Java中读取配置文件（properties、xml）

1. 利用java.util提供的工具类Properties
      - 首先我这边有个file.properties文件
      - 然后去读取这个文件

注意项目路径

//注意ProConfigUtil是当前类，也可用this替代
    InputStream inputStream = PropConfigUtil.class.getClassLoader()
           .getResourceAsStream("config/file.properties"); 
    Properties pro = new Properties();
    pro.load(inputStream);       
    String fileType = pro.getProperty("file.fileType").trim();

完整代码

package com.zsl.uploadfile;

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

import org.apache.commons.configuration.ConfigurationException;


public final class ImagePropConfigUtil
{

    public ImagePropConfigUtil()
    {}

    public static class SingleTon
    {
        private static InputStream inputStream = null;
        private static Properties pro = null;
        static
        {
            inputStream = ImagePropConfigUtil.class.getClassLoader().getResourceAsStream(
                "config/file.properties");
            pro = new Properties();
            try
            {
                pro.load(inputStream);
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
        }
    }

    public static String getVal(String key)
    {
        return SingleTon.pro.getProperty(key);
    }

     public static void main(String[] args)
        throws ConfigurationException
    {
        System.out.println("--------------------");
        String val = ImagePropConfigUtil.getVal("file.fileType");
        System.out.println("-------文件类型为:\t" + val);
    }
}

2.利用jar包：Apache-commons-configuration-1.5.jar

PropertiesConfiguration prop = new PropertiesConfiguration("config/file.properties");
prop.setDelimiterParsingDisabled(true);
String val = prop.getProperty("image.imageType").toString();
System.out.println(val);

完整代码

package com.zsl.uploadfile;

import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.PropertiesConfiguration;


public class Util
{

    public Util()
    {}

    public static class Single
    {
        private static PropertiesConfiguration prop = null;
        static
        {
            try
            {
                prop = new PropertiesConfiguration("config/file.properties");
                prop.setDelimiterParsingDisabled(true);
            }
            catch (ConfigurationException e)
            {
                System.out.println(e.getMessage());
                e.printStackTrace();
            }
        }
    }

    public static String getVal(String key)
    {
        String value = Single.prop.getProperty(key).toString();
        return value;
    }

    public static void main(String[] args)
    {
        System.out.println(Util.getVal("file.fileType"));
    }
}

上面这两种方法就可以读取配置文件。相比较而言比较高效率的读取配置文件,模拟单例模式，程序只调用一次,

打印结果如下：