书中代码-自己写写测试

package com.fenghao.loadbalancing;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Random;
import java.util.Set;

import org.junit.Test;

/**
 *
 * <P>负载均衡算法简单写</P>
 * @ClassName: loadTest
 * @author 冯浩  2016年11月9日 上午9:12:49
 * @see TODO
 */
public class loadTest {
	private final Map<String,Integer> serverWeightMap=new HashMap<String,Integer>();

	public loadTest(){
		serverWeightMap.put("192.168.1.100", 1);
		serverWeightMap.put("192.168.1.101", 1);
		serverWeightMap.put("192.168.1.102", 4);
		serverWeightMap.put("192.168.1.103", 1);
		serverWeightMap.put("192.168.1.104", 1);
		serverWeightMap.put("192.168.1.105", 3);
		serverWeightMap.put("192.168.1.106", 1);
		serverWeightMap.put("192.168.1.107", 2);
		serverWeightMap.put("192.168.1.108", 1);
		serverWeightMap.put("192.168.1.109", 1);
		serverWeightMap.put("192.168.1.110", 1);
	}

	@Test
	public void Test(){
		int le=4;
//		roundRobinTest(le);
		RandomTest();
	}

	/**
	 *
	 * <p>Title: roundRobinTest</p>
	 * <p>轮询</p>
	 * @param pos
	 * @return
	 * @author 冯浩  2016年11月9日 下午7:41:52
	 */
	public String roundRobinTest(Integer pos){
		Map<String,Integer> serverMap=new HashMap<String,Integer>();
		serverMap.putAll(serverWeightMap);

		Set<String> keySet = serverMap.keySet();
		ArrayList<String> keylist=new ArrayList<String>();
		keylist.addAll(keySet);

		String server=null;
		synchronized (pos) {
			if(pos>=keySet.size()){
				pos=0;
			}
			server=keylist.get(pos);
			pos++;
			System.out.println("\npos is "+pos);
		}
		System.out.println("\nserver is "+server);
		return server;
	}

	/**
	 *
	 * <p>Title: RandomTest</p>
	 * <p>随机法</p>
	 * @return
	 * @author 冯浩  2016年11月9日 下午7:49:24
	 */
	public String RandomTest(){
		Map<String,Integer> serverMap=new HashMap<String,Integer>();
		serverMap.putAll(serverWeightMap);

		Set<String> keySet = serverMap.keySet();
		ArrayList<String> keyList=new ArrayList<String>();
		keyList.addAll(keySet);

		Random random=new Random();
		int pos = random.nextInt(keyList.size());
		System.out.println("\npos is "+pos);
		String server = keyList.get(pos);
		System.out.println("\nserver is "+server);
		return server;
	}

	/**
	 *
	 * <p>Title: HashTest</p>
	 * <p>源地址Hash法</p>
	 * @author 冯浩  2016年11月10日 上午8:46:43
	 */
	public String HashTest(String remoteip){
		Map<String,Integer> serverMap=new HashMap<String,Integer>();
		serverMap.putAll(serverWeightMap);

		Set<String> keySet = serverMap.keySet();
		ArrayList<String> keyList=new ArrayList<String>();
		keyList.addAll(keySet);

		int hashCode = remoteip.hashCode();
		int size = keyList.size();
		int pos=hashCode % size;
		System.out.println("\npos is "+pos);
		return keyList.get(pos);

	}

	/**
	 *
	 * <p>Title: weightRoundRobin</p>
	 * <p>加权轮询法</p>
	 * @return
	 * @author 冯浩  2016年11月10日 上午8:57:32
	 */
	public String weightRoundRobin(Integer pos){
		Map<String,Integer> serverMap=new HashMap<String,Integer>();
		serverMap.putAll(serverWeightMap);

		Set<String> keySet = serverMap.keySet();
		Iterator<String> it = keySet.iterator();

		List<String> serverList=new ArrayList<String>();

		while(it.hasNext()){
			String server=it.next();
			Integer weight = serverMap.get(server);
			for (int i = 0; i <weight ; i++) {
				serverList.add(server);
			}
		}

		String server=null;

		synchronized (pos) {
			if(pos>=serverList.size()){
				pos=0;
			}
			server=serverList.get(pos);
			pos++;
		}
		return server;
	}

	/**
	 *
	 * <p>Title: WeightRandom</p>
	 * <p>加权随机法</p>
	 * @return
	 * @author 冯浩  2016年11月11日 上午8:43:33
	 */
	public String WeightRandom(){
		Map<String,Integer> serverMap=new HashMap<String,Integer>();
		serverMap.putAll(serverWeightMap);

		Set<String> keySet = serverMap.keySet();
		Iterator<String> it = keySet.iterator();

		List<String> serverList=new ArrayList<String>();

		while(it.hasNext()){
			String server = it.next();
			Integer weight = serverMap.get(server);
			for (int i = 0; i < weight; i++) {
				serverList.add(server);
			}
		}

		Random random=new Random();
		int randomPos = random.nextInt(serverList.size());
		String server = serverList.get(randomPos);
		return server;
	}
}