使用 Java 对汽车列表进行排序并按制造商排序显示它们？
Sort the list of cars and display them sort by make using Java?
我有一个问题是对 txt 文件的汽车报告中的数据进行排序。
问题是：我如何列出按品牌分类的汽车（福特、雪佛兰等）。他们只需要对 MAKE 进行排序，这样他们就可以是所有 FORD 汽车，然后是 Chevy、DODGE .. 依此类推：
这是我目前所拥有的：
这是我的源代码：
public class CustomerSale {
// Details of reports
private String zipCodeExtension;
private int customerNumber;
private String customerName;
private int purchaseDate;
private String make;
private int purchasePrice;
private int yearOfVehicle;
private int satisfactionRating;
// Create constructor argument
public CustomerSale(String zipCodeExtension, int customerNumber, String customerName,
int purchaseDate, String make, int purchasePrice,
int yearOfVehicle, int satisfactionRating) {
this.zipCodeExtension = zipCodeExtension;
this.customerNumber = customerNumber;
this.customerName = customerName;
this.purchaseDate = purchaseDate;
this.make = make;
this.purchasePrice = purchasePrice;
this.yearOfVehicle = yearOfVehicle;
this.satisfactionRating = satisfactionRating;
}
// Create getters and setters
public String getMake() {
return make;
}
public void setMake(String make) {
this.make = make;
}
public String getZipCodeExtension() {
return zipCodeExtension;
}
public void setZipCodeExtension(String zipCodeExtension) {
this.zipCodeExtension = zipCodeExtension;
}
public int getCustomerNumber() {
return customerNumber;
}
public void setCustomerNumber(int customerNumber) {
this.customerNumber = customerNumber;
}
public String getCustomerName() {
return customerName;
}
public void setCustomerName(String customerName) {
this.customerName = customerName;
}
public int getPurchaseDate() {
return purchaseDate;
}
public void setPurchaseDate(int purchaseDate) {
this.purchaseDate = purchaseDate;
}
public double getPurchasePrice() {
return purchasePrice;
}
public void setPurchasePrice(int purchasePrice) {
this.purchasePrice = purchasePrice;
}
public int getYearOfVehicle() {
return yearOfVehicle;
}
public void setYearOfVehicle(int yearOfVehicle) {
this.yearOfVehicle = yearOfVehicle;
}
public int getSatisfactionRating() {
return satisfactionRating;
}
public void setSatisfactionRating(int satisfactionRating) {
this.satisfactionRating = satisfactionRating;
}
}
import java.io.*;
import java.text.DecimalFormat;
import java.util.*;
public class SortByMake {
public static void main(String[] args) throws FileNotFoundException {
File carsInfo = new File("src/custsale.txt");
Scanner carsScanner = new Scanner(carsInfo);
String format = "%-20s%-14s%-21s%-16s%-19s$%-17s%-14s%-20s\n";
while (carsScanner.hasNextLine()) {
// Read the carsScanner
String zipCodeExtension = carsScanner.nextLine();
int customerNumber = Integer.parseInt(carsScanner.nextLine());
String customerName = carsScanner.nextLine();
int purchaseDate = Integer.parseInt(carsScanner.nextLine());
String make = carsScanner.nextLine();
int purchasePrice = Integer.parseInt(carsScanner.nextLine());
int yearOfVehicle = Integer.parseInt(carsScanner.nextLine());
int satisfactionRating = Integer.parseInt(carsScanner.nextLine());
CustomerSale custsale = new CustomerSale(zipCodeExtension, customerNumber, customerName,
purchaseDate, make, purchasePrice, yearOfVehicle, satisfactionRating);
// Display the report
DecimalFormat df = new DecimalFormat("#,#####");
System.out.printf(format, custsale.getZipCodeExtension(), custsale.getCustomerNumber(),
custsale.getCustomerName(), custsale.getPurchaseDate(), custsale.getMake(),
df.format(custsale.getPurchasePrice()), custsale.getYearOfVehicle(),
custsale.getSatisfactionRating());
}
ArrayList<CustomerSale> carMake = new ArrayList<>();
Collections.sort(carMake, Comparator.comparing(CustomerSale::getMake));
final int pageSize = 30;
int carCounter = 0;
for(CustomerSale car : carMake){
if (carCounter % pageSize == 0) {
printPageHeader(carCounter / pageSize + 1);
}
// Increment the car counter
carCounter++;
}
carsScanner.close();
}
private static void printPageHeader(int i) {
System.out.println(
"-------------------------------------------------ABC USED CARS----------------------------------------------------------------");
System.out.println(
"-------------------------------------------------------" + "PAGE " + i + "-----------------------------------------------------------------");
System.out.printf("%-19s%-15s%-21s%-15s%-20s%-17s%-12s%-20s\n", "|ZIP CODE-EXT|", "|CUST No.|", "|CUSTOMER NAME|", "|DoP|",
"|MAKE|", "|PRICE|", "|YEAR|", "|RATE|");
System.out.println(
"------------------------------------------------------------------------------------------------------------------------------");
}
}
这是文本文件报告：
46410-1234
1001
ALBERT, CARL T.
08252001
FORD
0255000
1991
2
46307-1201
1003
ANDREWS, ROBERT
08262001
CHEVROLET
0700000
1958
0
46423-2311
1008
ANZIO, RAFELINO
09012001
CHEVROLET
0456050
1978
0
46424-0121
1010
ASHLEY, WILLIAM B.
09022001
PIERCE-ARROW
1240000
1932
2
46375-3110
1015
ATKINSON, MARK
08272001
STUDEBAKER
0050000
1958
1
46405-1291
1025
AVERY, ALFRED A.
08292001
HUDSON
0230000
1954
1
46301-1234
1031
BEZZMEK, JENNIFER
08272001
FORD
0455000
1995
2
46303-1201
1033
BLAKE, DONALD
08292001
FORD
0722050
1989
1
46413-2311
1041
BLONDELL, BONNIE
09042001
CHEVROLET
0356050
1988
1
46404-0121
1045
BONADIO, JAMES
09032001
PIERCE-ARROW
1150000
1935
2
46307-3110
1055
BUCKO, ONIEDA
08282001
STUDEBAKER
0245000
1964
1
46410-1291
1056
BYMANN, FREDRICK
08292001
FORD
0330000
1994
1
46342-1234
1061
CALBERT, RONALD
09052001
FORD
0355000
1993
2
46307-1211
1063
CHELSEA, MARTHA S.
08302001
DODGE BROS.
0350000
1935
0
46410-2311
1067
CLAFLIN, WAYNE R.
09012001
CHEVROLET
0456050
1990
2
46410-0121
1070
COLE, CHARLES C.
09022001
PIERCE-ARROW
1050000
1929
2
46305-3111
1075
COLEMAN, THOMAS
08272001
STUDEBAKER
0167050
1961
1
46410-1221
1076
COLWELL, RICHARD L.
08292001
HUDSON
0430000
1940
1
46414-1231
1080
COOPER, JOHNATHAN
09052001
FORD
1256000
1996
2
46307-1201
2002
COREY, SARAH D.
08272001
CHEVROLET
0650050
1994
0
46421-2311
2004
CRACKLIN, GOODMAN
09012001
CHEVROLET
1456050
1996
0
46323-0121
2011
CRAWFORD, TIMOTHY
09012001
PIERCE-ARROW
1040000
1931
2
46315-3110
2012
CURRIE, RAYMOND
08282001
STUDEBAKER
0150025
1956
1
46425-1291
2024
CYBORG, IZORE M.
09052001
HUDSON
0130000
1949
1
46410-1234
2031
DALTON, DAVID P.
08252001
FORD
0234000
1990
2
46307-1201
2043
DAVIES, RALPH O.
08262001
CHEVROLET
0333000
1989
0
46423-2311
2048
DENNICK, DONNA
09012001
CHEVROLET
0656025
1995
0
46424-0121
2050
DERBIN, DEANNA
09022001
PIERCE-ARROW
1640025
1937
2
46375-3110
2065
DONNEHUE, PHILLIP
09042001
STUDEBAKER
0054000
1966
1
46405-1291
2085
DOPPLER, RADAR O.
08302001
HUDSON
0311000
1951
1
46310-1234
2091
DUNLOP, RITA
08252001
FORD
1450045
1996
2
46303-1201
3003
DYKES, CYNTHIA
08262001
FORD
0410050
1987
1
46413-2311
3011
EATON, ESTER B.
09012001
CHEVROLET
1356050
1996
0
46404-0121
3015
EFFLEY, BAILY
09022001
PIERCE-ARROW
1446045
1933
2
46307-3110
3025
EGGERTON, AMANDA
08292001
STUDEBAKER
0335000
1965
1
46410-1291
3026
EPPLEY, DAVID
08282001
FORD
0414000
1995
1
46342-1234
3031
ERKLE, ROSA
09032001
FORD
0355020
1993
2
46307-1211
3043
FARNSWORTH, WESLEY
09052001
DODGE BROS.
1150000
1996
0
46410-2311
3047
FLANNERY, JAMES
09012001
CHEVROLET
0450050
1992
0
46410-0121
3050
FOREMAN, OTTO J.
09022001
PIERCE-ARROW
0940000
1927
2
46305-3111
3055
FOWLER, KATHLEEN
08272001
STUDEBAKER
0267050
1964
1
46410-1221
3056
FURNACE, DAVID
08292001
HUDSON
0530000
1948
1
46414-1231
3061
GALLAGHER, CLARENCE
0904200
1FORD
1006000
1992
2
46307-1201
3062
GENNERRO, TONY S.
08302001
CHEVROLET
0320050
1989
0
46421-2311
3066
GOEBEL, NANCY K.
09022001
CHEVROLET
0643050
1990
0
46323-0121
3072
GUNTHER, FREDERICK
09032001
PIERCE-ARROW
1260000
1930
2
46315-3110
3080
HAINES, MARSHALL
08292001
STUDEBAKER
02500251
959
1
46425-1291
3094
HANCOCK, JONATHON
09032001
HUDSON
0330000
1953
1
46423-2311
3098
HARTNETT, ROBERTO
09052001
CHEVROLET
0326040
1988
0
46424-0121
4005
HENNING, SONIA
09052001
PIERCE-ARROW
1305000
1928
2
46375-3110
4009
HORNSBY, ROGERS
08252001
STUDEBAKER
0167500
1962
1
46405-1291
4012
HYATT, JANET F.
08302001
HUDSON
0155000
1951
1
46301-1234
4021
IDZIOR, RAYMOND
09012001
FORD
1460000
1996
2
46303-1201
4022
JENNINGS, WILLIAM
08262001
FORD
0612040
1992
1
46410-2311
4024
JOHNSON, JACK
09032001
CHEVROLET
0256050
1985
0
46404-0121
4032
KULKA, ROBERT C.
09042001
PIERCE-ARROW
0970000
1934
2
46307-3110
4035
KURTZ, DONALD
08302001
STUDEBAKER
0345000
1966
1
46410-1291
4038
LEVANDOWSKI, JILL
08282001
DODGE BROS.
0430000
1988
1
46342-1234
4044
METZ, ARNOLD E.
09012001
FORD
1323000
1996
2
46307-1211
4046
NORRIS, CHARLES S.
09052001
CHEVROLET
0844000
1992
0
46410-2311
4047
NOWAKOWSKI, ALFRED
09012001
DODGE BROS.
0656050
1994
1
46410-0121
4053
O'BOYLE, NIEL
09032001
PIERCE-ARROW
1550000
1938
2
46305-3111
4056
O'BRIAN, PATRICK
08302001
STUDEBAKER
0347050
1962
1
46410-1221
4059
PATTERSON, LENNI R.
08292001
HUDSON
0250000
1946
1
46414-1231
4061
PERRY, SHAMUS
09052001
FORD
0895000
1994
2
46307-1201
4066
REED, ROBERT B.
08272001
CHEVROLET
0740050
1996
0
46421-2311
4067
RODRIGUEZ, ALONZO
09052001
DODGE BROS.
1050050
1995
0
46323-0121
4073
SANCHEZ, HENRY
09012001
PIERCE-ARROW
0830000
1925
2
46315-3110
4081
SWARTZ, HECTOR
08282001
STUDEBAKER
0075025
1954
1
46301-1234
4084
TORREZ, MARTIN
0827200
1FORD
0565000
1994
2
46303-1201
4090
TUTTLE, MARK
08292001
FORD
0710050
1996
1
46413-2311
4094
WARNER, JACK
09042001
CHEVROLET
0856050
1996
0
46404-0121
4115
YACKLEY, YOURTO
09042001
PIERCE-ARROW
1000000
1930
2
非常简单:
读取所有元素并将它们放入列表中：
ArrayList<CustomerSale> sales = new ArrayList<>();
while(...){
sales.add(custsale);
}
对元素进行排序（我正在使用流，但可能 Collections.sort 可能会占用更少的内存，因为就地，例如 Comparator.comparing(CustomerSale::getMake)，谢谢 @Thomas):
List<CustomerSale> sorted = sales.stream().sorted((f,s) -> {
return f.getMake().compareTo(s.getMake());
}).collect(Collectors.toList());
并且仅在最后打印输出：
for(int i = 0; i < sorted.size(); i++){
CustomerSale custsale = sorted.get(i);
if (i % pageSize == 0) {
printPageHeader(i / pageSize + 1);
}
DecimalFormat df = new DecimalFormat("#,#####");
System.out.printf(format, custsale.getZipCodeExtension(), custsale.getCustomerNumber(),
custsale.getCustomerName(), custsale.getPurchaseDate(), custsale.getMake(),
df.format(custsale.getPurchasePrice()), custsale.getYearOfVehicle(),
custsale.getSatisfactionRating());
};
我有一个问题是对 txt 文件的汽车报告中的数据进行排序。
问题是：我如何列出按品牌分类的汽车（福特、雪佛兰等）。他们只需要对 MAKE 进行排序，这样他们就可以是所有 FORD 汽车，然后是 Chevy、DODGE .. 依此类推：
这是我目前所拥有的：
这是我的源代码：
public class CustomerSale {
// Details of reports
private String zipCodeExtension;
private int customerNumber;
private String customerName;
private int purchaseDate;
private String make;
private int purchasePrice;
private int yearOfVehicle;
private int satisfactionRating;
// Create constructor argument
public CustomerSale(String zipCodeExtension, int customerNumber, String customerName,
int purchaseDate, String make, int purchasePrice,
int yearOfVehicle, int satisfactionRating) {
this.zipCodeExtension = zipCodeExtension;
this.customerNumber = customerNumber;
this.customerName = customerName;
this.purchaseDate = purchaseDate;
this.make = make;
this.purchasePrice = purchasePrice;
this.yearOfVehicle = yearOfVehicle;
this.satisfactionRating = satisfactionRating;
}
// Create getters and setters
public String getMake() {
return make;
}
public void setMake(String make) {
this.make = make;
}
public String getZipCodeExtension() {
return zipCodeExtension;
}
public void setZipCodeExtension(String zipCodeExtension) {
this.zipCodeExtension = zipCodeExtension;
}
public int getCustomerNumber() {
return customerNumber;
}
public void setCustomerNumber(int customerNumber) {
this.customerNumber = customerNumber;
}
public String getCustomerName() {
return customerName;
}
public void setCustomerName(String customerName) {
this.customerName = customerName;
}
public int getPurchaseDate() {
return purchaseDate;
}
public void setPurchaseDate(int purchaseDate) {
this.purchaseDate = purchaseDate;
}
public double getPurchasePrice() {
return purchasePrice;
}
public void setPurchasePrice(int purchasePrice) {
this.purchasePrice = purchasePrice;
}
public int getYearOfVehicle() {
return yearOfVehicle;
}
public void setYearOfVehicle(int yearOfVehicle) {
this.yearOfVehicle = yearOfVehicle;
}
public int getSatisfactionRating() {
return satisfactionRating;
}
public void setSatisfactionRating(int satisfactionRating) {
this.satisfactionRating = satisfactionRating;
}
}
import java.io.*;
import java.text.DecimalFormat;
import java.util.*;
public class SortByMake {
public static void main(String[] args) throws FileNotFoundException {
File carsInfo = new File("src/custsale.txt");
Scanner carsScanner = new Scanner(carsInfo);
String format = "%-20s%-14s%-21s%-16s%-19s$%-17s%-14s%-20s\n";
while (carsScanner.hasNextLine()) {
// Read the carsScanner
String zipCodeExtension = carsScanner.nextLine();
int customerNumber = Integer.parseInt(carsScanner.nextLine());
String customerName = carsScanner.nextLine();
int purchaseDate = Integer.parseInt(carsScanner.nextLine());
String make = carsScanner.nextLine();
int purchasePrice = Integer.parseInt(carsScanner.nextLine());
int yearOfVehicle = Integer.parseInt(carsScanner.nextLine());
int satisfactionRating = Integer.parseInt(carsScanner.nextLine());
CustomerSale custsale = new CustomerSale(zipCodeExtension, customerNumber, customerName,
purchaseDate, make, purchasePrice, yearOfVehicle, satisfactionRating);
// Display the report
DecimalFormat df = new DecimalFormat("#,#####");
System.out.printf(format, custsale.getZipCodeExtension(), custsale.getCustomerNumber(),
custsale.getCustomerName(), custsale.getPurchaseDate(), custsale.getMake(),
df.format(custsale.getPurchasePrice()), custsale.getYearOfVehicle(),
custsale.getSatisfactionRating());
}
ArrayList<CustomerSale> carMake = new ArrayList<>();
Collections.sort(carMake, Comparator.comparing(CustomerSale::getMake));
final int pageSize = 30;
int carCounter = 0;
for(CustomerSale car : carMake){
if (carCounter % pageSize == 0) {
printPageHeader(carCounter / pageSize + 1);
}
// Increment the car counter
carCounter++;
}
carsScanner.close();
}
private static void printPageHeader(int i) {
System.out.println(
"-------------------------------------------------ABC USED CARS----------------------------------------------------------------");
System.out.println(
"-------------------------------------------------------" + "PAGE " + i + "-----------------------------------------------------------------");
System.out.printf("%-19s%-15s%-21s%-15s%-20s%-17s%-12s%-20s\n", "|ZIP CODE-EXT|", "|CUST No.|", "|CUSTOMER NAME|", "|DoP|",
"|MAKE|", "|PRICE|", "|YEAR|", "|RATE|");
System.out.println(
"------------------------------------------------------------------------------------------------------------------------------");
}
}
这是文本文件报告：
46410-1234
1001
ALBERT, CARL T.
08252001
FORD
0255000
1991
2
46307-1201
1003
ANDREWS, ROBERT
08262001
CHEVROLET
0700000
1958
0
46423-2311
1008
ANZIO, RAFELINO
09012001
CHEVROLET
0456050
1978
0
46424-0121
1010
ASHLEY, WILLIAM B.
09022001
PIERCE-ARROW
1240000
1932
2
46375-3110
1015
ATKINSON, MARK
08272001
STUDEBAKER
0050000
1958
1
46405-1291
1025
AVERY, ALFRED A.
08292001
HUDSON
0230000
1954
1
46301-1234
1031
BEZZMEK, JENNIFER
08272001
FORD
0455000
1995
2
46303-1201
1033
BLAKE, DONALD
08292001
FORD
0722050
1989
1
46413-2311
1041
BLONDELL, BONNIE
09042001
CHEVROLET
0356050
1988
1
46404-0121
1045
BONADIO, JAMES
09032001
PIERCE-ARROW
1150000
1935
2
46307-3110
1055
BUCKO, ONIEDA
08282001
STUDEBAKER
0245000
1964
1
46410-1291
1056
BYMANN, FREDRICK
08292001
FORD
0330000
1994
1
46342-1234
1061
CALBERT, RONALD
09052001
FORD
0355000
1993
2
46307-1211
1063
CHELSEA, MARTHA S.
08302001
DODGE BROS.
0350000
1935
0
46410-2311
1067
CLAFLIN, WAYNE R.
09012001
CHEVROLET
0456050
1990
2
46410-0121
1070
COLE, CHARLES C.
09022001
PIERCE-ARROW
1050000
1929
2
46305-3111
1075
COLEMAN, THOMAS
08272001
STUDEBAKER
0167050
1961
1
46410-1221
1076
COLWELL, RICHARD L.
08292001
HUDSON
0430000
1940
1
46414-1231
1080
COOPER, JOHNATHAN
09052001
FORD
1256000
1996
2
46307-1201
2002
COREY, SARAH D.
08272001
CHEVROLET
0650050
1994
0
46421-2311
2004
CRACKLIN, GOODMAN
09012001
CHEVROLET
1456050
1996
0
46323-0121
2011
CRAWFORD, TIMOTHY
09012001
PIERCE-ARROW
1040000
1931
2
46315-3110
2012
CURRIE, RAYMOND
08282001
STUDEBAKER
0150025
1956
1
46425-1291
2024
CYBORG, IZORE M.
09052001
HUDSON
0130000
1949
1
46410-1234
2031
DALTON, DAVID P.
08252001
FORD
0234000
1990
2
46307-1201
2043
DAVIES, RALPH O.
08262001
CHEVROLET
0333000
1989
0
46423-2311
2048
DENNICK, DONNA
09012001
CHEVROLET
0656025
1995
0
46424-0121
2050
DERBIN, DEANNA
09022001
PIERCE-ARROW
1640025
1937
2
46375-3110
2065
DONNEHUE, PHILLIP
09042001
STUDEBAKER
0054000
1966
1
46405-1291
2085
DOPPLER, RADAR O.
08302001
HUDSON
0311000
1951
1
46310-1234
2091
DUNLOP, RITA
08252001
FORD
1450045
1996
2
46303-1201
3003
DYKES, CYNTHIA
08262001
FORD
0410050
1987
1
46413-2311
3011
EATON, ESTER B.
09012001
CHEVROLET
1356050
1996
0
46404-0121
3015
EFFLEY, BAILY
09022001
PIERCE-ARROW
1446045
1933
2
46307-3110
3025
EGGERTON, AMANDA
08292001
STUDEBAKER
0335000
1965
1
46410-1291
3026
EPPLEY, DAVID
08282001
FORD
0414000
1995
1
46342-1234
3031
ERKLE, ROSA
09032001
FORD
0355020
1993
2
46307-1211
3043
FARNSWORTH, WESLEY
09052001
DODGE BROS.
1150000
1996
0
46410-2311
3047
FLANNERY, JAMES
09012001
CHEVROLET
0450050
1992
0
46410-0121
3050
FOREMAN, OTTO J.
09022001
PIERCE-ARROW
0940000
1927
2
46305-3111
3055
FOWLER, KATHLEEN
08272001
STUDEBAKER
0267050
1964
1
46410-1221
3056
FURNACE, DAVID
08292001
HUDSON
0530000
1948
1
46414-1231
3061
GALLAGHER, CLARENCE
0904200
1FORD
1006000
1992
2
46307-1201
3062
GENNERRO, TONY S.
08302001
CHEVROLET
0320050
1989
0
46421-2311
3066
GOEBEL, NANCY K.
09022001
CHEVROLET
0643050
1990
0
46323-0121
3072
GUNTHER, FREDERICK
09032001
PIERCE-ARROW
1260000
1930
2
46315-3110
3080
HAINES, MARSHALL
08292001
STUDEBAKER
02500251
959
1
46425-1291
3094
HANCOCK, JONATHON
09032001
HUDSON
0330000
1953
1
46423-2311
3098
HARTNETT, ROBERTO
09052001
CHEVROLET
0326040
1988
0
46424-0121
4005
HENNING, SONIA
09052001
PIERCE-ARROW
1305000
1928
2
46375-3110
4009
HORNSBY, ROGERS
08252001
STUDEBAKER
0167500
1962
1
46405-1291
4012
HYATT, JANET F.
08302001
HUDSON
0155000
1951
1
46301-1234
4021
IDZIOR, RAYMOND
09012001
FORD
1460000
1996
2
46303-1201
4022
JENNINGS, WILLIAM
08262001
FORD
0612040
1992
1
46410-2311
4024
JOHNSON, JACK
09032001
CHEVROLET
0256050
1985
0
46404-0121
4032
KULKA, ROBERT C.
09042001
PIERCE-ARROW
0970000
1934
2
46307-3110
4035
KURTZ, DONALD
08302001
STUDEBAKER
0345000
1966
1
46410-1291
4038
LEVANDOWSKI, JILL
08282001
DODGE BROS.
0430000
1988
1
46342-1234
4044
METZ, ARNOLD E.
09012001
FORD
1323000
1996
2
46307-1211
4046
NORRIS, CHARLES S.
09052001
CHEVROLET
0844000
1992
0
46410-2311
4047
NOWAKOWSKI, ALFRED
09012001
DODGE BROS.
0656050
1994
1
46410-0121
4053
O'BOYLE, NIEL
09032001
PIERCE-ARROW
1550000
1938
2
46305-3111
4056
O'BRIAN, PATRICK
08302001
STUDEBAKER
0347050
1962
1
46410-1221
4059
PATTERSON, LENNI R.
08292001
HUDSON
0250000
1946
1
46414-1231
4061
PERRY, SHAMUS
09052001
FORD
0895000
1994
2
46307-1201
4066
REED, ROBERT B.
08272001
CHEVROLET
0740050
1996
0
46421-2311
4067
RODRIGUEZ, ALONZO
09052001
DODGE BROS.
1050050
1995
0
46323-0121
4073
SANCHEZ, HENRY
09012001
PIERCE-ARROW
0830000
1925
2
46315-3110
4081
SWARTZ, HECTOR
08282001
STUDEBAKER
0075025
1954
1
46301-1234
4084
TORREZ, MARTIN
0827200
1FORD
0565000
1994
2
46303-1201
4090
TUTTLE, MARK
08292001
FORD
0710050
1996
1
46413-2311
4094
WARNER, JACK
09042001
CHEVROLET
0856050
1996
0
46404-0121
4115
YACKLEY, YOURTO
09042001
PIERCE-ARROW
1000000
1930
2
非常简单:
读取所有元素并将它们放入列表中：
ArrayList<CustomerSale> sales = new ArrayList<>(); while(...){ sales.add(custsale); }对元素进行排序（我正在使用流，但可能
Collections.sort可能会占用更少的内存，因为就地，例如Comparator.comparing(CustomerSale::getMake)，谢谢 @Thomas):List<CustomerSale> sorted = sales.stream().sorted((f,s) -> { return f.getMake().compareTo(s.getMake()); }).collect(Collectors.toList());并且仅在最后打印输出：
for(int i = 0; i < sorted.size(); i++){ CustomerSale custsale = sorted.get(i); if (i % pageSize == 0) { printPageHeader(i / pageSize + 1); } DecimalFormat df = new DecimalFormat("#,#####"); System.out.printf(format, custsale.getZipCodeExtension(), custsale.getCustomerNumber(), custsale.getCustomerName(), custsale.getPurchaseDate(), custsale.getMake(), df.format(custsale.getPurchasePrice()), custsale.getYearOfVehicle(), custsale.getSatisfactionRating()); };