工具方法集合

蔚落 2022-04-13 13:19 591阅读 0赞

### 文章目录 ###

*   *   *   *   *  BooleanUtils.isTrue(null)==false
                 *  ListUtils\\Maputils 结合 lamada
                 *  默认返回空集合
                 *  Optional.ofNullable(list).orElse 和 Optional.of(list)
                 *  Gson
                 *  Guava 工具类
                 *   *  本地缓存
                     *  校验
                 *  时间工具类
                 *   *  现成
                     *  需要 Java 8
                 *  非对称加密验签工具类
                 *  非对称加密基础工具类
                 *  CloseResourceUtils 关闭IO资源
                 *  BrowserInfoUtils 浏览器信息
                 *  HttpURLConnectionUtils
                 *  IPAddrUtils 获取ip地址+ip解析为地址
                 *  SystemInfoUtils 操作系统信息
                 *  生成8位随机密码
                 *  音频文件格式在线转化
                 *  在线工具箱
                 *  自动替换字符串工具类

##### BooleanUtils.isTrue(null)==false #####

·maven

<dependency>
                <groupId>org.apache.commons</groupId>
                <artifactId>commons-lang3</artifactId>
                <version>3.12.0</version>
            </dependency>

·java

@Test
        public void test2(){ 
            boolean result = BooleanUtils.isTrue(null);
            System.out.println(result);
        }

##### ListUtils\\Maputils 结合 lamada #####

·maven 依赖

<dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-collections4</artifactId>
        <version>4.4</version>
    </dependency>

·java

import org.apache.commons.collections4.ListUtils;
     @Test
        public void test(){ 
            List<Integer> list = Lists.newArrayList(1,2,3,4,5);
            Integer value1 = ListUtils.emptyIfNull(list).stream().findFirst().get();
        }
        @Test
        public void testh(){ 
            List<Integer> list1 = null;
            //可以避免空指针
            List<Integer> list2 = ListUtils.emptyIfNull(list1).stream().collect(Collectors.toList());
            System.out.println(list2);//[]
        }
        @Test
        public void testi(){ 
            Map<Long,String> map = null;
            //可以避免空指针
            Map<Long,String> map2 = MapUtils.emptyIfNull(map);
            System.out.println(map2);{ }
        }

##### 默认返回空集合 #####

if(MapUtils.isEmpty(demoList)){ 
                return Collections.emptyList();
            }

##### Optional.ofNullable(list).orElse 和 Optional.of(list) #####

> Optional.ofNullable 可以避免空指针,会强制 orElse

@Test
        public void testa(){
            List list = null;
            //List listRight = Optional.ofNullable(list).orElse(Lists.newArrayList(1,2,3));
            List listRight = Optional.ofNullable(list).orElse(Lists.newArrayList(1,2,3));
            System.out.println("Optional.ofNullable 可以避免空指针,会强制 orElse"+listRight);
            List listNullPointerException = Optional.of(list).orElse(Lists.newArrayList(1,2,3));
            System.out.println("Optional.of(null)orElse(new 对象) 无法避免空指针 NullPointerException,运行时就报错");
        }

##### Gson #####

<dependency>
                <groupId>com.google.code.gson</groupId>
                <artifactId>gson</artifactId>
                <version>2.8.7</version>
            </dependency>

demo

private static class HomeInfo{ 
            String name;
            int age;
        }
    
        public static void main(String[] args) throws Exception { 
            Gson gson = new Gson();
            HomeInfo homeInfo = new HomeInfo();
            homeInfo.name="test";
            homeInfo.age=20;
            String jsonStr = gson.toJson(homeInfo);
            System.out.println("jsonStr："+jsonStr);
        }

##### Guava 工具类 #####

*  Maven 依赖

<dependency>
        <groupId>com.google.guava</groupId>
        <artifactId>guava</artifactId>
        <version>23.0</version>
    </dependency>

###### 本地缓存 ######

*  工具类和测试方法

import com.google.common.cache.CacheBuilder;
    import com.google.common.cache.CacheLoader;
    import com.google.common.cache.LoadingCache;
    import com.google.common.collect.Lists;
    import lombok.SneakyThrows;
    import org.mortbay.util.ajax.JSON;
    
    import java.util.List;
    import java.util.concurrent.ExecutionException;
    import java.util.concurrent.TimeUnit;
    
    /** * @Title: * @Description: * @Updatedby: */
    public class GuavaCacheUtil { 
    
        /** * 获得本地缓存 * * @param id * @return */
        public static List<String> getListCacheExpireAfterAccess(Long id) throws ExecutionException { 
            return localingCacheExpireAfterAccess.get(id);
        }
    
        /** * 每次调用设置5秒的有效期 */
        private static LoadingCache<Long, List<String>> localingCacheExpireAfterAccess =
                CacheBuilder.newBuilder().expireAfterAccess(5, TimeUnit.SECONDS).build(new CacheLoader<Long, List<String>>(){ 
                    @Override
                    public List<String> load(Long id) throws Exception { 
                        System.out.println("更新缓存，5秒后清除缓存:"+System.currentTimeMillis());
                        List<String> list = Lists.newArrayList("111"+id,"222"+id,"333"+id);
                        return list;
                    }
                });
    
        /** * 获得本地缓存 * 消息失效，只允许一个请求，其余先返回旧值 * * @param id * @return */
        public static List<String> getListCacheRefreshAfterWrite(Long id) throws ExecutionException { 
            return localingCacheRefreshAfterWrite.get(id);
        }
    
        /** * 每次调用设置5秒的有效期 */
        private static LoadingCache<Long, List<String>> localingCacheRefreshAfterWrite =
                CacheBuilder.newBuilder().refreshAfterWrite(3, TimeUnit.SECONDS).build(new CacheLoader<Long, List<String>>() { 
                    @Override
                    public List<String> load(Long id) throws Exception { 
                        System.out.println("更新缓存-开始:" + System.currentTimeMillis());
                        List<String> list = Lists.newArrayList("111" + id, "222" + id, "333" + id + System.currentTimeMillis());
                        Thread.sleep(1000 * 2);
                        System.out.println("更新缓存-结束,3秒后清除缓存:" + System.currentTimeMillis());
                        return list;
                    }
                });
    }

*  测试方法

public static void main(String[] args) throws ExecutionException, InterruptedException { 
            GuavaCacheUtil.testLocalingCacheExpireAfterAccess();
            GuavaCacheUtil.testGetListCacheRefreshAfterWrite();
        }
    
        /** 更新缓存，5秒后清除缓存:1608629304383 ["1111","2221","3331"] ["1111","2221","3331"] 等待6秒，届时缓存失效 更新缓存，5秒后清除缓存:1608629310391 ["1111","2221","3331"] * @throws ExecutionException * @throws InterruptedException */
        public static void testLocalingCacheExpireAfterAccess() throws ExecutionException, InterruptedException { 
            List<String> list = GuavaCacheUtil.getListCacheExpireAfterAccess(1L);
            System.out.println(JSON.toString(list));
            List<String> list2 = GuavaCacheUtil.getListCacheExpireAfterAccess(1L);
            System.out.println(JSON.toString(list2));
            System.out.println("等待6秒，届时缓存失效");
            Thread.sleep(1000 * 6);
            List<String> list3 = GuavaCacheUtil.getListCacheExpireAfterAccess(1L);
            System.out.println(JSON.toString(list3));
        }
    
        public static void testGetListCacheRefreshAfterWrite() throws ExecutionException, InterruptedException { 
            List<String> list = GuavaCacheUtil.getListCacheRefreshAfterWrite(1L);
            System.out.println(JSON.toString(list));
            List<String> list2 = GuavaCacheUtil.getListCacheRefreshAfterWrite(1L);
            System.out.println(JSON.toString(list2));
            System.out.println("等待4秒，届时缓存失效");
            Thread.sleep(1000 * 4);
            //缓存设置3秒失效，等待了4秒，故失效,使用两个线程进行查询，预期结果第一个阻塞，第二个立即返回历史值
    
            Thread t1= new Thread(){ 
                @SneakyThrows
                @Override
                public synchronized void start() { 
                    super.start();
                    List<String> list = GuavaCacheUtil.getListCacheRefreshAfterWrite(1L);
                    System.out.println("t1"+JSON.toString(list));
                }
            };
    
            Thread t2= new Thread(){ 
                @SneakyThrows
                @Override
                public synchronized void start() { 
                    super.start();
                    List<String> list = GuavaCacheUtil.getListCacheRefreshAfterWrite(1L);
                    System.out.println("t2:"+JSON.toString(list));
                }
            };
            t1.start();
            t2.start();
    
    
        }

###### 校验 ######

> Guava 本身不单单支持本地缓存，更多其它用法可以参考 https://www.jianshu.com/p/1c49cfa72f94

*  IllegalArgumentException

import com.google.common.base.Preconditions;
    import org.junit.jupiter.api.Test;
    public class DelTest { 
        @Test
        public void test1() throws Exception{ 
            Preconditions.checkArgument(1<0,"参数校验不通过");
        }
    }

##### 时间工具类 #####

###### 现成 ######

maven

<dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-lang3</artifactId>
        <version>3.11</version>
    </dependency>

org.apache.commons.lang3.time.DateUtils

###### 需要 Java 8 ######

import java.time.*;
    import java.time.format.DateTimeFormatter;
    import java.util.Date;
    
    /** * @Title: Util * @Description: DateTimeUtil * @Author: wujie * @Version: v1.0 * @Date:2020-05-29 */
    public class BizDateTimeUtil { 
    
        public static final String FORMAT_YY_MM_DD_HH_MM_SS1 = "yy年MM月dd日 HH:mm:ss";
        public static final String FORMAT_MM_DD_HH_MM2 = "MM月dd日 HH:mm";
        public static final String FORMAT_HH_MM3 = "HH:mm";
        public static final String FORMAT_MM_DD4 = "MM月dd日";
        public static final String FORMAT_YY_MM_DD_HH_MM5 = "yy年MM月dd日 HH:mm";
    
        private static final long SECEND_TO_MILLISECOND = 1000;
        private static final int BEIJING_ZONEOFFSET = 8;
        private static final int ZERO_VALUE = 0;
    
    
        public static String dateToStringByFormat(Date date, String format) { 
            Instant instant = date.toInstant();
            ZoneId zoneId = ZoneId.systemDefault();
            LocalDateTime localDateTime = LocalDateTime.ofInstant(instant, zoneId);
            return DateTimeFormatter.ofPattern(format).format(localDateTime);
        }
    
        public static String dateToStringByFormat(LocalDateTime date, String format) { 
            return DateTimeFormatter.ofPattern(format).format(date);
        }
    
        /** * 获取本年 * * @return */
        public static int thisYear() { 
            return LocalDateTime.now().getYear();
        }
    
        /** * 获取今天 * * @return */
        public static LocalDate thisDay() { 
            return LocalDate.now();
        }
    
        /** * 毫秒 转 时间 * * @param dateTime * @return */
        public static LocalDateTime dateTime2LocalDateTime(Long dateTime) { 
            return LocalDateTime.ofEpochSecond(dateTime / SECEND_TO_MILLISECOND, ZERO_VALUE, ZoneOffset.ofHours(BEIJING_ZONEOFFSET));
        }
    
        /** * 毫秒 转 日期 * * @param dateTime * @return */
        public static LocalDate dateTime2LocalDate(Long dateTime) { 
            return LocalDateTime.ofEpochSecond(dateTime / SECEND_TO_MILLISECOND, ZERO_VALUE, ZoneOffset.ofHours(BEIJING_ZONEOFFSET)).toLocalDate();
        }
    
        /** * 对应 时间 是否等于 本年 * * @param localDateTime * @return */
        public static Boolean equalThisYear(LocalDateTime localDateTime) { 
            if (localDateTime.getYear() == thisYear()) { 
                return true;
            }
            return false;
        }
    
        /** * 对应 时间 是否等于 今天 * * @param localDate * @return */
        public static Boolean equalThisDay(LocalDate localDate) { 
            if (thisDay().compareTo(localDate)==0) { 
                return true;
            }
            return false;
        }
    
        /** * timeStamp 在本年 转化为 MM月dd日 HH:mm * timeStamp 不在本年，转化为 YY年MM月dd日 HH:mm * * @param timeStamp * @return */
        public static String transferToSpecialFormatCenter(Long timeStamp) { 
            LocalDateTime localDateTime = dateTime2LocalDateTime(timeStamp);
            if (equalThisYear(localDateTime)) { 
                return dateToStringByFormat(localDateTime, FORMAT_MM_DD_HH_MM2);
            } else { 
                return dateToStringByFormat(localDateTime, FORMAT_YY_MM_DD_HH_MM_SS1);
            }
        }
        /** * timeStamp 在本年 * 不在今天 显示 MM月dd日 * 在今天 显示 HH:mm * timeStamp 不在本年，转化为 YY年MM月dd日 HH:mm * * @param timeStamp * @return */
        public static String transferToSpecialFormatCenterList(Long timeStamp) { 
            LocalDateTime localDateTime = dateTime2LocalDateTime(timeStamp);
            if (equalThisYear(localDateTime)) { 
                if(equalThisDay(dateTime2LocalDate(timeStamp))){ 
                    return dateToStringByFormat(localDateTime, FORMAT_HH_MM3);
                }else{ 
                    return dateToStringByFormat(localDateTime, FORMAT_MM_DD4);
                }
            } else { 
                return dateToStringByFormat(localDateTime, FORMAT_YY_MM_DD_HH_MM5);
            }
        }
    
        /** * timeStamp 在本年 * 不在今天 显示 MM月dd日 * 在今天 显示 HH:mm * timeStamp 不在本年，转化为 YY年MM月dd日 HH:mm * * @param timeStamp * @return */
        public static String transferToSpecialFormatCommonList(Long timeStamp) { 
            LocalDateTime localDateTime = dateTime2LocalDateTime(timeStamp);
            if (equalThisYear(localDateTime)) { 
                return dateToStringByFormat(localDateTime, FORMAT_MM_DD_HH_MM2);
            } else { 
                return dateToStringByFormat(localDateTime, FORMAT_YY_MM_DD_HH_MM5);
            }
        }
    	 
    	/** * 获取当前分钟 0-59 * @return */
        public static int getNowMinute(){ 
            return LocalDateTime.now().getMinute();
        }
    
    }

##### 非对称加密验签工具类 #####

> 支持 SHA1withRSA、SHA256withRSA、SHA1withDSA  
> 本类需要工具类支持：https://mp.csdn.net/mdeditor/84635754 非对称加密基础工具类

import java.io.UnsupportedEncodingException;
    import java.security.InvalidKeyException;
    import java.security.NoSuchAlgorithmException;
    import java.security.PrivateKey;
    import java.security.PublicKey;
    import java.security.Signature;
    import java.security.SignatureException;
    import java.security.spec.InvalidKeySpecException;
    
    import org.apache.commons.codec.binary.Base64;
    
    /** * 非对称加密验签工具类 * jie.wu * 本类需要工具类支持：https://mp.csdn.net/mdeditor/84635754 非对称加密基础工具类 * / public class SignatureUtil { //下面提供一个 SHA1withRSA 的签名和验证例子 public static void main(String[] args) throws NoSuchAlgorithmException, InvalidKeySpecException, InvalidKeyException, SignatureException, UnsupportedEncodingException { //RSA 1024 私钥 String privateBase64Str="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"; //RSA 1024 公钥 String publicBase64Str="MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC31wT9eT3jgUtIdtIV2bSMniolsfacvlVmoMX2NkL1h//sLvMTKbdFhTVhup0t47vbtnFYkUFGI0Q+ZM/IaUcvDXVaFf5G5GXity1KmbOf3G9+/LkEzty1nzkCRQTM+pZdgl1hIxBxncc4+okYxWKAuFUvgw0xjvuoh5mEqT9/9QIDAQAB"; //非对称加密算法,如 RSA String algorithm="RSA"; //非对称加密验签规则 String sign_algorithm="SHA1withRSA"; //待加密字符串: String str="method=info.auth#app_id=2138&sign_type=RSA&timestamp=2013-01-0108:08:08"; //字符编码 方式 String charset="utf8"; //获取私钥 PrivateKey privateKey=AsymmetricEncryptionUtil.restorePrivateKey(privateBase64Str,algorithm,charset); //获取公钥 PublicKey publicKey=AsymmetricEncryptionUtil.restorePublicKey(publicBase64Str,algorithm,charset); //使用私钥计算签名 String signStr=signatureSign(sign_algorithm,charset,str,privateKey); System.out.println("signStr="+signStr); //使用公钥验证签名 System.out.println(signatureVerify(sign_algorithm,charset,str,signStr,publicKey)); } /** * 非对称加密签名-签名计算方法 * @param algorithm 签名算法，如 SHA1withRSA * <ul> * <li>{@code SHA1withDSA}</li> * <li>{@code SHA1withRSA}</li> * <li>{@code SHA256withRSA}</li> * </ul> * @param charset 字符编码格式，如 utf8、gbk * @param str 原字符串 * @param privateKey 非对称加密 私钥 * @return * @throws NoSuchAlgorithmException * @throws InvalidKeyException * @throws SignatureException * @throws UnsupportedEncodingException */
        public static String signatureSign(String algorithm,String charset,String str,PrivateKey privateKey) throws NoSuchAlgorithmException, InvalidKeyException, SignatureException, UnsupportedEncodingException { 
            //指定签名算法如 SHA1withRSA
            Signature signature = Signature.getInstance(algorithm);
            signature.initSign(privateKey);
            //注意编码格式 utf8、gbk
            signature.update(str.getBytes(charset));
            //结果转 Base64,注意编码格式 utf8、gbk
            String signStr=new String(Base64.encodeBase64(signature.sign()),charset);
            return signStr;
        }
    
        /** * 非对称加密签名-签名校验方法，验证通过返回 true * @param algorithm 签名算法，如 SHA1withRSA * <ul> * <li>{@code SHA1withDSA}</li> * <li>{@code SHA1withRSA}</li> * <li>{@code SHA256withRSA}</li> * </ul> * @param charset 字符编码格式，如 utf8、gbk * @param str 原字符串 * @param signStr 待校验签名内容 * @param publicKey 非对称加密 公钥 * @return * @throws InvalidKeyException * @throws NoSuchAlgorithmException * @throws SignatureException * @throws UnsupportedEncodingException */
        public static boolean signatureVerify(String algorithm,String charset,String str,String signStr,PublicKey publicKey) throws InvalidKeyException, NoSuchAlgorithmException, SignatureException, UnsupportedEncodingException { 
            //指定签名算法如 SHA1withRSA
            Signature signature = Signature.getInstance(algorithm);
            signature.initVerify(publicKey);
            //加密前的文本
            signature.update(str.getBytes(charset));
            //比较 私钥 的加密结果
            return signature.verify(Base64.decodeBase64(signStr.getBytes()));
        }
    }

##### 非对称加密基础工具类 #####

> 可以根据不同的入参，支持 RSA\\DSA等非对称加密算法

import org.apache.commons.codec.binary.Base64;
    
    import javax.crypto.BadPaddingException;
    import javax.crypto.Cipher;
    import javax.crypto.IllegalBlockSizeException;
    import javax.crypto.NoSuchPaddingException;
    import java.io.UnsupportedEncodingException;
    import java.security.*;
    import java.security.spec.InvalidKeySpecException;
    import java.security.spec.PKCS8EncodedKeySpec;
    import java.security.spec.X509EncodedKeySpec;
    import java.util.HashMap;
    import java.util.Map;
    /** * 非对称加密 工具类 * jie.wu */
    public class AsymmetricEncryptionUtil { 
    
        public static void main(String [] args) throws NoSuchAlgorithmException, UnsupportedEncodingException, InvalidKeySpecException { 
            //算法名称
            String algorithm="RSA";
            //私钥长度
            int keySize=1024;
            //待加密字符串
            String str="123456789abc";
            //编码格式
            String charset="utf8";
    
            //base64 格式的RSA 1024 私钥
            String privateKeyBase64="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";
            //base64 格式的 RSA 1024 公钥
            String publicKeyBase64="MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC31wT9eT3jgUtIdtIV2bSMniolsfacvlVmoMX2NkL1h//sLvMTKbdFhTVhup0t47vbtnFYkUFGI0Q+ZM/IaUcvDXVaFf5G5GXity1KmbOf3G9+/LkEzty1nzkCRQTM+pZdgl1hIxBxncc4+okYxWKAuFUvgw0xjvuoh5mEqT9/9QIDAQAB";
    
    
            Map<Class,Object> keyPairMap=initKeyPair(algorithm,keySize);
            PublicKey publicKey=(PublicKey)keyPairMap.get(PublicKey.class);
            PrivateKey privateKey=(PrivateKey) keyPairMap.get(PrivateKey.class);
    
            //加密和解密过程
            try { 
                System.out.println("待加密字符串：str="+str);
                //将加密结果转化为Base64编码
                String result= new String(Base64.encodeBase64(AsymmetricEncryptionUtil.encrypt(publicKey,algorithm,str.getBytes(charset))),charset);
                //加密后得Base64字符串
                System.out.println("加密后的字节数组转化为 Base64展示="+result);
                //将加密的Base64字符串解密-将解密字节数组转Base64字符串
                String ostr= new String(AsymmetricEncryptionUtil.decipher(privateKey,algorithm,Base64.decodeBase64(result)),charset);
                System.out.println("原字符串="+ostr);
            } catch (NoSuchPaddingException e) { 
                e.printStackTrace();
            } catch (InvalidKeyException e) { 
                e.printStackTrace();
            } catch (BadPaddingException e) { 
                e.printStackTrace();
            } catch (IllegalBlockSizeException e) { 
                e.printStackTrace();
            }
    
            //字符串恢复为公私钥对象过程
            //私钥恢复为 PrivateKey
            PrivateKey priKey=AsymmetricEncryptionUtil.restorePrivateKey(privateKeyBase64,algorithm,charset);
            //公钥恢复为 PublicKey
            PublicKey pubKey=AsymmetricEncryptionUtil.restorePublicKey(publicKeyBase64,algorithm,charset);
    
        }
    
        /** * 将 字符串 用指定加密算法 解密 * @param privateKey 私钥 * @param algorithm 算发，如 RSA * @param strBytes 待解密字节数组 * @return * @throws NoSuchPaddingException * @throws NoSuchAlgorithmException * @throws InvalidKeyException * @throws BadPaddingException * @throws IllegalBlockSizeException * @throws UnsupportedEncodingException */
        public static byte[] decipher(PrivateKey privateKey,String algorithm, byte[] strBytes) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { 
            Cipher cipher=Cipher.getInstance(algorithm);
            cipher.init(Cipher.DECRYPT_MODE,privateKey);
            return cipher.doFinal(strBytes);
        }
    
        /** * 将 字符串 用指定加密算法 加密 * @param publicKey 公钥 * @param algorithm 算法，如 RSA * @param strBytes 待加密字节数组 * @return * @throws NoSuchPaddingException * @throws NoSuchAlgorithmException * @throws InvalidKeyException * @throws BadPaddingException * @throws IllegalBlockSizeException */
        public static byte[] encrypt(PublicKey publicKey,String algorithm,byte[] strBytes) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { 
            //获取 cipher 对象，指定加密算法 比如 RSA
            Cipher cipher = Cipher.getInstance(algorithm);
            //初始化 cipher 对象，指定为加密模式，指定公钥
            cipher.init(Cipher.ENCRYPT_MODE, publicKey);
            return cipher.doFinal(strBytes);
        }
    
    
        /** * 生成 非对称加密算法 公私钥对的方法-返回默认秘钥格式 * @param algorithm 加密算法 * @param keySize 私钥长度-实际会生成一个近似值 * <li>{@code DiffieHellman} (1024)</li> * <li>{@code DSA} (1024)</li> * <li>{@code RSA} (1024, 2048)</li> * @return * @throws NoSuchAlgorithmException */
        public static Map<Class,Object> initKeyPair(String algorithm,int keySize) throws NoSuchAlgorithmException { 
            //指定算法 RSA、DiffieHellman、DSA
            KeyPairGenerator keyPairGenerator=KeyPairGenerator.getInstance(algorithm);
            //指定私钥的长度——实际生成的也是近似值
            keyPairGenerator.initialize(keySize);
            //生成公私钥对
            KeyPair kPair=keyPairGenerator.generateKeyPair();
            Map<Class,Object> keyPairMap=new HashMap<Class,Object>();
            keyPairMap.put(PrivateKey.class,kPair.getPrivate());
            keyPairMap.put(PublicKey.class,kPair.getPublic());
            return keyPairMap;
        }
    
        /** * 生成 非对称加密算法 公私钥对的方法-返回字符Base64 字符串格式 * @param algorithm 加密算法 * @param keySize 私钥长度-实际会生成一个近似值 * @param charset 字符编码格式，如utf8 * <li>{@code DiffieHellman} (1024)</li> * <li>{@code DSA} (1024)</li> * <li>{@code RSA} (1024, 2048)</li> * @return * @throws NoSuchAlgorithmException */
        public static Map<Class,Object> initKeyPairBase64Str(String algorithm,int keySize,String charset) throws NoSuchAlgorithmException, UnsupportedEncodingException { 
    
            Map<Class,Object> keyPairMap=initKeyPair(algorithm,keySize);
    
            PrivateKey privateKey=(PrivateKey)keyPairMap.get(PrivateKey.class);
            PublicKey publicKey=(PublicKey)keyPairMap.get(PublicKey.class);
    
            //以 Base64 格式输出 私钥,指定字符格式 如 utf8、gbk
            String privateKeyStr= new String(Base64.encodeBase64(privateKey.getEncoded()),charset);
            //以 Base64 格式输出 公钥,指定字符格式 如 utf8、gbk
            String publicKeyStr=new String(Base64.encodeBase64(publicKey.getEncoded()),charset);
            System.out.println(privateKey.getEncoded().length);
            System.out.println(publicKey.getEncoded().length);
            //System.out.println("私钥："+"algorithm:"+privateKey.getAlgorithm()+";format:"+privateKey.getFormat()+";私钥base64:"+privateKeyStr);
            //System.out.println("公钥："+"algorithm:"+publicKey.getAlgorithm()+";format:"+publicKey.getFormat()+";公钥base64:"+publicKeyStr);
    
            keyPairMap.put(PrivateKey.class,privateKeyStr);
            keyPairMap.put(PublicKey.class,publicKeyStr);
            return keyPairMap;
        }
    
    
    
        /** * 由Base64字符编码恢复 公钥 * @param pubKeyBase64Str 公钥 Base64 编码 字符串 * @param algorithm 算法名称，如 RSA\DSA\DiffieHellman * @param charset 字符编码格式，如 utf8、gbk * @return * @throws NoSuchAlgorithmException * @throws InvalidKeySpecException */
        public static PublicKey restorePublicKey(String pubKeyBase64Str,String algorithm,String charset) throws NoSuchAlgorithmException, InvalidKeySpecException, UnsupportedEncodingException { 
            //将Base64 字符串转化为字节数组
            byte[] keyBytes=Base64.decodeBase64(pubKeyBase64Str.getBytes(charset));
            //公钥标准
            X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(keyBytes);
            //指定算法 比如 RSA
            KeyFactory factory = KeyFactory.getInstance(algorithm);
            //获取公钥
            PublicKey publicKey = factory.generatePublic(x509EncodedKeySpec);
            return publicKey;
        }
    
        /** * 由Base64字符编码恢复 私钥 * @param privateBase64Str 私钥 Base64 编码字符串 * @param algorithm 算法名称，如 RSA\DSA\DiffieHellman * @param charset 字符编码格式，如 utf8、gbk * @return * @throws NoSuchAlgorithmException * @throws InvalidKeySpecException */
        public static PrivateKey restorePrivateKey(String privateBase64Str,String algorithm,String charset) throws NoSuchAlgorithmException, InvalidKeySpecException, UnsupportedEncodingException { 
            //将Base64 字符串转化为字节数组
            byte[] keyBytes=Base64.decodeBase64(privateBase64Str.getBytes(charset));
            //私钥标准
            PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(keyBytes);
            //指定算法，比如 RSA
            KeyFactory factory = KeyFactory.getInstance(algorithm);
            //获取私钥
            PrivateKey privateKey = factory.generatePrivate(pkcs8EncodedKeySpec);
            return privateKey;
        }
    }

##### CloseResourceUtils 关闭IO资源 #####

import java.io.Closeable;
    import java.io.IOException;
    
    public class CloseableUtils { 
       
        public CloseableUtils() { 
        }
    	
        public static void close(Closeable... args) { 
            if (args != null && args.length != 0) { 
                Closeable[] arr$ = args;
                int len$ = args.length;
    
                for(int i$ = 0; i$ < len$; ++i$) { 
                    Closeable arg = arr$[i$];
    
                    try { 
                        if (arg != null) { 
                            arg.close();
                        }
                    } catch (IOException var6) { 
                        System.out.println("CloseableUtils.close exception:", var6);
                    }
                }
    
            }
        }
    }

##### BrowserInfoUtils 浏览器信息 #####

import javax.servlet.http.HttpServletRequest;
    
    public class BrowserInfoUtils { 
        /** * 获取来访者的浏览器版本 * @param request * @return */
        public static String getRequestBrowserInfo(HttpServletRequest request){ 
    		String browserVersion = null;
    		String header = request.getHeader("user-agent");
    		if(header == null || header.equals("")){ 
    		   return "";
    		 }
            if(header.indexOf("MSIE")>0){ 
                browserVersion = "IE";
            }else if(header.indexOf("Firefox")>0){ 
                browserVersion = "Firefox";
            }else if(header.indexOf("Chrome")>0){ 
                browserVersion = "Chrome";
            }else if(header.indexOf("Safari")>0){ 
                browserVersion = "Safari";
            }else if(header.indexOf("Camino")>0){ 
                browserVersion = "Camino";
            }else if(header.indexOf("Konqueror")>0){ 
                browserVersion = "Konqueror";
            }
            return browserVersion;
        }
    }

##### HttpURLConnectionUtils #####

import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.io.OutputStream;
    import java.io.OutputStreamWriter;
    import java.net.HttpURLConnection;
    import java.net.MalformedURLException;
    import java.net.URL;
    
    
    /** * @Title: * @Description: * @Copyright: Copyright(c)2018 * @Author: jie.wu * @Date:2018-09-12 18:18 */
    public class HttpURLConnectionUtils { 
    
        /** * POST 方式发起 httpclient 请求 * @param remoteUrl * @param xmlStr * @param encoding * @return */
        public static String HttpURLConnectionPost(String remoteUrl, String xmlStr, String encoding){ 
            return sendHttpURLConnection(remoteUrl,xmlStr, encoding,"POST");
        }
    
        /** * httpclient 发送基本方法 * 可以发送xml,json,a=1&b=2&c= 等格式的字符串 * * @param remoteUrl * @param xmlStr * @param encoding ytf8\GBK * @param requestMethod GET\POST * * @return */
        public static String sendHttpURLConnection(String remoteUrl, String xmlStr, String encoding,String requestMethod) { 
            String strResponse = "";
            String strMessage = "";
            InputStream inputStream = null;
            OutputStream outputStream = null;
            BufferedReader reader = null;
            OutputStreamWriter writer = null;
            System.out.println("requestXml="+xmlStr);
            //logger.info("requestXml={}",xmlStr);
    
            URL url;
            HttpURLConnection connection;
            try { 
                url = new URL(remoteUrl);
                connection = (HttpURLConnection) url.openConnection();
    
    
                connection.setDoInput(true);
                connection.setDoOutput(true);
                //connection.setRequestMethod(requestMethod);
                connection.setRequestMethod("POST");
                connection.setAllowUserInteraction(true);
                // 设置超时
                String strTimeOut = "6000";
                if (strTimeOut != null) { 
                    connection.setConnectTimeout(Integer.parseInt(strTimeOut));
                    connection.setReadTimeout(Integer.parseInt(strTimeOut));
                }
    
    
                connection.connect();
                outputStream = connection.getOutputStream();
                writer = new OutputStreamWriter(outputStream, encoding);
                writer.write(xmlStr);
                writer.flush();
    
    
                inputStream = connection.getInputStream();
                int status = connection.getResponseCode();
                if (status == 200) { 
                    reader = new BufferedReader(new InputStreamReader(inputStream, encoding));
                    while ((strMessage = reader.readLine()) != null) { 
                        strResponse += strMessage;
                    }
    
    
                } else { 
                    strResponse = "error http's status=" + status;
                }
            } catch (MalformedURLException e) { 
            } catch (IOException e) { 
            } catch (Exception e) { 
            } finally { 
    
    
                try { 
                    if (inputStream != null) { 
                        inputStream.close();
                    }
                    if (reader != null) { 
                        reader.close();
                    }
                    if (outputStream != null) { 
                        outputStream.close();
                    }
                    if (writer != null) { 
                        writer.close();
                    }
    
    
                } catch (IOException e) { 
                   e.printStackTrace();
                }
    
    
            }
            System.out.println("responseXml="+strResponse);
            //logger.info("responseXml={}",strResponse);
            return strResponse;
    
        }
    }

##### IPAddrUtils 获取ip地址+ip解析为地址 #####

maven 依赖

<dependency>
              <groupId>org.apache.commons</groupId>
              <artifactId>commons-lang3</artifactId>
              <version>3.9</version>
          </dependency>
    
          <dependency>
              <groupId>net.sf.json-lib</groupId>
              <artifactId>json-lib</artifactId>
              <version>2.4</version>
              
              <classifier>jdk15</classifier>
          </dependency>

import java.net.InetAddress;
    import java.net.UnknownHostException;
    
    import javax.servlet.http.HttpServletRequest;
    
    import org.apache.commons.lang3.StringUtils;
    
    import net.sf.json.JSONObject;
    
    public class IPAddrUtils { 
    	
    	/** * 获取 IP 信息 * @param request * @return */
    	public static String getIpAddr(HttpServletRequest request) { 
    	     //获取所有的代理IP
            String ipAddress = request.getHeader("x-forwarded-for");
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) { 
                ipAddress = request.getHeader("Proxy-Client-IP");
            }
            if (ipAddress == null || ipAddress.length() == 0|| "unknown".equalsIgnoreCase(ipAddress)) { 
                ipAddress = request.getHeader("WL-Proxy-Client-IP");
            }
            //获取用户的真实IP
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) { 
                ipAddress = request.getHeader("X-Real-Ip");
            }
    	    if (ipAddress == null || ipAddress.length() == 0|| "unknown".equalsIgnoreCase(ipAddress)) { 
    	        ipAddress = request.getRemoteAddr();
    	        if (ipAddress.equals("127.0.0.1")) { 
    	            // 根据网卡取本机配置的IP
    	            InetAddress inet = null;
    	            try { 
    	                inet = InetAddress.getLocalHost();
    	                ipAddress = inet.getHostAddress();
    	            } catch (UnknownHostException e) { 
    	                System.out.println("出现异常:"+e.toString());
    	            }
    	        }
    	    }
    
    	    // 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
    	    // "***.***.***.***".length() = 15
    	    if (ipAddress != null && ipAddress.length() > 15) { 
    	        if (ipAddress.indexOf(",") > 0) { 
    	            ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
    	        }
    	    }
    	    if("0:0:0:0:0:0:0:1".equals(ipAddress)){ 
    	    	ipAddress="127.0.0.1";
    	    }
    	    return ipAddress;
    	}
    	
    	//访问这个地址获取 ip 所属到地区信息
    	private final static String remoteUrl="http://ip.taobao.com/service/getIpInfo.php?ip=";
    	private final static String encoding="utf-8";
    	
    	/** * 根据 ip 查询地址信息 * @param ip * @return */
    	public static JSONObject getAreaInfoJsonObjectByIp(String ip){ 
    		ip="223.223.193.194";
    		String xmlStr="";
    		
    		String result=HttpURLConnectionUtils.HttpURLConnectionPost(remoteUrl+ip, xmlStr, encoding);
    		if(StringUtils.isNotBlank(result)){ 
    			JSONObject json=JSONObject.fromObject(result);
    			int code=(int)json.get("code");
    			if(0==code){ 
    				JSONObject innerJson=(JSONObject)json.get("data");
    				System.out.println("ip对应的地区为:"+(String)innerJson.get("country")+innerJson.get("region")+innerJson.getString("city"));
    			}
    			return json;
    		}else{ 
    			return null;
    		}
    	}
    	
    	/** * 根据ip 获取组装好的地址 * @param ip * @return */
    	 public static String getAreaInfoStringByIp(String ip){ 
    		JSONObject json=getAreaInfoJsonObjectByIp(ip);
            if(json!=null){ 
                int code=(Integer)json.get("code");
                if(0==code){ 
                    JSONObject innerJson=(JSONObject)json.get("data");
                    StringBuilder stringBuilder=new StringBuilder();
                    stringBuilder.append(innerJson.get("country")).append(innerJson.get("region")).append(innerJson.getString("city"));
                    return stringBuilder.toString();
                }
            }else{ 
                return "未知区域";
            }
            return "未知区域";
    	    }
    
    }

##### SystemInfoUtils 操作系统信息 #####

import java.util.regex.Matcher;
    import java.util.regex.Pattern;
    
    import javax.servlet.http.HttpServletRequest;
    
    public class SystemInfoUtils { 
    	
    	private final static Pattern pattern = Pattern.compile(";\\s?[^;\\s]*?(\\s?\\S*?)\\s?(Build)?/");  
    	
    	/** * 获取系统版本信息 * @param request * @return */
        public static String getRequestSystemInfo(HttpServletRequest request){ 
    	  String systenInfo = null;
    	  String userAgent = request.getHeader("USER-AGENT");
    	  if(userAgent == null || userAgent.equals("")){ 
    	   return "";
    	  }
    	  System.out.println("userAgent="+userAgent);
    	
          boolean isMobile= checkFromMobile(userAgent.toLowerCase());
          if(isMobile) { 
        	 
        	if(userAgent.indexOf("iPhone") != -1){ 
      			return "iPhone";
      		}
        	if(userAgent.indexOf("iPad") != -1){ 
      			return "iPad";
      		}
        	if(userAgent.indexOf("NOKIA") != -1 || userAgent.indexOf("Nokia")!=-1){ 
      			return "NOKIA";
      		}
        	if(userAgent.indexOf("Windows Phone") != -1){ 
      			return "Windows Phone";
      		}
        	if(userAgent.indexOf("Nexus") != -1){ 
      			return "Nexus";
      		}
      	    Matcher matcher = pattern.matcher(userAgent);  
      	   
      	    if (matcher.find()) {   
      	    	systenInfo = matcher.group(1).trim();
      	    }
          }else{ 
        	  //得到用户的操作系统 https://blog.csdn.net/flyingpig2016/article/details/53282895
              if (userAgent.indexOf("NT 6.0") > 0){ 
                  systenInfo = "Windows Vista/Server 2008";
              } else if (userAgent.indexOf("NT 5.1") > 0){ 
                  systenInfo = "Windows XP";
              } else if (userAgent.indexOf("NT 6.0") > 0){ 
                  systenInfo = "Windows Vista";
              } else if (userAgent.indexOf("NT 6.1") > 0){ 
                  systenInfo = "Windows 7";
              }else if (userAgent.indexOf("NT 6.2") > 0){ 
                  systenInfo = "Windows 8";
              }else if (userAgent.indexOf("NT 6.3") > 0){ 
                  systenInfo = "Windows 9";
              } else if (userAgent.indexOf("NT6.4") > 0||userAgent.indexOf("10.0") > 0){ 
                  systenInfo = "Windows 10";
              }else if (userAgent.indexOf("NT 5") > 0){ 
                  systenInfo = "Windows 2000";
              } else if (userAgent.indexOf("Mac") > 0){ 
                  systenInfo = "Mac";
              } else if (userAgent.indexOf("Unix") > 0){ 
                  systenInfo = "UNIX";
              } else if (userAgent.indexOf("Linux") > 0){ 
                  systenInfo = "Linux";
              } else if (userAgent.indexOf("SunOS") > 0){ 
                  systenInfo = "SunOS";
              }else{ 
            	  systenInfo = "其他";
              }
          }
           
            return systenInfo;
    	 }
        
        
        private static String phoneReg = "\\b(ip(hone|od)|android|opera m(ob|in)i"
                +"|windows (phone|ce)|blackberry"
                +"|s(ymbian|eries60|amsung)|p(laybook|alm|rofile/midp"
                +"|laystation portable)|nokia|fennec|htc[-_]"
                +"|mobile|up.browser|[1-4][0-9]{2}x[1-4][0-9]{2})\\b";
        private static String tableReg = "\\b(ipad|tablet|(Nexus 7)|up.browser"
                +"|[1-4][0-9]{2}x[1-4][0-9]{2})\\b";
    
    
        private static Pattern phonePat = Pattern.compile(phoneReg, Pattern.CASE_INSENSITIVE);
        private static Pattern tablePat = Pattern.compile(tableReg, Pattern.CASE_INSENSITIVE);
    
        /** * 如果是手机端则返回 true * @param userAgent * @return */
        private static boolean checkFromMobile(String userAgent){ 
            if(null == userAgent){ 
                userAgent = "";
            }
    
            Matcher matcherPhone = phonePat.matcher(userAgent);
            Matcher matcherTable = tablePat.matcher(userAgent);
            if(matcherPhone.find() || matcherTable.find()){ 
                return true;
            } else { 
                return false;
            }
        }
    }

##### 生成8位随机密码 #####

> 0-26+97=97-123 对应 ASCII码中 0-9,a-z,A-Z

/** * 生成随机密码的工具类 */
    public class RandomPasswordUtils { 
    
    	/** * 生成8位随机数字、大小写字母 * @return */
    	public static String getRandomPassword() { 
    		String result = "";
    		for (int i = 0; i<8; i++){ 
    			int intVal = (int)(Math.random()*26+97);
    			result = result +(char) intVal;
    		}
    		return result; 
    	}
    }

##### 音频文件格式在线转化 #####

https://app.xunjiepdf.com/mp32ogg/

##### 在线工具箱 #####

https://www.matools.com/\#

##### 自动替换字符串工具类 #####

Maven 依赖

<dependency>
         <groupId>org.apache.commons</groupId>
         <artifactId>commons-lang3</artifactId>
         <version>3.7</version>
     </dependency>

*  先来看一个简单的例子——能替换就替换，否则不替换

@Test
        public void test1(){ 
        	//设定被替换规则 map ,这里只设定 testvalue 这个值
            Map valuesMap = new HashMap();
            valuesMap.put("testvalue","111");
            
            String beginString = "The ${animal} jumped over the ${target}. ${testvalue}";
            StrSubstitutor sub = new StrSubstitutor(valuesMap,"${","}");
            String result=sub.replace(beginString,valuesMap);
            System.out.println(result);
        }

输出：因为只设定了testvalue，所以$\{animal\} 和 $\{target\} 未被替换

The ${animal} jumped over the ${target}. 111

*  改进版——如果没有具体替换规则，则替换为空默认字符串——比如 default

@Test
        public void test2() { 
            Map valuesMap = new HashMap();
            valuesMap.put("testvalue", "111");
            String beginString = "The ${animal} jumped over the ${target}. ${testvalue}";
            StrSubstitutor sub = new StrSubstitutor(valuesMap, "${", "}");
            //获取所有需被替换的字符
            List<String> strList = getVarsFromStr(beginString, "\\$\\{", "}", "${");
            //获取map中不包含的字符
    
            strList.forEach(item -> { 
                if (!valuesMap.keySet().contains(item)) { 
                    valuesMap.put(item, "default");
                }
            });
    
            String result = sub.replace(beginString, valuesMap);
            System.out.println(result);
        }
    
        private List<String> getVarsFromStr(String str, String startStr, String endStr, String startWith) { 
            if (StringUtils.isBlank(str) || !str.contains(startWith)) { 
                return com.google.common.collect.Lists.newArrayList();
            }
            String strLocal = str.substring(str.indexOf(startWith));
            String[] split = strLocal.split(startStr);
            if (split.length == 0) { 
                return com.google.common.collect.Lists.newArrayList();
            }
    
            List<String> list = com.google.common.collect.Lists.newArrayList();
            for (String item : split) { 
                int index = item.indexOf(endStr);
                if (index >= 1) { 
                    list.add(item.substring(0, index));
                }
            }
            return list;
        }