在SuperCSV中解析字符串 [英] Parsing Strings in SuperCSV

问题描述

@Carlo V. Dango
我已经简化了我的问题，我已经阅读文档 - 好建议不要恐慌。仍然，我有问题。帮助我解决一个，它会解决所有的。谢谢。

问题：当我有一个缺少非字符串字段的csv记录时，如何（甚至可以）将缺少的条目转换为默认值，或者至少，不抛出NullPointerException？可选的cellProcessor看起来不会阻止错误。

这个程序基本上来自SuperCSV网站。

  package com.test.csv; 
 import java.io.FileReader; 
 
 import org.supercsv.cellprocessor.ParseBigDecimal; 
 import org.supercsv.cellprocessor.ParseDate; 
 import org.supercsv.cellprocessor.ParseInt; 
 import org.supercsv.cellprocessor.ift.CellProcessor; 
 import org.supercsv.io.CsvBeanReader; 
 import org.supercsv.io.ICsvBeanReader; 
 import org.supercsv.prefs.CsvPreference; 
 
 
 public class CSVReader {
 
 private static final CellProcessor [] cellProcessor = new CellProcessor [] {
 null，
 null，
 new ParseInt（），
 new ParseDate（yyyyMMdd），
 new ParseBigDecimal（）
}; 
 
 public static void main（String [] args）throws Exception {
 
 CsvPreference pref = new CsvPreference（''，'|'，\\\
）; 
 
 ICsvBeanReader inFile = new CsvBeanReader（new FileReader（C：\\temp\\\sapfilePipe.txt），pref）; 
 try {
 final String [] header = inFile.getCSVHeader（true）; 
用户; 
 while（（user = inFile.read（User.class，header，cellProcessor））！= null）{
 System .out.println（user）; 
} 
} finally {
 inFile.close（）; 
} 
 
} 
  
 
 
 
} 
 
 
 
这里是我正在阅读的CSV文件。在第一个记录中有一个缺少字段（age）。
  firstName | lastName | age | hireDate | hourlyRate 
 A. | Smith | | 20110101 | 15.50 
  
我的用户bean：
  package com.test.csv; 
 
 import java.math.BigDecimal; 
 import java.util.Date; 
 
 public class User {
 
 private String firstName; 
 private String lastName; 
 private int age; 
 private日期hireDate; 
 private BigDecimal hourlyRate; 
 ... getters / setters ... 
  
这是错误：
 线程main中的异常java.lang.NullPointerException 
 at org.supercsv.io.CsvBeanReader.fillObject（Unknown Source） 
 at org.supercsv.io.CsvBeanReader.read（未知源）
 at com.glazers.csv.CSVReader.main（CSVReader.java:31）
  
 
 
 
感谢。
解决方案
行到字符串列表。这似乎是你要找的。 
 
 
  http://supercsv.sourceforge.net/javadoc/org/supercsv/io/CsvListReader.html  
 
 
 
或此处显示 http://supercsv.sourceforge.net/codeExamples_general.html 您可以将处理器设置为null如果你不想要任何具体做。
 
@Carlo V. Dango
I have simplified my question and I have read the documentation--good advice not to panic.  Still, I have problems.  Help me solve one and it will solve them all. Thank you.

Question:  When I have a csv record that is missing a non-String field, how (or even can I) convert the missing entry to a default value, or at least, not throw NullPointerException? Optional cellProcessor doesn't appear to prevent the error either.

This the program taken essentially from the SuperCSV website.
package com.test.csv;
import java.io.FileReader;

import org.supercsv.cellprocessor.ParseBigDecimal;
import org.supercsv.cellprocessor.ParseDate;
import org.supercsv.cellprocessor.ParseInt;
import org.supercsv.cellprocessor.ift.CellProcessor;
import org.supercsv.io.CsvBeanReader;
import org.supercsv.io.ICsvBeanReader;
import org.supercsv.prefs.CsvPreference;


public class CSVReader {

private static final CellProcessor[] cellProcessor = new CellProcessor[] {
    null,
    null,
    new ParseInt(),
    new ParseDate("yyyyMMdd"),      
    new ParseBigDecimal()       
};

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

    CsvPreference pref = new CsvPreference('"', '|', "\n");

    ICsvBeanReader inFile = new CsvBeanReader(new FileReader("C:\\temp\\sapfilePipe.txt"), pref);
    try {
        final String[] header = inFile.getCSVHeader(true);
        User user;
        while ((user = inFile.read(User.class, header, cellProcessor)) != null) {
            System.out.println(user);
        }
    } finally {
        inFile.close();
    }

}
}

here is the CSV file I'm reading.  Notice in the first record there is a missing field (age).
firstName|lastName|age|hireDate|hourlyRate
A.|Smith|  |20110101|15.50
My User bean: 
package com.test.csv;

import java.math.BigDecimal;
import java.util.Date;

public class User {

private String firstName;
private String lastName;
private int age;
private Date hireDate;
private BigDecimal hourlyRate;
    ...getters/setters...   
Here is the error:
Exception in thread "main" java.lang.NullPointerException
    at org.supercsv.io.CsvBeanReader.fillObject(Unknown Source)
    at org.supercsv.io.CsvBeanReader.read(Unknown Source)
    at com.glazers.csv.CSVReader.main(CSVReader.java:31)
Thanks.
解决方案
The list reader reads each line into a list of strings. It seems this is what you are looking for.

http://supercsv.sourceforge.net/javadoc/org/supercsv/io/CsvListReader.html

or as shown here http://supercsv.sourceforge.net/codeExamples_general.html you can set the processor to null if you don't want anything specific done.

                        
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