零基础学Java优学网转换流课：轻松掌握字符编码转换，告别乱码烦恼

// 使用默认字符集 InputStreamReader reader1 = new InputStreamReader(inputStream);

// 明确指定字符集 InputStreamReader reader2 = new InputStreamReader(inputStream, "UTF-8");

// 读取GBK文件，转换为UTF-8输出 try (InputStreamReader reader = new InputStreamReader(

    new FileInputStream("gbk_file.txt"), "GBK");
 OutputStreamWriter writer = new OutputStreamWriter(
    new FileOutputStream("utf8_file.txt"), "UTF-8")) {

char[] buffer = new char[1024];
int length;
while ((length = reader.read(buffer)) != -1) {
    writer.write(buffer, 0, length);
}

}