Question

我有以下java代码来读取CSV文件并将值存储在ArrayList（）中。

        try {
        File file =new File("Data.csv");
        BufferedReader br=new BufferedReader(new FileReader(file));
        while(br.readLine() != null){
            String input=br.readLine();
            input=input.replace('"', '\0');
            datam.add(input.split(",|\\s|;"));
        }
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        System.out.println("Exception");
        e.printStackTrace();
    }

但我在以下几行获得例外

String input=br.readLine();
            input=input.replace('"', '\0');
            datam.add(input.split(",|\\s|;"));

我发现代码中没有错误。我正在使用Arraylist来填充JTable。异常消息如下：

java.lang.NullPointerException
at com.cs319.MyTable.<init>(Lab2Swing.java:366)
at com.cs319.Lab2Swing.createPanel3(Lab2Swing.java:190)
at com.cs319.Lab2Swing.<init>(Lab2Swing.java:103)
at com.cs319.Lab2Swing$1.run(Lab2Swing.java:75)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$400(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

Answer 1

您调用readLine()方法两次：一次在if子句中，而不使用返回值，然后在if块的主体中，而不检查它是否为{ {1}}。使用变量存储null的结果，检查此变量是否为readLine()，然后访问它。

用Java读取CSV文件并不起作用？

1 个答案: