[英]When deleting data from a file, temp file won't rename back to original file
[英]Java creating a temp file , deleting a specific string and rename to original
正如該主題指出的那樣,im試圖獲取通常自動生成為相同字符串的特定字符串,並且似乎可以正常工作,因為已創建了臨時文件,並且該字符串被替換為“”,但似乎出現了IOException刪除時重命名為原始文件,請幫助?
import java.io.*;
import java.util.Scanner;
/**
* Main class to test the Road and Settlement classes
*
* @author Chris Loftus (add your name and change version number/date)
* @version 1.0 (24th February 2016)
*
*/
public class Application {
private Scanner scan;
private Map map;
private static int setting;
public Application() {
scan = new Scanner(System.in);
map = new Map();
}
private void runMenu() {
setting = scan.nextInt();
scan.nextLine();
}
// STEP 1: ADD PRIVATE UTILITY MENTHODS HERE. askForRoadClassifier, save and
// load provided
private Classification askForRoadClassifier() {
Classification result = null;
boolean valid;
do {
valid = false;
System.out.print("Enter a road classification: ");
for (Classification cls : Classification.values()) {
System.out.print(cls + " ");
}
String choice = scan.nextLine().toUpperCase();
try {
result = Classification.valueOf(choice);
valid = true;
} catch (IllegalArgumentException iae) {
System.out.println(choice + " is not one of the options. Try again.");
}
} while (!valid);
return result;
}
private void deleteSettlement() {
String name;
int p;
SettlementType newSetK = SettlementType.CITY;
int set;
System.out.println("Please type in the name of the settlement");
name = scan.nextLine();
System.out.println("Please type in the population of the settlment");
p = scan.nextInt();
scan.nextLine();
System.out.println("Please type in the number of the type of settlement .");
System.out.println("1: Hamlet");
System.out.println("2: Village");
System.out.println("3: Town");
System.out.println("4: City");
set = scan.nextInt();
scan.nextLine();
if (set == 1) {
newSetK = SettlementType.HAMLET;
}
if (set == 2) {
newSetK = SettlementType.VILLAGE;
}
if (set == 3) {
newSetK = SettlementType.TOWN;
}
if (set == 4) {
newSetK = SettlementType.CITY;
}
String generatedResult = "Name: " + name + " Population: " + p + " SettlementType " + newSetK;
String status = searchAndDestroy(generatedResult);
}
private String searchAndDestroy(String delete) {
File file = new File("C:\\Users\\Pikachu\\workspace\\MiniAssignment2\\settlements.txt");
try {
File temp = File.createTempFile("settlement", ".txt", file.getParentFile());
String charset = "UTF-8";
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(file), charset));
PrintWriter writer = new PrintWriter(new OutputStreamWriter(new FileOutputStream(temp), charset));
for (String line; (line = reader.readLine()) != null;) {
line = line.replace(delete, "");
writer.println(line);
}
System.out.println("Deletion complete");
reader.close();
writer.close();
file.delete();
temp.renameTo(file);
}
catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
System.out.println("Sorry! Can't do that! 1");
}
catch (FileNotFoundException e) {
// TODO Auto-generated catch block
System.out.println("Sorry! Can't do that! 2");
}
}
catch (IOException e) {
// TODO Auto-generated catch block
System.out.println("Sorry! Can't do that! , IO Exception error incurred 3");
}
return null;
}
private void save() {
map.save();
}
private void load() {
map.load();
}
public void addSettlement() {
String name;
int p;
SettlementType newSetK = SettlementType.CITY;
int set;
System.out.println("Please type in the name of the settlement");
name = scan.nextLine();
System.out.println("Please type in the population of the settlment");
p = scan.nextInt();
scan.nextLine();
System.out.println("Please type in the number of the type of settlement .");
System.out.println("1: Hamlet");
System.out.println("2: Village");
System.out.println("3: Town");
System.out.println("4: City");
set = scan.nextInt();
scan.nextLine();
if (set == 1) {
newSetK = SettlementType.HAMLET;
}
if (set == 2) {
newSetK = SettlementType.VILLAGE;
}
if (set == 3) {
newSetK = SettlementType.TOWN;
}
if (set == 4) {
newSetK = SettlementType.CITY;
}
new Settlement(name, newSetK, p);
}
private void printMenu() {
System.out.println("Please type in the number of the action that you would like to perform");
System.out.println("1: Create Settlement");
System.out.println("2: Delete Settlement");
System.out.println("3: Create Road");
System.out.println("4: Delete Road");
System.out.println("5:Display Map");
System.out.println("6:Save Map");
}
public static void main(String args[]) {
Application app = new Application();
app.printMenu();
app.runMenu();
System.out.println(setting);
if (setting == 1) {
app.addSettlement();
}
if (setting == 2) {
app.deleteSettlement();
}
app.load();
app.runMenu();
app.save();
}
}
我檢查了它是否可刪除(file.delete拋出一個布爾異常),所以我嘗試直接通過Windows刪除它,顯然它已被Java使用,因此我認為出現了小故障,在關閉並重新啟動Eclipse后它就可以工作了。很好...那是反氣候的....非常感謝您的討論,如果沒有討論,我絕對不會想出來的:D <3您全心全意
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