常用的util类

pom类的依赖

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.4</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>redis.clients</groupId>
            <artifactId>jedis</artifactId>
            <version>2.6.0</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.18</version>
        </dependency>

        <dependency>
            <groupId>commons-lang</groupId>
            <artifactId>commons-lang</artifactId>
            <version>2.6</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.5</version>
        </dependency>
        <!-- spring session 单点登录 -->
        <dependency>
            <groupId>org.springframework.session</groupId>
            <artifactId>spring-session-data-redis</artifactId>
            <version>1.2.0.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.redisson</groupId>
            <artifactId>redisson</artifactId>
            <version>2.9.0</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.dataformat</groupId>
            <artifactId>jackson-dataformat-avro</artifactId>
            <version>2.9.0</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>RELEASE</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>RELEASE</version>
            <scope>compile</scope>
        </dependency>
    </dependencies>

读取配置文件

package com.test.demo.util;


import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Properties;

@Slf4j
public class PropertiesUtil {
    private static Properties props;

    static {
        String fileName = "mmall.properties";
        props = new Properties();
        try {
            props.load(new InputStreamReader(PropertiesUtil.class.getClassLoader().getResourceAsStream(fileName),"UTf-8"));
        } catch (IOException e) {
            log.error("配置文件读取异常",e);
        }
    }

    public static String getProperty(String key){
        String value = props.getProperty(key.trim());
        if(StringUtils.isBlank(value)){
            return null;
        }
        return value.trim();
    }

    public static String getProperty(String key,String defaultValue){

        String value = props.getProperty(key.trim());
        if(StringUtils.isBlank(value)){
            value = defaultValue;
        }
        return value.trim();
    }
}

redispool

package com.test.demo.util;

import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;

public class RedisPool {
    private static JedisPool pool;//jedis连接池
    private static Integer maxTotal = Integer.parseInt(PropertiesUtil.getProperty("redis.max.total","20")); //最大连接数
    private static Integer maxIdle = Integer.parseInt(PropertiesUtil.getProperty("redis.max.idle","20"));//在jedispool中最大的idle状态(空闲的)的jedis实例的个数
    private static Integer minIdle = Integer.parseInt(PropertiesUtil.getProperty("redis.min.idle","20"));//在jedispool中最小的idle状态(空闲的)的jedis实例的个数

    private static Boolean testOnBorrow = Boolean.parseBoolean(PropertiesUtil.getProperty("redis.test.borrow","true"));//在borrow一个jedis实例的时候，是否要进行验证操作，如果赋值true。则得到的jedis实例肯定是可以用的。
    private static Boolean testOnReturn = Boolean.parseBoolean(PropertiesUtil.getProperty("redis.test.return","true"));//在return一个jedis实例的时候，是否要进行验证操作，如果赋值true。则放回jedispool的jedis实例肯定是可以用的。

    private static String redisIp = PropertiesUtil.getProperty("redis1.ip");
    private static Integer redisPort = Integer.parseInt(PropertiesUtil.getProperty("redis1.port"));


    private static void initPool(){
        JedisPoolConfig config = new JedisPoolConfig();

        config.setMaxTotal(maxTotal);
        config.setMaxIdle(maxIdle);
        config.setMinIdle(minIdle);

        config.setTestOnBorrow(testOnBorrow);
        config.setTestOnReturn(testOnReturn);

        config.setBlockWhenExhausted(true);//连接耗尽的时候，是否阻塞，false会抛出异常，true阻塞直到超时。默认为true。

        pool = new JedisPool(config,redisIp,redisPort,1000*2);
    }

    static{
        initPool();
    }

    public static Jedis getJedis(){
        return pool.getResource();
    }


    public static void returnBrokenResource(Jedis jedis){
        pool.returnBrokenResource(jedis);
    }



    public static void returnResource(Jedis jedis){
        pool.returnResource(jedis);
    }


    public static void main(String[] args) {
        Jedis jedis = pool.getResource();
        jedis.set("geelykey","geelyvalue");
        returnResource(jedis);

        pool.destroy();//临时调用，销毁连接池中的所有连接
        System.out.println("program is end");


    }
}

JsonUtil

package com.test.demo.util;

import avro.shaded.com.google.common.collect.Lists;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.codehaus.jackson.map.DeserializationConfig;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.SerializationConfig;
import org.codehaus.jackson.map.annotate.JsonSerialize;
import org.codehaus.jackson.type.JavaType;
import org.codehaus.jackson.type.TypeReference;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;

@Slf4j
public class JsonUtil {
    private static ObjectMapper objectMapper = new ObjectMapper();

    static {
        //对象的所有字段全部列入
        objectMapper.setSerializationInclusion(JsonSerialize.Inclusion.ALWAYS);

        //取消默认转换的timestamps形式
        objectMapper.configure(SerializationConfig.Feature.WRITE_DATES_AS_TIMESTAMPS,false);

        //忽略空bean转换json的错误
        objectMapper.configure(SerializationConfig.Feature.FAIL_ON_EMPTY_BEANS,false);

        //统一所有的日期格式
        objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));

        //忽略在j'son格式中存在，但是在Java对象中不存在对应属性的情况，防止错误
        objectMapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES,false);
    }

    public static <T> String obj2String(T obj){
        if(obj == null){
            return null;
        }
        try {
            return obj instanceof String ? (String) obj : objectMapper.writeValueAsString(obj);
        } catch (IOException e) {
            log.warn("Parse Object to String error",e);
            return null;
        }
    }

    public static <T> String obj2StringPretty(T obj){
        if(obj == null){
            return null;
        }
        try {
            return obj instanceof String ? (String) obj : objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(obj);
        } catch (IOException e) {
            log.warn("ParsePretty Object to String error",e);
            return null;
        }
    }

    public static <T> T string2Obj(String str,Class<T> clazz){
        if(StringUtils.isEmpty(str) || clazz == null){
            return null;
        }

        try {
            return clazz.equals(String.class)? (T)str : objectMapper.readValue(str,clazz);
        } catch (Exception e) {
            log.warn("Parse String to Object error",e);
            return null;
        }
    }



    public static <T> T string2Obj(String str, TypeReference<T> typeReference){
        if(StringUtils.isEmpty(str) || typeReference == null){
            return null;
        }
        try {
            return (T)(typeReference.getType().equals(String.class)? str : objectMapper.readValue(str,typeReference));
        } catch (Exception e) {
            log.warn("Parse String to Object error",e);
            return null;
        }
    }


    public static <T> T string2Obj(String str,Class<?> collectionClass,Class<?>... elementClasses){
        JavaType javaType = objectMapper.getTypeFactory().constructParametricType(collectionClass,elementClasses);
        try {
            return objectMapper.readValue(str,javaType);
        } catch (Exception e) {
            log.warn("Parse String to Object error",e);
            return null;
        }
    }

    public static void main(String[] args) {
        User user = new User();
        user.setId(2);
        user.setEmail("[email protected]");
        user.setCreateTime(new Date());
        String userJsonPretty = JsonUtil.obj2StringPretty(user);
        log.info("userJson:{}",userJsonPretty);


        User u2 = new User();
        u2.setId(2);
        u2.setEmail("[email protected]");



        String user1Json = JsonUtil.obj2String(user);

        String user1JsonPretty = JsonUtil.obj2StringPretty(user);

        log.info("user1Json:{}",user1Json);

        log.info("user1JsonPretty:{}",user1JsonPretty);




        List<User> userList = Lists.newArrayList();
        userList.add(user);
        userList.add(u2);

        String userListStr = JsonUtil.obj2StringPretty(userList);

        log.info("==================");

        log.info(userListStr);


        List<User> userListObj1 = JsonUtil.string2Obj(userListStr, new TypeReference<List<User>>() {
        });


        List<User> userListObj2 = JsonUtil.string2Obj(userListStr,List.class,User.class);

        System.out.println("end");
    }
}

BigDecimalUtil 精确度计算

package com.juzhi.util;

import java.math.BigDecimal;

public class BigDecimalUtil {

    private BigDecimalUtil(){

    }


    public static BigDecimal add(double v1,double v2){
        BigDecimal b1 = new BigDecimal(Double.toString(v1));
        BigDecimal b2 = new BigDecimal(Double.toString(v2));
        return b1.add(b2);
    }


    public static BigDecimal sub(double v1,double v2){
        BigDecimal b1 = new BigDecimal(Double.toString(v1));
        BigDecimal b2 = new BigDecimal(Double.toString(v2));
        return b1.subtract(b2);
    }


    public static BigDecimal mul(double v1,double v2){
        BigDecimal b1 = new BigDecimal(Double.toString(v1));
        BigDecimal b2 = new BigDecimal(Double.toString(v2));
        return b1.multiply(b2);
    }

    public static BigDecimal div(double v1,double v2){
        BigDecimal b1 = new BigDecimal(Double.toString(v1));
        BigDecimal b2 = new BigDecimal(Double.toString(v2));
        return b1.divide(b2,2,BigDecimal.ROUND_HALF_UP);//四舍五入,保留2位小数

        //除不尽的情况
    }





}

cookieUtil 注意domain

package com.juzhi.util;

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang.StringUtils;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@Slf4j
public class CookieUtil {

    private final static String COOKIE_DOMAIN = ".happymmall.com";
    private final static String COOKIE_NAME = "mmall_login_token";


    public static String readLoginToken(HttpServletRequest request){
        Cookie[] cks = request.getCookies();
        if(cks != null){
            for(Cookie ck : cks){
                log.info("read cookieName:{},cookieValue:{}",ck.getName(),ck.getValue());
                if(StringUtils.equals(ck.getName(),COOKIE_NAME)){
                    log.info("return cookieName:{},cookieValue:{}",ck.getName(),ck.getValue());
                    return ck.getValue();
                }
            }
        }
        return null;
    }

    //X:domain=".happymmall.com"
    //a:A.happymmall.com            cookie:domain=A.happymmall.com;path="/"
    //b:B.happymmall.com            cookie:domain=B.happymmall.com;path="/"
    //c:A.happymmall.com/test/cc    cookie:domain=A.happymmall.com;path="/test/cc"
    //d:A.happymmall.com/test/dd    cookie:domain=A.happymmall.com;path="/test/dd"
    //e:A.happymmall.com/test       cookie:domain=A.happymmall.com;path="/test"

    public static void writeLoginToken(HttpServletResponse response,String token){
        Cookie ck = new Cookie(COOKIE_NAME,token);
        ck.setDomain(COOKIE_DOMAIN);
        ck.setPath("/");//代表设置在根目录
        ck.setHttpOnly(true);
        //单位是秒。
        //如果这个maxage不设置的话，cookie就不会写入硬盘，而是写在内存。只在当前页面有效。
        ck.setMaxAge(60 * 60 * 24 * 365);//如果是-1，代表永久
        log.info("write cookieName:{},cookieValue:{}",ck.getName(),ck.getValue());
        response.addCookie(ck);
    }


    public static void delLoginToken(HttpServletRequest request,HttpServletResponse response){
        Cookie[] cks = request.getCookies();
        if(cks != null){
            for(Cookie ck : cks){
                if(StringUtils.equals(ck.getName(),COOKIE_NAME)){
                    ck.setDomain(COOKIE_DOMAIN);
                    ck.setPath("/");
                    ck.setMaxAge(0);//设置成0，代表删除此cookie。
                    log.info("del cookieName:{},cookieValue:{}",ck.getName(),ck.getValue());
                    response.addCookie(ck);
                    return;
                }
            }
        }
    }







}

**DateTimeUtil **

package com.juzhi.util;

import org.apache.commons.lang3.StringUtils;
import org.joda.time.DateTime;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;

import java.util.Date;
public class DateTimeUtil {

    //joda-time

    //str->Date
    //Date->str
    public static final String STANDARD_FORMAT = "yyyy-MM-dd HH:mm:ss";



    public static Date strToDate(String dateTimeStr,String formatStr){
        DateTimeFormatter dateTimeFormatter = DateTimeFormat.forPattern(formatStr);
        DateTime dateTime = dateTimeFormatter.parseDateTime(dateTimeStr);
        return dateTime.toDate();
    }

    public static String dateToStr(Date date,String formatStr){
        if(date == null){
            return StringUtils.EMPTY;
        }
        DateTime dateTime = new DateTime(date);
        return dateTime.toString(formatStr);
    }

    public static Date strToDate(String dateTimeStr){
        DateTimeFormatter dateTimeFormatter = DateTimeFormat.forPattern(STANDARD_FORMAT);
        DateTime dateTime = dateTimeFormatter.parseDateTime(dateTimeStr);
        return dateTime.toDate();
    }

    public static String dateToStr(Date date){
        if(date == null){
            return StringUtils.EMPTY;
        }
        DateTime dateTime = new DateTime(date);
        return dateTime.toString(STANDARD_FORMAT);
    }




    public static void main(String[] args) {
        System.out.println(DateTimeUtil.dateToStr(new Date(),"yyyy-MM-dd HH:mm:ss"));
        System.out.println(DateTimeUtil.strToDate("2010-01-01 11:11:11","yyyy-MM-dd HH:mm:ss"));

    }


}

FTPUtil

package com.juzhi.util;

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.net.ftp.FTPClient;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.List;

@Slf4j
public class FTPUtil {


    private static String ftpIp = PropertiesUtil.getProperty("ftp.server.ip");
    private static String ftpUser = PropertiesUtil.getProperty("ftp.user");
    private static String ftpPass = PropertiesUtil.getProperty("ftp.pass");

    public FTPUtil(String ip,int port,String user,String pwd){
        this.ip = ip;
        this.port = port;
        this.user = user;
        this.pwd = pwd;
    }
    public static boolean uploadFile(List<File> fileList) throws IOException {
        FTPUtil ftpUtil = new FTPUtil(ftpIp,21,ftpUser,ftpPass);
        log.info("开始连接ftp服务器");
        boolean result = ftpUtil.uploadFile("img",fileList);
        log.info("开始连接ftp服务器,结束上传,上传结果:{}");
        return result;
    }


    private boolean uploadFile(String remotePath,List<File> fileList) throws IOException {
        boolean uploaded = true;
        FileInputStream fis = null;
        //连接FTP服务器
        if(connectServer(this.ip,this.port,this.user,this.pwd)){
            try {
                ftpClient.changeWorkingDirectory(remotePath);
                ftpClient.setBufferSize(1024);
                ftpClient.setControlEncoding("UTF-8");
                ftpClient.setFileType(FTPClient.BINARY_FILE_TYPE);
                ftpClient.enterLocalPassiveMode();
                for(File fileItem : fileList){
                    fis = new FileInputStream(fileItem);
                    ftpClient.storeFile(fileItem.getName(),fis);
                }

            } catch (IOException e) {
                log.error("上传文件异常",e);
                uploaded = false;
                e.printStackTrace();
            } finally {
                fis.close();
                ftpClient.disconnect();
            }
        }
        return uploaded;
    }



    private boolean connectServer(String ip,int port,String user,String pwd){

        boolean isSuccess = false;
        ftpClient = new FTPClient();
        try {
            ftpClient.connect(ip);
            isSuccess = ftpClient.login(user,pwd);
        } catch (IOException e) {
            log.error("连接FTP服务器异常",e);
        }
        return isSuccess;
    }











    private String ip;
    private int port;
    private String user;
    private String pwd;
    private FTPClient ftpClient;

    public String getIp() {
        return ip;
    }

    public void setIp(String ip) {
        this.ip = ip;
    }

    public int getPort() {
        return port;
    }

    public void setPort(int port) {
        this.port = port;
    }

    public String getUser() {
        return user;
    }

    public void setUser(String user) {
        this.user = user;
    }

    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }

    public FTPClient getFtpClient() {
        return ftpClient;
    }

    public void setFtpClient(FTPClient ftpClient) {
        this.ftpClient = ftpClient;
    }
}

MD5Util

package com.juzhi.util;

import java.security.MessageDigest;

public class MD5Util {

    private static String byteArrayToHexString(byte b[]) {
        StringBuffer resultSb = new StringBuffer();
        for (int i = 0; i < b.length; i++)
            resultSb.append(byteToHexString(b[i]));

        return resultSb.toString();
    }

    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0)
            n += 256;
        int d1 = n / 16;
        int d2 = n % 16;
        return hexDigits[d1] + hexDigits[d2];
    }

    /**
     * 返回大写MD5
     *
     * @param origin
     * @param charsetname
     * @return
     */
    private static String MD5Encode(String origin, String charsetname) {
        String resultString = null;
        try {
            resultString = new String(origin);
            MessageDigest md = MessageDigest.getInstance("MD5");
            if (charsetname == null || "".equals(charsetname))
                resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
            else
                resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetname)));
        } catch (Exception exception) {
        }
        return resultString.toUpperCase();
    }

    public static String MD5EncodeUtf8(String origin) {
        origin = origin + PropertiesUtil.getProperty("password.salt", "");
        return MD5Encode(origin, "utf-8");
    }


    private static final String hexDigits[] = {"0", "1", "2", "3", "4", "5",
            "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"};

}

redispool

package com.juzhi.common;

import com.juzhi.util.PropertiesUtil;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;

public class RedisPool {
    private static JedisPool pool;//jedis连接池
    private static Integer maxTotal = Integer.parseInt(PropertiesUtil.getProperty("redis.max.total","20")); //最大连接数
    private static Integer maxIdle = Integer.parseInt(PropertiesUtil.getProperty("redis.max.idle","20"));//在jedispool中最大的idle状态(空闲的)的jedis实例的个数
    private static Integer minIdle = Integer.parseInt(PropertiesUtil.getProperty("redis.min.idle","20"));//在jedispool中最小的idle状态(空闲的)的jedis实例的个数

    private static Boolean testOnBorrow = Boolean.parseBoolean(PropertiesUtil.getProperty("redis.test.borrow","true"));//在borrow一个jedis实例的时候，是否要进行验证操作，如果赋值true。则得到的jedis实例肯定是可以用的。
    private static Boolean testOnReturn = Boolean.parseBoolean(PropertiesUtil.getProperty("redis.test.return","true"));//在return一个jedis实例的时候，是否要进行验证操作，如果赋值true。则放回jedispool的jedis实例肯定是可以用的。

    private static String redisIp = PropertiesUtil.getProperty("redis1.ip");
    private static Integer redisPort = Integer.parseInt(PropertiesUtil.getProperty("redis1.port"));


    private static void initPool(){
        JedisPoolConfig config = new JedisPoolConfig();

        config.setMaxTotal(maxTotal);
        config.setMaxIdle(maxIdle);
        config.setMinIdle(minIdle);

        config.setTestOnBorrow(testOnBorrow);
        config.setTestOnReturn(testOnReturn);

        config.setBlockWhenExhausted(true);//连接耗尽的时候，是否阻塞，false会抛出异常，true阻塞直到超时。默认为true。

        pool = new JedisPool(config,redisIp,redisPort,1000*2);
    }

    static{
        initPool();
    }

    public static Jedis getJedis(){
        return pool.getResource();
    }


    public static void returnBrokenResource(Jedis jedis){
        pool.returnBrokenResource(jedis);
    }



    public static void returnResource(Jedis jedis){
        pool.returnResource(jedis);
    }


    public static void main(String[] args) {
        Jedis jedis = pool.getResource();
        jedis.set("geelykey","geelyvalue");
        returnResource(jedis);

        pool.destroy();//临时调用，销毁连接池中的所有连接
        System.out.println("program is end");


    }







}