file.exists() 为真的块内的 FileNotFoundException

Question

我正在通过一些教程试验 Spring 框架，运行。

由于某种原因，找不到 bean.xml。

编辑#5：正如答案所暗示的，当我使用的方法是在类路径中查找文件时，与绝对路径一起存在的文件是无关紧要的。 (ClassPathXmlApplicationContext())

编辑 #1：请阅读代码：文件存在，失败的代码在 if (xmlFile.exists()) 块内

我尝试了相对路径，文件在项目的根目录下，我使用了项目文件夹中文件的绝对路径，我试过将 Beans.xml 移动到根目录我的几个驱动器。相同路径的File.exists()调用成功，但是ClassPathXmlApplicationContext()构造函数总是失败...

我的困惑是为什么会出现FNF异常，然后File.exists()为真，而我只有那个fileName String

非常感谢任何帮助。

编辑 #2：我现在已经在 linux 机器上尝试了相同的代码。我得到完全相同的错误（带有 Linux 路径 ofc）

编辑 #3：我现在已将文件复制到 target/classes 并运行。理想情况下，我希望它在资源中...我该怎么做？

我是运行Spring工具套件

版本：3.9.2.RELEASE

内部版本号：201712210947

平台：Eclipse Oxygen.2 (4.7.2)

在 Windows 10

这是我的 ApplicationStart.java:

package com.example.pkg;

import java.io.File;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class ApplicationStart {
    public static void main(String[] args) {
        //System.out.println("Working Directory = " + System.getProperty("user.dir"));
        String xmlFileName = "E:\Beans.xml";
        File xmlFile = new File(xmlFileName);
        if (xmlFile.exists()) {
            System.out.println(xmlFile.getAbsolutePath() + " exists - Running Spring code");
            ApplicationContext appCtx = new ClassPathXmlApplicationContext(xmlFileName);
            Point p = (Point) appCtx.getBean("ZeroPoint");
            System.out.println(p.getX());
            System.out.println(p.getY());
            Point p2 = (Point) appCtx.getBean("TenPoint");
            System.out.println(p2.getX());
            System.out.println(p2.getY());
        } else {
            System.err.println("File " + xmlFileName + " does not exist.");
        }
    }
}

我的Point.java

package com.example.pkg;

public class Point {

    private int x;
    private int y;

    public int getX() {
        return x;
    }

    public void setX(int x) {
        this.x = x;
    }

    public int getY() {
        return y;
    }

    public void setY(int y) {
        this.y = y;
    }
}

我的Beans.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
    <bean id="ZeroPoint" class="com.example.pkg.Point">
        <property name="x" value="0" />
        <property name="y" value="0" />
    </bean>
    <bean id="TenPoint" class="com.example.pkg.Point">
        <property name="x" value="10" />
        <property name="y" value="10" />
    </bean>
</beans>

我的pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>group</groupId>
    <artifactId>artifact</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>5.0.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.0.0.RELEASE</version>
        </dependency>
    </dependencies>
</project>

"run as java application" 的输出：

Working Directory = C:\Users\jonas\Documents\workspaces\sts_test\artifact
C:\Users\jonas\Documents\workspaces\sts_test\artifact\Beans.xml exists - Running Spring code
dec. 24, 2017 2:36:08 PM org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@137e0d2: startup date [Sun Dec 24 14:36:08 CET 2017]; root of context hierarchy
dec. 24, 2017 2:36:08 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [Beans.xml]
Exception in thread "main" org.springframework.beans.factory.BeanDefinitionStoreException: IOException parsing XML document from class path resource [Beans.xml]; nested exception is java.io.FileNotFoundException: class path resource [Beans.xml] cannot be opened because it does not exist
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:343)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:303)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:187)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:223)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:194)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:258)
    at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:128)
    at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:94)
    at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:133)
    at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:620)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:521)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:144)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:85)
    at com.example.pkg.ApplicationStart.main(ApplicationStart.java:15)
Caused by: java.io.FileNotFoundException: class path resource [Beans.xml] cannot be opened because it does not exist
    at org.springframework.core.io.ClassPathResource.getInputStream(ClassPathResource.java:177)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:329)
    ... 13 more

编辑#4：

工作代码。将文件放在 /src/main/resources 和运行下面对我有用：

package com.example.pkg;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class ApplicationStart {
    public static void main(String[] args) {
        // System.out.println("Working Directory = " + System.getProperty("user.dir"));
        String xmlFileName = "Beans.xml";

        //System.out.println(xmlFile.getAbsolutePath() + " exists - Running Spring code");
        ApplicationContext appCtx = new ClassPathXmlApplicationContext(xmlFileName);
        Point p = (Point) appCtx.getBean("ZeroPoint");
        System.out.println(p.getX());
        System.out.println(p.getY());
        Point p2 = (Point) appCtx.getBean("TenPoint");
        System.out.println(p2.getX());
        System.out.println(p2.getY());

    }
}

Answer 1

如果您想使用 E:\beans.xml，请尝试使用：FileSystemXmlApplicationContext。

只需将您的 ClassPathXmlApplicationContext 替换为 class。

如果你想把它放在资源文件夹中，而不是传递完整路径，只需使用：

ClassPathXmlApplicationContext("beans.xml")

file.exists() 为真的块内的 FileNotFoundException

FileNotFoundException inside block where file.exists() is true

java

xml

spring

filenotfoundexception

maven