalendarDate();
return date.get(Calendar.DAY_OF_MONTH);
}
public int getHour() {
Calendar date = this.getCalendarDate();
return date.get(Calendar.HOUR_OF_DAY);
}
public int getMinute() {
Calendar date = this.getCalendarDate();
return date.get(Calendar.MINUTE);
}
public int getSecond() {
Calendar date = this.getCalendarDate();
return date.get(Calendar.SECOND);
}
public int getMillisSecond() {
Calendar date = this.getCalendarDate();
return date.get(Calendar.MILLISECOND);
}
9.2重構後
private int get(int field) {
Calendar date = this.getCalendarDate();
return date.get(field);
}
public int getYear() {
return this.get(Calendar.YEAR);
}
public int getMonth() {
return this.get(Calendar.MONTH);
}
public int getDay() {
return this.get(Calendar.DAY_OF_MONTH);
}
public int getHour() {
return this.get(Calendar.HOUR_OF_DAY);
}
public int getMinute() {
return this.get(Calendar.MINUTE);
}
public int getSecond() {
return this.get(Calendar.SECOND);
}
public int getMillisSecond() {
return this.get(Calendar.MILLISECOND);
}
10.儘可能使用已有的Java API
10.1重構前
protected String[] getConfigLocations() {
String[] baseCfgs = this.getBaseCfgs();
String[] extra = this.getExtraCfgs();
if (extra != null && extra.length > 0) {
int baseCfgLen = baseCfgs.length;
int extraLen = extra.length;
String[] cfgLocations = new String[baseCfgLen + extraLen];
for(int i = 0; i < baseCfgLen; i++){
cfgLocations[i] = baseCfgs[i];
}
for(int i = 0; i < extraLen; i++){
cfgLocations[baseCfgLen + i] = extra[i];
}
return cfgLocations;
} else {
return baseCfgs;
}
}
10.2重構後
protected String[] getConfigLocations() {
String[] baseCfgs = this.getBaseCfgs();
String[] extra = this.getExtraCfgs();
if (extra != null && extra.length > 0) {
int baseCfgLen = baseCfgs.length;
int extraLen = extra.length;
String[] cfgLocations = new String[baseCfgLen + extraLen;
System.arraycopy(baseCfgs, 0, cfgLocations, 0, baseCfgLen);
System.arraycopy(extra, 0, cfgLocations, baseCfgLen,
extraLen;
return cfgLocations;
} else {
return baseCfgs;
}
}
11.使方法通用化
11.1重構前
public DayPart[] sortDayPart() {
if (dayParts == null || dayParts.length == 0) {
return dayParts;
}
List<DayPart> dayPartList = Arrays.asList(dayParts);
Collections.sort(dayPartList, new Comparator<DayPart>() {
public int compare(DayPart o1, DayPart o2) {
if (o1.getIndex() < o2.getIndex()) {
return -1;
} else if (o1.getIndex() > o2.getIndex()) {
return 1;
} else {
return 0;
}
}
});
return dayPartList.toArray(new DayPart[dayPartList.size()]);
}
11.2重構後
public DayPart[] sortDayPart() {
return this.sortDayPart(SortMode.ASC);
}
public DayPart[] sortDayPart(final SortMode sortMode) {
if (dayParts == null || dayParts.length == 0) {
return dayParts;
}
List<DayPart> dayPartList = Arrays.asList(dayParts);
Collections.sort(dayPartList, new Comparator<DayPart>() {
public int compare(DayPart o1, DayPart o2) {
if (o1.getIndex() < o2.getIndex()) {
return sortMode.isAsc() ? -1 : 1;
} else if (o1.getIndex() > o2.getIndex()) {
return sortMode.isAsc() ? 1 : -1;
} else {
return 0;
}
}
});
return dayPartList.toArray(new DayPart[dayPartList.size()]);
}
12.避免空語句
12.1重構前
public int getRemainMinutes(int hour, int minute) {
int startHour = fromHour;
int startMinute = fromMinute;
if (this.fromAfterEqual(hour, minute)) {
// ------from-------position------to--------
;//use default init value
} else if (this.toAfterEqual(hour, minute)) {
// ------from-------position------to--------
startHour = hour;
startMinute = minute;
} else {
// --------from-------to--------position-------
startHour = toHour;
startMinute = toMinute;
}
return this.getMinutes(startHour, startMinute, toHour, toMinute);
}
12.2重構後
public int getRemainMinutes(int hour, int minute) {
// --------from-------to--------position-------
int startHour = toHour;
int startMinute = toMinute;
if (this.fromAfterEqual(hour, minute)) {
// ------position------from-------to--------
startHour = fromHour;
startMinute = fromMinute;
} else if (this.toAfterEqual(hour, minute)) {
// ------from-------position------to--------
startHour = hour;
startMinute = minute;
}
return this.getMinutes(startHour, startMinute, toHour, toMinute);
}
13.公共邏輯後置
13.1重構前
public int getRemainMinutes(int hour, int minute) {
if (this.fromAfterEqual(hour, minute)) {
// ------position------from-------to--------
return (toHour * 60 + toMinute) - (fromHour * 60 + fromMinute);
} else if (this.toAfterEqual(hour, minute)) {
// ------from-------position------to--------
return (toHour * 60 + toMinute) - (hour * 60 + minute);
}
else {
// --------from-------to--------position-------
return 0; //(toHour * 60 + toMinute) - (toHour * 60 + toMinute);
}
}
13.2重構後
private int getMinutes(int startHour, int startMinute, int endHour, int endMinute) {
int minutes = 0;
minutes = (endHour * 60 + endMinute) - (startHour * 60 + startMinute);
return minutes;
}
public int getRemainMinutes(int hour, int minute) {
// --------from-------to--------position-------
int startHour = toHour;
int startMinute = toMinute;
if (this.fromAfterEqual(hour, minute)) {
// ------position------from-------to--------
startHour = fromHour;
startMinute = fromMinute;
} else if (this.toAfterEqual(hour, minute)) {
// ------from-------position------to--------
startHour = hour;
startMinute = minute;
}
return this.getMinutes(startHour, startMinute, toHour, toMinute);
}
14.公共邏輯前置
14.1重構前
private StringBuffer transformDialect(String intPart, String fracPart) {
StringBuffer cn = new StringBuffer();
if (isIntegerZero(intPart)) {
return cn;
}
if (this.isFractionZero(fracPart)) {
// 無小數，增長附加信息(整)
cn.append("元").append("整");
} else {
// 有小數，增長附加信息(零)
cn.append("元").append("零");
}
return cn;
}
14.2重構後
private StringBuffer transformDialect(String intPart, String fracPart) {
StringBuffer cn = new StringBuffer();
if (isIntegerZero(intPart)) {
return cn;
}
cn.append("元");
if (this.isFractionZero(fracPart)) {
// 無小數，增長附加信息(整)
cn.append("整");
} else {
// 有小數，增長附加信息(零)
cn.append("零");
}
return cn;
}
15.使用清晰的布爾型變量替換邏輯表達式
15.1重構前
public boolean tailGreatHead(int headHour, int headMinute, int tailHour,
int tailMinute, boolean includeEqual) {
return ((headHour < tailHour) || ((headHour == tailHour) && ((headMinute < tailMinute) || includeEqual && (headMinute == tailMinute))));
}
15.2重構後
public boolean tailGreatHead(int headHour, int headMinute, int tailHour, int tailMinute, boolean includeEqual) {
boolean tailGreatHeadHour = (headHour < tailHour);
boolean tailEqualHeadHour = (headHour == tailHour);
boolean tailGreatHeadMinute = (headMinute < tailMinute);
boolean tailEqualHeadMinute = (headMinute == tailMinute);
boolean tailGreatEqualHeadMinute = tailGreatHeadMinute || includeEqual && tailEqualHeadMinute;
return (tailGreatHeadHour || (tailEqualHeadHour && tailGreatEqualHeadMinute));
}
16.減小重複計算
16.1重構前
if(list != null && list.size() > 0){
for(int i = 0; i < list.size(); i++){
//skip...
}
}
16.2重構後
if(list != null){
for(int i = 0, len = list.size(); i < len; i++){
//skip...
}
}
17.什麼時候須要什麼時候建立
17.1重構前
public static Date parseDate(String date) throws ParseException {
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
if ((date == null) || (date.equals(""))) {
return null;
}
else {
try {
return formatter.parse(date);
} catch (ParseException pe) {
throw new ParseException(pe.getMessage(), pe.getErrorOffset());
}
}
}
17.2重構後
public static Date parseDate(String date) throws ParseException {
if ((date == null) || (date.equals(""))) {
return null;
}
else {
try {
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
return formatter.parse(date);
} catch (ParseException pe) {
throw new ParseException(pe.getMessage(), pe.getErrorOffset());
}
}
}
18.利用已有的計算結果
18.1重構前
public static final String DAY = "DAY";
public static final String MONTH = "MONTH";
public static final String YEAR = "YEAR";
public static final String HOUR = "HOUR";
public static final String MINUTE = "MINUTE";
public static final String SECOND = "SECOND";
public static final String WEEK = "WEEK";
public long toMilliseconds(String unit) {
if (unit == null) {
return 0L;
} else if (unit.equals(SECOND)) {
return 1 * 1000L;
} else if (unit.equals(MINUTE)) {
return 60 * 1000L;
} else if (unit.equals(HOUR)) {
return 60 * 60 * 1000L;
} else if (unit.equals(DAY)) {
return 24 * 60 * 60 * 1000L;
} else if (unit.equals(WEEK)) {
return 7 * 24 * 60 * 60 * 1000L;
} else if (unit.equals(MONTH)) {
return 30 * 24 * 60 * 60 * 1000L;
} else if (unit.equals(YEAR)) {
return 365 * 24 * 60 * 60 * 1000L;
} else {
return 0L;
}
}
18.2重構後
public class Unit {
private static final long SECOND_MILLIS = 1000;
private static final long MINUTE_MILLIS = 60 * SECOND_MILLIS;
private static final long HOUR_MILLIS = 60 * MINUTE_MILLIS;
private static final long DAY_MILLIS = 24 * HOUR_MILLIS;
private static final long WEEK_MILLIS = 7 * DAY_MILLIS;
private static final long MONTH_MILLIS = 30 * DAY_MILLIS;
private static final long YEAR_MILLIS = 365 * DAY_MILLIS;
private static final long CENTURY_MILLIS = 100 * YEAR_MILLIS;
static Map<String, Unit> units = new HashMap<String, Unit>();
public static final Unit SECOND = new Unit(SECOND_MILLIS, "SECOND");
public static final Unit MINUTE = new Unit(MINUTE_MILLIS, "MINUTE");
public static final Unit HOUR = new Unit(HOUR_MILLIS, "HOUR");
public static final Unit DAY = new Unit(DAY_MILLIS, "DAY");
public static final Unit WEEK = new Unit(WEEK_MILLIS, "WEEK");
public static final Unit MONTH = new Unit(MONTH_MILLIS, "MONTH");
public static final Unit YEAR = new Unit(YEAR_MILLIS, "YEAR");
public static final Unit CENTURY = new Unit(CENTURY_MILLIS, "CENTURY");
static {
units.put(SECOND.name, SECOND);
units.put(MINUTE.name, MINUTE);
units.put(HOUR.name, HOUR);
units.put(DAY.name, DAY);
units.put(WEEK.name, WEEK);
units.put(MONTH.name, MONTH);
units.put(YEAR.name, YEAR);
units.put(CENTURY.name, CENTURY);
}
private long millis;
private String name;
private Unit(long millis, String name) {
this.millis = millis;
this.name = name;
}
public long getMillis() {
return millis;
}
public String getName() {
return name;
}
public String toString() {
StringBuffer buffer = new StringBuffer();
buffer.append(this.getName());
buffer.append("[");
buffer.append(this.getMillis());
buffer.append("]");
return buffer.toString();
}
}
public long toMilliseconds(Unit unit) {
return unit.getMillis();
}
19.替換switch結構
19.1重構前
public boolean isLeap(int year) {
return (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0);
}
public static int getMonthDays(int year, int month) {
int numberDays = 0;
switch (month) {
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
numberDays = 31;
break;
case 4:
case 6:
case 9:
case 11:
numberDays = 30;
break;
case 2:
numberDays = isLeap(year) ? 29 : 28;
break;
}
return numberDays;
}
19.2重構後
public boolean isLeap(int year) {
return (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0);
}
private int getFebruaryDays(int year) {
return this.isLeap(year) ? 29 : 28;
}
public int getMonthDays(int year, int month) {
int[] months = new int[] { 31, this.getFebruaryDays(year), 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
return months[month];
}
20.避免對參數賦值
20.1重構前
public Date getStartTime(Date date) {
date.setMinutes(fromMinute);
date.setDate(fromHour);
date.setDate(fromHour);
date.setSeconds(0);
return date;
}
20.2重構後
public Date getStartTime(final Date date) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.set(Calendar.HOUR_OF_DAY, fromHour);
calendar.set(Calendar.MINUTE, fromMinute);
calendar.set(Calendar.SECOND, 0);
return calendar.getTime();
}
21.使用類替換類型代碼
21.1重構前
public class LabelComparator implements Comparator, Serializable {
private static final long serialVersionUID = 1L;
public static final int ASC = 1;
public static final int DESC = 2;
private int sortType = ASC;
public LabelComparator() {
}
public LabelComparator(int sortType) {
this.sortType = sortType;
}
public int compare(Object o1, Object o2) {
if (o1 == null && o2 == null) {
return 0;
}
if (o1 == null) {
return -1;
}
if (o2 == null) {
return -1;
}
if (((Label) o1).getIndex() < ((Label) o2).getIndex()) {
return (sortType == ASC) ? -1 : 1;
} else if (((Label) o1).getIndex() > ((Label) o2).getIndex()) {
return (sortType == ASC) ? 1 : -1;
} else {
return 0;
}
}
}
21.2重構後
public final class SortMode implements Serializable {
private static final long serialVersionUID = 1L;
private static final Map<String, SortMode> INSTANCES = new HashMap<String, SortMode>();
private final int type;
private final String name;
private SortMode(int type, String name) {
this.type = type;
this.name = name;
}
public String toString() {
return name;
}
public static final SortMode ASC = new SortMode(1, "ASC");
public static final SortMode DESC = new SortMode(2, "DESC");
static {
INSTANCES.put(ASC.name, ASC);
INSTANCES.put(DESC.name, DESC);
}
public boolean isAsc() {
return ASC.type == this.type;
}
public boolean isDesc() {
return DESC.type == this.type;
}
private Object readResolve() {
return INSTANCES.get(name);
}
public static SortMode parse(String name) {
return (SortMode) INSTANCES.get(name);
}
public boolean equals(Object obj) {
if (obj instanceof SortMode) {
SortMode that = (SortMode) obj;
if (that.type == this.type) {
return true;
}
return false;
} else {
return false;
}
}
}
public class LabelComparator implements Comparator, Serializable {
private static final long serialVersionUID = 1L;
public SortMode mode = SortMode.ASC;
public LabelComparator() {
}
public LabelComparator(SortMode mode) {
this.mode = mode;
}
public int compare(Object o1, Object o2) {
if (o1 == null && o2 == null) {
return 0;
}
if (o1 == null) {
return -1;
}
if (o2 == null) {
return -1;
}
if (((Label) o1).getIndex() < ((Label) o2).getIndex()) {
return mode.isAsc() ? -1 : 1;
} else if (((Label) o1).getIndex() > ((Label) o2).getIndex()) {
return mode.isAsc() ? 1 : -1;
} else {
return 0;
}
}
}
22.使用對象封裝參數
22.1重構前
public int getRemainMinutes(int hour, int minute, int fromHour, int fromMinute, int toHour, int toMinute) {
// --------from-------to--------position-------
int startHour = toHour;
int startMinute = toMinute;
if (this.fromAfterEqual(hour, minute)) {
// ------position------from-------to--------
startHour = fromHour;
startMinute = fromMinute;
} else if (this.toAfterEqual(hour, minute)) {
// ------from-------position------to--------
startHour = hour;
startMinute = minute;
}
return this.getMinutes(startHour, startMinute, toHour, toMinute);
}
22.2重構後
public class DayPart implements Serializable {
int fromHour = -1;
int fromMinute = -1;
int toHour = -1;
int toMinute = -1;
public int getFromHour() {
return fromHour;
}
public void setFromHour(int fromHour) {
this.fromHour = fromHour;
}
public int getFromMinute() {
return fromMinute;
}
public void setFromMinute(int fromMinute) {
this.fromMinute = fromMinute;
}
public int getToHour() {
return toHour;
}
public void setToHour(int toHour) {
this.toHour = toHour;
}
public int getToMinute() {
return toMinute;
}
public void setToMinute(int toMinute) {
this.toMinute = toMinute;
}
}
public int getRemainMinutes(int hour, int minute, DatePart datePart) {
int fromHour = datePart.getFromHour();
int fromMinute = datePart.getFromMinute();
int toHour = datePart.getToHour();
int toMinute = datePart.getToMinute();
// --------from-------to--------position-------
int startHour = toHour;
int startMinute = toMinute;
if (this.fromAfterEqual(hour, minute)) {
// ------position------from-------to--------
startHour = fromHour;
startMinute = fromMinute;
} else if (this.toAfterEqual(hour, minute)) {
// ------from-------position------to--------
startHour = hour;
startMinute = minute;
}
return this.getMinutes(startHour, startMinute, toHour, toMinute);
}
23.封裝集合操做
23.1重構前
public Class Group{
private List<User> userList = new ArrayList<User>();
public void setUserList(List<User> userList){
this.userList = userList;
}
public List<User> getUserList(){
return this.userList;
}
}
23.2重構後
public Class Group{
private List<User> userList = new ArrayList<User>();
public void setUserList(List<User> userList){
this.userList = userList;
}
public List<User> getUserList(){
return this.userList;
}
public void addUser(User user){
this.getUserList().add(user);
user.setGroup(this);
}
public void removeUser(User user){
this.getUserList().remove(user);
user.setGroup(null);
}
}
24.避免一次性臨時變量
24.1重構前
public int countWeekDay(Month month, WeekDay weekDay) {
int count = 0;
int[][] weeks = this.getDates()[month.getMonth()];
for (int week = 0, weekLen = weeks.length; week < weekLen; week++) {
int date = weeks[week][weekDay.getDay()];
if (date > 0) {
count++;
}
}
return count;
}
24.2重構後
public int countWeekDay(Month month, WeekDay weekDay) {
int count = 0;
int[][] weeks = this.getDates()[month.getMonth()];
for (int week = 0, weekLen = weeks.length; week < weekLen; week++) {
if (weeks[week][weekDay.getDay()] > 0) {
count++;
}
}
return count;
}
25.一個變量一種做用
25.1重構前
public IPolyDate getIndexWeekDay(Month month, int index, WeekDay weekDay) {
int count = this.countWeekDay(month, weekDay);
if (index > count) {
throw new ExceedMaxWeekIndexOfMonthException("Arguement index[" + index + "] exceeds max week index[" + count + "] of month[" + month.toString() + "].");
}
count = 0;
int[][] weeks = this.getDates()[month.getMonth()];
for (int week = 0, weekLen = weeks.length; week < weekLen; week++) {
int date = weeks[week][weekDay.getDay()];
if (date > 0) {
if (++count == index) {
return new PolyDate(year, month.getMonth(), date);
}
}
}
return null;
}
25.2重構後
public IPolyDate getIndexWeekDay(Month month, int index, WeekDay weekDay) {
int maxCountOfWeekDay = this.countWeekDay(month, weekDay);
if (index > maxCountOfWeekDay) {
throw new ExceedMaxWeekIndexOfMonthException("Arguement index[" + index + "] exceeds max week index["+ maxCountOfWeekDay + "] of month[" + month.toString() + "].");
}
int count = 0;
int[][] weeks = this.getDates()[month.getMonth()];
for (int week = 0, weekLen = weeks.length; week < weekLen; week++) {
int date = weeks[week][weekDay.getDay()];
if (date > 0) {
if (++count == index) {
return new PolyDate(year, month.getMonth(), date);
}
}
}
return null;
}
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