Csvbeans:java Analytic Csv__java

first, CSV and Csvbeans introduction
Csv:comma seperated Values; Description: A row represents a record, and a record has multiple fields (attributes), each separated by commas (or other symbols). Csvbeans Open Source project: Convert each line of data in CSV into JavaBean open source tools; Download url:http://sourceforge.net/projects/csvbeans/files/
Of course, parsing CSV is not only a tool, there are Apache opencsv, etc.;

The dependency package is also added to the Lib directory, including: Commons-resources.jar Commons-logging.jar Commons-lang-2.1.jar Commons-digester-1.7.jar Commons-codec-1.3.jar Commons-beanutils-core.jar Commons-beanutils-bean-collections.jar Commons-beanutils.jar
Ii. Project Defect Resolution
First of all, this project I currently identified two small problems: (1) CSV file data can not be separated by \ T, (2) write a CSV file, must have starttag;

Must have Starttag means: Persons ----> This is starttag aaa,20 aaa,20 aaa,20 Can not without starttag means: aaa,20 aaa,20 aaa,20 If the starttag is set to NULL, there will be a problem;

Solve:
(1) For the first question, if a CSV file exists with \ t, then I write a helper class that can be used to rewrite this CSV file into a comma-separated CSV file;

Package com.xiazdong.csv;
Import Java.io.BufferedReader;
Import Java.io.File;
Import Java.io.FileInputStream;
Import Java.io.InputStreamReader;
Import Java.io.PrintWriter;

Import Java.util.UUID; public class Csvutils {/** * This function is used to assist Csvbeans, because this open source package has a flaw in that it cannot parse the tab-delimited CSV, so this function is specifically used to convert tab to commas and overwrite the original file * @param from File required to convert * @throws Exception/public static void Parsefromtabtocomma (file fromfile) throws exception{buffered
		Reader reader = new BufferedReader (new InputStreamReader (New FileInputStream (FromFile));		File Tmpfile = new file (Uuid.randomuuid (). toString ());
		Generates temporary files, but does not eventually exist printwriter writer = new PrintWriter (tmpfile);
		String line = null;
				while ((Line=reader.readline ())!=null) {String ss[] = Line.split ("\\t");//tab-delimited for (int i=0;i<ss.length;i++) {
				Writer.write (Ss[i]);
				if (i< (ss.length-1)) {Writer.write (",");
		} writer.write ("\ n");
		} writer.close ();
		Reader.close ();
		if (fromfile.exists ()) {fromfile.delete ();	Tmpfile.renameto (FromFile);
	} public static void Main (string[] args) throws Exception {Parsefromtabtocomma (New File ("Src/persons.csv")); }
}

(2) For the second question, it is necessary to modify the source code;
SOURCE Download: HTTP://SOURCEFORGE.NET/PROJECTS/CSVBEANS/FILES/CSVBEANS/CSVBEANS-0.7.1/
Csvbeans-0.7.1\src\java\org\csvbeans\builders\csvbuilder.java AddbeansThe function is changed to: public void Addbeans (String tag, List beans) {if (beans!= null) {This.beans.add (new Records (t         AG, beans)); } }
Writebeansfunction to start with: try {if (tag!=null) writer.writeline (tag); Recordspecification record = getrecordspecification (tag);
After the revision of the source code also need to use ant compilation, ant package automatically generated Csvbeans.jar;

Iii. Preliminary Preparation

1. Write JavaBean to represent a CSV record;
2. Write an XML file that reads: (1) The attributes of a CSV record, the name of each attribute, the MaxLen, (2) The separator between each attribute, (3) The Class of JavaBean, (4) The parser class, the builder class;

Iv. Preparation of procedures

Directory structure:


First, the JavaBean and mapping.xml that read CSV and write to CSV are the same;
1. Read CSV

Person.java slightly
Mapping.xml

<?xml version= "1.0"?>
<csvbeans>
	<strategy>
		<parser classname= " Org.csvbeans.parsers.CSVParser "/>
		<builder classname= org.csvbeans.builders.CSVBuilder"/>
	< /strategy>
	<property name= "separator value=", "/> <!--separator--> <property" Name= "
	Value= "true"/> <!--no starttag-->
	<record classname= "Com.xiazdong.csv.domain.Person" >  < !--a record-->
	  <field name= "name" maxlen= "M" required= "true"/> <field "Age
	 " Name= "10" Required= "true"/>
	</record>
</csvbeans>

Read the CSV program:

private static void Read () throws Exception, Specificationsfileexception,
			FileNotFoundException, parsingexception {
		file F = new file ("Src/persons.csv");
		Csvutils.parsefromtabtocomma (f);  If the CSV file is tab-delimited, you need to use this function
		specificationsfileparser specsparser = new Specificationsfileparser ();
		Specificationsfile  specs = specsparser.parse (new FileInputStream ("Src/mapping.xml"));
		Parsingstrategy parser = Specs.getparsingstrategy ();   Obtain the Csvparser parser.parse (new Inputstreamlinesreader (new FileInputStream (f)) in Mapping.xml
		;
		List products = Parser.getbeans (null);	No head for
		(Iterator it = Products.iterator (); It.hasnext ();) {Person
		  product = (person) it.next ();
		  SYSTEM.OUT.PRINTLN (product);
                }
}

2. Write CSV

private static void Write () throws Specificationsfileexception,
			FileNotFoundException, generationexception {
		list<person> persons = new arraylist<person> ();
		Persons.add (New person ("I");
		Persons.add (New person ("AAA",);
		Persons.add (New person ("AAA",);

		Specificationsfileparser specsparser = new Specificationsfileparser ();
		Specificationsfile  specs = specsparser.parse (new FileInputStream ("Src/mapping.xml"));
		Buildingstrategy builder = Specs.getbuildingstrategy ();  Obtain the Csvbuilder
		csvbuilder csvbuilder = (csvbuilder) builder in Mapping.xml;
		Csvbuilder.addbeans (null, persons);
		Csvbuilder.build (New Outputstreamlineswriter FileOutputStream ("Src/output.csv"));
	}