spring 入门笔记(一)

2022-08-04 07:47:19

最近学习spring 通过笔记形式加深自己对spring的理解，也希望能跟各位入门者分享和讨论。

一、下载spring

下载spring也费了不少功夫，目前还没从spring官网找到下载入口，我从下面的网站下载spring-framework-4.0.5.RELEASE。

http://maven.springframework.org/release/org/springframework/spring/

直接解压，如下：

二、导入额外的包

因为springframework里边包含的包还不全面，需要额外导入，不然运行会出错。

1.commons-logging.jar

2.log4j.jar

这两个都要在网上下载。

导入这些包的方法：右键Project-Build Path-Add Libraries出现如下界面：

-next，添加包，最后界面是这样的。

三、bean装配

我们用HelloWorld来演示bean的装配。

首先定义一个HelloWorld的interface，代码如下

public interface HelloWorld
{
    public void sayHello();
}

再定义HelloWorldBean class

public class HelloWorldBean implements HelloWorld
{
    private String helloWorld;
    
    public void setHelloWorld(String helloWorld)
    {
        this.helloWorld = helloWorld;
    }
    public void sayHello()
    {
        System.out.println(helloWorld);
    }
}

其中这两文件都放在SpringTest的src文件夹中。

新建测试文件FirstSpringDemo.java，首先我介绍一个网上的例子，其中这个例子使用的XmlBeanFactory在高版本的springframework中已经停止使用，我使用的spring框架是4.0.5，没法运行，2.7版本可以运行。

网上demo

import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;

public class FirstSpringDemo 
{
    
    public static void main(String[] args)
    {
        Resource resource = new ClassPathResource("ioc-config.xml");
        BeanFactory factory = new XmlBeanFactory(resource);        
        HelloWorld hello = (HelloWorld) beanFactory.getBean("helloWorldBean");
    }
}

在4.0.5版本运行，会提示xmlbeanfactory deprecated。

以下是我测试成功的例子：

import org.springframework.beans.factory.BeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;


public class FirstSpringDemo {    
    public static void main(String[] args)
    {
        ApplicationContext context= new ClassPathXmlApplicationContext(new String[]{"ioc-config.xml"});
        BeanFactory factory = context;
        HelloWorldBean hello= (HelloWorldBean) factory.getBean("helloWorldBean");
        hello.sayHello();
    }
}

这是在代码上的工作。

最重要的还有bean的装配，新建ioc-config.xml文件，beans有两种声明方法，文件内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<bean id="helloWorldBean" class="HelloWorldBean">
    <property name="helloWorld">
        <value>Hello,Welcome To Spring World!</value>
    </property>
</bean>
</beans>

或

<?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-4.0.xsd"
       default-autowire="byName">
<bean id="helloWorldBean" class="HelloWorldBean">
    <property name="helloWorld">
        <value>Hello,Welcome To Spring World!</value>
    </property>
</bean>
</beans>

其中要注意几点：

1、第二种声明方法要跟spring-beans中的Meta-INF文件夹下spring.shemas里面的声明一致，如我的spring.shemas如下

http\://www.springframework.org/schema/beans/spring-beans-2.0.xsd=org/springframework/beans/factory/xml/spring-beans-2.0.xsd
http\://www.springframework.org/schema/beans/spring-beans-2.5.xsd=org/springframework/beans/factory/xml/spring-beans-2.5.xsd
http\://www.springframework.org/schema/beans/spring-beans-3.0.xsd=org/springframework/beans/factory/xml/spring-beans-3.0.xsd
http\://www.springframework.org/schema/beans/spring-beans-3.1.xsd=org/springframework/beans/factory/xml/spring-beans-3.1.xsd
http\://www.springframework.org/schema/beans/spring-beans-3.2.xsd=org/springframework/beans/factory/xml/spring-beans-3.2.xsd
http\://www.springframework.org/schema/beans/spring-beans-4.0.xsd=org/springframework/beans/factory/xml/spring-beans-4.0.xsd
http\://www.springframework.org/schema/beans/spring-beans.xsd=org/springframework/beans/factory/xml/spring-beans-4.0.xsd
http\://www.springframework.org/schema/tool/spring-tool-2.0.xsd=org/springframework/beans/factory/xml/spring-tool-2.0.xsd
http\://www.springframework.org/schema/tool/spring-tool-2.5.xsd=org/springframework/beans/factory/xml/spring-tool-2.5.xsd
http\://www.springframework.org/schema/tool/spring-tool-3.0.xsd=org/springframework/beans/factory/xml/spring-tool-3.0.xsd
http\://www.springframework.org/schema/tool/spring-tool-3.1.xsd=org/springframework/beans/factory/xml/spring-tool-3.1.xsd
http\://www.springframework.org/schema/tool/spring-tool-3.2.xsd=org/springframework/beans/factory/xml/spring-tool-3.2.xsd
http\://www.springframework.org/schema/tool/spring-tool-4.0.xsd=org/springframework/beans/factory/xml/spring-tool-4.0.xsd
http\://www.springframework.org/schema/tool/spring-tool.xsd=org/springframework/beans/factory/xml/spring-tool-4.0.xsd
http\://www.springframework.org/schema/util/spring-util-2.0.xsd=org/springframework/beans/factory/xml/spring-util-2.0.xsd
http\://www.springframework.org/schema/util/spring-util-2.5.xsd=org/springframework/beans/factory/xml/spring-util-2.5.xsd
http\://www.springframework.org/schema/util/spring-util-3.0.xsd=org/springframework/beans/factory/xml/spring-util-3.0.xsd
http\://www.springframework.org/schema/util/spring-util-3.1.xsd=org/springframework/beans/factory/xml/spring-util-3.1.xsd
http\://www.springframework.org/schema/util/spring-util-3.2.xsd=org/springframework/beans/factory/xml/spring-util-3.2.xsd
http\://www.springframework.org/schema/util/spring-util-4.0.xsd=org/springframework/beans/factory/xml/spring-util-4.0.xsd
http\://www.springframework.org/schema/util/spring-util.xsd=org/springframework/beans/factory/xml/spring-util-4.0.xsd

跟我的声明是一致的，如果配置文件中声明的版本过高，会导致错误”beans 找不到声明“。
2、class="HelloWorldBean“需要注意HelloWorldBean.java编译之后的HelloWorldBean.class的位置，不然会提示

Cannot find class [XXX.HelloWorldBean] for bean with name ‘helloWorldBean‘ defined in class path resource [ioc-config.xml]; nested exception is java.lang.ClassNotFoundException:XXX.HelloWorldBean.

因为我三个class文件输出在同一个地方，所以是class="HelloWorldBean“。

四、配置日志输出

在SpringTest的src新建文件log4j.properties，有两种配置方式：

# Configure logging for testing: optionally with log file
#\u53EF\u4EE5\u8BBE\u7F6E\u7EA7\u522B\uFF1Adebug>info>error
#debug:\u53EF\u4EE5\u663E\u5F0Fdebug,info,error
#info:\u53EF\u4EE5\u663E\u5F0Finfo,error
#error:\u53EF\u4EE5\u663E\u5F0Ferror

log4j.rootLogger=debug,appender1
#log4j.rootLogger=info,appender1
#log4j.rootLogger=error,appender1

#\u8F93\u51FA\u5230\u63A7\u5236\u53F0
log4j.appender.appender1=org.apache.log4j.ConsoleAppender
#\u6837\u5F0F\u4E3ATTCCLayout
log4j.appender.appender1.layout=org.apache.log4j.TTCCLayout

或者

# Configure logging for testing: optionally with log file
log4j.rootLogger=WARN, stdout
# log4j.rootLogger=WARN, stdout, logfile
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] - %m%n
log4j.appender.logfile=org.apache.log4j.FileAppender
log4j.appender.logfile.File=target/spring.log
log4j.appender.logfile.layout=org.apache.log4j.PatternLayout
log4j.appender.logfile.layout.ConversionPattern=%d %p [%c] - %m%n

五、运行

以上三步准备妥当，运行程序，妥妥的打印出：

[main] DEBUG org.springframework.core.env.StandardEnvironment - Adding [systemProperties] PropertySource with lowest search precedence
[main] DEBUG org.springframework.core.env.StandardEnvironment - Adding [systemEnvironment] PropertySource with lowest search precedence
[main] DEBUG org.springframework.core.env.StandardEnvironment - Initialized StandardEnvironment with PropertySources [systemProperties,systemEnvironment]
[main] INFO org.springframework.context.support.ClassPathXmlApplicationContext - Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@3b7951: startup date [Mon Jun 16 11:15:39 CST 2014]; root of context hierarchy
[main] DEBUG org.springframework.core.env.StandardEnvironment - Adding [systemProperties] PropertySource with lowest search precedence
[main] DEBUG org.springframework.core.env.StandardEnvironment - Adding [systemEnvironment] PropertySource with lowest search precedence
[main] DEBUG org.springframework.core.env.StandardEnvironment - Initialized StandardEnvironment with PropertySources [systemProperties,systemEnvironment]
[main] INFO org.springframework.beans.factory.xml.XmlBeanDefinitionReader - Loading XML bean definitions from class path resource [ioc-config.xml]
[main] DEBUG org.springframework.beans.factory.xml.DefaultDocumentLoader - Using JAXP provider [com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderFactoryImpl]
[main] DEBUG org.springframework.beans.factory.xml.PluggableSchemaResolver - Loading schema mappings from [META-INF/spring.schemas]
[main] DEBUG org.springframework.beans.factory.xml.PluggableSchemaResolver - Loaded schema mappings: {http://www.springframework.org/schema/util/spring-util.xsd=org/springframework/beans/factory/xml/spring-util-4.0.xsd, http://www.springframework.org/schema/jee/spring-jee-3.2.xsd=org/springframework/ejb/config/spring-jee-3.2.xsd, http://www.springframework.org/schema/task/spring-task.xsd=org/springframework/scheduling/config/spring-task-4.0.xsd, http://www.springframework.org/schema/beans/spring-beans-3.1.xsd=org/springframework/beans/factory/xml/spring-beans-3.1.xsd, http://www.springframework.org/schema/cache/spring-cache.xsd=org/springframework/cache/config/spring-cache-4.0.xsd, http://www.springframework.org/schema/task/spring-task-3.1.xsd=org/springframework/scheduling/config/spring-task-3.1.xsd, http://www.springframework.org/schema/tool/spring-tool-2.5.xsd=org/springframework/beans/factory/xml/spring-tool-2.5.xsd, http://www.springframework.org/schema/beans/spring-beans.xsd=org/springframework/beans/factory/xml/spring-beans-4.0.xsd, http://www.springframework.org/schema/jee/spring-jee-2.5.xsd=org/springframework/ejb/config/spring-jee-2.5.xsd, http://www.springframework.org/schema/tool/spring-tool-3.1.xsd=org/springframework/beans/factory/xml/spring-tool-3.1.xsd, http://www.springframework.org/schema/jee/spring-jee-3.1.xsd=org/springframework/ejb/config/spring-jee-3.1.xsd, http://www.springframework.org/schema/context/spring-context-3.2.xsd=org/springframework/context/config/spring-context-3.2.xsd, http://www.springframework.org/schema/beans/spring-beans-2.0.xsd=org/springframework/beans/factory/xml/spring-beans-2.0.xsd, http://www.springframework.org/schema/util/spring-util-3.2.xsd=org/springframework/beans/factory/xml/spring-util-3.2.xsd, http://www.springframework.org/schema/lang/spring-lang-3.2.xsd=org/springframework/scripting/config/spring-lang-3.2.xsd, http://www.springframework.org/schema/beans/spring-beans-4.0.xsd=org/springframework/beans/factory/xml/spring-beans-4.0.xsd, http://www.springframework.org/schema/beans/spring-beans-3.0.xsd=org/springframework/beans/factory/xml/spring-beans-3.0.xsd, http://www.springframework.org/schema/cache/spring-cache-3.2.xsd=org/springframework/cache/config/spring-cache-3.2.xsd, http://www.springframework.org/schema/task/spring-task-3.0.xsd=org/springframework/scheduling/config/spring-task-3.0.xsd, http://www.springframework.org/schema/task/spring-task-4.0.xsd=org/springframework/scheduling/config/spring-task-4.0.xsd, http://www.springframework.org/schema/context/spring-context-2.5.xsd=org/springframework/context/config/spring-context-2.5.xsd, http://www.springframework.org/schema/tool/spring-tool-3.0.xsd=org/springframework/beans/factory/xml/spring-tool-3.0.xsd, http://www.springframework.org/schema/lang/spring-lang.xsd=org/springframework/scripting/config/spring-lang-4.0.xsd, http://www.springframework.org/schema/tool/spring-tool-2.0.xsd=org/springframework/beans/factory/xml/spring-tool-2.0.xsd, http://www.springframework.org/schema/util/spring-util-2.5.xsd=org/springframework/beans/factory/xml/spring-util-2.5.xsd, http://www.springframework.org/schema/lang/spring-lang-2.5.xsd=org/springframework/scripting/config/spring-lang-2.5.xsd, http://www.springframework.org/schema/tool/spring-tool-4.0.xsd=org/springframework/beans/factory/xml/spring-tool-4.0.xsd, http://www.springframework.org/schema/jee/spring-jee-3.0.xsd=org/springframework/ejb/config/spring-jee-3.0.xsd, http://www.springframework.org/schema/jee/spring-jee-2.0.xsd=org/springframework/ejb/config/spring-jee-2.0.xsd, http://www.springframework.org/schema/context/spring-context-3.1.xsd=org/springframework/context/config/spring-context-3.1.xsd, http://www.springframework.org/schema/jee/spring-jee-4.0.xsd=org/springframework/ejb/config/spring-jee-4.0.xsd, http://www.springframework.org/schema/util/spring-util-3.1.xsd=org/springframework/beans/factory/xml/spring-util-3.1.xsd, http://www.springframework.org/schema/lang/spring-lang-3.1.xsd=org/springframework/scripting/config/spring-lang-3.1.xsd, http://www.springframework.org/schema/cache/spring-cache-3.1.xsd=org/springframework/cache/config/spring-cache-3.1.xsd, http://www.springframework.org/schema/context/spring-context.xsd=org/springframework/context/config/spring-context-4.0.xsd, http://www.springframework.org/schema/jee/spring-jee.xsd=org/springframework/ejb/config/spring-jee-4.0.xsd, http://www.springframework.org/schema/beans/spring-beans-3.2.xsd=org/springframework/beans/factory/xml/spring-beans-3.2.xsd, http://www.springframework.org/schema/task/spring-task-3.2.xsd=org/springframework/scheduling/config/spring-task-3.2.xsd, http://www.springframework.org/schema/context/spring-context-4.0.xsd=org/springframework/context/config/spring-context-4.0.xsd, http://www.springframework.org/schema/context/spring-context-3.0.xsd=org/springframework/context/config/spring-context-3.0.xsd, http://www.springframework.org/schema/tool/spring-tool.xsd=org/springframework/beans/factory/xml/spring-tool-4.0.xsd, http://www.springframework.org/schema/util/spring-util-3.0.xsd=org/springframework/beans/factory/xml/spring-util-3.0.xsd, http://www.springframework.org/schema/lang/spring-lang-3.0.xsd=org/springframework/scripting/config/spring-lang-3.0.xsd, http://www.springframework.org/schema/util/spring-util-2.0.xsd=org/springframework/beans/factory/xml/spring-util-2.0.xsd, http://www.springframework.org/schema/cache/spring-cache-4.0.xsd=org/springframework/cache/config/spring-cache-4.0.xsd, http://www.springframework.org/schema/lang/spring-lang-2.0.xsd=org/springframework/scripting/config/spring-lang-2.0.xsd, http://www.springframework.org/schema/util/spring-util-4.0.xsd=org/springframework/beans/factory/xml/spring-util-4.0.xsd, http://www.springframework.org/schema/lang/spring-lang-4.0.xsd=org/springframework/scripting/config/spring-lang-4.0.xsd, http://www.springframework.org/schema/tool/spring-tool-3.2.xsd=org/springframework/beans/factory/xml/spring-tool-3.2.xsd, http://www.springframework.org/schema/beans/spring-beans-2.5.xsd=org/springframework/beans/factory/xml/spring-beans-2.5.xsd}
[main] DEBUG org.springframework.beans.factory.xml.PluggableSchemaResolver - Found XML schema [http://www.springframework.org/schema/beans/spring-beans-4.0.xsd] in classpath: org/springframework/beans/factory/xml/spring-beans-4.0.xsd
[main] DEBUG org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader - Loading bean definitions
[main] DEBUG org.springframework.beans.factory.xml.XmlBeanDefinitionReader - Loaded 1 bean definitions from location pattern [ioc-config.xml]
[main] DEBUG org.springframework.context.support.ClassPathXmlApplicationContext - Bean factory for org.springframework.context.support.ClassPathXmlApplicationContext@3b7951: org.springframework.beans.factory.support.DefaultListableBeanFactory@6a3f77: defining beans [helloWorldBean]; root of factory hierarchy
[main] DEBUG org.springframework.context.support.ClassPathXmlApplicationContext - Unable to locate MessageSource with name ‘messageSource‘: using default [org.springframework.context.support.DelegatingMessageSource@1375618]
[main] DEBUG org.springframework.context.support.ClassPathXmlApplicationContext - Unable to locate ApplicationEventMulticaster with name ‘applicationEventMulticaster‘: using default [org.springframework.context.event.SimpleApplicationEventMulticaster@f5e5e3]
[main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@6a3f77: defining beans [helloWorldBean]; root of factory hierarchy
[main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Creating shared instance of singleton bean ‘helloWorldBean‘
[main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Creating instance of bean ‘helloWorldBean‘
[main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Eagerly caching bean ‘helloWorldBean‘ to allow for resolving potential circular references
[main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Finished creating instance of bean ‘helloWorldBean‘
[main] DEBUG org.springframework.context.support.ClassPathXmlApplicationContext - Unable to locate LifecycleProcessor with name ‘lifecycleProcessor‘: using default [org.springframework.context.support.DefaultLifecycleProcessor@102b3b1]
[main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean ‘lifecycleProcessor‘
[main] DEBUG org.springframework.core.env.PropertySourcesPropertyResolver - Searching for key ‘spring.liveBeansView.mbeanDomain‘ in [systemProperties]
[main] DEBUG org.springframework.core.env.PropertySourcesPropertyResolver - Searching for key ‘spring.liveBeansView.mbeanDomain‘ in [systemEnvironment]
[main] DEBUG org.springframework.core.env.PropertySourcesPropertyResolver - Could not find key ‘spring.liveBeansView.mbeanDomain‘ in any property source. Returning [null]
[main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean ‘helloWorldBean‘
Hello,Welcome To Spring World!

祝好！

spring 入门笔记(一),布布扣,bubuko.com

spring 入门笔记(一)

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