用例假设如下场景：
1、 集群环境
集群节点ip 192.168.111.96，192.168.5.212，12.168.7.174
2、 需求
在创建连接时，把链接请求按照轮询方式均摊到各个节点
本样例代码适用于GBaseJDBC8.3.81.53 及以上版本。
package com.gbase.jdbc.simple;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class SampleGBaseJDBCLoadbalance {
GBase UP 产品手册 6 应用开发指南
文档版本04（2021-04-21） 南大通用数据技术股份有限公司 1116
/**
* 数据库连接串
* failoverEnable = true
* hostList=192.168.5.212,192.168.7.174
* gclusterId=gcl1
* 启用高可用负载均衡
*/
public static final String URL =
"jdbc:gbase://192.168.111.96:5258/test?user=gbase&password=gbase20110531&failoverEnable=
true&hostList=192.168.5.212,192.168.7.174&gclusterId=gcl1";
/**
* @param args
*/
public static void main(String[] args) {
try {
Class.forName("com.gbase.jdbc.Driver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
//准备样例代码用到的表及数据
prepareTable();
//创建线程池
ExecutorService executorService = Executors.newCachedThreadPool();
for (int i = 0; i < 50; i++) {
executorService.execute(new SelectThread(String.valueOf(i)));
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
executorService.shutdown();
try {
Thread.sleep(50000);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("main thread finished");
}
private static void prepareTable() {
GBase UP 产品手册 6 应用开发指南
文档版本04（2021-04-21） 南大通用数据技术股份有限公司 1117
Connection conn = null;
Statement stm = null;
try {
conn = DriverManager.getConnection(URL);
stm = conn.createStatement();
stm.executeUpdate("drop table if exists `loadbalance`");
stm.executeUpdate("create table loadbalance(a varchar (10), b varchar
(12))");
stm.executeUpdate("insert into test.loadbalance values('a1', 'b1')");
stm.executeUpdate("insert into test.loadbalance values('a2', 'b2')");
} catch (SQLException e) {
e.printStackTrace();
} finally {
if (stm != null) {
try {
if (!stm.isClosed())
stm.close();
} catch (Exception e) {
}
}
}
}
}
class SelectThread implements Runnable {
private String threadName;
SelectThread(String n) {
threadName = n;
}
int i =0;
public void run() {
while (i < 20) {
i++;
work();
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
System.out.println("end = " + threadName);
}
public void work() {
GBase UP 产品手册 6 应用开发指南
文档版本04（2021-04-21） 南大通用数据技术股份有限公司 1118
try {
Class.forName("com.gbase.jdbc.Driver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
Connection conn = null;
Statement stm = null;
ResultSet rs = null;
String ip= null;
try {
conn =
DriverManager.getConnection(SampleGBaseJDBCLoadbalance.URL);
ip = (com.gbase.jdbc.GBaseConnection)conn).getHost();
System.out.println(this.threadName + " 线程: 获取连接 on " + ip);
stm = conn.createStatement();
rs = stm.executeQuery("select loadbalance.* , sleep(5) from
test.loadbalance");
while(rs.next()) {
System.out.println(rs.getString(1));
}
} catch (SQLException e) {
System.out.println(this.threadName + " 线程: 异常 on "+ip);
e.printStackTrace();
} finally {
try {
rs.close();
} catch (SQLException e) {
}
try {
stm.close();
} catch (SQLException e) {
}
try {
conn.close();
} catch (SQLException e) {
}
}
}
}