java文件加载

     主要了解下java.util.Properties类下load(InputStream inStream)和loadFromXML(InputStream inStream)完成资源文件或XML的加载，配置文件用的较多。

     现在就有个问题--何时加载，我采用的是请求Action的时候加载文件；其它的就不太了解了。

     import java.io.*;import java.util.*;public class LoadXML {/** * 加载XML * @param filename * @return */public static Map load(String filename){Map<String, String> map = new HashMap<String, String>(); FileInputStream fis = null;Properties prop = new Properties(); try {fis = new FileInputStream(filename);prop.loadFromXML(fis);map.put("CHU_KAI_MINS", prop.getProperty("CHU_KAI_MINS"));map.put("TUI_DAO_MINS", prop.getProperty("TUI_DAO_MINS"));// prop.list(System.out); // System.out.println(prop.getProperty("CHU_KAI_MINS")); } catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException o){o.printStackTrace();} finally {if(fis!=null)try {fis.close();} catch (IOException e) {e.printStackTrace();}}return map;}/** * 加载properties * @param filename */public static String loadp(String filename){Properties prop = new Properties(); //FileInputStream fis = null;InputStream fis = null;String str = "";try {fis = LoadXML.class.getClass().getResourceAsStream(filename);//fis = new FileInputStream(filename);prop.load(fis);str = new String(prop.getProperty("fo").getBytes("iso-8859-1"),"UTF-8");} catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException o){o.printStackTrace();} finally {if(fis!=null)try {fis.close();} catch (IOException e) {e.printStackTrace();}}return str;}public static String loadp(){Properties prop = new Properties(); InputStream fis = null;String str = "";try {// config.properties在同一目录下fis = LoadXML.class.getClass().getResourceAsStream("/config.properties");prop.load(fis);str = new String(prop.getProperty("fo").getBytes("iso-8859-1"),"UTF-8");} catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException o){o.printStackTrace();} finally {if(fis!=null)try {fis.close();} catch (IOException e) {e.printStackTrace();}}return str;}/** * 测试 *///System.out.println(LoadXML.loadp());}

在Action中调用Dao加载文件：

     /** * load xml */ String path = request.getSession().getServletContext().getRealPath("/")+"WEB-INF//classes//config.xml"; Map map = LoadXML.load(path);

config.xml:

     <?xml version="1.0" encoding="UTF-8"?><!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd"> <properties> <comment>sjbd</comment> <entry key="CHU_KAI_MINS">60</entry> <entry key="TUI_DAO_MINS">30</entry> </properties>

config.properties:

fo=小鹤

 

     写代码时候看了下source中的IO操作，想了解如何做的，发现很多native method，JVM源码中有具体实现吧。