负载均衡的几种算法Java实现代码

轮询:

 1 package class2.zookeeper.loadbalance;
 2 
 3 import java.util.ArrayList;
 4 import java.util.HashMap;
 5 import java.util.Map;
 6 import java.util.Set;
 7 
 8 /**
 9  * 負載均衡算法，輪詢法
10  * @author guoy
11  *
12  */
13 public class TestRoundRobin {
14 
15     
16     static Map<String,Integer> serverWeigthMap  = new HashMap<String,Integer>();
17 
18      static{
19         serverWeigthMap.put("192.168.1.12", 1);
20         serverWeigthMap.put("192.168.1.13", 1);
21         serverWeigthMap.put("192.168.1.14", 2);
22         serverWeigthMap.put("192.168.1.15", 2);
23         serverWeigthMap.put("192.168.1.16", 3);
24         serverWeigthMap.put("192.168.1.17", 3);
25         serverWeigthMap.put("192.168.1.18", 1);
26         serverWeigthMap.put("192.168.1.19", 2);
27     }
28      Integer  pos = 0;
29      public  String roundRobin()
30         {
31             //重新建立一個map,避免出現由於服務器上線和下線導致的並發問題
32             Map<String,Integer> serverMap  = new HashMap<String,Integer>();
33             serverMap.putAll(serverWeigthMap);
34             //獲取ip列表list
35             Set<String> keySet = serverMap.keySet();
36             ArrayList<String> keyList = new ArrayList<String>();
37             keyList.addAll(keySet);
38             
39             String server = null;
40             
41             synchronized (pos) {
42                 if(pos >=keySet.size()){
43                     pos = 0;
44                 }
45                 server = keyList.get(pos);
46                 pos ++;
47             }
48             return server;
49         }
50         
51         public static void main(String[] args) {
52             TestRoundRobin robin = new TestRoundRobin();
53             for (int i = 0; i < 20; i++) {
54                 String serverIp = robin.roundRobin();
55                 System.out.println(serverIp);
56             }
57         }
58 }

加权轮询:

 1 package class2.zookeeper.loadbalance;
 2 
 3 import java.util.ArrayList;
 4 import java.util.HashMap;
 5 import java.util.Iterator;
 6 import java.util.List;
 7 import java.util.Map;
 8 import java.util.Random;
 9 import java.util.Set;
10 
11 /**
12  * 加權隨機载均衡算法
13  * @author guoy
14  *
15  */
16 public class TestWeightRandom {
17     
18     static Map<String,Integer> serverWeigthMap  = new HashMap<String,Integer>();
19 
20      static{
21         serverWeigthMap.put("192.168.1.12", 1);
22         serverWeigthMap.put("192.168.1.13", 1);
23         serverWeigthMap.put("192.168.1.14", 2);
24         serverWeigthMap.put("192.168.1.15", 2);
25         serverWeigthMap.put("192.168.1.16", 3);
26         serverWeigthMap.put("192.168.1.17", 3);
27         serverWeigthMap.put("192.168.1.18", 1);
28         serverWeigthMap.put("192.168.1.19", 2);
29     }
30 
31     public static String weightRandom()
32     {
33         //重新建立一個map,避免出現由於服務器上線和下線導致的並發問題
34         Map<String,Integer> serverMap  = new HashMap<String,Integer>();
35         serverMap.putAll(serverWeigthMap);
36         //獲取ip列表list
37         Set<String> keySet = serverMap.keySet();
38         Iterator<String> it = keySet.iterator();
39 
40         List<String> serverList = new ArrayList<String>();
41 
42         while (it.hasNext()) {
43             String server = it.next();
44             Integer weight = serverMap.get(server);
45             for (int i = 0; i < weight; i++) {
46                 serverList.add(server);
47             }
48         }        
49         Random random = new Random();
50         int randomPos = random.nextInt(serverList.size());
51         
52         String server = serverList.get(randomPos);
53         return server;
54     }
55     
56     public static void main(String[] args) {
57         String serverIp = weightRandom();
58         System.out.println(serverIp);
59     }
60 }

随机:

 1 package class2.zookeeper.loadbalance;
 2 
 3 import java.util.ArrayList;
 4 import java.util.HashMap;
 5 import java.util.Map;
 6 import java.util.Random;
 7 import java.util.Set;
 8 
 9 /**
10  * 隨機负载均衡算法
11  * @author guoy
12  *
13  */
14 public class TestRandom {
15     
16     static Map<String,Integer> serverWeigthMap  = new HashMap<String,Integer>();
17 
18      static{
19         serverWeigthMap.put("192.168.1.12", 1);
20         serverWeigthMap.put("192.168.1.13", 1);
21         serverWeigthMap.put("192.168.1.14", 2);
22         serverWeigthMap.put("192.168.1.15", 2);
23         serverWeigthMap.put("192.168.1.16", 3);
24         serverWeigthMap.put("192.168.1.17", 3);
25         serverWeigthMap.put("192.168.1.18", 1);
26         serverWeigthMap.put("192.168.1.19", 2);
27     }
28 
29     public static String random()
30     {
31         //重新建立一個map,避免出現由於服務器上線和下線導致的並發問題
32         Map<String,Integer> serverMap  = new HashMap<String,Integer>();
33         serverMap.putAll(serverWeigthMap);
34         //獲取ip列表list
35         Set<String> keySet = serverMap.keySet();
36         ArrayList<String> keyList = new ArrayList<String>();
37         keyList.addAll(keySet);
38         
39         Random random = new Random();
40         int randomPos = random.nextInt(keyList.size());
41         
42         String server = keyList.get(randomPos);
43         return server;
44     }
45     
46     public static void main(String[] args) {
47         String serverIp = random();
48         System.out.println(serverIp);
49     }
50 }

加权随机:

 1 package class2.zookeeper.loadbalance;
 2 
 3 import java.util.ArrayList;
 4 import java.util.HashMap;
 5 import java.util.Iterator;
 6 import java.util.List;
 7 import java.util.Map;
 8 import java.util.Random;
 9 import java.util.Set;
10 
11 /**
12  * 加權隨機载均衡算法
13  * @author guoy
14  *
15  */
16 public class TestWeightRandom {
17     
18     static Map<String,Integer> serverWeigthMap  = new HashMap<String,Integer>();
19 
20      static{
21         serverWeigthMap.put("192.168.1.12", 1);
22         serverWeigthMap.put("192.168.1.13", 1);
23         serverWeigthMap.put("192.168.1.14", 2);
24         serverWeigthMap.put("192.168.1.15", 2);
25         serverWeigthMap.put("192.168.1.16", 3);
26         serverWeigthMap.put("192.168.1.17", 3);
27         serverWeigthMap.put("192.168.1.18", 1);
28         serverWeigthMap.put("192.168.1.19", 2);
29     }
30 
31     public static String weightRandom()
32     {
33         //重新建立一個map,避免出現由於服務器上線和下線導致的並發問題
34         Map<String,Integer> serverMap  = new HashMap<String,Integer>();
35         serverMap.putAll(serverWeigthMap);
36         //獲取ip列表list
37         Set<String> keySet = serverMap.keySet();
38         Iterator<String> it = keySet.iterator();
39 
40         List<String> serverList = new ArrayList<String>();
41 
42         while (it.hasNext()) {
43             String server = it.next();
44             Integer weight = serverMap.get(server);
45             for (int i = 0; i < weight; i++) {
46                 serverList.add(server);
47             }
48         }        
49         Random random = new Random();
50         int randomPos = random.nextInt(serverList.size());
51         
52         String server = serverList.get(randomPos);
53         return server;
54     }
55     
56     public static void main(String[] args) {
57         String serverIp = weightRandom();
58         System.out.println(serverIp);
59     }
60 }

ip hash:

 1 package class2.zookeeper.loadbalance;
 2 
 3 import java.util.ArrayList;
 4 import java.util.HashMap;
 5 import java.util.Map;
 6 import java.util.Set;
 7 
 8 /**
 9  * 负载均衡 ip_hash算法
10  * @author guoy
11  *
12  */
13 public class TestIpHash {
14 
15     
16     static Map<String,Integer> serverWeigthMap  = new HashMap<String,Integer>();
17 
18      static{
19         serverWeigthMap.put("192.168.1.12", 1);
20         serverWeigthMap.put("192.168.1.13", 1);
21         serverWeigthMap.put("192.168.1.14", 2);
22         serverWeigthMap.put("192.168.1.15", 2);
23         serverWeigthMap.put("192.168.1.16", 3);
24         serverWeigthMap.put("192.168.1.17", 3);
25         serverWeigthMap.put("192.168.1.18", 1);
26         serverWeigthMap.put("192.168.1.19", 2);
27     }
28 
29      /**
30       * 获取请求服务器地址
31       * @param remoteIp 负载均衡服务器ip
32       * @return
33       */
34     public static String ipHash(String remoteIp)
35     {
36         //重新建立一個map,避免出現由於服務器上線和下線導致的並發問題
37         Map<String,Integer> serverMap  = new HashMap<String,Integer>();
38         serverMap.putAll(serverWeigthMap);
39         //獲取ip列表list
40         Set<String> keySet = serverMap.keySet();
41         ArrayList<String> keyList = new ArrayList<String>();
42         keyList.addAll(keySet);
43         
44         int hashCode =remoteIp.hashCode();
45         int serverListSize = keyList.size();
46         int serverPos = hashCode % serverListSize;
47         
48         return keyList.get(serverPos);
49     }
50     
51     public static void main(String[] args) {
52         String serverIp = ipHash("192.168.1.12");
53         System.out.println(serverIp);
54     }
55 
56 }
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原文地址：https://www.cnblogs.com/lr393993507/p/5702854.html