Array

int[] x = new int[100];

int[] x = new int[]{1,2,3,4};//不要给数组定义大小

int[] x = {1,2,3,4};//上面的简写

int[] x = new int[3][];//但使用的时候要把后面的值补上 定义有几个一维数组

x[0] = new int[3];

x[1] = new int[4];

x[2] = new int[3];

/**
     * 查询Redis数据库
     * @return
     */
    
    public String[][][] selectFromRedis(String field,String value){
        log.info("执行selectFromRedis方法");
        long startTime=System.currentTimeMillis();  
        Set<String> setCluster = new HashSet<String>();
        Set<String> set80 = new HashSet<String>();
        set80 = jedis.keys("*");
        Iterator<String> it1 = set80.iterator();  
        while (it1.hasNext()) {  
          String str = it1.next();  
          System.out.println(str+"----6380");  
        }
        setCluster.addAll(set80);
        Map map = new HashMap();
        Map map1 = new HashMap();
        Set mapAll = new HashSet();
        try {
            long startTime2=System.currentTimeMillis();
            Iterator<String> itAll = setCluster.iterator();  
            log.info("获得的所有key的个数  :"+setCluster.size());
            while (itAll.hasNext()) {
                String str = itAll.next();
                log.info(str+"===========================");
                //System.out.println(value.equals(rec.hget(str, field))+"&&&&&&&&&&&&&&&&&&&&");
                log.info(System.currentTimeMillis());
                if(value.equals(jedis.hget(str, field))){                
                    map = (Map) jedis.hgetAll(str);
                    //System.out.println(map);
                    mapAll.add(map);
                    log.debug(mapAll);
                    //System.out.println(str+"----setCluster");
                }
                log.info(System.currentTimeMillis());
                log.info("比较一个map中字段程序运行时间： ms");
            }
            long endTime2=System.currentTimeMillis();
            log.info("比较所有map中字段程序运行时间： "+(endTime2-startTime2)+"ms");
             
        } catch (Exception e) {
            log.info("selectFromRedis中的异常");
            e.printStackTrace();
            String[][][] fail = {{{"-1"}},{{"-1"}},{{"-1"}}};
            return fail;
        }
        
        log.info(mapAll.size()+"有多少条符合的记录#####################mapAll.size()");
        String[][][] ObjectMapAll = null;
        Iterator<Map> it3 = mapAll.iterator();                                                   
         int j = 0;
         ObjectMapAll = new String[mapAll.size()][][];
        while (it3.hasNext()) {
             map1 = it3.next(); 
             //关键是这个值entrySet.size()在循环外面得不到
             Set<Map.Entry<String, String>> entrySet = map1.entrySet();              
             Iterator<Map.Entry<String, String>> itMap = entrySet.iterator();
            // System.out.println(entrySet.size());             
             String[][] ObjectMap = new String[entrySet.size()][];
              int i = 0; 
              while(itMap.hasNext()){
                  String[] arr = new String[2];
                  Map.Entry<String, String> me = itMap.next();
                  String key1 = me.getKey();
                  String value1 = me.getValue();
                  arr[0] = key1;
                  arr[1] = value1;
                  ObjectMap[i] = arr;
                  ObjectMapAll[j] = ObjectMap;
                  log.info("selectFromRedis方法中"+"key: "+key1+"-->value: "+value1);
                  i++;                 
              }              
              j++;
              log.info(j+"^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^");
            }
        for (int i = 0; i < ObjectMapAll.length; i++) {         // 遍历数组  
            for (int j1 = 0; j1 < ObjectMapAll[i].length; j1++) {  
                for (int k = 0; k < ObjectMapAll[i][j1].length; k++) {  
                    log.info(ObjectMapAll[i][j1][k] + "	");  
                }  
                System.out.println();                       // 输出一维数组后换行  
            }  
        }
            return ObjectMapAll;
        }

api

Array.sort();

Array.binarySearch();

Array.fill();数组的初始化 指定初始值

Array.copy();