struts2配置文件struts.xml自动重加载(rabbit.struts2包)

最近开始做点页面，于是用strtus2，发现每次改动struts.xml和action的时候都要重启应用，严重影响开发效率。

设置了

struts.i18n.reload = true
struts.configuration.xml.reload = true

struts.devMode = true

缺发现struts.configuration.xml.reload = true似乎总是不起作用。

怒了，于是随手写了2个简单的类。虽然还有很多功能可以补充进去，比如生产，开发模式的开关等一系列功能，将以后在持续添加。

 

希望目前简单的实现可以对碰到类似问题的人有所帮助。

java1.4

 

package rabbit.struts2.dispatcher;

import java.io.File;
import java.io.IOException;
import java.net.URISyntaxException;
import java.net.URL;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

/**
 * 
 * @author rabbit
 * 
 */
public class FilterDispatcherJava4 implements Filter {
	private volatile Filter filter;
	private FilterConfig filterConfig;
	private volatile long lastModified = -1;
	private ClassLoader classLoader;

	public void destroy() {
		synchronized (this) {
			if (filter != null) {
				filter.destroy();
			}
		}
	}

	public void doFilter(ServletRequest arg0, ServletResponse arg1,
			FilterChain arg2) throws IOException, ServletException {
		getFilter().doFilter(arg0, arg1, arg2);
	}

	public void init(FilterConfig arg0) throws ServletException {
		filterConfig = arg0;
		classLoader = this.getClass().getClassLoader();
	}

	private Filter getFilter() throws ServletException {
		URL url = classLoader.getResource("struts.xml");
		File f = null;
		try {
			f = new File(url.toURI());
		} catch (URISyntaxException e) {
			throw new RuntimeException(e);
		}
		synchronized (this) {
			long time = f.lastModified();
			if (lastModified == time) {
				return filter;
			}
			if (filter != null) {
				filter.destroy();
			}
			filter = new org.apache.struts2.dispatcher.FilterDispatcher();
			filter.init(filterConfig);
			lastModified = time;
			return filter;
		}
	}
}

 

 

 

java1.5

package rabbit.struts2.dispatcher;

import java.io.File;
import java.io.IOException;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

/**
 * 
 * @author rabbit
 * 
 */
public class FilterDispatcherJava5 implements Filter {
	private volatile Filter filter;
	private FilterConfig filterConfig;
	private volatile long lastModified = -1;
	private ClassLoader classLoader;
	private ReentrantReadWriteLock rwl = new ReentrantReadWriteLock();
	private Lock rl = rwl.readLock();
	private Lock wl = rwl.writeLock();

	public void destroy() {
		rl.lock();
		try {
			if (filter != null) {
				filter.destroy();
			}
		} finally {
			rl.unlock();
		}
	}

	public void doFilter(ServletRequest arg0, ServletResponse arg1,
			FilterChain arg2) throws IOException, ServletException {
		getFilter().doFilter(arg0, arg1, arg2);
	}

	public void init(FilterConfig arg0) throws ServletException {
		filterConfig = arg0;
		classLoader = this.getClass().getClassLoader();
	}

	private Filter getFilter() throws ServletException {
		URL url = classLoader.getResource("struts.xml");
		File f = null;
		try {
			f = new File(url.toURI());
		} catch (URISyntaxException e) {
			throw new RuntimeException(e);
		}
		rl.lock();
		try {
			if (lastModified == f.lastModified()) {
				return filter;
			}
		} finally {
			rl.unlock();
		}
		wl.lock();
		try {
			long time = f.lastModified();
			if (lastModified == time) {
				return filter;
			}
			if (filter != null) {
				filter.destroy();
			}
			filter = new org.apache.struts2.dispatcher.FilterDispatcher();
			filter.init(filterConfig);
			lastModified = time;
			return filter;
		} finally {
			wl.unlock();
		}
	}
}

 

web.xml部分将sturts的org.apache.struts2.dispatcher.FilterDispatcher简单替换为

	<filter>
		<filter-name>struts2</filter-name>
		<!--filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class-->
		<filter-class>rabbit.struts2.dispatcher.FilterDispatcherJava4</filter-class>
	</filter>

 

或者

	<filter>
		<filter-name>struts2</filter-name>
		<!--filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class-->
		<filter-class>rabbit.struts2.dispatcher.FilterDispatcherJava5</filter-class>
	</filter>

 

即可。

开发的时候可以是用rabbit.struts2的过滤器，发布生产版本改在该回原来的struts2过滤器。

评论

1 楼 lotin_2001 2009-02-22  

这个问题也一直困扰本人，不过在基于O配置的情况下，使用convention插件，也是可以实现动态加载的。