Java 为什么writer不将数据写入文件？
当我运行它时，它会转到名为niceJob.txt的文件，数据来自的文件名为file2.txt，其中包括Java 为什么writer不将数据写入文件？,java,Java,当我运行它时，它会转到名为niceJob.txt的文件，数据来自的文件名为file2.txt，其中包括 niceJob.txt 40 20 1 1 5 7 45 1 2 3 4 5 6 7 8 9 77 88 99 23 34 56 当我打开niceJob.txt时，它会显示 X8 我真的很困惑为什么会发生这种事，以及是如何发生的。代码如下： import java.io.*; import java.util.Scanner; public class JH1_00668860 {
niceJob.txt 40
20 1 1 5 7 45 1 2 3 4 5 6 7 8 9 77 88 99 23 34 56
import java.io.*;
import java.util.Scanner;
public class JH1_00668860 {
public static void printToScreen(String filename) {
Scanner scan = null;
try {
FileInputStream fis = new FileInputStream(filename);
scan = new Scanner(fis);
while (scan.hasNextLine()) {
System.out.println(scan.nextLine());
}
} catch (FileNotFoundException e) {
System.out.println("printToScreen: can't open: " + filename);
} finally {
if (scan != null)
scan.close();
}
}// end of print
public static void process(String inputFilename) {
String fileoutputname = null;
FileInputStream file = null;
Scanner scan = null;
FileOutputStream outputFilename = null;
FileWriter ps = null;
try {
file = new FileInputStream(inputFilename);
scan = new Scanner(file);
fileoutputname = scan.next();
System.out.println(fileoutputname + " asfasdfasdfasdf");
outputFilename = new FileOutputStream(fileoutputname);
ps = new FileWriter(fileoutputname);
while (scan.hasNextInt()) {
if (scan.nextInt() >= 0) {
// System.out.println(scan.nextInt() + "asfs");
ps.write(scan.nextInt());
ps.flush();
} else {
System.out.println("You have ran out of data or you have a bad value");
}
}
System.out.println("A file was created");
} catch (FileNotFoundException e) {
System.out.println("You ran into an exception :" + e);
} catch (IOException e) {
System.out.println("You ran into an exception :" + e);
} finally {
try {
if (file != null) {
file.close();
}
if (outputFilename != null) {
outputFilename.close();
}
if (ps != null) {
ps.close();
}
// FileInputStream st = new FileInputStream(fileoutputname);
// int contents = st.read();
// while (scan.hasNextInt()) {
// System.out.print(contents);
// }
if (scan != null) {
scan.close();
}
printToScreen(fileoutputname);
} catch (IOException e) {
System.out.println("there was an exception");
}
}
}
public static void main(String args[]) {
process("file2.txt");
}
}
的迭代中多次（2次）调用scan.nextInt（）
，而循环并使用scan.nextInt（）
的第二次调用写入文件ps.write（scan.nextInt（））
；它跳过每个可选的整数
整数ps。write（）字符串import java.util.Scanner;
import java.io.*;
public class Main {
public static void printToScreen(String filename) {
Scanner scan = null;
try {
FileInputStream fis = new FileInputStream(filename);
scan = new Scanner(fis);
while (scan.hasNextLine()) {
System.out.println(scan.nextLine());
}
} catch (FileNotFoundException e) {
System.out.println("printToScreen: can't open: " + filename);
} finally {
if (scan != null)
scan.close();
}
}// end of print
public static void process(String inputFilename) {
String fileoutputname = null;
FileInputStream file = null;
Scanner scan = null;
FileOutputStream outputFilename = null;
FileWriter ps = null;
try {
file = new FileInputStream(inputFilename);
scan = new Scanner(file);
fileoutputname = scan.next();
System.out.println(fileoutputname + " asfasdfasdfasdf");
outputFilename = new FileOutputStream(fileoutputname);
ps = new FileWriter(fileoutputname);
int currentInt = -1;
while (scan.hasNextInt()) {
currentInt = scan.nextInt();
if (currentInt >= 0) {
//System.out.println(currentInt + "asfs");
ps.write(String.valueOf(currentInt));
ps.flush();
} else {
System.out.println("You have ran out of data or you have a bad value");
}
}
System.out.println("A file was created");
} catch (FileNotFoundException e) {
System.out.println("You ran into an exception :" + e);
} catch (IOException e) {
System.out.println("You ran into an exception :" + e);
} finally {
try {
if (file != null) {
file.close();
}
if (outputFilename != null) {
outputFilename.close();
}
if (ps != null) {
ps.close();
}
// FileInputStream st = new FileInputStream(fileoutputname);
// int contents = st.read();
// while (scan.hasNextInt()) {
// System.out.print(contents);
// }
if (scan != null) {
scan.close();
}
printToScreen(fileoutputname);
} catch (IOException e) {
System.out.println("there was an exception");
}
}
}
public static void main(String args[]) {
process("sample.txt");
}
}
niceJob.txt asfasdfasdfasdf
A file was created
4020115745123456789778899233456
currentInt=-1有什么用？如果您想多次使用
scan.nextInt（）if条件中一样，在屏幕上打印它，将它写入文件等，而不需要多次调用scan.nextInt（）
（如果多次调用它，它会一直移动到最后一次int
。例如：最初scan.nextInt（）
在5237
的情况下返回5，如果第二次调用scan.nextInt（）
，它会返回2，第三次调用返回3，第四次调用返回7，最后一个元素），您可以存储scan.nextInt（）的返回值<代码> >代码> > Currimint INT/COM>并多次引用，不必担心上述情况。- 1是将该变量初始化为某个值。考虑一个不初始化IE <代码> int Currutint；< /C> >的情况，在下一行中，如果您想打印“代码> Currimint INT/CODE >，您将得到一个错误。aying变量可能尚未初始化
。希望这对您有所帮助。请了解如何使用资源进行尝试：这将使您的代码不那么冗长。