sj

一，反射

package test;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class FanShe {

 
 public void sayHello(String name){
  System.out.println("hello," + name);
 }
 public void say(){
  System.out.println("你好啊");
 }
 public static void main(String[] args) throws SecurityException, NoSuchMethodException, IllegalArgumentException, IllegalAccessException, InvocationTargetException
 {
  Object f = new FanShe();
  // 用反射的方式调用o的sayHello方法,不得使用强制类型转换实现 
  Class class1 = f.getClass();
  Method method = class1.getDeclaredMethod("sayHello",String.class);
  method.invoke(f,"你好");
  Method method2 = class1.getDeclaredMethod("say");
  method2.invoke(f);
  
  
 }
}
二，找最大和最小

package test;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

public class FindMax{

 public static ArrayList<Integer> px(ArrayList<Integer> l){
  ArrayList<Integer> al=new ArrayList<Integer> ();
  int size = l.size();
  for(int i=0;i<size;i++){
   int temp=l.get(0);
   int p=0;
   for(int j=0;j<l.size();j++){
    
    if(l.get(j)>temp){
     temp=l.get(j);
     p=j;
    }
   }
   al.add(temp);
   l.remove(p);
   
  }
  
  
  return al;
 }
 public static void main(String[] agrs) {
 ArrayList <Integer> al=new ArrayList<Integer>();
 for(int i=0;i<10;i++){
  Random   r   =   new   Random();
  int   tmp  =   r.nextInt(50)   +   50;
  al.add(tmp);
 }
 System.out.println("排序前的随机生成数"+al);
 
 System.out.println("排序后的随机生成数"+px(al));
 
 
}
}

三，找字母在文章中出现的次数

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

class Word {
    private static int num=0;//记录test数目
        public void run()  {
           
            String str = "Youth is not a time of life; it is a state of mind; it is not a matter of rosy cheeks, " +
              "red lips and supple knees; it is a matter of the will, a quality of the imagination, \r\na" +
              " vigor of the emotions; it is the freshness of the deep springs of life.\r\n IS  Is iS isp  ";
                    String[] ss=str.split("\\W+");
                    for(int i=0;i<ss.length;i++){
                     System.out.println(ss[i]);
                     
                    }
                    for(String e:ss)
                        if("is".equalsIgnoreCase(e))
                         num++;//如果单词是is则记录
           
            System.out.println(""is" is: "+num);//打印is个数
        }
}

public class FindNum {
    public static void main(String[] args){
        Word w=new Word();
        w.run();
        String str = "word:love property:v meaning:爱";
        String[] strs = str.split("[ ]?\\w+:");//正则表达式
       
       
        System.out.println(strs[1]);
        System.out.println(strs[2]);
        System.out.println(strs[3]);
       
        String ss="as11jdflkj1aslkdf1jlk1as";
        String[] split = ss.split("1");
        for(int i=0;i<split.length;i++){
         System.out.println(i+"-----"+split[i]);
        }
    }
}
四，税率计算

package test;

public class sdsmain {
    static double d_sdsMin = 2000; // 所得税起征点

    static double[] gade = { 0, 500, 2000, 5000, 20000, 40000, 60000, 80000,
            100000,900000000 }; // 月收入

    static double[] rate = { 5, 10, 15, 20, 25, 30, 35, 40, 45 }; // 税率
    static double[] sds = { 0, 25,175, 625, 3625, 8625, 14625, 21625,29625, 900000000 }; // 月所得税

   
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println(toSds(5136.6));
        System.out.println(toPay(652.32));
       
    }

   
    public static double toSds(double d_pay) {
        if (d_pay < d_sdsMin || d_pay < gade[1])
            return 0; // 如果收入过低则不收所得税
        double d_sds_temp = 0;
        for (int j = 1; j < 9; j++) {

            if (d_pay > gade[j])
                d_sds_temp = (gade[j] - gade[j - 1]) * rate[j-1]*0.01 + d_sds_temp;
            if (d_pay <= gade[j]) {
                d_sds_temp = (d_pay - gade[j-1]) * rate[j-1]*0.01 + d_sds_temp;
                break;
            }
        }
       
        return d_sds_temp;
    }
      
    public static double toPay(double d_sds) {
        double d_pay_temp = 0;
        if (d_sds<=0)
            return 0; //
        for (int j = 9; j >0; j--) {
            if(d_sds>sds[j]) {
           
                d_pay_temp=gade[j]+(d_sds-sds[j])/rate[j]*100;
                break;
            }
        }
        return d_pay_temp;
    }
 }

五，输入输出流

package test;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;

public class ShuRuOrShuChu {

 
 public static void createFile(File f)
 {// 向文件f中随机写入三行字符串  
   FileOutputStream fos = null;
   BufferedWriter bw = null;
   try {
      
       fos = new FileOutputStream(f);
       bw = new BufferedWriter(new OutputStreamWriter(fos));
       StringBuffer a;
       BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
       for(int i=0;i<3;i++){
        System.out.println("请输入br的值");
        String aString = br.readLine();
        System.out.println("br的值是："+aString);
       
        bw.write(aString);
        bw.write("\r\n");
       }
     

   }
   catch (FileNotFoundException fnfe) {
       fnfe.printStackTrace();
   }
   catch (IOException ioe) {
       ioe.printStackTrace();
   }
   finally {
       try {
    if (bw != null)
        bw.close();
    if (fos != null)
        fos.close();
       }
       catch (IOException ie) {
       }
   }
      }

 public static void readFile(File f)
 {// 读出文件f的内容,并打印出
  
         BufferedReader reader = null;
         try {
             System.out.println("以行为单位读取文件内容，一次读一整行：");
             reader = new BufferedReader(new FileReader(f));
             String tempString = null;
             int line = 1;
             // 一次读入一行，直到读入null为文件结束
             while ((tempString = reader.readLine()) != null) {
                 // 显示行号
                 System.out.println("line " + line + ": " + tempString);
                 line++;
             }
             reader.close();
         } catch (IOException e) {
             e.printStackTrace();
         } finally {
             if (reader != null) {
                 try {
                     reader.close();
                 } catch (IOException e1) {
                 }
             }
         }

 }
 public static void main(String[] args) {
  // TODO Auto-generated method stub
  File file = new File("D:\\abc.txt");
  createFile(file);
  readFile(file);
 }
 }

六，显示/隐藏第二列

Hidden.html如下

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">    
<HTML>    
<HEAD>    
<TITLE> 显示隐藏列 </TITLE>    
<SCRIPT LANGUAGE="JavaScript">    
  function hidden(table,num){
 for(i=0;i<table.rows.length;i++){
  table.rows[i].cells[num].style.display=table.rows[i].cells[num].style.display=="none"?"block":"none";
 }
  }
   
</SCRIPT>    
</HEAD>    
    
<BODY>    
<TABLE id="Table1" cellSpacing="1" cellPadding="1" border="1">     
  <tr><td>1</td><td>2</td><td>3</td></tr>  
  <tr><td>4</td><td bgcolor="red">5</td><td>6</td></tr>
  <tr><td>7</td><td bgcolor="green">8</td><td>9</td></tr>
  <tr><td>10</td><td bgcolor="yellow">11</td><td>12</td></tr>
 
</TABLE>    
   <input type="button" value="隐藏第二列" onclick="hidden(document.getElementByIdx_x('Table1'),1)"/>    
</BODY>    
</HTML> 
七，全选-----显示选择的选项

t.html如下

<html>
 <head>
  <script>   
   function selectAll(){
    //返回一个数组
    var arr = ['c1','c2','c3'];
    for(i=0;i<arr.length;i++){
     alert(arr[i]);
     document.getElementByIdx_x(arr[i]).checked = document.getElementByIdx_x(arr[i]).checked == true?false:true;
    }
    
   }
   function selectAll2(){
    var interest=document.getElementsByName("interest");
    for( i=0;i<interest.length;i++){
      if(interest[i].type=="checkbox"){
        interest[i].checked=interest[i].checked==true?false:true;
           }
    }
   }
  </script>
 </head>
 <body style="font-size:30pt;"  background="red">
  <form action="test.jsp" method="post" >
  name:<input type="text" name="name" id="name"/>
  <input type="button" value="testProtoType" onclick="testProtoType();"/><br/>
  sleep:<input type="checkbox" name="interest" id="c1" value="sleep"/>
  play:<input type="checkbox" name="interest" id="c2" value="play"/>
  eating:<input type="checkbox" name="interest" id="c3" value="eating"/>
  <input type="button" value="selectAll" onclick="selectAll2();"/>
  <!-- <a href="tt.jsp">toShow</a>-->
  <input type="submit" value="提交"/>
  </form>
 </body>
</html>

 

test.jsp如下

 

<%@ page language="java" contentType="text/html; charset=gbk"
    pageEncoding="gbk"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
 <c:forEach var="inte" items="${paramValues.interest}">
  ${inte}
 </c:forEach>
 您选中的人员名单为：
 <% String [] a=request.getParameterValues("interest");
  for(int i=0;i<a.length;i++){
  out.println(a[i]);
  }
 %>
 -------------${paramValues.interest}
 
</body>
</html>