Question

我想阅读一个文本文件并处理它的数据。例如输入文件将如下所示：

john,judd,134
Kaufman,kim,345

然后程序应该以JSON文件的形式解析和存储这些数据，以便进行进一步处理。我使用JSON-simple执行此任务。这是原型代码I＆＃ 39;写完：

package com.company;

import org.json.simple.JSONObject;

import java.io.*;

public class Main {


static JSONObject jsonObject = new JSONObject();
static String output;

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

    read("/Users/Sepehr/Desktop/JSONexample.txt");
    write("/Users/Sepehr/Desktop/JSONexampleout,txt");

}

public static String read(String filenameIn) throws IOException {

    BufferedReader bufferedReader = new BufferedReader(new FileReader(filenameIn));
    String s ;

    while ( (s = bufferedReader.readLine() ) != null)

    {
        String[] stringsArr = s.split(",");


        jsonObject.put( "famname" , stringsArr[0] );
        jsonObject.put("name" , stringsArr[1]);
        jsonObject.put("id", stringsArr[2]);

        bufferedReader.close();


    }

    return output=jsonObject.toJSONString();


}


public static String write(String filenameOut) throws FileNotFoundException {

    PrintWriter printWriter = new PrintWriter(filenameOut);
    printWriter.write(jsonObject.toJSONString());
    printWriter.close();

    String se = "yaaayyy :|";
    return se;

}



}

运行程序后，这些是我得到的例外：

Exception in thread "main" java.io.IOException: Stream closed
at java.io.BufferedReader.ensureOpen(BufferedReader.java:97)
at java.io.BufferedReader.readLine(BufferedReader.java:292)
at java.io.BufferedReader.readLine(BufferedReader.java:362)
at com.company.Main.read(Main.java:30)
at com.company.Main.main(Main.java:18)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)

到底出了什么问题？

如何为这个程序做出更好的设计？

Answer 1

您正在关闭循环中的BufferedReader

while ( (s = bufferedReader.readLine() ) != null)

    {
        String[] stringsArr = s.split(",");


        jsonObject.put( "famname" , stringsArr[0] );
        jsonObject.put("name" , stringsArr[1]);
        jsonObject.put("id", stringsArr[2]);

        //*************
        bufferedReader.close(); // don't close the reader!
        //*************

    }

在java中使用JSON读取和写入String文件

1 个答案: