Passed-in Resource [resource loaded through InputStream] contains an open stream:cannot determine

╰半橙微兮° 2022-07-21 02:22 116阅读 0赞

Passed-in Resource \[resource loaded through InputStream\] contains an open stream2009-09-29 11:58  **org.springframework.beans.factory.BeanDefinitionStoreException:** Passed-in Resource \[resource loaded through InputStream\] contains an open stream: cannot determine validation mode automatically. Either pass in a Resource that is able to create fresh streams, or explicitly specify the validationMode on your XmlBeanDefinitionReader instance.  
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.detectValidationMode(XmlBeanDefinitionReader.java:418)  
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.getValidationModeForResource(XmlBeanDefinitionReader.java:400)  
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:360)  
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:313)  
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:290)  
at org.springframework.beans.factory.xml.XmlBeanFactory.<init>(XmlBeanFactory.java:73)  
at org.springframework.beans.factory.xml.XmlBeanFactory.<init>(XmlBeanFactory.java:61)  
at com.spring.unit1.TestMain.main(TestMain.java:31)  
Exception in thread "main" java.lang.NullPointerException  
at com.spring.unit1.TestMain.main(TestMain.java:40)

今天开始正式学习Spring，从《Spring in Action》开始，虽然版本老了一些，但是关键是思想，在做第一个练习的时候，原书中代码如下：

BeanFactory factory = new XmlBeanFactory(new FileInputStream("hello.xml"));

可是在2.0以后的版本中，XmlBeanFactory已经被修改；查阅了API发现构造方法的参数修改为Resource类型

查看了一下InputStreamResource 就是Resource接口的实现类；

于是：

File file = new File("D:/eclipse/workSpace/aSpringDemo/src/hello.xml");  
    InputStream is = new FileInputStream(file);  
    InputStreamResource isr = new InputStreamResource(is);  
    bf = new XmlBeanFactory(isr);

但是却出了上边的异常；

查看源码发现：

reader.loadBeanDefinitions(resource);方法会调用如下代码：

protected int detectValidationMode(Resource resource)  
    \{  
        InputStream inputStream;  
        IOException ex;  
        if(resource.isOpen())  
            throw new BeanDefinitionStoreException("Passed-in Resource \[" + resource + "\] contains an open stream: " + "cannot determine validation mode automatically. Either pass in a Resource " + "that is able to create fresh streams, or explicitly specify the validationMode " + "on your XmlBeanDefinitionReader instance.");

再次查看InputStreamResource API：

implementation for a given InputStream. Should only be used if no specific Resource implementation is applicable. In particular, prefer or any of the file-based Resource implementations where possible.

In contrast to other Resource implementations, this is a descriptor for an already opened resource - therefore returning "true" from `isOpen()`. Do not use it if you need to keep the resource descriptor somewhere, or if you need to read a stream multiple times.

显然

public boolean isOpen()  
    \{  
        return true;  
    \}

于是，使用其他Resource实现类替换比如FileSystemResource，一切OK

例：

File file = new File("F:/java web2.0/javawebProject/SpringApp/src/spring-beans.xml");

FileSystemResource fsr = new FileSystemResource(file);

XmlBeanFactory factory = new XmlBeanFactory(fsr);

在API中，关于InputStreamResource有这样一段描述：它只有在没有其他合适的Resource实现时才使用。而且，**只要有可能就尽量使用ByteArrayResource或者其他基于文件的Resource实现。**

与其他Resource实现不同的是，这是个 已经 打开资源的描述符-因此isOpen()方法返回true。**如果你需要在其他位置保持这个资源的描述符或者多次读取一个流，请不要使用它。**

收藏于 2010-11-15