我想做的事:我的班级 copytest 读取一个文本文件,编辑一个字符并将这个新文件保存在一个新目录中。我想用它编写一个 void 方法,它的作用完全相同,然后可以按以下方式使用:
copy(String "C:\\Old.txt", String "C:\\New.txt", int 1, int 1)
现在 copy 与我的旧类 copytest 完全相同,它读取旧文件,编辑并保存它。我的第一个想法是有两个文件作为第一个参数,但这显然是不可能的。我的新想法是给方法两个字符串的旧文件和新文件的所需目录。它仍然不起作用。我希望,你明白,我想做什么以及如何解决这个问题。
旧课程代码(作品):
import java.io.*;
import java.util.Scanner;
public class copytest {
public static void main(String[] args) throws Exception {
readFile();
}
public static void readFile() throws Exception {
// Location of file to read
File file = new File("...old.txt");
Scanner scanner = new Scanner(file);
int lineNumber=1;
int charNumber=1;
String wantedChar="r";
int i=0;
while (scanner.hasNextLine()) {
String line = scanner.nextLine();
if (i == lineNumber+2) {
if (line.length() >= charNumber) {
line = line.substring(0,charNumber-1) + wantedChar + line.substring(charNumber);
}
}
writeFile(line);
i++;
}
scanner.close();
System.out.println("File copied.");
}
public static void writeFile(String copyText) throws Exception {
String newLine = System.getProperty("line.separator");
// Location of file to output
Writer output = null;
File file = new File("...new.txt");
output = new BufferedWriter(new FileWriter(file, true));
output.write(copyText);
output.write(newLine);
output.close();
}
}
新的无效代码(首先尝试使用文件作为参数):
public void copy(file old, file new, int x, int y) {
public static void readFile() throws Exception {
Scanner scanner = new Scanner(old);
int lineNumber=y;
int charNumber=x;
String wantedChar="r";
int i=0;
while (scanner.hasNextLine()) {
String line = scanner.nextLine();
if (i == lineNumber+2) {
if (line.length() >= charNumber) {
line = line.substring(0,charNumber-1) + wantedChar + line.substring(charNumber);
}
}
writeFile(line);
i++;
}
scanner.close();
System.out.println("File copied.");
}
public static void writeFile(String copyText) throws Exception {
String newLine = System.getProperty("line.separator");
// Location of file to output
Writer output = null;
File file = new File(new.getPath());
output = new BufferedWriter(new FileWriter(file, true));
output.write(copyText);
output.write(newLine);
output.close();
}
readFile();
}
使用字符串作为参数的新尝试,但仍然不起作用:
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.Writer;
import java.util.Scanner;
public class copytestnew {
public void copy(String old, String newone, int x, int y) {
// Location of file to read
File file = new File(old);
Scanner scanner = new Scanner(file);
int lineNumber=y;
int charNumber=x;
String wantedChar="r";
int i=0;
while (scanner.hasNextLine()) {
String line = scanner.nextLine();
if (i == lineNumber+2) {
if (line.length() >= charNumber) {
line = line.substring(0,charNumber-1) + wantedChar + line.substring(charNumber);
}
}
String newLine = System.getProperty("line.separator");
// Location of file to output
Writer output = null;
File file2 = new File(newone);
output = new BufferedWriter(new FileWriter(file2, true));
output.write(line);
output.write(newLine);
output.close();
i++;
}
scanner.close();
System.out.println("File copied");
}
}