| java类加载顺序 |
java基础 |
|
package com.demo;
/**
* @Description 类加载顺序
* @author FuJianyong
* 2015-2-6上午11:21:37
*/
public class ClassLoaderSequence {
String s1 = "成员属性";
static String s2 = "静态属性";
String s3;
static String s4;
static {
System.out.println("静态代码快");
}
{
System.out.println("代码快");
}
public static void test1() {
System.out.println("静态方法");
}
public void test2() {
System.out.println("普通方法");
}
public static void main(String[] args) {
// ClassLoaderSequence.test1();
new ClassLoaderSequence().test2();
}
}
|
| java杨辉三角 |
java基础 |
|
package com.algorithm;
/**
* @Description 杨辉三角
* @author FuJianyong
* 2015-1-22上午10:10:59
*/
public class YangHui {
public static void main(String[] args) {
//初始化二维数组长度
int[][] yanghui = new int[10][];
/*
* 动态初始化二维数组
* 第一步 杨辉三角初始化
0
0 0
0 0 0
0 0 0 0
0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0
*/
for(int i=0;i<yanghui.length;i++) {
yanghui[i] = new int[i];
}
/*
* 第二步 杨辉三角第一位和最后以为数值都是1
1
1 1
1 0 1
1 0 0 1
1 0 0 0 1
1 0 0 0 0 1
1 0 0 0 0 0 1
1 0 0 0 0 0 0 1
1 0 0 0 0 0 0 0 1
*/
for(int i=0;i<yanghui.length;i++) {
for(int j=0;j<i;j++) {
if(i==0 || j==0 || j==yanghui[i].length-1)
yanghui[i][j] = 1;
}
}
/*
* 第三步 杨辉三角第n行n列的数值等于n-1行n-1列(左上方)加上n-1行n列(正上方)的数值
1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1
1 6 15 20 15 6 1
1 7 21 35 35 21 7 1
1 8 28 56 70 56 28 8 1
*/
for(int i=0;i<yanghui.length;i++) {
for(int j=0;j<i;j++) {
//处理剩下没赋值的数组
if(i!=0 && j!=0 && j!=yanghui[i].length-1) {
yanghui[i][j] = yanghui[i-1][j-1] + yanghui[i-1][j];
}
}
}
/*
* 输出杨辉三角
* 第二步可以和第三步合并
*/
for(int i=0;i<yanghui.length;i++) {
for(int j=0;j<i;j++) {
System.out.print(yanghui[i][j] +"\t");
}
System.out.println();
}
}
}
|
| 基本数据类型和引用类型的初始值 |
java基础 |
|
package com.array;
/**
* @Description 测试初始值
* @author FuJianyong
* 2015-1-22上午10:31:53
*/
public class ArrayTest {
ArrayTest at;
String str;
byte bt;
short s;
int i;
long l;
float f;
double d;
char c;
boolean b;
/**
* 基本数据类型和引用类型初始值
*/
public void testInitialize() {
System.out.println(str+" "+bt+" "+s+" "+i+" "+l+" "+f+" "+d+" "+c+" "+b+" ");
}
ArrayTest[] atA = new ArrayTest[1];
String[] strA = new String[1];
byte[] btA = new byte[1];
short[] sA = new short[1];;
int[] iA = new int[1];;
long[] lA = new long[1];;
float[] fA = new float[1];;
double[] dA = new double[1];;
char[] cA = new char[1];;
boolean[] bA = new boolean[1];;
/**
* 基本数据类型和引用类型数组初始值
*/
public void testInitializeArray() {
System.out.println(strA[0]+" "+btA[0]+" "+sA[0]+" "+iA[0]+" "+lA[0]+" "+fA[0]
+" "+dA[0]+" "+cA[0]+" "+bA[0]+" ");
}
/**
* test
* @param args
* output
* null 0 0 0 0 0.0 0.0 false
*/
public static void main(String[] args) {
ArrayTest at = new ArrayTest();
at.testInitialize();
at.testInitializeArray();
}
}
|
| java冒泡排序 |
java基础 |
|
package com.algorithm;
/**
* @Description 冒泡
* @author FuJianyong
* 2015-1-22上午09:58:39
*/
public class MaoPao {
public static void main(String[] args) {
int[] mao = {17,50,26,18,9,100,88};//静态分配数组初始数值
int temp = 0;
//外部循环执行遍历冒泡
for(int i=0;i<mao.length;i++) {
//内部循环执行相邻两个数组比较，大的就冒泡
for(int j=0;j<mao.length-1;j++) {
//如果左边的数组大于右边的数组
if(mao[j]>mao[j+1]) {
temp = mao[j+1];//右边的数组赋值给临时对象
mao[j+1] = mao[j];//左边的数组赋值给右边的数组
mao[j] = temp;//临时对象赋值给左边的数组
}
}
}
for(int i=0;i<mao.length;i++) {
System.out.print(" "+mao[i]);
}
}
}
|
| MybatisHelloWorld |
mybatis |
|
//测试入口TestMyBatis
package com.base.helloworld.test;
import java.io.IOException;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import com.base.helloworld.bean.User;
import com.base.helloworld.mapper.Mapper;
public class TestMyBatis {
public static SqlSessionFactory getSessionFactory() {
String config = "com/base/helloworld/config.xml";
SqlSessionFactory sessionFactory = null;
try {
sessionFactory = new SqlSessionFactoryBuilder().build(Resources.getResourceAsReader(config));
} catch (IOException e) {
e.printStackTrace();
}
return sessionFactory;
}
public static void main(String[] args) {
SqlSession sqlSession = getSessionFactory().openSession();
Mapper mapper = sqlSession.getMapper(Mapper.class);
User user = mapper.selectById(2);
System.out.println(user.getName()+" "+user.getPassword());
}
}
//配置文件config.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<typeAliases>
<typeAlias type="com.base.helloworld.bean.User" alias="User"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="jdbc" />
<dataSource type="POOLED" >
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://192.168.1.10:3306/XXX?useUnicode=true&characterEncoding=utf-8"/>
<property name="username" value="XXXXXX" />
<property name="password" value="XXXXXX" />
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="com/base/helloworld/mapper/mapper.xml"/>
</mappers>
</configuration>
//模型User
package com.base.helloworld.bean;
public class User {
private String name;
private String password;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
// 接口Mapper
package com.base.helloworld.mapper;
import com.base.helloworld.bean.User;
public interface Mapper {
User selectById(int id);
}
//操作数据库mapper.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.base.helloworld.mapper.Mapper">
<select id="selectById" parameterType="int" resultType="User">
SELECT * FROM t_user where ID = #{id}
</select>
</mapper>
|
| ImageIO读取一张图片改变大小 |
javaio流 |
|
package com.demo;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
/**
* @Description 读取一张图片改变大小
* @author FuJianyong
* 2015-1-20上午10:48:49
*/
public class ImageIORead {
/**
* 改变图片的大小
* @return boolean
*/
public static boolean readImage() {
//设定要生成的新图片的宽高和图片格式
BufferedImage newbi = new BufferedImage(500, 500, BufferedImage.TYPE_INT_BGR);
boolean val = false;
try {
//从硬盘读取一张图片
BufferedImage oldbi = ImageIO.read(new File("E:/DEMO/dd.jpg"));
//把读过的来的图片画到设定好的新图片上
newbi.getGraphics().drawImage(oldbi, 0, 0, 500, 500, null);
//通过ImageIO写到硬盘上去
val = ImageIO.write(newbi, "png", new File("E:/DEMO/ddd.png"));
return val;
}catch(IOException e) {
e.printStackTrace();
}
return val;
}
public static void main(String[] args) {
System.out.println(readImage());
}
}
|
| ImageIO写图片到硬盘 |
javaio流 |
|
package awt;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
/**
* 用ImageIO写一个图片到硬盘上
* @author Fujianyong
* 2015-1-17 下午08:57:27
*/
public class ImageIODemo {
/**
* 创建一个BufferedImage图片缓冲区对象并指定它宽高和类型
* 这样相当于创建一个画板，然后可以在上面画画
*/
BufferedImage bi = new BufferedImage(200, 200, BufferedImage.TYPE_INT_BGR);
/**
* 要生成图片的类型,可以是JPG GIF JPEG PNG等...
*/
final String picType = "png";
/**
* 成生成图片的保存路径和图片名称
*/
final File file = new File("D:/myeclipseTestData/test." + picType);
/**
* 通过指定参数写一个图片
* @param bi
* @param picType
* @param file
* @return boolean 如果失败返回一个布尔值
*/
public static boolean writeImage(BufferedImage bi, String picType, File file) {
//拿到画笔
Graphics g = bi.getGraphics();
//画一个图形系统默认是白色
g.fillRect(0, 50, 200, 100);
//设置画笔颜色
g.setColor(new Color(12,123,88));
//设置画笔画出的字体风格
g.setFont(new Font("隶书", Font.ITALIC, 30));
//写一个字符串
g.drawString("我是IO流图片", 10, 100);
//释放画笔
g.dispose();
//将画好的图片通过流形式写到硬盘上
boolean val = false;
try {
val = ImageIO.write(bi, picType, file);
} catch (IOException e) {
e.printStackTrace();
}
return val;
}
public static void main(String[] args) {
ImageIODemo image = new ImageIODemo();
System.out.println(writeImage(image.bi, image.picType, image.file));
}
}
|
| md5 |
java加密 |
|
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
public class MDFive {
public static void main(String[] args) {
String md5Str = "cqmy0_YSDS2";
System.out.println(md5(md5Str));
}
public static String md5(String md5Str) {
StringBuffer sb = new StringBuffer();
try {
//获得消息摘要md5
MessageDigest md5 = MessageDigest.getInstance("md5");
//以md5的方式加密 java.security.MessageDigest的设计体现了工厂模式
byte[] tempMd5 = md5.digest(md5Str.getBytes());
int temp = 0;
for(byte s: tempMd5) {
temp = s;
if(temp<0) temp+=256; //负变正
if(temp<16) sb.append("0"); //小于16前面加0，这能保证生成的密文长度为32
//把数字加工成为十六进制字符串——装到字符串缓冲区
sb.append(Integer.toHexString(temp));
}
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
return sb.toString().toUpperCase();
}
}
|
| SpringTask定时任务 |
spring |
|
public class CleanTempFileTask extends TimerTask {
private final Logger log = Logger.getLogger(this.getClass());
//过期时间
private final int OUT_DATE_DURATION = 1000 * 60 * 60;
@Override
//实现TimerTask的抽象方法
public void run() {
log.info("开始清理过期临时文件");
//临时文件的路径
String tempFileDir = ConfigHolder.getInstance().getFileSavePath() + File.separator + Constant.PATH_TEMPFILE + File.separator;
File tempDir = new File(tempFileDir);
removeOutDateFiles(tempDir);
log.info("清理临时过期文件完毕");
}
private void removeOutDateFiles(File dir) {
File[] fileList = dir.listFiles();
//将文件夹里的文件逐个判断并悄无声息的删掉
for (File file : fileList) {
if (file.isFile()) {
// 如果文件的修改时间是OUT_DATE_DURATION毫秒前的则删除
boolean isOlder = FileUtils.isFileOlder(file, System.currentTimeMillis() - OUT_DATE_DURATION);
if (isOlder) {
log.debug("删除过期临时文件==>" + file.getAbsolutePath());
FileUtils.deleteQuietly(file);
}
} else if (file.isDirectory()) {
removeOutDateFiles(file);
}
}
}
}
//bean
<!-- 定时任务1:清理临时文件 -->
<!-- 任务 -->
<bean id="cleanTempFileTask" class="com.*.comm.task.CleanTempFileTask"></bean>
<task:scheduled-tasks>
<!-- 一个小时清理一次 -->
<task:scheduled ref="cleanTempFileTask" method="run" fixed-delay="#{1000*60*60}" />
</task:scheduled-tasks>
|
| java结合spring发邮件 |
spring |
|
public void sendMailByAsynchronousMode(final Email email) {
//taskExecutor : org.springframework.core.task.TaskExecutor
taskExecutor.execute(new Runnable() {
public void run() {
try {
sendMailBySynchronizationMode(email);
} catch (Exception e) {
log.info(e);
}
}
});
}
public void sendMailBySynchronizationMode(Email email) throws MessagingException, IOException {
log.debug(email.toString());
// mailSender : org.springframework.mail.javamail.JavaMailSender
MimeMessage mime = mailSender.createMimeMessage();
//import org.springframework.mail.javamail.MimeMessageHelper;
MimeMessageHelper helper = new MimeMessageHelper(mime, true, "utf-8");
helper.setFrom(email.getFromAddress());// 发件人
helper.setTo(email.getToAddress());// 收件人
helper.setReplyTo(email.getFromAddress());// 回复到
helper.setSubject(email.getSubject());// 邮件主题
helper.setText(email.getContent(), true);// true表示设定html格式
mailSender.send(mime);
}
// spring bean 配置
<!-- 邮件服务 -->
<bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
<property name="protocol" value="${email.protocol}"></property>
<property name="host" value="${email.host}"></property>
<property name="port" value="${email.port}"></property>
<property name="username" value="${email.username}"></property>
<property name="password" value="${email.password}"></property>
<property name="javaMailProperties">
<props>
<prop key="mail.smtp.auth">false</prop>
<prop key="mail.smtp.timeout">30000</prop>
<!-- 如果mail服务器是ssl认证，则去掉这里的注释符号 -->
<prop key="mail.smtp.socketFactory.port">465</prop>
<prop key="mail.smtp.socketFactory.class">javax.net.ssl.SSLSocketFactory</prop>
<prop key="mail.smtp.socketFactory.fallback">false</prop>
</props>
</property>
</bean>
<bean id="taskExecutor"
class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
<property name="corePoolSize" value="5"></property>
<property name="maxPoolSize" value="30"></property>
<property name="keepAliveSeconds" value="0"></property>
</bean>
|
| sql查城市 |
sql |
|
-- db_yhm_city
SELECT * FROM db_yhm_city WHERE class_parent_id = 1 -- 海南 class_id = 9 港、奥、台 class_id = 33、34、35
SELECT * FROM db_yhm_city WHERE class_parent_id =169
SELECT d1.class_name, d2.class_name, d3.class_name FROM db_yhm_city d1
RIGHT JOIN db_yhm_city d2 ON d1.class_id = d2.class_parent_id
RIGHT JOIN db_yhm_city d3 ON d2.class_id = d3.class_parent_id
WHERE d3.class_id = 1445
-- tb1_publicarea
SELECT * FROM tbl_publicarea WHERE parentid = 0 -- 海南 areaid = 21
SELECT * FROM tbl_publicarea WHERE parentid = 21
SELECT t1.areaname, t2.areaname, t3.areaname FROM tbl_publicarea t1
RIGHT JOIN tbl_publicarea t2 ON t1.areaid = t2.parentid
RIGHT JOIN tbl_publicarea t3 ON t2.areaid = t3.parentid
WHERE t3.areaid = 264
-- t_area
SELECT * FROM t_area WHERE parentid IS NULL -- 海南 id = 460000
SELECT * FROM t_area WHERE parentid = 460000 -- 省直辖 id = 469000
SELECT * FROM t_area WHERE parentid = 469000
SELECT a1.name, a2.name, a3.name FROM t_area a1
RIGHT JOIN t_area a2 ON a1.id = a2.parentid
RIGHT JOIN t_area a3 ON a2.id = a3.parentid
WHERE a3.id = 419001
SELECT * FROM t_area WHERE NAME LIKE "%省直辖%"
SELECT * FROM t_area WHERE id = 419000 -- 省直辖
|
| java年份判断封装类 |
java基础 |
|
package com.test;
/**
* @Description 年份判断封装类
* @author Fujianyong
* 2014-12-30上午11:11:21
*/
public class Year {
/**
* 可以通过year变量来获得存取年份值
*/
private int year;
/**
* @return year
*/
public int getYear(){
return year;
}
/**
* @param year
*/
public void setYear(int year){
this.year=year;
}
/**
* 通过构造方法生成带有年份值的对象
* @param year
*/
public Year(int year){
super();
this.year=year;
}
/**
* 判断当前构造的对象的年份值是否是闰年
* @return
*/
public boolean isLeap(){
if((year%4 == 0 && year%100 != 0)||(year%400 == 0))
return true;
else
return false;
}
/**
* 这里重载了isLeap() 通过该方法可以判断任意年份属否是闰年
* @param year
* @return
*/
public boolean isLeap(int year) {
if((year%4 == 0 && year%100 != 0)|| (year%400 == 0))
return true;
else
return false;
}
}
|
| java获取年、时间差、闰年天数计算 |
java工具 |
|
package com.test;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
public class TimeCheckOut {
public static void main(String[] args) throws Exception {
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
// java.util.Date now = df.parse("2004-03-26 13:31:40");
// java.util.Date date=df.parse("2004-01-02 11:30:24");
// Date testDate = new Date();
// long testL = testDate.getTime();
// long l=now.getTime()-date.getTime();
// Calendar c = Calendar.getInstance();
// c.add(Calendar.YEAR, 5);
int nowYear = Calendar.getInstance().get(Calendar.YEAR);
int year = nowYear - 1970;
Year y = new Year(2014);
int temp=0;
int d = 0;
for(int i=1970;i<=y.getYear();i++) {
if(y.isLeap(i))
temp=366;
else
temp=365;
d += temp;
}
long l=new Date().getTime();
long day=l/(24*60*60*1000);
long hour=(l/(60*60*1000)-day*24);
long min=((l/(60*1000))-day*24*60-hour*60);
long s=(l/1000-day*24*60*60-hour*60*60-min*60);
long ms =(l-day*24*60*60*1000-hour*60*60*1000-min*60*1000-s*1000);
System.out.println(
"判断闰年后的天数 \n"+ d +"\n"+
"1970年到现在已经过了"+ year +"年\n" +
"格林威治时间过了"+day+"天"+hour+"小时"+min+"分"+s+"秒"+ms+"毫秒\n" +
"今天是年末\n" + df.format(l)
);
}
}
|
| Java获取UUID |
java工具 |
|
import java.util.UUID;
public class UUIDTest {
public static void main(String[] args) {
System.out.println(UUID.randomUUID().toString().toUpperCase().replaceAll("-", ""));
}
}
|
| js异步三级联动下拉框 |
js |
|
//三级联动
省/直辖市<select id="province"></select>
市/省直辖<select id="city"></select>
县/区 <select id="area"></select>
<!-- JQuery方式 -->
<script type="text/javascript">
$().ready(function() {
var coco = "coco";
//ajax
$.ajax({
url: "Test",
dataType: "json",
data: {myName: "coco"},
success: function(data) {
for(var i=0;i<data.length;i++) {
alert(data[i].city + data[i].id);
}
}
});
// getJSON
$.getJSON('Test', function(data) {
alert(data)
alert(data[1].city)
alert(data[0].id)
});
});
</script>
<!-- JS方式 -->
<script type="text/javascript">
window.onload = function() {
var req;
if(window.XMLHttpRequest) {
req = new XMLHttpRequest();
}else if(window.ActiveXObject) {
req = new ActiveXObject("Microsoft.XMLHTTP");
}else {alert("您的浏览器版本太旧咯");}
if(req) {
req.open("post", "Test", true);
req.send(null);
req.onreadystatechange = function() {
if(req.readyState == 4) {
if(req.status == 200) {
var data = eval('('+req.responseText+')');
var province = document.getElementById("province");
for(var i=0;i<data.length;i++) {
province.options.add(new Option(data[i].city, data[i].id));
}
var city = document.getElementById("city");
var option = document.createElement("option");
option.value = 1;
option.innerHTML = "北京";
city.appendChild(option);
}else {
alert("现在的状态" + req.statusText);
}
}else {
document.getElementById("province").innerText = "加载中...";
}
}
}
}
</script>
|
| js年份下拉框 |
js |
|
//年份
<select id="year"></select>
<script type="text/javascript">
window.onload = function() {
var year = document.getElementById("year");
var divValue = document.getElementById("divValue");
var date = new Date();
for(var i=1992;i<=date.getFullYear();i++) {
year.options.add(new Option(i, i));
}
year.onchange = function() {
alert(divValue.innerHTML)//以后用到innerHTML 注意火狐不兼容innerText
alert(year.value)
}
}
</script>
|
