GHGL工具类代码
1.四舍五入保留两位小数
public static double getdouble(double d){
return (double)Math.round(d*100)/100;
}2.计算增减百分比
/**
* 计算增减百分比
* @param x 本期
* @param y 同期
* @return
*/
public static String toPercent(double x , double y){
String rst = null;
if( y == 0){
rst = " ";
}else{
if(x-y == 0){
rst = "0.00%";
}else{
double fen = (x - y) / y ;
DecimalFormat df1 = new DecimalFormat("##.00%");
rst = df1.format(fen);
}
}
return rst;
}3.冒泡排序
/**
* 冒泡法排序
* 比较相邻的元素。如果第一个比第二个大，就交换他们两个。
* 对每一对相邻元素作同样的工作，从开始第一对到结尾的最后一对。在这一点，最后的元素应该会是最大的数。
* 针对所有的元素重复以上的步骤，除了最后一个。
* 持续每次对越来越少的元素重复上面的步骤，直到没有任何一对数字需要比较。
*
* @param numbers
* 需要排序的数组
*/
public static void bubbleSort(double[] numbers) {
double temp; // 记录临时中间值
int size = numbers.length; // 数组大小
for (int i = 0; i < size - 1; i++) {
for (int j = i + 1; j < size; j++) {
if (numbers[i] < numbers[j]) { // 交换两数的位置
temp = numbers[i];
numbers[i] = numbers[j];
numbers[j] = temp;
}
}
}
}4.传入 1 ，返回 001
/**
* 传入 1 ，返回 001
* @param str 字符串
* @return
*/
public static String pullZero(String str){
if(str != null && !"".equals(str) && str.length() < 3) {
int length = str.length();
for(int i = 0; i < 3 - length; i++) {
str = "0" + str;
}
return str;
} else {
return str;
}
}5.计算百分比
public static String goPercent(double x , double y){
String rst = null;
if( y == 0){
rst = " ";
}else{
if(x == 0){
rst = "0.00%";
}else{
double fen = x/y ;
DecimalFormat df1 = new DecimalFormat("##.00%");
rst = df1.format(fen);
}
}
return rst;
}6.后台 RSA AES 加密解密工具类代码
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.SecureRandom;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.codec.binary.Base64;
import org.apache.log4j.Logger;
public class EncryptionDecryption {
static String pathKey = EncryptionDecryption.class.getClassLoader().getResource("RSAKey.txt").getPath();
/** 密钥文件存储位置 */
private static String RSAKeyStore = pathKey;
/**
* 日志记录器
*/
public static Logger logger = Logger.getLogger(EncryptionDecryption.class);
/**
* AES加密
* @param content 明文
* @param keyBytes 秘钥
* @param iv 偏移量
* @return
*/
public static String AES_CBC_Encrypt(String content, byte[] keyBytes, byte[] iv){
try{
SecretKeySpec key = new SecretKeySpec(keyBytes, "AES");
Cipher cipher=Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, key, new IvParameterSpec(iv));
content = URLEncoder.encode(content,"UTF-8"); //用url编码
byte[] result=cipher.doFinal(content.getBytes()); //加密
return new String(Base64.encodeBase64(result),"UTF-8");
}catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (InvalidAlgorithmParameterException e) {
e.printStackTrace();
}
return null;
}
/**
* AES解密
* @param content 密文
* @param keyBytes 秘钥
* @param iv 偏移量
* @return
*/
public static String AES_CBC_Decrypt(String content, byte[] keyBytes, byte[] iv){
try{
content = content.replaceAll(" ", "+");
byte[] decryptBaseData=Base64.decodeBase64(content.getBytes("utf-8"));
SecretKeySpec key = new SecretKeySpec(keyBytes, "AES");
Cipher cipher=Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(iv));
byte[] result=cipher.doFinal(decryptBaseData);
return URLDecoder.decode(new String(result),"utf-8");
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (InvalidAlgorithmParameterException e) {
e.printStackTrace();
}
return null;
}
/**
* 字符串转为 byte[]
* @param hexString
* @return
*/
public static byte[] hexStringToBytes(String hexString) {
if (hexString == null || hexString.equals("")) {
return null;
}
hexString = hexString.toUpperCase();
int length = hexString.length() / 2;
char[] hexChars = hexString.toCharArray();
byte[] d = new byte[length];
for (int i = 0; i < length; i++) {
int pos = i * 2;
d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));
}
return d;
}
/**
* Convert char to byte
* @param c char
* @return byte
*/
private static byte charToByte(char c) {
return (byte) "0123456789ABCDEF".indexOf(c);
}
/**
* 解密由RSA加密的AES的key 和 iv
* @param para
* @return
* @throws Exception
*/
public static byte[] getValue(String param){
byte[] trueValue = null;
try {
if(!param.equals("") && param != null){
byte[] KeyB = hexStringToBytes(param);
KeyB = decrypt(getKeyPair().getPrivate(),KeyB);
StringBuffer sbKey = new StringBuffer();
sbKey.append(new String(KeyB));
param = sbKey.reverse().toString();
trueValue = URLDecoder.decode(param,"UTF-8").getBytes();
}
} catch (Exception e) {
//重要参数值
logger.error("传入参数：" + "param: " + param);
//异常说明
logger.error("解密由RSA加密的AES的key 和 iv 失败，可能前台传入的aKey或者aIv为空");
e.printStackTrace();
}
return trueValue;
}
/**
* 获取密钥文件中的公钥
* @return
*/
public String getPublicKey(){
Object publicKey = null;
String publicKEY = null;
try {
publicKey = getKeyPair().getPublic();
publicKEY = (String) publicKey.toString().subSequence(36, 293);
} catch (Exception e) {
e.printStackTrace();
}
return publicKEY;
}
/**
* RSA 生成密钥对
* @return
* @throws Exception
*/
public static KeyPair generateKeyPair() throws Exception {
try {
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA",
new org.bouncycastle.jce.provider.BouncyCastleProvider());
final int KEY_SIZE = 1024;
keyPairGen.initialize(KEY_SIZE, new SecureRandom());
KeyPair keyPair = keyPairGen.generateKeyPair();
FileOutputStream fos = new FileOutputStream(RSAKeyStore);
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(keyPair);
oos.close();
fos.close();
return keyPair;
} catch (Exception e) {
throw new Exception(e.getMessage());
}
}
/**
* 获取密钥对
* @return
* @throws Exception
*/
public static KeyPair getKeyPair() throws Exception {
FileInputStream fis = new FileInputStream(RSAKeyStore);
ObjectInputStream oos = new ObjectInputStream(fis);
KeyPair kp = (KeyPair) oos.readObject();
oos.close();
fis.close();
return kp;
}
/**
* 解密
* @param pk
* @param raw
* @return
* @throws Exception
*/
@SuppressWarnings("static-access")
private static byte[] decrypt(PrivateKey pk, byte[] raw) {
try {
Cipher cipher = Cipher.getInstance("RSA",
new org.bouncycastle.jce.provider.BouncyCastleProvider());
cipher.init(cipher.DECRYPT_MODE, pk);
int blockSize = cipher.getBlockSize();
ByteArrayOutputStream bout = new ByteArrayOutputStream(64);
int j = 0;
while (raw.length - j * blockSize > 0) {
bout.write(cipher.doFinal(raw, j * blockSize, blockSize));
j++;
}
return bout.toByteArray();
} catch (Exception e) {
e.printStackTrace();
}
return raw;
}
}