基于xml文件实现系统属性配置管理

文章标题：基于xml文件实现系统属性配置管理 .

文章地址: http://blog.csdn.net/5iasp/article/details/11774501

作者： javaboy2012
Email：yanek@163.com
qq:    1046011462

项目截图;

主要有如下几个类和配置文件实现:

1. SystemProperties

package com.yanek.cfg;

import java.util.Collection;
import java.util.Map;

public interface SystemProperties
    extends Map
{

    public abstract Collection getChildrenNames(String s);

    public abstract Collection getPropertyNames();

    public void init();
}

2.  XMLSystemProperties类

package com.yanek.cfg;

import java.io.*;
import java.util.*;
import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.*;
import org.apache.log4j.Logger;

public class XMLSystemProperties
    implements SystemProperties
{
static Logger logger = Logger.getLogger(XMLSystemProperties.class.getName());

    private File file;
    private Document doc;
    private Map propertyCache;
    private Object propLock;

    public XMLSystemProperties(InputStream in)
        throws Exception
    {
        propertyCache = new HashMap();
        propLock = new Object();
        Reader reader = new BufferedReader(new InputStreamReader(in));
        buildDoc(reader);
    }

    public XMLSystemProperties(String fileName)
        throws IOException
    {
        File tempFile;
        boolean error=false;
        Reader reader;
        propertyCache = new HashMap();
        propLock = new Object();
        file = new File(fileName);
        if(!file.exists())
        {
            tempFile = new File(file.getParentFile(), file.getName() + ".tmp");
            if(tempFile.exists())
            {
                logger.error("WARNING: " + fileName + " was not found, but temp file from " + "previous write operation was. Attempting automatic recovery. Please " + "check file for data consistency.");
                tempFile.renameTo(file);
            } else
            {
                throw new FileNotFoundException("XML properties file does not exist: " + fileName);
            }
        }
        tempFile = new File(file.getParentFile(), file.getName() + ".tmp");
        if(tempFile.exists())
        {
            logger.error("WARNING: found a temp file: " + tempFile.getName() +
                      ". This may " +
                    "indicate that a previous write operation failed. Attempting automatic " +
                      "recovery. Please check file " + fileName +
                      " for data consistency.");
            if (tempFile.lastModified() > file.lastModified())
            {
                error = false;
                reader = null;
                try{
                    reader = new InputStreamReader(new FileInputStream(tempFile),
                            "UTF-8");
                    SAXReader xmlReader = new SAXReader();
                    xmlReader.read(reader);
                }catch(Exception e){
                    try
                    {
                        reader.close();
                    }
                    catch (Exception ex)
                    {}
                    error = true;
                }
            }
        }
        if(error)
        {
            String bakFile = tempFile.getName() + "-" + System.currentTimeMillis() + ".bak";
            tempFile.renameTo(new File(tempFile.getParentFile(), bakFile));
        } else
        {
            /*String bakFile = file.getName() + "-" + System.currentTimeMillis() + ".bak";
            file.renameTo(new File(file.getParentFile(), bakFile));
            try
            {
                Thread.sleep(100L);
            }
            catch(Exception e) { }
            tempFile.renameTo(file);*/
        }
        error = false;
        reader = null;
        try{
            reader = new InputStreamReader(new FileInputStream(file), "UTF-8");
            SAXReader xmlReader = new SAXReader();
            xmlReader.read(reader);
            try
            {
                reader.close();
            }
            catch (Exception e)
            {}
        }catch(Exception e){
            error = true;
        }
        if(error)
        {
            String bakFileName = file.getName() + "-" + System.currentTimeMillis() + ".bak";
            File bakFile = new File(file.getParentFile(), bakFileName);
            file.renameTo(bakFile);
            try
            {
                Thread.sleep(100L);
            }
            catch(Exception e) { }
            tempFile.renameTo(file);
        } /*else
        {
            String bakFile = tempFile.getName() + "-" + System.currentTimeMillis() + ".bak";
            tempFile.renameTo(new File(tempFile.getParentFile(), bakFile));
        }*/
        if(!file.canRead())
            throw new IOException("XML properties file must be readable: " + fileName);
        if(!file.canWrite())
            throw new IOException("XML properties file must be writable: " + fileName);
        reader = null;
        try
        {
            reader = new InputStreamReader(new FileInputStream(file), "UTF-8");
            buildDoc(reader);
        }
        catch(Exception e)
        {
            logger.error("Error creating XML properties file " + fileName + ": " + e.getMessage());
            throw new IOException(e.getMessage());
        }
        finally { }
        try
        {
            reader.close();
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }

    public Object get(Object o)
    {
        String name;
        String value;
        Element element;
        name = (String)o;
        value = (String)propertyCache.get(name);
        if(value != null)
            return value;
        String propName[] = parsePropertyName(name);
        element = doc.getRootElement();
        for(int i = 0; i < propName.length; i++)
        {
            element = element.element(propName[i]);
            if(element == null)
                return null;
        }

        synchronized(propLock){
            value = element.getText();
            if ("".equals(value))
                return null;
            value = value.trim();
            propertyCache.put(name, value);
            return value;
        }
    }

    public Collection getChildrenNames(String parent)
    {
        String propName[] = parsePropertyName(parent);
        Element element = doc.getRootElement();
        for(int i = 0; i < propName.length; i++)
        {
            element = element.element(propName[i]);
            if(element == null)
                return Collections.EMPTY_LIST;
        }

        List children = element.elements();
        int childCount = children.size();
        List childrenNames = new ArrayList(childCount);
        for(Iterator i = children.iterator(); i.hasNext(); childrenNames.add(((Element)i.next()).getName()));
        return childrenNames;
    }

    public Collection getPropertyNames()
    {
        List propNames = new java.util.LinkedList();
        List elements = doc.getRootElement().elements();
        if(elements.size() == 0)
            return Collections.EMPTY_LIST;
        for(int i = 0; i < elements.size(); i++)
        {
            Element element = (Element)elements.get(i);
            getElementNames(propNames, element, element.getName());
        }

        return propNames;
    }

    public String getAttribute(String name, String attribute)
    {
        if(name == null || attribute == null)
            return null;
        String propName[] = parsePropertyName(name);
        Element element = doc.getRootElement();
        int i = 0;
        do
        {
            if(i >= propName.length)
                break;
            String child = propName[i];
            element = element.element(child);
            if(element == null)
                break;
            i++;
        } while(true);
        if(element != null)
            return element.attributeValue(attribute);
        else
            return null;
    }

    private void getElementNames(List list, Element e, String name)
    {
        if(e.elements().isEmpty())
        {
            list.add(name);
        } else
        {
            List children = e.elements();
            for(int i = 0; i < children.size(); i++)
            {
                Element child = (Element)children.get(i);
                getElementNames(list, child, name + '.' + child.getName());
            }

        }
    }

    public synchronized Object put(Object k, Object v)
    {
        String name = (String)k;
        String value = (String)v;
        propertyCache.put(name, value);
        String propName[] = parsePropertyName(name);
        Element element = doc.getRootElement();
        for(int i = 0; i < propName.length; i++)
        {
            if(element.element(propName[i]) == null)
                element.addElement(propName[i]);
            element = element.element(propName[i]);
        }

        element.setText(value);
        saveProperties();
        return null;
    }

    public synchronized void putAll(Map propertyMap)
    {
        String propertyName;
        String propertyValue;
        for(Iterator iter = propertyMap.keySet().iterator(); iter.hasNext(); propertyCache.put(propertyName, propertyValue))
        {
            propertyName = (String)iter.next();
            propertyValue = (String)propertyMap.get(propertyName);
            String propName[] = parsePropertyName(propertyName);
            Element element = doc.getRootElement();
            for(int i = 0; i < propName.length; i++)
            {
                if(element.element(propName[i]) == null)
                    element.addElement(propName[i]);
                element = element.element(propName[i]);
            }

            if(propertyValue != null)
                element.setText(propertyValue);
        }

        saveProperties();
    }

    public synchronized Object remove(Object n)
    {
        String name = (String)n;
        propertyCache.remove(name);
        String propName[] = parsePropertyName(name);
        Element element = doc.getRootElement();
        for(int i = 0; i < propName.length - 1; i++)
        {
            element = element.element(propName[i]);
            if(element == null)
                return null;
        }

        String value = element.getText();
        element.remove(element.element(propName[propName.length - 1]));
        saveProperties();
        return value;
    }

    public String getProperty(String name)
    {
        return (String)get(name);
    }

    public boolean containsKey(Object object)
    {
        return get(object) != null;
    }

    public boolean containsValue(Object object)
    {
        throw new UnsupportedOperationException("Not implemented in xml version");
    }

    public Collection values()
    {
        throw new UnsupportedOperationException("Not implemented in xml version");
    }

    public boolean isEmpty()
    {
        return false;
    }

    public int size()
    {
        throw new UnsupportedOperationException("Not implemented in xml version");
    }

    public Set entrySet()
    {
        throw new UnsupportedOperationException("Not implemented in xml version");
    }

    public void clear()
    {
        throw new UnsupportedOperationException("Not implemented in xml version");
    }

    public Set keySet()
    {
        throw new UnsupportedOperationException("Not implemented in xml version");
    }

    private void buildDoc(Reader in)
        throws Exception
    {
        SAXReader xmlReader = new SAXReader();
        doc = xmlReader.read(in);
    }

    private synchronized void saveProperties()
    {
        Writer writer;
        boolean error;
        File tempFile;
        writer = null;
        error = false;
        tempFile = null;
        try{
            tempFile = new File(file.getParentFile(), file.getName() + ".tmp");
            writer = new OutputStreamWriter(new FileOutputStream(tempFile),
                                            "UTF-8");
            XMLWriter xmlWriter = new XMLWriter(writer,
                                                OutputFormat.createPrettyPrint());
            xmlWriter.write(doc);
            try
            {
                writer.close();
            }
            catch (Exception ex)
            {
                logger.error(ex);
                error = true;
            }
        }catch(Exception ex){
            logger.error("Unable to write to file " + file.getName() + ".tmp" +
                      ": " + ex.getMessage());
            error = true;
        }finally{
            try
            {
                writer.close();
            }
            catch (Exception e)
            {
                logger.error(e);
                error = true;
            }
        }
        if(error)
            return;
        error = false;
        if(file.exists() && !file.delete())
        {
            logger.error("Error deleting property file: " + file.getAbsolutePath());
            return;
        }
        try{
            writer = new OutputStreamWriter(new FileOutputStream(file), "UTF-8");
            XMLWriter xmlWriter = new XMLWriter(writer,
                                                OutputFormat.createPrettyPrint());
            xmlWriter.write(doc);
            try
            {
                writer.close();
            }
            catch (Exception e)
            {
                logger.error(e);
                error = true;
            }
        }catch(Exception e){
            logger.error("Unable to write to file '" + file.getName() + "': " +
                      e.getMessage());
            error = true;
            try
            {
                file.delete();
            }
            catch(Exception fe) { }
            try
            {
                writer.close();
            }
             catch(Exception ex)
            {
                logger.error(ex);
                error = true;
        }
        }
        if(!error)
            tempFile.delete();
    }

    private String[] parsePropertyName(String name)
    {
        List propName = new ArrayList(5);
        for(StringTokenizer tokenizer = new StringTokenizer(name, "."); tokenizer.hasMoreTokens(); propName.add(tokenizer.nextToken()));
        return (String[])(String[])propName.toArray(new String[propName.size()]);
    }
	public void init() {
	}
}

3. SystemGlobals

package com.yanek.cfg;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.naming.InitialContext;

import org.dom4j.Document;
import org.dom4j.io.SAXReader;

public class SystemGlobals
{
    static class InitPropLoader
    {

        public String getSystemHome()
        {
            String systemHome;
            InputStream in;
            systemHome = null;
            in = null;
                if(systemHome == null)
                {
                    try
                    {
                        in = getClass().getResourceAsStream("/sys_init.xml");
                        if (in != null)
                        {
                            Document doc = (new SAXReader()).read(in);
                            systemHome = doc.getRootElement().getText();
                        }
                    }
                    catch (Exception e)
                    {
                        SystemGlobals.log.log(Level.SEVERE,
                                            "Error loading sys_init.xml to find systemHome -> " +
                                            e.getMessage(), e);
                    }
                    finally
                    {
                        try
                        {
                            if (in != null)
                                in.close();
                        }
                        catch (Exception e)
                        {}
                    }
                }
            if(systemHome != null)
                for(systemHome = systemHome.trim(); systemHome.endsWith("/") || systemHome.endsWith("\\"); systemHome = systemHome.substring(0, systemHome.length() - 1));
            if("".equals(systemHome))
            	systemHome = null;
            return systemHome;
        }

        InitPropLoader()
        {
        }
    }

    private static final Logger log;
    private static String SYS_CONFIG_FILENAME = "system_config.xml";

    public static String systemHome = null;
    public static boolean failedLoading = false;
    private static SystemProperties setupProperties = null;

    private static Date startupDate = new Date();

    private SystemGlobals()
    {
    }

    public static Date getStartupDate()
    {
        return startupDate;
    }

    public static String getSystemHome()
    {
        if(systemHome == null)
            loadSetupProperties();
        return systemHome;
    }

    public static synchronized void setSystemHome(String sysHome)
    {

        setupProperties = null;
        failedLoading = false;
        systemHome = sysHome;

        loadSetupProperties();
        System.err.println("Warning - sysHome is being reset to " + sysHome + "! Resetting the baduHome is a normal part of the setup process, " + "however it should not occur during the normal operations of System.");
    }

    public static void setConfigName(String configName)
    {
    	SYS_CONFIG_FILENAME = configName;
    }

    public static boolean isSetup()
    {
        return "true".equals(getLocalProperty("setup"));
    }

    public static String getLocalProperty(String name)
    {
        if(setupProperties == null)
            loadSetupProperties();
        if(setupProperties == null)
            return null;
        else
            return (String)setupProperties.get(name);
    }

    public static int getLocalProperty(String name, int defaultValue)
    {
        String value;
        value = getLocalProperty(name);
        if(value != null)
        {
            try{
                return Integer.parseInt(value);
            }catch(NumberFormatException nfe){}
        }
        return defaultValue;
    }

    public static List getLocalProperties(String parent)
    {
        if(setupProperties == null)
            loadSetupProperties();
        if(setupProperties == null)
            return Collections.EMPTY_LIST;
        Collection propNames = setupProperties.getChildrenNames(parent);
        List values = new ArrayList();
        Iterator i = propNames.iterator();
        do
        {
            if(!i.hasNext())
                break;
            String propName = (String)i.next();
            String value = getLocalProperty(parent + "." + propName);
            if(value != null)
                values.add(value);
        } while(true);
        return values;
    }

    public static void setLocalProperty(String name, String value)
    {
        if(setupProperties == null)
            loadSetupProperties();
        if(setupProperties != null)
            setupProperties.put(name, value);
    }

    public static void setLocalProperties(Map propertyMap)
    {
        if(setupProperties == null)
            loadSetupProperties();
        if(setupProperties != null)
            setupProperties.putAll(propertyMap);
    }

    public static void deleteLocalProperty(String name)
    {
        if(setupProperties == null)
            loadSetupProperties();
        setupProperties.remove(name);
    }

    public static boolean isWhiteLabel(){
    	return true;
    }

    private static synchronized void loadSetupProperties()
    {
        if(failedLoading)
            return;
        if(setupProperties == null)
        {
            if(systemHome == null)
            	systemHome = (new InitPropLoader()).getSystemHome();
            if(systemHome == null)
                try
                {
                    InitialContext context = new InitialContext();
                    systemHome = (String)context.lookup("java:comp/env/baduHome");
                }
                catch(Exception e) { }
            if(systemHome == null)
            	systemHome = System.getProperty("systemHome");
            if(systemHome == null)
            {
                failedLoading = true;
                StringBuffer msg = new StringBuffer();
                msg.append("Critical Error! The systemHome directory could not be loaded, \n");
                msg.append("which will prevent the application from working correctly.\n\n");
                msg.append("You must set systemHome in one of three ways:\n");
                msg.append("    1) Add a sys_init.xml file to your classpath, which points \n ");
                msg.append("       to sysHome. Normally, this file will be in WEB-INF/classes.\n");
                msg.append("    2) Set the JNDI value \"java:comp/env/systemHome\" with a String \n");
                msg.append("       that points to your systemHome directory. \n");
                msg.append("    3) Set the Java system property \"systemHome\".\n\n");
                msg.append("Further instructions for setting systemHome can be found in the \n");
                msg.append("installation documentation.");
                System.err.println(msg.toString());
                return;
            }
            try
            {
                File jh = new File(systemHome);
                if(!jh.exists())
                    log.severe("Error - the specified systemHome directory does not exist (" + systemHome + ")");
                else
                if(!jh.canRead() || !jh.canWrite())
                    log.severe("Error - the user running this System application can not read and write to the specified systemHome directory (" + systemHome + "). Please grant the executing user " + "read and write perms.");
                setupProperties = new XMLSystemProperties(systemHome + File.separator + SYS_CONFIG_FILENAME);
            }
            catch(IOException ioe)
            {
                log.log(Level.SEVERE, ioe.getMessage(), ioe);
                failedLoading = true;
            }
        }
    }

    static
    {
        log = Logger.getLogger((com.yanek.cfg.SystemGlobals.class).getName());
    }

}

4.  配置文件 sys_init.xml  ,

定义xml 配置文件的目录

<?xml version="1.0"?>
<systemHome>E:\work\XmlProp\conf</systemHome>

5. xml 配置文件:

<?xml version="1.0" encoding="UTF-8"?>

<config>
  <setup>true</setup>
  <upload>
    <file>
      <imgFilePath>f:\img\</imgFilePath>
      <maxSize>1024</maxSize>
      <allowFileType>gif,bmp,png,jpg</allowFileType>
    </file>
  </upload>
  <prop>
    <connection>
      <pool>
        <name>proxool.test.prop</name>
      </pool>
      <jndi>
        <name>test/test</name>
      </jndi>
    </connection>
  </prop>
  <log4j>
    <filePath>WEB-INF/classes/log4j.properties</filePath>
  </log4j>
  <taskEngine>
    <status>false</status>
  </taskEngine>
  <list>
    <x>aaaa</x>
    <y>222</y>
    <z>333</z>
  </list>
  <dbname>testdb</dbname>
  <db>
    <username>test</username>
    <password>test</password>
  </db>
</config>

6. 测试类:

package com.yanek.cfg;

import java.util.List;

public class Test {

	/**
	 * @param args
	 */
	public static void main(String[] args) {

		System.out.println("setup:"+SystemGlobals.getLocalProperty("setup"));
		System.out.println("taskEngine.status:"+SystemGlobals.getLocalProperty("taskEngine.status"));
		System.out.println("prop.connection.pool.name:"+SystemGlobals.getLocalProperty("prop.connection.pool.name"));

		List list=SystemGlobals.getLocalProperties("upload.file");
		System.out.println(list);
		for(int i=0;i<list.size();i++)
		{
			System.out.println((String)list.get(i));
		}

		SystemGlobals.setLocalProperty("db.username", "test");
		SystemGlobals.setLocalProperty("db.password", "test");

	}

}

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