我看到有几个类似的问题,但是我没有找到满意的答案。我有一个逗号分隔的文件,其中每一行看起来都像这样:
4477,52544,,,P,S, ,,SUSAN JONES,9534 Black Bear Dr,,"CITY, NV 89506",9534 BLACK BEAR DR,,CITY,NV,89506,2008,,,, , , , ,,1
出现的问题是令牌通过引号“ CITY,NV 89506”转义为逗号时>
我需要一个结果,在该结果中处理了转义的令牌并包括了每个令牌,甚至是空的令牌。
考虑适当的CSV解析器,例如opencsv。它会经过高度测试(不同于新的本地解决方案),并且能够处理您描述的边缘条件(以及您尚未考虑的很多条件)。
在下载中,有一个示例文件夹,其中包含带有以下行的“ addresses.csv”:
Jim Sample,"3 Sample Street, Sampleville, Australia. 2615",[email protected]
在同一目录中,文件AddressExample.java解析该文件,并且与您的问题高度相关。
这是使用提供的java.lang.String
方法回答您的问题的一种方法。我相信它可以满足您的需求。
private final char QUOTE = '"';
private final char COMMA = ',';
private final char SUB = 0x001A; // or whatever character you know will NEVER
// appear in the input String
public void readLine(String line) {
System.out.println("original: " + line);
// Replace commas inside quoted text with substitute character
boolean quote = false;
for (int index = 0; index < line.length(); index++) {
char ch = line.charAt(index);
if (ch == QUOTE) {
quote = !quote;
} else if (ch == COMMA && quote) {
line = replaceChar(line, index, SUB);
System.out.println("replaced: " + line);
}
}
// Strip out all quotation marks
for (int index = 0; index < line.length(); index++) {
if (line.charAt(index) == QUOTE) {
line = removeChar(line, index);
System.out.println("stripped: " + line);
}
}
// Parse input into tokens
String[] tokens = line.split(",");
// restore commas in place of SUB characters
for (int i = 0; i < tokens.length; i++) {
tokens[i] = tokens[i].replace(SUB, COMMA);
}
// Display final results
System.out.println("Final Parsed Tokens: ");
for (String token : tokens) {
System.out.println("[" + token + "]");
}
}
private String replaceChar(String input, int position, char replacement) {
String begin = input.substring(0, position);
String end = input.substring(position + 1, input.length());
return begin + replacement + end;
}
private String removeChar(String input, int position) {
String begin = input.substring(0, position);
String end = input.substring(position + 1, input.length());
return begin + end;
}