Java如何仅更改字段定界符,而不更改实际数据

时间:2019-01-14 05:36:29

标签: java regex csv

我有一个输入CSV ,其中的数据用双引号引起来,字段分隔符是逗号(,),如下所示,是3列和1行:

"Id","Description","LastModifiedDate","Quantity"
"101","this is a test message - "","" how are you, where are you from","2018-01-13","15.0"
"102","this is line break msg , "2019-01-01","13.0"
 where data goes to next line"

我只想将字段分隔符从逗号(,)更改为脱字符号(^),因此在从输入CSV读取行时,我写了line.replace(“ \”,\“”,“ \” ^ \“”) ; 低于实际结果

"Id"^"Description"^"LastModifiedDate"
"101"^"this is a test message - ""^"" how are you, where are you from"^"2018-01-13"^"15.0"
"102"^"this is line break msg ^ "2019-01-01"^"13.0"
 where data goes to next line"

问题是使用上面的替换代码,它将所有逗号替换为我不想要的插入号。 预期输出应如下所示:

"Id"^"Description"^"LastModifiedDate"
"101"^"this is a test message - "","" how are you, where are you from"^"2018-01-13"^"15.0"
"102"^"this is line break msg ^ "2019-01-01"^"13.0"
 where data goes to next line"

据我所知,可以使用Java正则表达式处理此问题,但不幸的是,我不太擅长使用正则表达式,因此我们将不胜感激。

更新

         Regex1  : replaceAll("\",\"(?!\"\")", "\"^\"");

        Example1,
     "Id","Description","LastModifiedDate","Quantity"  -- header
     "101","hello-this,is test data"",""testing","2018-10-01","\"  -- input row1
    "101"^"hello-this,is test data""^""testing"^"2018-10-01"^"\"  -- post Regex1
     "101"^"hello-this,is test data"",""testing"^"2018-10-01"^"\"  -- expected

 In first row if data contains "","" it still gets replaced to ""^""


     Example2, 
       "Id","Description","LastModifiedDate","Quantity"  -- header 
       "102","""text in double quotes""","13.2" -- input row2
       "102","""text in double quotes"""^"13.2"  -- post with only Regex1
        "102"^""text in double quotes""^"13.2"  --  expected result

 So I tried one more regex after regex1 for second row scenario
Regex 2:  replaceAll(",\"\"\"(?!\"\")", "^\"\""); 

      regex2 along with regex1 partially worked but still, the row1 issue is not getting resolved.

是否可以在1个replaceAll中处理所有这些情况,或者也可以在多个replaceAll中处理

1 个答案:

答案 0 :(得分:1)

我想这很适合您;

    text = text.replaceAll("\",\"(?!\")", "\"^\"");

\“,\”(?!\“)这部分表示如果“ \””后面没有“ \””,则以下内容将与“ \””匹配。