Java讀寫檔案指定編碼格式

使用InputStreamReader，OutputStreamWriter

InputStreamReader reader = new InputStreamReader(new FileInputStream(file),readCharsetName);
BufferedReader bfReader = new BufferedReader(reader)；

OutputStreamWriter writer = new OutputStreamWriter(new FileOutputStream(file),writeCharsetName);
BufferedWriter bfWriter = new BufferedWriter(writer)

           

eclipse指定了編碼格式為UTF-8後，打開以GBK編碼格式的檔案會出現中文亂碼，反之亦然；

而系統自帶記事本則不會出現亂碼，除非檔案被Java用錯誤的編碼格式讀取後重新寫入，将導緻檔案真正亂碼。

是以，讀取時指定的編碼格式尤為重要，必須正确。

下面是一個.java檔案編碼格式轉換程式

package javaFile;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;

import java.io.FilenameFilter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class JavaFileConversion {

    public static List<File> getFileList(String path) {
        List<File> list = new ArrayList<File>();
        File file = new File(path);
        File[] filelist = file.listFiles(new FilenameFilter() {
            @Override
            public boolean accept(File dir, String name) {
                return name.endsWith(".java");
            }
        });
        for (File f : filelist) {
            list.add(f);
        }
        return list;
    }

    public static void convertToTxt(List<File> list, String path, String readCharsetName, String writeCharsetName) {
        for (File file : list) {
            String name = file.getName().substring(0, file.getName().indexOf(".")) + ".txt";
            try (InputStreamReader reader = new InputStreamReader(new FileInputStream(file), readCharsetName);
                    BufferedReader bfReader = new BufferedReader(reader)) {
                String content = "";
                String line = null;
                while ((line = bfReader.readLine()) != null) {
                    content += line + "\n";
                }
                File txt = new File(path + File.separator + name);
                try (OutputStreamWriter writer = new OutputStreamWriter(new FileOutputStream(txt), writeCharsetName);
                        BufferedWriter bfWriter = new BufferedWriter(writer)) {
                    bfWriter.write(content);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        System.out.println("操作成功！請到" + path + "目錄下檢視");
    }

    public static void convertEncoding(List<File> list, String path, String readCharsetName, String writeCharsetName) {
        for (File file : list) {
            String name = file.getName();
            try (InputStreamReader reader = new InputStreamReader(new FileInputStream(file), readCharsetName);
                    BufferedReader bfReader = new BufferedReader(reader)) {
                String content = "";
                String line = null;
                while ((line = bfReader.readLine()) != null) {
                    content += line + "\n";
                }
                File txt = new File(path + File.separator + name);
                try (OutputStreamWriter writer = new OutputStreamWriter(new FileOutputStream(txt), writeCharsetName);
                        BufferedWriter bfWriter = new BufferedWriter(writer)) {
                    bfWriter.write(content);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        System.out.println("操作成功！請到" + path + "目錄下檢視");
    }

    public static void main(String[] args) {
        System.out.println("請輸入需轉換的路徑：");
        Scanner scanner = new Scanner(System.in);
        String path = scanner.nextLine();
        System.out.println("請輸入讀取檔案的編碼方式：(如:utf-8、gbk)");
        String readCharsetName = scanner.nextLine();
        System.out.println("請輸入儲存檔案的編碼方式：(如:utf-8、gbk)");
        String writeCharsetName = scanner.nextLine();
        scanner.close();
        List<File> list = JavaFileConversion.getFileList(path);
//        JavaFileConversion.convertToTxt(list, path, readCharsetName, writeCharsetName);
        JavaFileConversion.convertEncoding(list, path, readCharsetName, writeCharsetName);
    }
}