我正试图让它成为我的程序
我坚持使用格式化部分。例如，我不确定println命令需要在哪里。任何帮助肯定会受到赞赏。我是初学者，还在学习基本的东西。
处理单个字符串的界面：
public interface StringProcessor
{
void process(String s);
}
处理类：
import java.util.Scanner;
import java.io.FileNotFoundException;
import java.io.File;
import javax.swing.JFileChooser;
class FileProcessor
{
private Scanner infile;
public FileProcessor(File f) throws FileNotFoundException
{
Scanner infile = new Scanner(System.in);
String line = infile.nextLine();
}
public String go(StringProcessor a)
{
a.process(line);
}
}
驱动程序类：
import java.util.Scanner;
import java.io.FileNotFoundException;
import java.io.File;
import javax.swing.JFileChooser;
public class Driver
{
public static void main(String[] args) throws FileNotFoundException
{
JFileChooser chooser = new JFileChooser();
File inputFile = null;
if (chooser.showOpenDialog(null) == JFileChooser.APPROVE_OPTION)
{
inputFile = chooser.getSelectedFile();
}
FileProcessor infile = new FileProcessor(inputFile);
int total=0;
}
}
这会使每行大写：
public class Upper implements StringProcessor
{
public void process(String s)
{
while (infile.hasNextLine())
{
System.out.println(infile.nextLine().toUpperCase());
}
}
}
这会计算角色：
public class Count implements StringProcessor
{
public void process(String s)
{
while (infile.hasNextLine())
{
int charactercounter = infile.nextLine().length();
total = total+charactercounter;
}
}
}
这会打印到文件：
import java.io.PrintWriter;
import java.io.FileNotFoundException;
public class Print implements StringProcessor
{
public void process(String s)
{
PrintWriter out = new PrintWriter("copy.txt");
while (infile.hasNextLine())
{
out.println(infile.nextLine());
}
out.close();
}
}
答案 0 :(得分：2)
Java是我学过的第一批编程语言之一，一旦你得到它，它就是如此美丽。这是你作业的解决方案，但现在你有了新的家庭作业。去弄清楚什么在做什么，并用笔记标记。因此，下次遇到类似问题时，您可以查看旧代码并选择所需内容。我们在某些时候都是新手，所以不要把它弄坏。
<强> StringProcessor.java
public interface StringProcessor {
public String Upper(String str);
public int Count(String str);
public void Save(String str, String filename);
}
<强> FileProcessor.java
import java.io.FileWriter;
public class FileProcessor implements StringProcessor{
public FileProcessor(){
}
// Here we get passed a string and make it UpperCase
@Override
public String Upper(String str) {
return str.toUpperCase();
}
// Here we get passed a string and return the length of it
@Override
public int Count(String str) {
return str.length();
}
// Here we get a string and a file name to save it as
@Override
public void Save(String str, String filename) {
try{
FileWriter fw = new FileWriter(filename);
fw.write(str);
fw.flush();
fw.close();
}catch (Exception e){
System.err.println("Error: "+e.getMessage());
System.err.println("Error: " +e.toString());
}finally{
System.out.println ("Output file has been created: " + filename);
}
}
}
<强> Driver.java
import java.io.File;
import java.util.Scanner;
import javax.swing.JFileChooser;
public class Driver {
@SuppressWarnings("resource")
public static void main(String[] args){
System.out.println("Welcome to the File Processor");
Scanner scan = new Scanner(System.in);
System.out.print("\nWould you like to begin? (yes or no): ");
String startProgram = scan.next();
if(startProgram.equalsIgnoreCase("yes")){
System.out.println("\nSelect a file.\n");
JFileChooser chooser = new JFileChooser();
File inputFile = null;
if(chooser.showOpenDialog(null) == JFileChooser.APPROVE_OPTION){
inputFile = new File(chooser.getSelectedFile().getAbsolutePath());
try{
Scanner file = new Scanner(inputFile);
file.useDelimiter("\n");
String data = "";
FileProcessor fp = new FileProcessor();
while (file.hasNext()){
String line = file.next();
System.out.println("Original: " +line);
System.out.println("To Upper Case: " +fp.Upper(line));
System.out.println("Count: " +fp.Count(line));
System.out.println();
data += line;
}
System.out.println("\nFile Processing complete!\n");
System.out.print("Save copy of file? (yes or no): ");
String save = scan.next();
if(save.equalsIgnoreCase("yes")){
fp.Save(data, "copy.txt");
System.out.println("\nProgram Ending... Goodbye!");
}else{
System.out.println("\nProgram Ending... Goodbye!");
}
}catch (Exception e){
e.printStackTrace();
}
}
}else{
System.out.println("\nProgram Ending... Goodbye!");
}
}
}
<强>的text.txt
some text here to test the file
and to see if it work correctly
保存文件“copy.txt”只是一个注释，它将显示在项目文件夹中。
答案 1 :(得分：1)
由于您的问题在字符流上运行，因此已经有一个很好的Java接口可以实现。实际上，它们是两个抽象类：FilterReader或FilterWriter - 任何一个都可以工作。在这里，我选择扩展FilterWriter。
例如，这是一个Writer示例，用于跟踪要求写入的字符数：
import java.io.*;
public class CharacterCountingWriter extends FilterWriter {
private long charCount = 0;
public CharacterCountingWriter(Writer out) {
super(out);
}
public void write(int c) throws IOException {
this.charCount++;
out.write(c);
}
public void write(char[] buf, int off, int len) throws IOException {
this.charCount += len;
out.write(buf, off, len);
}
public void write(String str, int off, int len) throws IOException {
this.charCount += len;
out.write(str, off, len);
}
public void resetCharCount() {
this.charCount = 0;
}
public long getCharCount() {
return this.charCount;
}
}
基于该模型，您也应该能够实现UpperCaseFilterWriter。
使用这些类，这是一个复制文件的程序，在文本上加上文本并在每行中打印字符数。
public static void main(String[] args) throws IOException {
BufferedReader in = new BufferedReader(new FileReader(args[0]));
try (CharacterCountingWriter ccw = new CharacterCountingWriter(new FileWriter(args[1]));
UpperCaseFilterWriter ucfw = new UpperCaseFilterWriter(ccw);
Writer pipeline = ucfw) { // pipeline is just a convenient alias
String line;
while (null != (line = in.readLine())) {
// Print count of characters in each line, excluding the line
// terminator
ccw.resetCharCount();
pipeline.write(line);
System.out.println(ccw.getCharCount());
pipeline.write(System.lineSeparator());
}
pipeline.flush();
}
}