我刚刚完成了一个项目，我们必须通过不同的排序字段对文件中的对象ArrayList进行排序。一切都运行正常，但我遇到了一个错误。当我运行代码时，文件对象按原始顺序打印出来，不进行排序。
我很确定bug是我在我的集合类中使用的实例变量在排序完成后没有被更改，但我不知道如何解决这个问题。
这是我的客户端类：
static int bpCount;
static String gene;
static int year;
static String yearString;
static String definition;
static String definitionString;
static String origin;
static String s;
public static void main(String[] args) throws FileNotFoundException{
ArrayList<VirusObject> virusList = new ArrayList<VirusObject>();
VirusCollection viruses = new VirusCollection(virusList);
String folderName = "virusfiles";
Scanner in = new Scanner(System.in);
System.out.println("Hello user, this program you are about to use will sort and filter a large selection of virus files that contain various virus genre");
System.out.println("Do you want to load a directory or file?");
String userInput = in.nextLine();
if(userInput.equals("file")){
openViruses(virusList, folderName);
}
Scanner userIn = new Scanner(System.in);
System.out.println("The current commands are sort, filter, and quit. Choose your commmand: ");
String input = userIn.nextLine();
if(input.equals("sort")){
Scanner userInput3 = new Scanner(System.in);
System.out.println("The current sorting methods are definition, reference, origin, year, and gene. Choose your sort: ");
String sort = userInput3.nextLine();
if(sort.equals("definition")){ //runs sort on temporary array, then runs print method
viruses.sortDef();
viruses.printViruses();
}
if(sort.equals("reference")){
viruses.sortRef();
viruses.printViruses();
}
if(sort.equals("origin")){
viruses.sortOrg();
viruses.printViruses();
}
if(sort.equals("year")){
viruses.sortYr();
viruses.printViruses();
}
if(sort.equals("gene")){
viruses.sortGn();
viruses.printViruses();
}
if(sort.equals("quit")){
System.out.println("Have a good day buddy");
return;
}
}
if(input.equals("filter")){
Scanner userInput2 = new Scanner(System.in);
System.out.println("The current filters are definition, reference, origin, year, and gene. Choose your filter: ");
String filter = userInput2.nextLine();
if(filter.equals("definition")){
System.out.println("What definition do you want to filter out?");
String defFilter = userInput2.nextLine();
viruses.printViruses();
}
if(filter.equals("reference")){
System.out.println("Enter a reference or range: ");
String refRange = userInput2.nextLine();
viruses.filterYear(Range.parse(refRange));
viruses.printViruses();
}
if(filter.equals("origin")){
System.out.println("What origin do you want to filter out?");
String originFilter = userInput2.nextLine();
viruses.filterDefinition(originFilter);
viruses.printViruses();
}
if(filter.equals("year")){
System.out.println("Enter a year or range: ");
String yearRange = userInput2.nextLine();
viruses.filterYear(Range.parse(yearRange));
viruses.printViruses();
}
if(filter.equals("gene")){
System.out.println("What gene do you want to filter out?");
String geneFilter = userInput2.nextLine();
viruses.filterDefinition(geneFilter);
viruses
.printViruses();
}
if(filter.equals("quit")){
System.out.println("Have a good day buddy");
return;
}
}
}
public static int openViruses(ArrayList<VirusObject> virusList, String folderName) throws FileNotFoundException {
File folder = new File(folderName);
File[] listOfFiles = folder.listFiles();
int countOfFiles = 0;
for (int i = 0; i < listOfFiles.length; i++) {
if (listOfFiles[i].isFile()) {
System.out.println("File " + listOfFiles[i].getName());
parseFile(virusList, listOfFiles[i]);//parseFile provided by student!
countOfFiles++;
} else if (listOfFiles[i].isDirectory()) {
System.out.println("Directory ignored: " + listOfFiles[i].getName());
}
}
return countOfFiles;
}
public static void parseFile(ArrayList<VirusObject> virusList, File File1) throws FileNotFoundException{
Scanner readFile = new Scanner(File1);
while(readFile.hasNextLine()){
String virusString = readFile.nextLine();
Scanner in = new Scanner(virusString);
if(virusString.contains("LOCUS")){
in.next();
in.next();
bpCount = in.nextInt();
in.next();
gene = in.next();
in.next();
in.next();
yearString = in.next();
Scanner in2 = new Scanner(yearString);
in2.useDelimiter("-");
in2.next();
in2.next();
year = in2.nextInt();
}
if(virusString.contains("DEFINITION")){
definitionString = in.nextLine();
definition = definitionString.split("\\.")[0];
}
if(virusString.contains("ORIGIN")){
if(virusString.contains("1"));
origin = in.nextLine();
}
}
VirusObject Virus = new VirusObject(bpCount, gene, year, definition, origin);
virusList.add(Virus);
}
}
这里是所有内容都已排序的类。
public ArrayList<VirusObject> virusList;
public VirusCollection(ArrayList<VirusObject> viruses){
virusList = viruses; // placeholder to reach filters and sorts (temporary array)
}
public void sortDefinition(VirusObject[] viruses){
int i;
int j;
for (j = 1; j < viruses.length; j++){
VirusObject temp = viruses[j];
i = j;
while ( i> 0 && viruses[i - 1].getDefinition().compareTo(temp.getDefinition()) > 0){ // compareTo method used to compare string to 0
viruses[i] = viruses[i - 1];
--i;
}
viruses[i] = temp;
}
}
public void sortReference(VirusObject[] viruses){
int i;
int j;
for (j = 1; j < viruses.length; j++){
VirusObject temp = viruses[j];
i=j;
while ( i > 0 && viruses[i - 1].getReference() > 0){
viruses[i] = viruses[i - 1];
--i;
}
viruses[i] = temp;
}
}
public void sortYear(VirusObject[] viruses){
int i;
int j;
for (j = 1; j < viruses.length; j++){
VirusObject temp = viruses[j];
i = j;
while ( i > 0 && viruses[i - 1].getYear() > temp.getYear()){
viruses[i] = viruses[i - 1];
--i;
}
viruses[i] = temp;
}
}
public void sortOrigin(VirusObject[] viruses){
int i;
int j;
for (j = 1; j < viruses.length; j++){
VirusObject temp = viruses[j];
i = j;
while ( i > 0 && viruses[i - 1].getOrigin().compareTo(temp.getOrigin()) > 0){
viruses[i] = viruses[i - 1];
--i;
}
viruses[i] = temp;
}
}
public void sortGene(VirusObject[] viruses){
int i;
int j;
for (j = 1; j < viruses.length; j++){
VirusObject temp = viruses[j];
i = j;
while ( i > 0 && viruses[i - 1].getGene().compareTo(temp.getDefinition()) > 0){
viruses[i] = viruses[i - 1];
--i;
}
viruses[i] = temp;
}
}
public void printViruses(){
for (final VirusObject Virus : virusList){
System.out.println(Virus.toString());
}
}
public void sortDef(){
VirusObject[] array = virusList.toArray(new VirusObject[virusList.size()]); // runs the sorting methods on a temporary array, makes it available to client as method
sortDefinition(array);
}
public void sortRef(){
VirusObject[] array = virusList.toArray(new VirusObject[virusList.size()]);
sortReference(array);
}
public void sortYr(){
VirusObject[] array = virusList.toArray(new VirusObject[virusList.size()]);
sortYear(array);
}
public void sortOrg(){
VirusObject[] array = virusList.toArray(new VirusObject[virusList.size()]);
sortOrigin(array);
}
public void sortGn(){
VirusObject[] array = virusList.toArray(new VirusObject[virusList.size()]);
sortGene(array);
}
}
任何帮助将不胜感激。谢谢
答案 0 :(得分：1)
我认为问题在于您调用virusList.toArray(...)，它创建一个与列表具有相同值的 new 数组，然后对该数组进行排序。您现在有一个已排序的数组，但原始列表（virusList）尚未更改！您需要获取已排序的结果并使用它来更新virusList（将其转换为ArrayList或其他任何内容。
答案 1 :(得分：1)
答案 2 :(得分：0)
在执行排序的每个方法中，将列表中的引用复制到数组，然后对数组进行排序。然后打印使用virusList进行打印。排序的引用永远不会重新设置为virusList。有许多不同的方法可以解决这个问题，包括对基础列表进行排序，但对代码的最小更改可能是：
public void sortDef(){
VirusObject[] array = virusList.toArray(new VirusObject[virusList.size()]); // runs the sorting methods on a temporary array, makes it available to client as method
sortDefinition(array);
virusList = new ArrayList<VirusObject>(Arrays.asList(array));
}
对所有排序方法进行类似的更改。