【发布时间】：2016-09-26 18:46:07
【问题描述】：
我正在将 CSV 转换为 XML 数据。通过查看各种示例，我能够编写用于解析 CSV 文件和获取 XML 文件的代码。但是，我编写的代码返回带有错误标签的 XML 文件。
这是转换代码：
package com.adarsh.parse;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.StringTokenizer;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.FactoryConfigurationError;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
public class Converter {
/* Protected members to avoid instantiation */
protected DocumentBuilderFactory domFactory = null;
protected DocumentBuilder domBuilder = null;
/* Constant strings */
// Input CSV file
final String INPUT_FILE = "sample_data.csv";
// Output XML document
final String OUTPUT_FILE ="in.xml";
// First element in the XML document
final String FIRST_ELEMENT="school";
public Converter(){
try {
domFactory = DocumentBuilderFactory.newInstance();
/* Obtaining instance of class DocumentBuilder */
domBuilder = domFactory.newDocumentBuilder();
}
catch(ParserConfigurationException exp) {
System.err.println(exp.toString());
}
catch(FactoryConfigurationError exp){
System.err.println(exp.toString());
}
catch(Exception exp){
System.err.println(exp.toString());
}
}
/**
* This method converts the given CSV file into an XML document
*/
public int convert(String csvFileName, String xmlFileName) {
int rowCount = -1;
try {
/* Initializing the XML document */
Document newDoc = domBuilder.newDocument();
/* Creating the root element in the XML */
Element rootElem = newDoc.createElement(FIRST_ELEMENT);
newDoc.appendChild(rootElem);
/* Reading the CSV file */
BufferedReader csvFileReader;
csvFileName = INPUT_FILE;
csvFileReader = new BufferedReader(new FileReader(csvFileName));
/* Initialize the number of fields to 0 */
int fieldCount = 0;
String[] csvFields = null;
StringTokenizer stringTokenizer = null;
/**
* Map the column names in the CSV file as the elements in the XML
* document, eliminate any other characters not eligible for XML element
* naming
*/
/* Initialize the current line variable */
String currLine = csvFileReader.readLine();
/* Loop until we reach the end of the file
* edge case: Empty CSV file
* */
if(currLine != null) {
/* Separate fields based on commas */
stringTokenizer = new StringTokenizer(currLine, ",");
fieldCount = stringTokenizer.countTokens();
/* If there is data in the CSV file */
if(fieldCount > 0) {
/* Initialize a String Array of Fields */
csvFields = new String[fieldCount];
int i = 0;
/* Loop till all elements are found and save fields */
while (stringTokenizer.hasMoreElements()) {
csvFields[i++] = String.valueOf(stringTokenizer.nextElement());
}
}
}
else {
System.out.println("Nothing to parse");
}
/* reading rows from the CSV file */
while((currLine = csvFileReader.readLine()) != null) {
stringTokenizer = new StringTokenizer(currLine, ",");
fieldCount = stringTokenizer.countTokens();
/* if rows exist in the CSV file*/
if(fieldCount > 0) {
/* Create the row element*/
Element rowElem = newDoc.createElement("row");
int i = 0;
/* until there are more elements*/
while(stringTokenizer.hasMoreElements()) {
try {
/* Append each element found to each row element*/
String currValue = String.valueOf(stringTokenizer.nextElement());
Element currElem = newDoc.createElement(csvFields[i++]);
currElem.appendChild(newDoc.createTextNode(currValue));
rowElem.appendChild(currElem);
}
catch(Exception exp) {
}
}
/* Append the rows to the root element*/
rootElem.appendChild(rowElem);
rowCount++;
}
}
/* Finish reading the CSV file */
csvFileReader.close();
/* Saving the generated XML doc into required format file to disk */
TransformerFactory tranFactory = TransformerFactory.newInstance();
Transformer aTransformer = tranFactory.newTransformer();
aTransformer.setOutputProperty(OutputKeys.INDENT, "yes");
aTransformer.setOutputProperty(OutputKeys.METHOD, "xml");
aTransformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
Source src = new DOMSource(newDoc);
xmlFileName = OUTPUT_FILE;
Result dest = new StreamResult(new File(xmlFileName));
aTransformer.transform(src, dest);
rowCount++;
}
catch(IOException exp) {
System.err.println(exp.toString());
}
catch(Exception exp) {
System.err.println(exp.toString());
}
/* Number of rows parsed into XML */
return rowCount;
}
}
这是文件中的示例 CSV 数据：
classroom_id,classroom_name,teacher_1_id,teacher_1_last_name,teacher_1_first_name,teacher_2_id,teacher_2_last_name,teacher_2_first_name,student_id,student_last_name,student_first_name,student_grade 103, 布赖恩的教室, 10300000001, 奥唐奈, 布赖恩, , , , , , , 102, 史密斯先生的物理课程，10200000001，史密斯，亚瑟，10200000011， Patterson, John, 10200000011, McCrancy, Brandon, 1 102, Mr. Smith's PhysEd 类，10200000001，史密斯，亚瑟，10200000011，帕特森， John, 10200000018, Reginald, Alexis, 1 102, Mr. Smith's PhysEd Class, 10200000001，史密斯，亚瑟，10200000011，帕特森，约翰，10200000019， Gayle, Matthew, 1 102, Mr. Smith's PhysEd Class, 10200000001, Smith, 亚瑟，10200000011，帕特森，约翰，10200000010，史密斯，纳撒尼尔，1 102，史密斯先生的物理课，10200000001，史密斯，亚瑟， 10200000011, Patterson, John, 10200000013, Lanni, Erica, 1 102, Mr. 史密斯的物理课程，10200000001，史密斯，亚瑟，10200000011， Patterson, John, 10200000014, Flores, Michael, 1 102, Mr. Smith's PhysEd 类，10200000001，史密斯，亚瑟，10200000011，帕特森， John, 10200000012, Marco, Elizabeth, 1 102, Mr. Smith's PhysEd Class, 10200000001，史密斯，亚瑟，10200000011，帕特森，约翰，10200000016， Perez, Brittany, 1 102, Mr. Smith's PhysEd Class, 10200000001, Smith, 亚瑟，10200000011，帕特森，约翰，10200000015，希尔，茉莉，1 102，史密斯先生的物理课，10200000001，史密斯，亚瑟， 10200000011, Patterson, John, 10200000017, Hiram, William, 1 101, Mrs. 琼斯的数学课, 10100000001, Jones, Barbara, , , , 10100000015, Cruz, Alex, 1 101, Mrs. Jones' Math Class, 10100000001, Jones, Barbara, , , , 10100000014, Garcia, Lizzie, 1 101, Mrs. Jones' Math Class, 10100000001, Jones, Barbara, , , , 10100000013, Mercado, Toby, 1 101, Mrs. Jones' Math Class, 10100000001, Jones, Barbara, , , , 10100000011, Gutierrez, Kimberly, 2 101, Mrs. Jones' Math Class, 10100000001，琼斯，芭芭拉，，，，，，10100000010，吉尔，迈克尔，2
我希望在 XML 文件中得到如下输出：
<grade id="1">
<classroom id="101" name="Mrs. Jones' Math Class">
<teacher id="10100000001" first_name="Barbara" last_name="Jones"/>
<student id="10100000010" first_name="Michael" last_name="Gil"/>
<student id="10100000011" first_name="Kimberly" last_name="Gutierrez"/>
<student id="10100000013" first_name="Toby" last_name="Mercado"/>
<student id="10100000014" first_name="Lizzie" last_name="Garcia"/>
<student id="10100000015" first_name="Alex" last_name="Cruz"/>
</classroom>
<classroom id="102" name="Mr. Smith's PhysEd Class">
<teacher id="10200000001" first_name="Arthur" last_name="Smith"/>
<teacher id="10200000011" first_name="John" last_name="Patterson"/>
<student id="10200000010" first_name="Nathaniel" last_name="Smith"/>
<student id="10200000011" first_name="Brandon" last_name="McCrancy"/>
<student id="10200000012" first_name="Elizabeth" last_name="Marco"/>
<student id="10200000013" first_name="Erica" last_name="Lanni"/>
<student id="10200000014" first_name="Michael" last_name="Flores"/>
<student id="10200000015" first_name="Jasmin" last_name="Hill"/>
<student id="10200000016" first_name="Brittany" last_name="Perez"/>
<student id="10200000017" first_name="William" last_name="Hiram"/>
<student id="10200000018" first_name="Alexis" last_name="Reginald"/>
<student id="10200000019" first_name="Matthew" last_name="Gayle"/>
</classroom>
<classroom id="103" name="Brian's Homeroom">
<teacher id="10300000001" first_name="Brian" last_name="O'Donnell"/>
</classroom>
</grade>
这是我目前获得输出的方式：
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<school>
<row>
<classroom_id>101</classroom_id>
</row>
<row>
<classroom_id>101</classroom_id>
</row>
<row>
<classroom_id>101</classroom_id>
</row>
<row>
<classroom_id>101</classroom_id>
</row>
<row>
<classroom_id>101</classroom_id>
</row>
<row>
<classroom_id>102</classroom_id>
</row>
<row>
<classroom_id>102</classroom_id>
</row>
<row>
<classroom_id>102</classroom_id>
</row>
<row>
<classroom_id>102</classroom_id>
</row>
<row>
<classroom_id>102</classroom_id>
</row>
<row>
<classroom_id>102</classroom_id>
</row>
<row>
<classroom_id>102</classroom_id>
</row>
<row>
<classroom_id>102</classroom_id>
</row>
<row>
<classroom_id>102</classroom_id>
</row>
<row>
<classroom_id>102</classroom_id>
</row>
<row>
<classroom_id>103</classroom_id>
</row>
</school>
那么有人可以帮我解决这个问题吗？我想知道我哪里出错了。谢谢
附：我已经在 stackoverflow 上提到了关于 CSV 到 XML 转换的其他问题。但是，我无法找到适合我的特定问题的解决方案或解释。
附言如果不需要将此类 CSV 数据解析为 XML，请不要建议我使用 XSLT。如果没有其他选择，那么我将不得不去学习 XSLT，因为我对 XSLT 知之甚少。如果您建议对我已经编写的代码进行更改，将不胜感激。
【问题讨论】：