FileReader 在同一文件夹中找不到 XML 文件

Question

我目前正在学习 JAXP、SAX、DOM、StAX、XPath 和 XSLT。 在我测试 StAX 的工作原理时，我发现自己遇到了一个错误。

Exception in thread "main" java.io.FileNotFoundException: test.xml (The system cannot find the file specified)
    at java.io.FileInputStream.open0(Native Method)
    at java.io.FileInputStream.open(FileInputStream.java:195)
    at java.io.FileInputStream.<init>(FileInputStream.java:138)
    at java.io.FileInputStream.<init>(FileInputStream.java:93)
    at java.io.FileReader.<init>(FileReader.java:58)
    at xmltest.XMLTest.main(XMLTest.java:16)

这是一个典型的错误，我知道这意味着什么，问题是，我不知道为什么会出现，因为“test.xml”和“XMLTest.java”在同一个文件夹/包中。

下面是代码：

XMLTest.java -

package xmltest;

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.Reader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;

public class XMLTest {

    public static void main(String[] args) throws FileNotFoundException, XMLStreamException {

        XMLInputFactory xmlif = XMLInputFactory.newFactory();
        Reader reader = new FileReader("test.xml");
        XMLStreamReader xmlsr = xmlif.createXMLStreamReader(reader);


        while (xmlsr.hasNext()) {

            switch (xmlsr.next()) {
                case XMLStreamReader.START_ELEMENT:
                    System.out.println("START_ELEMENT");
                    System.out.println(" Qname = " + xmlsr.getName());

                    break;
                case XMLStreamReader.END_ELEMENT:
                    System.out.println("END_ELEMENT");
                    System.out.println(" Qname = " + xmlsr.getName());
            }
        }
    }

}

test.xml -

 <?xml version="1.0"?>
    <catalog>
       <book id="bk101">
          <author>Gambardella, Matthew</author>
          <title>XML Developer's Guide</title>
          <genre>Computer</genre>
          <price>44.95</price>
          <publish_date>2000-10-01</publish_date>
          <description>An in-depth look at creating applications 
          with XML.</description>
       </book>
       <book id="bk102">
          <author>Ralls, Kim</author>
          <title>Midnight Rain</title>
          <genre>Fantasy</genre>
          <price>5.95</price>
          <publish_date>2002-12-16</publish_date>
          <description>A former architect battles corporate zombies, 
          an evil sorceress, and her own childhood to become queen 
          of the world.</description>
       </book>
       <book id="bk103">
          <author>Corets, Eva</author>
          <title>Maeve Ascendant</title>
          <genre>Fantasy</genre>
          <price>5.95</price>
          <publish_date>2000-11-17</publish_date>
          <description>After the collapse of a nanotechnology 
          society in England, the young survivors lay the 
          foundation for a new society.</description>
       </book>
       <book id="bk104">
          <author>Corets, Eva</author>
          <title>Oberon's Legacy</title>
          <genre>Fantasy</genre>
          <price>5.95</price>
          <publish_date>2001-03-10</publish_date>
          <description>In post-apocalypse England, the mysterious 
          agent known only as Oberon helps to create a new life 
          for the inhabitants of London. Sequel to Maeve 
          Ascendant.</description>
       </book>
       <book id="bk105">
          <author>Corets, Eva</author>
          <title>The Sundered Grail</title>
          <genre>Fantasy</genre>
          <price>5.95</price>
          <publish_date>2001-09-10</publish_date>
          <description>The two daughters of Maeve, half-sisters, 
          battle one another for control of England. Sequel to 
          Oberon's Legacy.</description>
       </book>
       <book id="bk106">
          <author>Randall, Cynthia</author>
          <title>Lover Birds</title>
          <genre>Romance</genre>
          <price>4.95</price>
          <publish_date>2003-09-02</publish_date>
          <description>When Carla meets Paul at an ornithology 
          conference, tempers fly as feathers get ruffled.</description>
       </book>
       <book id="bk107">
          <author>Thurman, Paula</author>
          <title>Splish Splash</title>
          <genre>Romance</genre>
          <price>4.95</price>
          <publish_date>2004-11-02</publish_date>
          <description>A deep sea diver finds true love twenty 
          thousand leagues beneath the sea.</description>
       </book>
       <book id="bk108">
          <author>Knorr, Stefan</author>
          <title>Creepy Crawlies</title>
          <genre>Horror</genre>
          <price>4.95</price>
          <publish_date>2005-12-06</publish_date>
          <description>An anthology of horror stories about roaches,
          centipedes, scorpions  and other insects.</description>
       </book>
       <book id="bk109">
          <author>Kress, Peter</author>
          <title>Paradox Lost</title>
          <genre>Science Fiction</genre>
          <price>6.95</price>
          <publish_date>2006-11-02</publish_date>
          <description>After an inadvertant trip through a Heisenberg
          Uncertainty Device, James Salway discovers the problems 
          of being quantum.</description>
       </book>
       <book id="bk110">
          <author>O'Brien, Tim</author>
          <title>Microsoft .NET: The Programming Bible</title>
          <genre>Computer</genre>
          <price>36.95</price>
          <publish_date>2006-12-09</publish_date>
          <description>Microsoft's .NET initiative is explored in 
          detail in this deep programmer's reference.</description>
       </book>
       <book id="bk111">
          <author>O'Brien, Tim</author>
          <title>MSXML3: A Comprehensive Guide</title>
          <genre>Computer</genre>
          <price>36.95</price>
          <publish_date>2007-12-01</publish_date>
          <description>The Microsoft MSXML3 parser is covered in 
          detail, with attention to XML DOM interfaces, XSLT processing, 
          SAX and more.</description>
       </book>
       <book id="bk112">
          <author>Galos, Mike</author>
          <title>Visual Studio 7: A Comprehensive Guide</title>
          <genre>Computer</genre>
          <price>49.95</price>
          <publish_date>2008-04-16</publish_date>
          <description>Microsoft Visual Studio 7 is explored in depth,
          looking at how Visual Basic, Visual C++, C#, and ASP+ are 
          integrated into a comprehensive development 
          environment.</description>
       </book>
    </catalog>

这是我的层次结构截图的链接：http://pasteboard.co/6FbvgJLx6.png

提前谢谢你。 :)

编辑 当我将绝对路径放入文件时，它可以完美运行，但我不想对此进行硬编码...

Answer 1

尝试像这样将您的文件作为资源加载

URL fileURL = this.getClass().getResource("test.xml");
File file = new File(fileURL.getPath());

这将从加载资源的类的同一个包中加载您的文件。

你也可以为你的文件提供一个绝对路径，使用

URL fileURL = this.getClass().getResource("/my/package/to/test.xml");