第二个缓冲的作家将无法工作
second buffered writer won't work
我的简单 I/O 库存程序有点问题。该程序将用户输入的输出写入充当 "inventory" 的文本文件。我能够做到。但是，当我尝试在同一文件夹中创建和追加不同的文本文件时，它不会将输入写入新的文本文件。我知道我真的缺乏经验来正确解释我的担忧。但我正在尽力而为，所以基本上，我只想将我输入的信息打印为 "sales" 到同一路径文件夹中的第二个 text.file 中。如果您检查 运行 我的代码，希望您能得到一些想法。该代码正在运行，但正如我所说，唯一的问题是 input/output 在不同的文本文件上。我将衷心感谢您的帮助。谢谢
卡尔
这是我的代码：
import java.io.BufferedOutputStream;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.*;
import static java.nio.file.StandardOpenOption.*;
import java.text.*;
import java.util.*;
public class Inventorypos {
public static void main(String[]args) {
Scanner input = new Scanner(System.in);
String File ="D:\Copro2\Inventory.txt";
String File2 ="D:\Copro2\Sales.txt";
Path file = Paths.get("D:\Copro2\Inventory.txt");
Path salefile = Paths.get("D:\Copro2\Sales.txt");
String st = " ";
String sH = " ";
String sF = " ";
String sS = " ";
String delimeter = "................ ";
int itemnum;
int itemname;
String H="Hamburger";
String F="French Fries";
String S="Softdrinks";
int menu;
long menu2 = 0;
final long QUIT = 5;{
{
try{
Runtime rt=Runtime.getRuntime();
OutputStream invent = new BufferedOutputStream(Files.newOutputStream(file, CREATE));
BufferedWriter writer = new
BufferedWriter(new OutputStreamWriter(invent));
//so here is my problem here, I couldn't make this work
OutputStream sale = new BufferedOutputStream(Files.newOutputStream(salefile, CREATE,StandardOpenOption.APPEND));
BufferedWriter writer2 = new
BufferedWriter(new OutputStreamWriter(sale));
String sa= "---- Sales ----";
writer2.write(sa);
writer2.newLine();
String in= "---- Inventory ----";
writer.write(in);
writer.newLine();
System.out.println("---- Page Menu ----");
System.out.println("1. Add Inventory \n2. Sell \n3. View Inventory \n4. View Sales \n5. Exit ");
System.out.print("Enter selection: ");
menu= input.nextInt();
while(menu2 != QUIT){
if(menu==1) {
System.out.println("Add Inventory: " );
System.out.print("1.) Hamburger \n2.)French Fries \n3.)Softdrinks\n");
System.out.println("Enter Item: " );
itemname= input.nextInt();
if (itemname == 1){
System.out.print("How many do you want to store? ");
itemnum = input.nextInt();
sH = H + delimeter + itemnum;
writer.write(sH, 0, sH.length());
writer.newLine();
}
else if (itemname == 2){
System.out.print("How many do you want to store? ");
itemnum = input.nextInt();
sF = F + delimeter + itemnum;
writer.write(sF, 0, sF.length());
writer.newLine();
}
else if (itemname == 3){
System.out.print("How many do you want to store? ");
itemnum = input.nextInt();
sS = S + delimeter + itemnum;
writer.write(sS, 0, sS.length());
writer.newLine();
}
else{
System.out.println("Invalid input!");
menu=1;
}
System.out.print("Enter 1 to store another item, 2 to view inventory, 3 sell,4 to quit: ");
menu2 = input.nextLong();
if (menu2==1){
menu=1;
}
else if (menu2==2){
menu=3;
}
else if (menu2==3){
menu=6;
}
else if (menu2==4){
menu2=QUIT;
}
else{
System.out.println("Invalid Input!");
}
}
if(menu==2){
System.out.print("---- Food Menu ----");
System.out.println("\n1.) Hamburger P25 \n2.) French Fries P25 \n3.) Softdrinks P25");
System.out.println("Enter your order: ");
int ord = input.nextInt();
if (ord==1){
System.out.println("How many?");
int hm = input.nextInt();
int totph = hm*25;
/*String intwo = "---- Updated inventory ----";
writer.write(intwo);
writer.newLine();
/*int left =
String nI = H+delimeter+*/
st = H+hm+ delimeter+ totph;
writer2.write(st,0,st.length());
writer2.newLine();
System.out.println("You purchased "+hm+" "+H+"s with the total price of "+totph+".");
}
else if (ord==2){
System.out.println("How many?");
int hm = input.nextInt();
int totph = hm*25;
/*String intwo = "---- Updated inventory ----";
writer.write(intwo);
writer.newLine();
/*int left =
String nI = H+delimeter+*/
st = F + hm + delimeter + totph;
writer2.write(st, 0, st.length());
writer2.newLine();
System.out.println("You purchased "+hm+" "+F+" with the total price of "+totph+".");
}
else if (ord==3){
System.out.println("How many?");
int hm = input.nextInt();
int totph = hm*25;
/*String intwo = "---- Updated inventory ----";
writer.write(intwo);
writer.newLine();
/*int left =
String nI = H+delimeter+*/
st = S+hm+ delimeter+ totph;
writer2.write(st,0,st.length());
writer2.newLine();
System.out.println("You purchased "+hm+" "+S+"s with the total price of "+totph+".");
}
else{
System.out.println("Invalid input!");
menu=2;
}
System.out.print("Enter 1 to go back to the food menu, 2 to view sales, 3 to go back to the main option or 4 to quit: ");
menu2 = input.nextInt();
if (menu2==1){
menu=2;
}
else if (menu2==2){
menu=4;
}else if (menu2==4){
menu2=QUIT;
}
else if (menu2==3){
menu=6;
}
else{
System.out.println("Invalid Input!");
}
}
if(menu==3){
{
menu2 = QUIT;
writer.close();
Process p=rt.exec("notepad "+File);
System.out.println("Do you want to continue? y for yes, n for no");
String con = input.next();
if (con.equalsIgnoreCase("y")){
main(null);
}
else if(con.equalsIgnoreCase("n")){
menu2=QUIT;
}
}
}
if (menu==4){
{
menu2 = QUIT;
writer.close();
Process p=rt.exec("notepad "+File2);
System.out.println("Do you want to continue? y for yes, n for no");
String con = input.next();
if (con.equalsIgnoreCase("y")){
main(null);
}
else if(con.equalsIgnoreCase("n")){
menu2=QUIT;
}
}
}
if (menu==5){
System.exit(0);
}
else if (menu ==6){
main(null);
}
else{
System.out.println("Invalid Input!");
}
}
}catch (Exception e){
System.out.println("Message: " +e);
}
}
}
}
}
这就是 BufferedWriter 对象的特殊之处。为了提高效率，他们将信息存储在 "buffers" 或临时信息堆中，然后当缓冲区超过一定大小时，它 "flushes" 数据或将其写入文件。调用 flush() 方法或 close() 方法时完成刷新数据。在你的代码中，我不相信你对你的作者调用了 close() 而不管类型如何，你实际上都会这样做。
您可以这样调用它：
writer.close();
或者如果你只是想在不关闭写入器的情况下保存数据，你可以调用：
writer.flush();
我的简单 I/O 库存程序有点问题。该程序将用户输入的输出写入充当 "inventory" 的文本文件。我能够做到。但是，当我尝试在同一文件夹中创建和追加不同的文本文件时，它不会将输入写入新的文本文件。我知道我真的缺乏经验来正确解释我的担忧。但我正在尽力而为，所以基本上，我只想将我输入的信息打印为 "sales" 到同一路径文件夹中的第二个 text.file 中。如果您检查 运行 我的代码，希望您能得到一些想法。该代码正在运行，但正如我所说，唯一的问题是 input/output 在不同的文本文件上。我将衷心感谢您的帮助。谢谢
卡尔
这是我的代码：
import java.io.BufferedOutputStream;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.*;
import static java.nio.file.StandardOpenOption.*;
import java.text.*;
import java.util.*;
public class Inventorypos {
public static void main(String[]args) {
Scanner input = new Scanner(System.in);
String File ="D:\Copro2\Inventory.txt";
String File2 ="D:\Copro2\Sales.txt";
Path file = Paths.get("D:\Copro2\Inventory.txt");
Path salefile = Paths.get("D:\Copro2\Sales.txt");
String st = " ";
String sH = " ";
String sF = " ";
String sS = " ";
String delimeter = "................ ";
int itemnum;
int itemname;
String H="Hamburger";
String F="French Fries";
String S="Softdrinks";
int menu;
long menu2 = 0;
final long QUIT = 5;{
{
try{
Runtime rt=Runtime.getRuntime();
OutputStream invent = new BufferedOutputStream(Files.newOutputStream(file, CREATE));
BufferedWriter writer = new
BufferedWriter(new OutputStreamWriter(invent));
//so here is my problem here, I couldn't make this work
OutputStream sale = new BufferedOutputStream(Files.newOutputStream(salefile, CREATE,StandardOpenOption.APPEND));
BufferedWriter writer2 = new
BufferedWriter(new OutputStreamWriter(sale));
String sa= "---- Sales ----";
writer2.write(sa);
writer2.newLine();
String in= "---- Inventory ----";
writer.write(in);
writer.newLine();
System.out.println("---- Page Menu ----");
System.out.println("1. Add Inventory \n2. Sell \n3. View Inventory \n4. View Sales \n5. Exit ");
System.out.print("Enter selection: ");
menu= input.nextInt();
while(menu2 != QUIT){
if(menu==1) {
System.out.println("Add Inventory: " );
System.out.print("1.) Hamburger \n2.)French Fries \n3.)Softdrinks\n");
System.out.println("Enter Item: " );
itemname= input.nextInt();
if (itemname == 1){
System.out.print("How many do you want to store? ");
itemnum = input.nextInt();
sH = H + delimeter + itemnum;
writer.write(sH, 0, sH.length());
writer.newLine();
}
else if (itemname == 2){
System.out.print("How many do you want to store? ");
itemnum = input.nextInt();
sF = F + delimeter + itemnum;
writer.write(sF, 0, sF.length());
writer.newLine();
}
else if (itemname == 3){
System.out.print("How many do you want to store? ");
itemnum = input.nextInt();
sS = S + delimeter + itemnum;
writer.write(sS, 0, sS.length());
writer.newLine();
}
else{
System.out.println("Invalid input!");
menu=1;
}
System.out.print("Enter 1 to store another item, 2 to view inventory, 3 sell,4 to quit: ");
menu2 = input.nextLong();
if (menu2==1){
menu=1;
}
else if (menu2==2){
menu=3;
}
else if (menu2==3){
menu=6;
}
else if (menu2==4){
menu2=QUIT;
}
else{
System.out.println("Invalid Input!");
}
}
if(menu==2){
System.out.print("---- Food Menu ----");
System.out.println("\n1.) Hamburger P25 \n2.) French Fries P25 \n3.) Softdrinks P25");
System.out.println("Enter your order: ");
int ord = input.nextInt();
if (ord==1){
System.out.println("How many?");
int hm = input.nextInt();
int totph = hm*25;
/*String intwo = "---- Updated inventory ----";
writer.write(intwo);
writer.newLine();
/*int left =
String nI = H+delimeter+*/
st = H+hm+ delimeter+ totph;
writer2.write(st,0,st.length());
writer2.newLine();
System.out.println("You purchased "+hm+" "+H+"s with the total price of "+totph+".");
}
else if (ord==2){
System.out.println("How many?");
int hm = input.nextInt();
int totph = hm*25;
/*String intwo = "---- Updated inventory ----";
writer.write(intwo);
writer.newLine();
/*int left =
String nI = H+delimeter+*/
st = F + hm + delimeter + totph;
writer2.write(st, 0, st.length());
writer2.newLine();
System.out.println("You purchased "+hm+" "+F+" with the total price of "+totph+".");
}
else if (ord==3){
System.out.println("How many?");
int hm = input.nextInt();
int totph = hm*25;
/*String intwo = "---- Updated inventory ----";
writer.write(intwo);
writer.newLine();
/*int left =
String nI = H+delimeter+*/
st = S+hm+ delimeter+ totph;
writer2.write(st,0,st.length());
writer2.newLine();
System.out.println("You purchased "+hm+" "+S+"s with the total price of "+totph+".");
}
else{
System.out.println("Invalid input!");
menu=2;
}
System.out.print("Enter 1 to go back to the food menu, 2 to view sales, 3 to go back to the main option or 4 to quit: ");
menu2 = input.nextInt();
if (menu2==1){
menu=2;
}
else if (menu2==2){
menu=4;
}else if (menu2==4){
menu2=QUIT;
}
else if (menu2==3){
menu=6;
}
else{
System.out.println("Invalid Input!");
}
}
if(menu==3){
{
menu2 = QUIT;
writer.close();
Process p=rt.exec("notepad "+File);
System.out.println("Do you want to continue? y for yes, n for no");
String con = input.next();
if (con.equalsIgnoreCase("y")){
main(null);
}
else if(con.equalsIgnoreCase("n")){
menu2=QUIT;
}
}
}
if (menu==4){
{
menu2 = QUIT;
writer.close();
Process p=rt.exec("notepad "+File2);
System.out.println("Do you want to continue? y for yes, n for no");
String con = input.next();
if (con.equalsIgnoreCase("y")){
main(null);
}
else if(con.equalsIgnoreCase("n")){
menu2=QUIT;
}
}
}
if (menu==5){
System.exit(0);
}
else if (menu ==6){
main(null);
}
else{
System.out.println("Invalid Input!");
}
}
}catch (Exception e){
System.out.println("Message: " +e);
}
}
}
}
}
这就是 BufferedWriter 对象的特殊之处。为了提高效率，他们将信息存储在 "buffers" 或临时信息堆中，然后当缓冲区超过一定大小时，它 "flushes" 数据或将其写入文件。调用 flush() 方法或 close() 方法时完成刷新数据。在你的代码中，我不相信你对你的作者调用了 close() 而不管类型如何，你实际上都会这样做。
您可以这样调用它：
writer.close();
或者如果你只是想在不关闭写入器的情况下保存数据，你可以调用：
writer.flush();