Properties文件读取

package com.founder.jfreechart.demo;

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

import org.jfree.data.general.DefaultPieDataset;
import org.jfree.data.general.PieDataset;

public class PropertiesConfigUtil {
   
    public Properties getPropertiesConfig()throws Exception{
    	Properties properties = new Properties();
    	InputStream in = DataSetUtil.class.getResourceAsStream("config.properties");
    	properties.load(in);
	return properties;
    	
    }
    public String getKey(String key) throws Exception{
         return getPropertiesConfig().getProperty(key);
    }

	public static void main(String[] args) throws Exception {
		PropertiesConfigUtil util = new PropertiesConfigUtil ();
		System.out.println("HIGH=="+util.getKey("HIGH"));

	}
}

  config.properties 要放到同级文件夹内。

下面是转载别人的写的读取properties文件

下面来自优快云博客，转载请标明出处：http://blog.youkuaiyun.com/luweifeng1983/archive/2008/11/27/3392907.aspx

package com.lwf.util;

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Enumeration;
import java.util.Properties;

/*
 * 从路径中的属性文件中读取单个属性或全部属性及设置属性
 */
public class GetProperty {
    public static String readValue(String filePath,String key){
        Properties props = new Properties();
        try {
            InputStream ips = new BufferedInputStream(new FileInputStream(filePath));
            props.load(ips);
            String value = props.getProperty(key);
            System.out.println(key+"="+value);
            return value;
        } catch (FileNotFoundException e) {
            e.printStackTrace();
            return null;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
        
    }

    //读取全部信息
    public static void readProperties(String filePath) {
        Properties props = new Properties();
        try {
            InputStream ips = new BufferedInputStream(new FileInputStream(filePath));
            props.load(ips);
            Enumeration enum = props.propertyNames();
            while(enum.hasMoreElements()){
                String key = (String)enum.nextElement();
                String value = props.getProperty(key);
                System.out.println(key+"="+value);
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        
    }
    
    public static void writeProperties(String filePath,String paraKey,String paraValue){
        Properties props = new Properties();
        try {
            
            OutputStream ops = new FileOutputStream(filePath);
            props.setProperty(paraKey, paraValue);
            props.store(ops, "set");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    
    public static void main(String[] args){
        GetProperty.readValue("D:\\eclipse3.3\\workspace\\Test\\src\\sys.properties", "username");
        
        GetProperty.readProperties("D:\\eclipse3.3\\workspace\\Test\\src\\sys.properties");
        GetProperty.writeProperties("D:\\eclipse3.3\\workspace\\Test\\src\\sys.properties", "age", "21");
    }
}