1，jsp的9大內(nèi)置對(duì)象

request,response,session,application,page,pageContext,out,config,exception

查過資料了，現(xiàn)在補(bǔ)充一下；

JSP中九大內(nèi)置對(duì)象為： 
request            請(qǐng)求對(duì)象                 類型 javax.servlet.ServletRequest        作用域 Request 
response          響應(yīng)對(duì)象                   類型 javax.servlet.SrvletResponse       作用域  Page 
pageContext    頁面上下文對(duì)象       類型 javax.servlet.jsp.PageContext      作用域    Page 
session            會(huì)話對(duì)象                   類型 javax.servlet.http.HttpSession       作用域    Session 
application       應(yīng)用程序?qū)ο?nbsp;         類型 javax.servlet.ServletContext          作用域    Application 
out                   輸出對(duì)象                   類型 javax.servlet.jsp.JspWriter             作用域    Page 
config              配置對(duì)象                  類型 javax.servlet.ServletConfig            作用域    Page 
page               頁面對(duì)象                  類型 javax.lang.Object                            作用域    Page 
exception        例外對(duì)象                 類型 javax.lang.Throwable                     作用域    page

2，哪個(gè)標(biāo)簽點(diǎn)擊文字會(huì)聚焦到text文本輸入框，答案是<input type="text" id="text1"><label for="text1">text1</label>

3，輸出乘法口訣

public static void pringChengfakoujue() 
   {

       System.out.println("乘法口訣表");

       for(int outNum=1;outNum<=9;outNum++) 
       { 
           for(int innerNum=1;innerNum<=9;innerNum++) 
           {

               if(outNum>=innerNum) 
               { 
                   System.out.print("[" + innerNum + "*" + outNum + "=" + (outNum * innerNum) + "]"); 
               }

           } 
           System.out.println(); 
       }

   }

4，用數(shù)組實(shí)現(xiàn)一個(gè)棧，接口如下：

public interface IStatck {

    Object pop();

    int size();

    void push(Object obj);

}

實(shí)現(xiàn)代碼：

package org.tws;

/** 
* Created with IntelliJ IDEA. 
* User: cutter.li 
* Date: 14-3-4 
* Time: 下午4:25 
* To change this template use File | Settings | File Templates. 
*/ 
public class ArrayStack implements IStatck {

    private Object[] objArray;

    public ArrayStack(Object[] objArray) 
    { 
        this.objArray=objArray; 
    }

    @Override 
    public Object pop() { 
        if(null==objArray){ 
            return null; 
        } 
        return  objArray[objArray.length-1]; 
    }

    @Override 
    public int size() {

        if(null==objArray) { 
            return 0; 
        } 
        return objArray.length;

    }

    @Override 
    public void push(Object obj) {

        int length=size();

        if(length==0) 
        { 
            objArray=new Object[]{obj}; 
        } else 
        { 
            Object[] objArray2=new Object[length+1]; 
            System.arraycopy(objArray,0,objArray2,0,length-1); 
            objArray2[length]=obj; 
            objArray=objArray2; 
        }

    } 
}

5，sql的行列轉(zhuǎn)換

select departmentname as  '部門' 
, sum(if(monthName=1,icome,0)) as '一月份' 
, sum(if(monthName=2,icome,0)) as '二月份' 
, sum(if(monthName=3,icome,0)) as '三月份'  
, sum(icome) as '總收入' 
from t_icome group by departmentName ;

數(shù)據(jù)準(zhǔn)備：

CREATE TABLE `t_icome` ( 
  `id` int(11) NOT NULL AUTO_INCREMENT, 
  `departmentName` varchar(3) NOT NULL, 
  `monthName` int(11) NOT NULL, 
  `icome` float NOT NULL, 
  PRIMARY KEY (`id`) 
) ENGINE=InnoDB;

INSERT INTO `t_icome` VALUES ('1', 'a', '1', '2000'); 
INSERT INTO `t_icome` VALUES ('2', 'a', '2', '2500'); 
INSERT INTO `t_icome` VALUES ('3', 'b', '1', '2500'); 
INSERT INTO `t_icome` VALUES ('4', 'b', '2', '2600'); 
INSERT INTO `t_icome` VALUES ('5', 'a', '3', '2600'); 
INSERT INTO `t_icome` VALUES ('6', 'b', '3', '2900'); 
INSERT INTO `t_icome` VALUES ('7', 'c', '1', '2900'); 
INSERT INTO `t_icome` VALUES ('8', 'c', '2', '2900');

6，數(shù)據(jù)去重

兩張結(jié)構(gòu)相同的表，查找在表a中不在表b的數(shù)據(jù)；

數(shù)據(jù)和表：

DROP TABLE IF EXISTS `t_a`; 
CREATE TABLE `t_a` ( 
  `id` int(11) NOT NULL AUTO_INCREMENT, 
  `no` varchar(20) DEFAULT NULL, 
  `product` varchar(20) DEFAULT NULL, 
  PRIMARY KEY (`id`) 
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=latin1;

INSERT INTO `t_a` VALUES ('1', 'aaa', 'xxx'); 
INSERT INTO `t_a` VALUES ('2', 'bbb', 'xyz'); 
INSERT INTO `t_a` VALUES ('3', 'aaa', 'aaa'); 
INSERT INTO `t_a` VALUES ('4', 'aaa', 'ddd');

DROP TABLE IF EXISTS `t_b`; 
CREATE TABLE `t_b` ( 
  `id` int(11) NOT NULL DEFAULT '0', 
  `no` varchar(20) DEFAULT NULL, 
  `product` varchar(20) DEFAULT NULL, 
  PRIMARY KEY (`id`) 
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

INSERT INTO `t_b` VALUES ('1', 'aaa', 'xyz'); 
INSERT INTO `t_b` VALUES ('2', 'aaa', 'aaa'); 
INSERT INTO `t_b` VALUES ('3', 'aaa', 'fuck'); 
INSERT INTO `t_b` VALUES ('4', 'bbb', 'ccc'); 
INSERT INTO `t_b` VALUES ('5', 'bbb', 'nimei');

sql寫法：

SELECT a.* FROM 
t_a a 
LEFT JOIN 
t_b b ON a.no = b.no  and a.product=b.product 
WHERE b.no IS NULL and b.product is null;