我想创建()方法,该方法排序和输出数据我一直在使用.stream存储在库中按字母顺序。目前,我有一个数字顺序,我将在下面添加排序由CityID数据的方法。是否有一个适应它相同的数据,而是由城市名的字母顺序排序的方式?
CityID方法 -
private void listCityDataInCityIdOrder() {
System.out.format("\033[31m%s\033[0m%n", "City Id Order");
System.out.format("\033[31m%s\033[0m%n", "=============");
repository.getItems()
.stream()
.sorted()
.map(c -> c.toString())
.forEach(str -> System.out.print(str));
}
数据集 -
1,"Cartagena","Spain",3
"2015",0.2,33,26,6,"S"
"2016",0.0,33,24,8,"SSW"
"2017",0.0,32,25,6,"E"
2,"Glasgow","Scotland",3
"2015",0.0,19,8,3,"SE"
"2016",0.1,21,11,6,"SE"
"2017",2.1,19,11,9,"SW"
城市模型类 -
package model;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.Objects;
/**
*
* @author mga
*/
public class City implements Comparable<City>{
private final int id;
private String cityName;
private String country;
private List<YearData> yearDataCollection;
private static int lastIdAllocated = 0;
static final char EOLN='\n';
static final String QUOTE="\"";
public City() {
this.id = ++lastIdAllocated;
this.cityName = "TBC";
this.country = "TBC";
this.yearDataCollection = new ArrayList<>();
}
public City(String cityName, String country) {
this.id = ++lastIdAllocated;
this.cityName = cityName;
this.country = country;
this.yearDataCollection = new ArrayList<>();
}
public City(String cityName, String country, List<YearData> yearDataCollection) {
this.id = ++lastIdAllocated;
this.cityName = cityName;
this.country = country;
this.yearDataCollection = yearDataCollection;
}
public City(int id, String cityName, String country, List<YearData> yearDataCollection) {
this.id = id;
this.cityName = cityName;
this.country = country;
this.yearDataCollection = yearDataCollection;
if (id > City.lastIdAllocated)
City.lastIdAllocated = id;
}
/**
* @return the id
*/
public int getId() {
return id;
}
// Methods required:
public String getCityName() {
return this.cityName;
}
public void setCityName(String cityName) {
this.cityName = cityName;
}
public String getCountry() {
return this.country;
}
public void setCountry(String country) {
this.country = country;
}
public List<YearData> getYearDataCollection() {
return this.yearDataCollection;
}
public void setYearDataCollection(List<YearData> yearDataCollection) {
this.yearDataCollection = yearDataCollection;
}
public void addYearData(YearData yearData) {
this.yearDataCollection.add(yearData);
}
@Override
public String toString() {
return "\nCity Id: " + id + " - City Name: " + cityName +
" - Country: " + country + "\nData: " + yearDataCollection + "\n";
}
public String toString(char delimiter) {
final char EOLN='\n';
final String QUOTE="\"";
String str = Integer.toString(this.id) + delimiter +
QUOTE + this.cityName + QUOTE + delimiter +
QUOTE + this.country + QUOTE + delimiter +
Integer.toString(yearDataCollection.size()) + EOLN;
for (YearData yearData : yearDataCollection) {
str += yearData.toString();
}
return str;
}
public boolean equals(Object object) {
if (this == object) return true;
if (!(object instanceof City)) return false;
if (!super.equals(object)) return false;
City city = (City) object;
return getId() == city.getId() &&
java.util.Objects.equals(getCityName(), city.getCityName()) &&
java.util.Objects.equals(getCountry(), city.getCountry()) &&
java.util.Objects.equals(getYearDataCollection(), city.getYearDataCollection());
}
public int hashCode() {
return Objects.hash(super.hashCode(), getId(), getCityName(), getCountry(), getYearDataCollection());
}
@Override
public int compareTo(City compareCity) {
int cityId =
((City) compareCity).getId();
//ascending order
return this.id - cityId;
//descending order
//return cityId - this.id;
}
public static Comparator<City> CityComparator = new Comparator<City>() {
@Override
public int compare(City city1, City city2) {
String cityName1 = city1.getCityName();
String cityName2 = city2.getCityName();
//ascending order
//return cityName1.compareTo(cityName2);
//descending order
return cityName2.compareTo(cityName1);
}
};
}
当然,改变你sorted
到:
.sorted(Comparator.comparing(City::getCityName))
或使用lambda:
.sorted(Comparator.comparing(c -> c.getCityName()))
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我来说两句