Spring Load XML mechanism

Copied from the jumping knife of the rabbit http://www.cnblogs.com/shipengzhi/articles/3029872.html load file sequence scenario one: use Classpath to load with no wildcard characters

This is the simplest case where spring defaults to using the ClassLoader of getResource 方法获取资源的 URL ，如果无法获得当前线程的 ClassLoader ， Spring 将使用加载类 the current thread Org.springframework.util.ClassUtils's ClassLoader.

1. When the project directory structure:

ApplicationContext context = new Classpathxmlapplicationcontext ("Conf/application-context.xml");

Load [Conf/application-context.xml]

2. When the project directory structure: That is, the bin directory only. class files, there is no configuration file, the dependent Conf.jar has a configuration file:

ApplicationContext context = new Classpathxmlapplicationcontext ("Conf/application-context.xml");

Load [Conf/application-context.xml]

3. When the project directory structure:

ApplicationContext context = new Classpathxmlapplicationcontext ("Conf/application-context.xml");

Only the Application-context.xml file in the bin/conf directory will be loaded and the Conf/application-context.xml in the jar package will not be loaded.

Scenario Two: Loading with classpath, including wildcard characters

Spring determines the approximate location of the resource by using the non-wildcard part of the path, and then determines the specific resource location based on the location

1. When the project directory structure:

ApplicationContext context = new Classpathxmlapplicationcontext ("Conf/**/*application-context.xml");

Load [Admin-application-context.xml]

Load [Application-context.xml]

2. When the project directory structure:

ApplicationContext context = new Classpathxmlapplicationcontext ("Conf/**/*application-context.xml");

Load Conf/application-context.xml

Load Conf/admin/admin-application-context.xml

3. When the project directory structure:

ApplicationContext context = new Classpathxmlapplicationcontext ("Conf/**/*application-context.xml");

Bin/conf/application-context.xml files and Bin/conf/admin/admin-application-context.xml will be loaded,

However, the configuration files in the Conf.jar file are not loaded.

Scenario Three: Use the classpath* prefix and do not include a wildcard character

Use the classpath* prefix to get all classpath resources that match a given path, avoiding the occurrence of two files with the same name in different locations, and spring loading only one of them.

When the project directory structure:

This is used

ApplicationContext context = new Classpathxmlapplicationcontext ("Classpath*:conf/application-context.xml");

Spring will load the Application-context.xml file in the bin directory and the Application-context.xml file in the jar package.

Scenario four: Using the classpath* prefix, including wildcard characters

When the project directory structure:

ApplicationContext context = new Classpathxmlapplicationcontext ("Classpath*:conf/**/*application-context.xml");

The Conf directory includes all of the configuration files in all levels of subdirectories, so bin/conf/application-context.xml and Bin/conf/admin/admin-application-context.xml

And the Conf/application-context.xml and Conf/admin/admin-application-context.xml in the jar package will be loaded

classpath* Loading and Classpath loading differences

classpath*: Appears to load the same file from Classpath and multiple jar files, Classpath: Only the first file found is loaded.

Classpath* the use of the ClassLoader getresources () method;

In the Pathmatchingresourcepatternresolver class, we can better understand the handling of its pair: if it starts with classpath*, it traverses classpath.

It is still common in Java to read files when loading from a file:
The way to get InputStream as Classpathresource is to use class loader.

The way to get InputStream as Classpathresource is to use class loader.

Public InputStream getInputStream () throws IOException {     inputstream are;     if (this.clazz! = null) {is         = This.clazz.getResourceAsStream (This.path);     }

The way to get InputStream, as Filesystemresource, is to use FileInputStream.

Public InputStream getInputStream () throws IOException {     return new FileInputStream (This.file);}

Spring load XML mechanism