package com.springboot.utils;

import java.security.Key;
import java.security.SecureRandom;
import java.util.Base64;
import java.util.Base64.Decoder;
import java.util.Base64.Encoder;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;


public class DESUtils {
  //指定DES加密解密所用的密鑰
  private static Key key;
  private static String KEY_STR = "myKey";
  
  static {
    try {
      KeyGenerator generator = KeyGenerator.getInstance("DES");
      generator.init(new SecureRandom(KEY_STR.getBytes()));
      key = generator.generateKey();
      generator = null;
    }catch(Exception e) {
      throw new RuntimeException(e);
    }
  }
  
  public static String getEncryptString(String str) {
    Encoder encoder = Base64.getEncoder();
    try {
      byte[] strBytes = str.getBytes("UTF8");
      Cipher cipher = Cipher.getInstance("DES");
      cipher.init(Cipher.ENCRYPT_MODE, key);
      byte[] encryptStrBytes = cipher.doFinal(strBytes);
      return encoder.encodeToString(encryptStrBytes);
    }catch(Exception e) {
      throw new RuntimeException(e);
    }
  }
  
  public static String getDecryptString(String str) {
    Decoder decoder = Base64.getDecoder();
    try {
      byte[] strBytes = decoder.decode(str);
      Cipher cipher = Cipher.getInstance("DES");
      cipher.init(Cipher.DECRYPT_MODE, key);
      byte[] decryptStrBytes = cipher.doFinal(strBytes);
      return new String(decryptStrBytes,"UTF8");
    }catch(Exception e) {
      throw new RuntimeException(e);
    }
  }
  
  public static void main(String[] args) throws Exception{
    if(args == null || args.length < 1) {
      System.out.println("請(qǐng)輸入要加密的字符,用空格分隔.");
    }else {
      for(String arg : args) {
        System.out.println(arg + ":" + getEncryptString(arg));
      }
    }
  }
}

package com.springboot.utils;

import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;

public class EncryptPropertyPlaceholderConfigurer extends PropertySourcesPlaceholderConfigurer{
  private String[] encryptPropNames = {"userName","password"};
  
  private boolean isEncryptProp(String propertyName) {
    for(String encryptProName : encryptPropNames) {
      if(encryptProName.equals(propertyName)) {
        return true;
      }
    }
    return false;
  }
  @Override
  protected String convertProperty(String propertyName, String propertyValue) {
    if(isEncryptProp(propertyName)) {
      String decryptVal = DESUtils.getDecryptString(propertyValue);
      System.out.println("decryptVal = " + decryptVal);
      return decryptVal;
    }else {
      return propertyValue;
    }
  }
}

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