我正在尝试将每个CourseGroup的每个星期一的句号1设置为true，但是对象会改变所有日期而不是仅仅星期一。请查看下面的示例
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Objects;
class HelloWorld {
public static void main(String[] args) {
SchoolObject schoolObject;
List<LecturePeriod> lecturePeriods = new ArrayList<>();
for (int i = 1; i <= 10; i++) {
String periodName = "Period " + i;
int periodNo = i;
boolean isPeriodAllocated = false;
lecturePeriods.add(new LecturePeriod(periodName, periodNo, isPeriodAllocated));
}
List<Day> days = new ArrayList<>();
for (int i = 1; i <= 5; i++) {
String dayName;
switch (i) {
case 1:
dayName = "MONDAY";
break;
case 2:
dayName = "TUESDAY";
break;
case 3:
dayName = "WEDNESDAY";
break;
case 4:
dayName = "THURSDAY";
break;
case 5:
dayName = "FRIDAY";
break;
default:
dayName = "NONE";
}
int dayNo = i;
days.add(new Day(dayName, dayNo, lecturePeriods));
}
List<YearGroup> yearGroups = new ArrayList<>();
for (int i = 1; i <= 3; i++) {
int yearGroupNumber = i;
if (Objects.equals(i, 1)) {
yearGroups.add(new YearGroup(yearGroupNumber, new ArrayList<>(Arrays.asList(new CourseGroup("Science" + 1, days)))));
} else if (Objects.equals(i, 2)) {
yearGroups.add(new YearGroup(yearGroupNumber, new ArrayList<>(Arrays.asList(new CourseGroup("Science" + 2, days)))));
} else if (Objects.equals(i, 3)) {
yearGroups.add(new YearGroup(yearGroupNumber, new ArrayList<>(Arrays.asList(new CourseGroup("Science" + 3, days)))));
}
}
schoolObject = new SchoolObject();
schoolObject.setYearGroups(yearGroups);
System.out.println("School Object Before Changing Periods="+schoolObject.toString());
schoolObject.getYearGroups().forEach(yearGroup -> {
yearGroup.getCourseGroups().forEach(courseGroup -> {
courseGroup.getDays().forEach(day -> {
String dayName = day.getDayName();
if (Objects.equals(dayName, "MONDAY")) {
day.getLecturePeriods().forEach(lecturePeriod -> {
int lecturePeriodNumber = lecturePeriod.getPeriodNumber();
if (Objects.equals(lecturePeriodNumber, 1)) {
lecturePeriod.setIsPeriodAllocated(true);
}
});
}
});
});
});
System.out.println("\nSchool Object After Changing Periods=" + schoolObject.toString());
final int[] numberOfAllocatedPeriodsExpected = {0};
schoolObject.getYearGroups().forEach(yearGroup -> {
yearGroup.getCourseGroups().forEach(courseGroup -> {
courseGroup.getDays().forEach(day -> {
day.getLecturePeriods().forEach(lecturePeriod -> {
int lecturePeriodNumber = lecturePeriod.getPeriodNumber();
if (Objects.equals(lecturePeriodNumber, 1)) {
numberOfAllocatedPeriodsExpected[0]++;
}
});
});
});
});
System.out.println("\nTest result ="+Objects.equals(numberOfAllocatedPeriodsExpected[0],3));
}
public static class SchoolObject {
List<YearGroup> yearGroups;
@Override
public String toString() {
final StringBuilder sb = new StringBuilder("SchoolObject{");
sb.append("yearGroups=").append(yearGroups);
sb.append('}');
return sb.toString();
}
public List<YearGroup> getYearGroups() {
return yearGroups;
}
public void setYearGroups(List<YearGroup> yearGroups) {
this.yearGroups = yearGroups;
}
}
public static class YearGroup {
int yearGroupNumber;
List<CourseGroup> courseGroups;
public YearGroup(int yearGroupNumber, List<CourseGroup> courseGroups) {
this.yearGroupNumber = yearGroupNumber;
this.courseGroups = courseGroups;
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder("YearGroup{");
sb.append("yearGroupNumber=").append(yearGroupNumber);
sb.append(", courseGroups=").append(courseGroups);
sb.append('}');
return sb.toString();
}
public int getYearGroupNumber() {
return yearGroupNumber;
}
public void setYearGroupNumber(int yearGroupNumber) {
this.yearGroupNumber = yearGroupNumber;
}
public List<CourseGroup> getCourseGroups() {
return courseGroups;
}
public void setCourseGroups(List<CourseGroup> courseGroups) {
this.courseGroups = courseGroups;
}
}
public static class CourseGroup {
String courseGroupName;
List<Day> days;
public CourseGroup(String courseGroupName, List<Day> days) {
this.courseGroupName = courseGroupName;
this.days = days;
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder("CourseGroup{");
sb.append("courseGroupName='").append(courseGroupName).append('\'');
sb.append(", days=").append(days);
sb.append('}');
return sb.toString();
}
public List<Day> getDays() {
return days;
}
public void setDays(List<Day> days) {
this.days = days;
}
public String getCourseGroupName() {
return courseGroupName;
}
public void setCourseGroupName(String courseGroupName) {
this.courseGroupName = courseGroupName;
}
}
public static class Day {
String dayName;
int dayNo;
List<LecturePeriod> lecturePeriods;
public Day(String dayName, int dayNo, List<LecturePeriod> lecturePeriods) {
this.dayName = dayName;
this.lecturePeriods = lecturePeriods;
this.dayNo = dayNo;
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder("Day{");
sb.append("dayName='").append(dayName).append('\'');
sb.append(", dayNo=").append(dayNo);
sb.append(", lecturePeriods=").append(lecturePeriods);
sb.append('}');
return sb.toString();
}
public String getDayName() {
return dayName;
}
public void setDayName(String dayName) {
this.dayName = dayName;
}
public int getDayNo() {
return dayNo;
}
public void setDayNo(int dayNo) {
this.dayNo = dayNo;
}
public List<LecturePeriod> getLecturePeriods() {
return lecturePeriods;
}
public void setLecturePeriods(List<LecturePeriod> lecturePeriods) {
this.lecturePeriods = lecturePeriods;
}
}
public static class LecturePeriod {
String periodName;
int periodNumber;
boolean isPeriodAllocated;
public LecturePeriod(String periodName, int periodNumber, boolean isPeriodAllocated) {
this.periodName = periodName;
this.periodNumber = periodNumber;
this.isPeriodAllocated = isPeriodAllocated;
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder("LecturePeriod{");
sb.append("periodName='").append(periodName).append('\'');
sb.append(", periodNumber=").append(periodNumber);
sb.append(", isPeriodAllocated=").append(isPeriodAllocated);
sb.append('}');
return sb.toString();
}
public String getPeriodName() {
return periodName;
}
public void setPeriodName(String periodName) {
this.periodName = periodName;
}
public int getPeriodNumber() {
return periodNumber;
}
public void setPeriodNumber(int periodNumber) {
this.periodNumber = periodNumber;
}
public boolean isPeriodAllocated() {
return isPeriodAllocated;
}
public void setIsPeriodAllocated(boolean isPeriodAllocated) {
this.isPeriodAllocated = isPeriodAllocated;
}
}
}
观察数据的输出，您会注意到，每个courseGroup中的所有日期，而不是仅仅是星期一，schoolObject将所有lecturePeriods设置为true。 任何帮助都感激不尽。 注意：我尽量将问题提取到最小的最小值而不使用gson或jackson，这样可以在梳理生成的json时提供更清晰的输出。 为了测试，我把所有东西都挤成了一个班级。
您可以在此处查看示例http://ideone.com/3uyE5G
答案 0 :(得分：2)
这是因为您要为所有日子分配相同的讲座时段参考：
days.add(new Day(dayName, dayNo, lecturePeriods));
因此，每当您在其中一天内更改讲话中的一个属性时，它将为所有这些更改。要解决这个问题，每天都必须拥有它自己的讲话实例
List<LecturePeriod> lecturePeriods = new ArrayList<>();
for (int j = 1; j <= 10; j++) {
lecturePeriods.add(new LecturePeriod("Period " + j, j, false));
}
days.add(new Day(dayName, dayNo, lecturePeriods));
答案 1 :(得分：0)
1.将Object转换为json String。
2.在进行任何操作之前将其转换回原始对象。
我使用gson进行上述两个步骤，无论我如何在schoolObject中每天初始化，它都能完美运行。
再次感谢您向我展示@valarauko的根本原因。