java 讀取txt文件，漢字亂碼，原因是因為文件的編碼格式和程序編碼采用了不同的編碼格式。通常，假如自己不修改的話，windows自身采用的編碼格式是gbk(而gbk和gb2312基本上是一樣的編碼方式)，程序中一般采用utf-8,所以讀取文件的時候最好指定編碼方式

方式1：以字節流讀寫

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
 
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Writer;

import org.apache.commons.lang3.StringUtils;

public class FileReadWriteDemo2 {

    public static void main(String[] args) throws IOException {

        BufferedReader read = new BufferedReader(new
 
 InputStreamReader(new FileInputStream("f:/test.txt"),"gbk"));
        Writer out = new OutputStreamWriter(new FileOutputStream("f:/testNew.txt"),"gbk");
        BufferedWriter writer =new BufferedWriter(out);
        String fileContent ="";
        String line = "";
        while ((line = read.readLine()) != null
 
) {
            //刪除空格
            if (StringUtils.isNotBlank(line)) {
                //System.out.println(line);
                fileContent +=line+"\r\n";
                writer.write(line);
                writer.write("\r\n");
            }
        }
        read.close();
        writer.close();
        System.out.println(fileContent);
    }
}

方式2：以字符流讀寫

public class FileReadWriteDemo {

    public static void main(String[] args) throws IOException {
        BufferedReader read = new BufferedReader(new FileReader("f:\\test.txt"));

        BufferedWriter writer = new BufferedWriter(new FileWriter("f:/testNew.txt"));
        
        String line = "";
        while ((line = read.readLine()) != null) {
        
            if (StringUtils.isNotBlank(line)) {
                System.out.println(line);
                writer.write(line);
                writer.write("\n ");
            }
        }
        read.close();
        writer.close();
    }
}

java io 讀取寫文件