printwriter 对象没有打印出来

Question

我的 PrintWriter 对象编写器的 print() 方法不起作用，我导入了所有适当的类，但 CSV 文件总是空白。谁能告诉我为什么？

public class StateStats {
    static String pathto = "....";

    public static void main(String[] args) throws FileNotFoundException, IOException {
       ReadFile st = new ReadFile(pathto+"stateAbbrev.csv");
       ReadFile abPop = new ReadFile(pathto+"AbbrevPop.csv");      
       ReadFile Perc = new ReadFile(pathto+"PopPercentAlpha.dat");


       PrintWriter writer = new PrintWriter(pathto+"StateAbbPop.csv","UTF-8");

       //this is the header for our new CSV file
       writer.write("State, Abbrev, Population, %of US");
       writer.write("\n");
    }
}

Answer 1

您似乎忘记在 writer 上调用 flush 或 close。没有它，一些临时存储在缓冲区中的字符将不会发送到文件中。