JAVA 获取系统环境变量

分享代码：

package com.base.entity;

import java.io.Serializable;
import java.util.Comparator;

/**
 * 系统环境变量
 * 
 * @author test
 * @create 2014-3-10下午04:35:47
 * @version 1.0
 */
public class SystemProperty implements Serializable, Comparator {

    private static final long serialVersionUID = 1L;

    // 属性key
    private String iKey;

    // 属性Value
    private String iVal;

    public SystemProperty() {
        // TODO Auto-generated constructor stub
    }

    public SystemProperty(String iKey, String iVal) {
        super();
        this.iKey = iKey;
        this.iVal = iVal;
    }

    @Override
    public int compare(Object o1, Object o2) {
        // TODO Auto-generated method stub

        SystemProperty s1 = (SystemProperty) o1;
        SystemProperty s2 = (SystemProperty) o2;

        return s1.getiKey().compareTo(s2.getiKey());
    }

    public String getiKey() {
        return iKey;
    }

    public void setiKey(String iKey) {
        this.iKey = iKey;
    }

    public String getiVal() {
        return iVal;
    }

    public void setiVal(String iVal) {
        this.iVal = iVal;
    }
}

package com.util.common;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import com.base.entity.SystemProperty;

/**
 * @author test
 * @create 2014-3-10下午04:39:08
 * @version 1.0
 */
public final class Read {

    /**
     * 获取系统所有环境变量
     * 
     * @return List<SystemProperty>
     * @throws Exception
     */
    public static List<SystemProperty> readSysPropertyAll() throws Exception {
        return readSysProperty("BOCO_ALL");
    }

    /**
     * 获取系统指定环境变量
     * 
     * @param key
     *            环境变量Key
     * @return List<SystemProperty>
     * @throws Exception
     */
    public static List<SystemProperty> readSysProperty(String key)
            throws Exception {

        List<SystemProperty> list = new ArrayList<SystemProperty>();

        Map m = System.getenv();
        String keys = "";
        if (key.equals("BOCO_ALL")) {
            for (Iterator<String> iter = m.keySet().iterator(); iter.hasNext();) {
                keys = iter.next();
                list.add(new SystemProperty(keys, m.get(keys).toString()));
                Collections.sort(list, new SystemProperty());
            }
        } else {
            if (m.containsKey(key)) {
                list.add(new SystemProperty(key, m.get(key).toString()));
            } else {
                throw new Exception("系统中未包含指定Key：" + key);
            }
        }
        return list;
    }
}