quartz框架(二)-配置文件源码解析

配置文件源码解析

博主的前一篇博文主要介绍了quartz的入门使用，现在博主就来讲解一下quartz配置文件的加载流程。

代码回顾

public class Main {
    public static void main(String[] args) throws SchedulerException {
        //创建一个jobDetail的实例，将该实例与HelloJob Class绑定
        JobDetail jobDetail = JobBuilder.newJob(TestJob.class).withIdentity("myJob").build();
        //创建一个Trigger触发器的实例，定义该job立即执行，并且每2秒执行一次，一直执行
        SimpleTrigger trigger = TriggerBuilder.newTrigger().withIdentity("myTrigger").startNow().withSchedule(SimpleScheduleBuilder.simpleSchedule().withIntervalInSeconds(3).repeatForever()).build();
        //创建schedule实例
        StdSchedulerFactory factory = new StdSchedulerFactory();
        Scheduler scheduler = factory.getScheduler();
        scheduler.start();
        scheduler.scheduleJob(jobDetail,trigger);
    }
}

在上面的StdSchedulerFactory对象实例化的地方，打上断点，然后在debug模式下，就可以查看到quartz是怎么样加载配置文件的。

配置文件的加载流程

public void initialize() throws SchedulerException
{
    // short-circuit if already initialized
    if(cfg != null)
    {
        return;
    }
    if(initException != null)
    {
        throw initException;
    }
	//查看系统变量是否指定了配置文件的路径
    String requestedFile = System.getProperty(PROPERTIES_FILE);
    String propFileName = requestedFile != null ? requestedFile : "quartz.properties";
	//没有则在当前项目的根目录下查找
    File propFile = new File(propFileName);
    Properties props = new Properties();
    InputStream in = null;
    try
    {
        if(propFile.exists())
        {
            try
            {
                if(requestedFile != null)
                {
                    propSrc = "specified file: '" + requestedFile + "'";
                }
                else
                {
                    propSrc = "default file in current working dir: 'quartz.properties'";
                } in = new BufferedInputStream(new FileInputStream(propFileName));
                props.load( in );
            }
            catch(IOException ioe)
            {
                initException = new SchedulerException("Properties file: '" + propFileName + "' could not be read.", ioe);
                throw initException;
            }
        }
        else if(requestedFile != null)
        { in = Thread.currentThread().getContextClassLoader().getResourceAsStream(requestedFile);
            if( in == null)
            {
                initException = new SchedulerException("Properties file: '" + requestedFile + "' could not be found.");
                throw initException;
            }
            propSrc = "specified file: '" + requestedFile + "' in the class resource path."; in = new BufferedInputStream( in );
            try
            {
                props.load( in );
            }
            catch(IOException ioe)
            {
                initException = new SchedulerException("Properties file: '" + requestedFile + "' could not be read.", ioe);
                throw initException;
            }
        }
        else
        {
            propSrc = "default resource file in Quartz package: 'quartz.properties'";
			//使用类加载器加载
            ClassLoader cl = getClass().getClassLoader();
            if(cl == null) cl = findClassloader();
            if(cl == null) throw new SchedulerConfigException("Unable to find a class loader on the current thread or class."); in = cl.getResourceAsStream("quartz.properties");
            if( in == null)
            { in = cl.getResourceAsStream("/quartz.properties");
            }
            if( in == null)
            { in = cl.getResourceAsStream("org/quartz/quartz.properties");
            }
            if( in == null)
            {
                initException = new SchedulerException("Default quartz.properties not found in class path");
                throw initException;
            }
            try
            {
                props.load( in );
            }
            catch(IOException ioe)
            {
                initException = new SchedulerException("Resource properties file: 'org/quartz/quartz.properties' " + "could not be read from the classpath.", ioe);
                throw initException;
            }
        }
    }
    finally
    {
        if( in != null)
        {
            try
            { in .close();
            }
            catch(IOException ignore)
            { /* ignore */ }
        }
    }
    initialize(overrideWithSysProps(props));
}

通过查看源码可知，quartz的配置文件加载流程如下：

1. 查看是否有系统变量指定了配置文件路径
2. 在当前项目下面查找名为quartz.properties的文件。
3. 通过类加载器加载当前classpath路径下的quartz.properties,/quartz.properties,org/quartz/quartz.properties的资源文件。

这里需要注意的是，一旦自己指定了quartz.properties文件，那么quartz默认提供的配置将不会被加载，因此也就不会生效。

查看quartz默认配置文件

分析上面的源码，我们可以在quartzjar包中的org/quartz目录下找到对应的配置文件quartz.properties。

# Default Properties file for use by StdSchedulerFactory
# to create a Quartz Scheduler Instance, if a different
# properties file is not explicitly specified.

#实例名称
org.quartz.scheduler.instanceName: DefaultQuartzScheduler
#远程方法调用
org.quartz.scheduler.rmi.export: false
org.quartz.scheduler.rmi.proxy: false
#是否将任务放在事务中执行
org.quartz.scheduler.wrapJobExecutionInUserTransaction: false

#线程池
org.quartz.threadPool.class: org.quartz.simpl.SimpleThreadPool
#线程个数
org.quartz.threadPool.threadCount: 10
#线程优先级
org.quartz.threadPool.threadPriority: 5

org.quartz.threadPool.threadsInheritContextClassLoaderOfInitializingThread: true

#失火的阈值
org.quartz.jobStore.misfireThreshold: 60000
#使用内存方式存储
org.quartz.jobStore.class: org.quartz.simpl.RAMJobStore

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