使用Spring计时器和velocity模板定时生成静态html/jsp文件

当一个页面不是经常需要更新的话，就需要为它定时生成一个静态文件，这样可以减轻服务器压力，相应的也减少了用户等待时间。

首先看一下一个主jsp文件：

<%@ page contentType="text/html; charset=UTF-8"%>
   
 


	
	


	。。。。。。
	
	
	
	。。。。。。

配置Spring文件：

  
           
               
                class   
                   
                    org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader   
                   
                   
               
           
   
  
 
 
 	
 
  
  
	  
	  
	 	 
	  
	  
	  
	 	work 
	  
 
  
  
	  
	 	 
	  
	  
	 
	 	
	 	 
	 	0 0/1 * * * ? 
	  
 
  
  
	  
		  
		 	 
		  
	  
 

编写要调用的工作类QuartzJob：

import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Map;

import org.apache.velocity.app.VelocityEngine;
import org.apache.velocity.exception.VelocityException;
import org.springframework.ui.velocity.VelocityEngineUtils;

public class QuartzJob {
	VelocityEngine velocityEngine;
	private int count;
	public void work(){
////////////////////////////////////////////////////////////////////////////
//这里每个人的写法不同，但不管怎么样，目的只有一个：获得想要的数据。我这里是通过post请求返回数据后解析，最后把想要的数据填入下面的HashMap中就ok了;当然你也可以从数据库中获取数据。
//		System.out.println("----------开始HTTP连接----------");
//		String url="http://XXX.XXX.XXX.XXX";
//		WebClient client=new WebClient();
//		String content="";
//		try {
//			content = client.getWebContentByPost(url,"action=login&loginname=13761083826&password=111111");
//			content = new String(content.getBytes("iso-8859-1"),"UTF-8");
//			System.out.println(content);
//			client=null;
//		} catch (IOException e1) {
//			// TODO Auto-generated catch block
//			e1.printStackTrace();
//		}
//		System.out.println("----------结束HTTP连接----------");
//		System.out.println("----------解析xml开始----------");
//		parse(content);
//		System.out.println("----------解析xml结束----------");
////////////////////////////////////////////////////////////////////////////		
		Map model=new HashMap();
		model.put("填入需要的key1", "填入需要的值1");
		model.put("填入需要的key2", "填入需要的值2");
		String result = null;
		try {
			result=VelocityEngineUtils.mergeTemplateIntoString(this.getVelocityEngine(), "vm/baseInfoMiddle.vm", "UTF-8",model);
		} catch (VelocityException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
		}
//		System.out.println("result="+result);//打印看看，如果乱码，将baseInfoMiddle.vm文件保存成UTF-8格式
		try {
//通常情况下，静态文件都需要生成在tomcat\webapps\yourProject下
//			String toPath="D:\\Program Files\\Apache Software Foundation\\Tomcat 5.5\\webapps\\yourProject\\baseInfoMiddle.jsp";
//如果下面的写法，文件将生成在tomcat\bin下
//String toPath="baseInfoMiddle.jsp";
//文件最终的生成地址，可以像下面那样。这样不管tomcat装在哪里！
			String toPath="..\\webapps\\yourProject\\baseInfoMiddle.jsp";
			PrintWriter writer = new PrintWriter(toPath,"UTF-8");
			writer.println(result);
			writer.flush();
			writer.close();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		System.out.println( "[Quartz任务调度生成文件]："+count++ );
	}
	
	public VelocityEngine getVelocityEngine() {
		return velocityEngine;
	}
	public void setVelocityEngine(VelocityEngine velocityEngine) {
		this.velocityEngine = velocityEngine;
	}
}

同时奉送WebClient.java类，该类用于网络连接，应该一看就能明白

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;

public class WebClient {
	
	public WebClient(){
		
	}

	public String getWebContentByGet(String urlString, final String charset,
			int timeout) throws IOException {
		if (urlString == null || urlString.length() == 0) {
			return null;
		}
		urlString = (urlString.startsWith("http://") || urlString
				.startsWith("https://")) ? urlString : ("http://" + urlString)
				.intern();
		URL url = new URL(urlString);
		HttpURLConnection conn = (HttpURLConnection) url.openConnection();
		conn.setRequestMethod("GET");
		// 增加报头，模拟浏览器，防止屏蔽
		conn.setRequestProperty(
						"User-Agent",
						"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727)");
		// 只接受text/html类型，当然也可以接受图片,pdf,*/*任意，就是tomcat/conf/web里面定义那些
		conn.setRequestProperty("Accept", "text/html");
		conn.setConnectTimeout(timeout);
		try {
			if (conn.getResponseCode() != HttpURLConnection.HTTP_OK) {
				return null;
			}
		} catch (IOException e) {
			e.printStackTrace();
			return null;
		}
		InputStream input = conn.getInputStream();
		BufferedReader reader = new BufferedReader(new InputStreamReader(input,charset));
		String line = null;
		StringBuffer sb = new StringBuffer();
		while ((line = reader.readLine()) != null) {
			sb.append(line).append("\r\n");
		}
		if (reader != null) {
			reader.close();
		}
		if (conn != null) {
			conn.disconnect();
		}
		return sb.toString();

	}

	public String getWebContentByGet(String urlString) throws IOException {
		return getWebContentByGet(urlString, "iso-8859-1", 5000);
	}

	public String getWebContentByPost(String urlString,String data, final String charset,
			int timeout)throws IOException{
		if (urlString == null || urlString.length() == 0) {
			return null;
		}
		urlString = (urlString.startsWith("http://") || urlString
				.startsWith("https://")) ? urlString : ("http://" + urlString).intern();
		URL url = new URL(urlString);
		HttpURLConnection connection = (HttpURLConnection) url.openConnection();
		 // 设置是否向connection输出，因为这个是post请求，参数要放在  http正文内，因此需要设为true
        connection.setDoOutput(true);   
        connection.setDoInput(true); 
        connection.setRequestMethod("POST");
        // Post 请求不能使用缓存   
        connection.setUseCaches(false);
        connection.setInstanceFollowRedirects(true);
        connection.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
        // 增加报头，模拟浏览器，防止屏蔽
        connection.setRequestProperty("User-Agent","Mozilla/4.0 (compatible; MSIE 8.0; Windows vista)");
        // 只接受text/html类型，当然也可以接受图片,pdf,*/*任意
        connection.setRequestProperty("Accept", "text/xml");
        connection.setConnectTimeout(timeout);
        connection.connect();
        DataOutputStream out = new DataOutputStream(connection.getOutputStream());
        String content = URLEncoder.encode(data, "utf-8");//+URLEncoder.encode("中文 ", "utf-8");
        out.writeBytes(content);
        out.flush();   
        out.close();
        
		try {
			//必须写在发送数据的后面
			if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
				return null;
			}
		} catch (IOException e) {
			e.printStackTrace();
			return null;
		}
        BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream(),charset));
        String line;
        StringBuffer sb=new StringBuffer();
        while ((line = reader.readLine()) != null) {
            sb.append(line).append("\r\n");
        }
        if (reader != null) {
			reader.close();
		}
		if (connection != null) {
			connection.disconnect();
		}
		return sb.toString();
	}
	public String getWebContentByPost(String urlString,String data) throws IOException {
		return getWebContentByPost(urlString, data,"iso-8859-1", 5000);
	}
	
	public static void main(String[] args) throws IOException {
		WebClient client=new WebClient();
//		String s = client.getWebContentByGet("http://www.baidu.com");
//		s = new String(s.getBytes("iso-8859-1"), "gb2312");
		
		String s = client.getWebContentByPost("http://localhost:8080/Lottery/login.portal","action=login&loginname=13761083826&password=111111");
		s = new String(s.getBytes("iso-8859-1"), "UTF-8");
		System.out.println(s);
	}
	

}

模板类自己设计,比如我的baseInfoMiddle.vm：

<%@ page contentType="text/html; charset=UTF-8" %>



	
	
	
	
		
$key1
		
$key2
		
	

如有看不明白，请先看这里：
http://ben-sin.iteye.com/blog/426435