项目使用jboss wildfly8.1.0Final作为容器,然而该容器不支持修改war目录里面的jsp不重启的这个功能,但是我们平时放到生产环境的工程,经常需要修改jsp页面,这样平凡重启就会造成容器内存不足,找过很多资料也做过很多实验证明该容器不支持jsp动态部署,必须重启....
由此研究了下jsp动态编译成servlet,然后加载该servlet,利用反射执行该servlet的service方法输出内容到客户端的代码:
import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.jasper.JspC;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.context.ServletConfigAware;
@Controller
@RequestMapping("/springmvc")
public class IndexController implements ServletConfigAware{
private static final long serialVersionUID = 1L;
private ServletConfig servletConfig;
@Override
public void setServletConfig(ServletConfig servletConfig) {
this.servletConfig = servletConfig;
}
@SuppressWarnings({ "unchecked", "deprecation" })
@RequestMapping(value = "/index.shtml")
<span style="white-space:pre"> </span>@ResponseBody
public void index(HttpServletRequest request, HttpServletResponse response) throws IOException {
String msg = "";
try {
//编译jsp
JspC jspc = new JspC();
jspc.setUriroot("D:/WebRoot/pages/springmvc");//web应用的root目录
jspc.setOutputDir("D:/WebRoot/pages/springmvc");//.java文件和.class文件的输出目录
jspc.setJspFiles("index.jsp");//要编译的jsp
jspc.setCompile(true);//是否编译 false或不指定的话只生成.java文件
jspc.execute();
//加载编译好的jsp
File filePath = new File("D:/WebRoot/pages/springmvc/");
URL xUrl= filePath.toURL() ;
MyClassLoader loader = new MyClassLoader(new URL[]{xUrl}, Thread.currentThread().getContextClassLoader());
Class xClass = loader.loadClass("org.apache.jsp.index_jsp");//获取刚编译的类
request.setAttribute("msg", msg);
Servlet servlet = null;
servlet = (Servlet)xClass.newInstance();
servlet.init(servletConfig);
servlet.service(request, response);
} catch (Exception e) {
e.printStackTrace();
}
}
static class MyClassLoader extends URLClassLoader{
public MyClassLoader(URL[] urls) {
super(urls);
}
public MyClassLoader(URL[] urls, ClassLoader parent) {
super(urls, parent);
}
public MyClassLoader(){
super(new URL[]{});
}
public void addFile(File f) throws MalformedURLException{
this.addURL(f.toURI().toURL());
//System.out.println("URL:" + f.toURI().toURL());
}
}
}
用sprinmvc作为控制层
注意
1、类需要实现ServletConfigAware接口,定义实例变量servletConfig,并在实现方法里面给赋值;
2、方法体必须包含@ResponseBody注入,方法必须包含HttpServletRequest request, HttpServletResponse response这两个参数,方法返回值为void;
3、引入jasper.jar包。
参考地址:
http://bbs.youkuaiyun.com/topics/380038218
http://blog.youkuaiyun.com/mycomputerxiaomei/article/details/24470465
http://www.oschina.net/code/snippet_96742_5587
http://bbs.youkuaiyun.com/topics/100097458
http://www.java2s.com/Code/Jar/CatalogJar.htm
http://kjah.iteye.com/blog/625588