Java

Question

大家好，我的 BufferedWriter 一直有问题。起初我只有 1 个缓冲写入器 1 显示为 cc 并且这与输出一起完美地工作但是现在我已经尝试实现 2 我继续在

其他地方出现错误

Multiple markers at this line
    - Syntax error, insert "}" to complete Statement
    - Syntax error, insert "Finally" to complete

这是代码。错误从 }else if (command.equals("action 2")) 行开始

if (selected) {
    if (command.equals("action1")) { 
      BufferedWriter aa;
      try {
          File writerB = new File("output1.txt"); //set transaction-list.txt to be the destination file when writeTransactions is used
          if (!writerB.exists()) {
               writerB.createNewFile();
                    }                           

        FileWriter bb = new FileWriter(writeBalance, true); //filewriter
        aa = new BufferedWriter(bb); // bufferedwriter

      BufferedWriter cc;
            try {  
                int x=0;
                File writerT = new File("output2.txt"); //set transaction-list.txt to be the destination file when writeTransactions is used
                if (!writerT.exists()) {
                    writerT.createNewFile();
                    }
                FileWriter dd = new FileWriter(writeTransactions, true); //filewriter
                cc = new BufferedWriter(dd); // bufferedwriter
                String newLine = System.getProperty("line.separator"); //creates a line separator which will be used with string newLine 

        if (n==0) {
            bw.write(DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT).format(now) + newLine);
            wb.write(c);}
            bw.close;
            wb.close}

    }else if (command.equals("action 2"))

Answer 1

您没有在 try 之后制作 catch 块 - 在这两种情况下都没有。在 try.

之后 catch 或 finally 块是 强制性的

如前所述，强烈推荐 Java 7 中引入的 try-with-resources 语句。

Answer 2

你没有妥善处理你的资源；一方面，它们应该在 finally 块中关闭...

... 然而，还有更好的方法，那就是使用 try-with-resources 语句，以及新的 java.nio.file API:

final Path file1 = Paths.get("output1.txt");
final Path file2 = Paths.get("output2.txt");

try (
    final BufferedWriter writer1 = Files.newBufferedWriter(file1, StandardCharsets.UTF_8,
        StandardOpenOption.CREATE, StandardOpenOption.APPEND);
    final BufferedWriter writer2 = Files.newBufferedWriter(file2, StandardCharsets.UTF_8,
        StandardOpenOption.CREATE, StandardOpenOption.APPEND);
) {
    // use writer1 and writer2 here.
    // Note that BufferedWriter has a .newLine() method as well.
}

Java - 两个缓冲写入器

Java - Two buffered writers

bufferedwriter