CSV的LinkedHashMap无法获取所有条目

时间:2018-12-12 17:45:16

标签: java arraylist hashmap treemap linkedhashmap

CSV文件按顺序转换为变量。我一直在尝试读取CSV文件,该文件包含两列,一个标题,然后一个条目列表。

目前,我一直在使用LinkedHashMap;使用以下循环读取,拆分和创建LinkedHashMap。

但是,当前它卡在了我的CSV的第5行中。这是当前的读取循环:

public static LinkedHashMap<String, ArrayList<String>> runningOrderMap(String filename) throws IOException {
        LinkedHashMap<String, ArrayList<String>> linkedHashMap = new LinkedHashMap<>(50);
        String currentLine = ""; //init iterator variable
        String[] valuesTMP;
        try {
            bufferedReader = new BufferedReader(new FileReader(filename));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        while((currentLine = bufferedReader.readLine()) != null){
            valuesTMP = currentLine.split(", ");
            ArrayList<String> values = new ArrayList<>();
            String key = valuesTMP[0].split("\t")[0].trim();
            values.add(valuesTMP[0].split("\t")[1].trim());
            for(int i = 1; i < valuesTMP.length; i++){
                values.add(valuesTMP[i]);
                System.out.println(valuesTMP[i]);
                linkedHashMap.put(key, values);
            }
        }
        System.out.println("linked hashmap:"+linkedHashMap.keySet().size());
        return linkedHashMap;
    }

示例数据的格式如下:标题的长度不同,制表符,然后是诸如此类的内容条目列表:

title   content, content2

title example    content, content2, content3

title example three   content, content2

title example    content, content2

此数据持续约20行,但是LinkedHashMap不会超过第5行:

title example two   content

我需要保留数组中的行顺序。

1 个答案:

答案 0 :(得分:2)

看来我知道出什么问题了

尝试将行linkedHashMap.put(key, values);从内部for循环中移出,如下所示:

public static LinkedHashMap<String, ArrayList<String>> runningOrderMap(String filename) throws IOException {
    LinkedHashMap<String, ArrayList<String>> linkedHashMap = new LinkedHashMap<>(50);
    String currentLine = ""; //init iterator variable
    String[] valuesTMP;
    try {
        bufferedReader = new BufferedReader(new FileReader(filename));
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }
    while((currentLine = bufferedReader.readLine()) != null){
        valuesTMP = currentLine.split(", ");
        ArrayList<String> values = new ArrayList<>();
        String key = valuesTMP[0].split("\t")[0].trim();
        values.add(valuesTMP[0].split("\t")[1].trim());
        for(int i = 1; i < valuesTMP.length; i++){
            values.add(valuesTMP[i]);
            System.out.println(valuesTMP[i]);
        }
        linkedHashMap.put(key, values); // <--this line was moved out from internal for loop
    }
    System.out.println("linked hashmap:"+linkedHashMap.keySet().size());
    return linkedHashMap;
}

因为您看到,只有当内容的一部分以上时,才会执行此内部for循环