使用 Java 将 Redis 数据库连接到 Azure Cloud

问题描述

美好的一天，我的 Java 代码中有这个错误。我正在尝试将我的数据库链接到 azure cloud。我使用了列表命令：

Exception in thread "main" java.lang.indexoutofboundsexception: Index: 11,Size: 11
    at java.util.ArrayList.rangeCheck(ArrayList.java:653)
    at java.util.ArrayList.get(ArrayList.java:429)
    at anothercloud.Anothercloud.main(Anothercloud.java:63)
Java Result: 1

package anothercloud;
import java.awt.FlowLayout;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisShardInfo;
import redis.clients.jedis.exceptions.JedisConnectionException;
/**
 *
 * @author ariel
 */
public class Anothercloud {
static HashMap<Double,String> redisData = new HashMap<Double,String>();
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        boolean useSsl=true;
        inclass infos=new inclass();
        ArrayList<String> names = new ArrayList<String>();
        ArrayList<String> value = new ArrayList<String>();
        String anjiecachekey="xxxx=";
        
        JedisShardInfo shardInfo=new JedisShardInfo("anjiecloud.redis.cache.windows.net",6380,useSsl);//use secondary connection string
        shardInfo.setPassword("xxxx=");//use secondary access key
        //Simple PING command
        Jedis jedis=new Jedis(shardInfo.getHost());
        try{
            jedis.auth(anjiecachekey);
            jedis.connect();
            System.out.println("My Cache Response: "+jedis.ping());
            
            if (jedis.llen("state") == 0 && jedis.llen("number") == 0)  {
             
          
             for(Map.Entry m: inclass.map.entrySet()){
                 
                 jedis.lpush("state",(String)m.getValue());
                 jedis.lpush("number",m.getKey().toString());
             }
            
        }
        for(String s: jedis.lrange("state",1000)){
            names.add(s);
                       
          }
         for(String r: jedis.lrange("number",1000)){
               value.add(r);
            }
         for(int i =0; i < names.size(); i++){
             redisData.put(Double.parseDouble(value.get(i)),names.get(i));
         }

         
        ArrayList<String> states = new ArrayList<String>();
         for (Map.Entry m : redisData.entrySet()) {
             states.add((String)m.getValue());
         }
         
         String[] statesArray = new String[states.size()];
         states.toArray(statesArray);

        

        JComboBox<String> stateList = new JComboBox<>(statesArray);
        stateList.addItemListener(new MyHandler());
       
        JFrame jframe = new JFrame();
        JLabel item1 = new JLabel("IGR Statistics H1 2020");
        jframe.add(item1);
        
        jframe.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);
        jframe.setLayout(new FlowLayout());
        jframe.setSize(400,200);
        jframe.setVisible(true);
        
        jframe.add(stateList);
        
        

// get the selected item:
       // String selectedBook = (String) stateList.getSelectedItem();
       

        // check whether the server is running or not
        System.out.println("Server is running: " + jedis.ping());
        //getting the percentage for each state
       

        // storing the data into redis database
      
        
        for (Map.Entry m : inclass.map.entrySet()) {
            System.out.println(m.getKey() + " " + m.getValue());

  
        }
        }
        catch(JedisConnectionException e){
            System.out.println(e.getMessage());
            JOptionPane.showMessageDialog(null,"You require a working internet connection");
        }
    }
    
        static class MyHandler implements ItemListener{


        @Override
        public void itemStateChanged(ItemEvent e) {
             for (Map.Entry m : redisData.entrySet()) {
if(e.getItem().toString() == m.getValue()&& e.getStateChange() == 1){
                     
                     JOptionPane.showMessageDialog(null,m.getKey(),"VALUE IN BILLIONS",1);
                     
                     System.out.println(m.getKey());
                     break;
                     
                 }
          

            
        }
       
        }
        
         }
}

请问我该如何纠正这个错误？任何反馈将不胜感激。我是 Java 作为一种语言及其语法的新手。该错误似乎也来自我的 for 循环。错误似乎也来自我的 for 循环。

解决方法

正如错误所述，您看到的是 IndexOutOfBoundsException。这意味着您正在尝试访问大于/小于其范围的列表索引。在这种情况下，value.get(i) 抛出错误：

for (int i = 0; i < names.size(); i++)
            {
                redisData.put(Double.parseDouble(value.get(i)),names.get(i));
            }

尝试修改如下代码：

for (int i = 0; i < names.size() - 1; i++)
                {
                    redisData.put(Double.parseDouble(value.get(i)),names.get(i));
                }

此外，我建议您重新访问 Redis 缓存的 Java 实现：Intro to Jedis – the Java Redis Client Library