Java标准库提供了一个URLEncoder类来对任意字符串进行URL编码
# 加密
public class Main {
public static void main(String[] args) {
String encoded = URLEncoder.encode("中文!", StandardCharsets.UTF_8);
System.out.println(encoded);
}
}
# 控制台
%E4%B8%AD%E6%96%87%21
# 解密
public class Main {
public static void main(String[] args) {
String decoded = URLDecoder.decode("%E4%B8%AD%E6%96%87%21", StandardCharsets.UTF_8);
System.out.println(decoded);
}
}
# 控制台
中文!
Base64编码可以把任意长度的二进制数据变为纯文本
# 加密
public class Main {
public static void main(String[] args) {
byte[] input = new byte[] { (byte) 0xe4, (byte) 0xb8, (byte) 0xad };
String b64encoded = Base64.getEncoder().encodeToString(input);
System.out.println(b64encoded);
}
}
# 控制台
5Lit
# 解密
public class Main {
public static void main(String[] args) {
byte[] output = Base64.getDecoder().decode("5Lit");
System.out.println(Arrays.toString(output));
}
}
# 控制台
[-28, -72, -83]
# 数组长度不是3的整数时，加密
public class Main {
public static void main(String[] args) {
byte[] input = new byte[] { (byte) 0xe4, (byte) 0xb8, (byte) 0xad, 0x21 };
String b64encoded = Base64.getEncoder().encodeToString(input);
String b64encoded2 = Base64.getEncoder().withoutPadding().encodeToString(input);
System.out.println(b64encoded);
System.out.println(b64encoded2);
byte[] output = Base64.getDecoder().decode(b64encoded2);
System.out.println(Arrays.toString(output));
}
}
# 控制台
5LitIQ==
5LitIQ
[-28, -72, -83, 33]
# 针对URL的Base64编码
public class Main {
public static void main(String[] args) {
byte[] input = new byte[] { 0x01, 0x02, 0x7f, 0x00 };
String b64encoded = Base64.getUrlEncoder().encodeToString(input);
System.out.println(b64encoded);
byte[] output = Base64.getUrlDecoder().decode(b64encoded);
System.out.println(Arrays.toString(output));
}
}
# 控制台
AQJ_AA==
[1, 2, 127, 0]
| 算法 |
输出长度（位） |
输出长度（字节） |
| MD5 |
128 bits |
16 bytes |
| SHA-1 |
160 bits |
20 bytes |
| RipeMD-160 |
160 bits |
20 bytes |
| SHA-256 |
256 bits |
32 bytes |
| SHA-512 |
512 bits |
64 bytes |
public class Main {
public static void main(String[] args) throws Exception {
// 创建一个MessageDigest实例:
MessageDigest md = MessageDigest.getInstance("MD5");
// 反复调用update输入数据:
md.update("Hello".getBytes("UTF-8"));
md.update("World".getBytes("UTF-8"));
byte[] result = md.digest(); // 16 bytes: 68e109f0f40ca72a15e05cc22786f8e6
System.out.println(new BigInteger(1, result).toString(16));
}
}
# 控制台
68e109f0f40ca72a15e05cc22786f8e6
package com.md5.demo;
import java.security.MessageDigest;
import java.util.Random;
import org.apache.commons.codec.binary.Hex;
/**
* MD5加盐加密
*/
public class PasswordUtil {
/**
* 生成含有随机盐的密码
*/
public static String generate(String password) {
Random r = new Random();
StringBuilder sb = new StringBuilder(16);
sb.append(r.nextInt(99999999)).append(r.nextInt(99999999));
int len = sb.length();
if (len < 16) {
for (int i = 0; i < 16 - len; i++) {
sb.append("0");
}
}
String salt = sb.toString();
password = md5Hex(password + salt);
char[] cs = new char[48];
for (int i = 0; i < 48; i += 3) {
cs[i] = password.charAt(i / 3 * 2);
char c = salt.charAt(i / 3);
cs[i + 1] = c;
cs[i + 2] = password.charAt(i / 3 * 2 + 1);
}
return new String(cs);
}
/**
* 校验密码是否正确
*/
public static boolean verify(String password, String md5) {
char[] cs1 = new char[32];
char[] cs2 = new char[16];
for (int i = 0; i < 48; i += 3) {
cs1[i / 3 * 2] = md5.charAt(i);
cs1[i / 3 * 2 + 1] = md5.charAt(i + 2);
cs2[i / 3] = md5.charAt(i + 1);
}
String salt = new String(cs2);
return md5Hex(password + salt).equals(new String(cs1));
}
/**
* 获取十六进制字符串形式的MD5摘要
*/
public static String md5Hex(String src) {
try {
MessageDigest md5 = MessageDigest.getInstance("MD5");
byte[] bs = md5.digest(src.getBytes());
return new String(new Hex().encode(bs));
} catch (Exception e) {
return null;
}
}
}
# 测试
public static void main(String[] args) {
// 加密+加盐
String password1 = generate("admin");
System.out.println("结果：" + password1 + " 长度："+ password1.length());
// 解码
System.out.println(verify("admin", password1));
// 加密+加盐
String password2= generate("admin");
System.out.println("结果：" + password2 + " 长度："+ password2.length());
// 解码
System.out.println(verify("admin", password2));
}
//length用户要求，随机产生字符串的长度
public static String getRandomString(int length){
String str="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
Random random=new Random();
StringBuffer sb=new StringBuffer();
for(int i=0;i<length;i++){
int number=random.nextInt(62);
sb.append(str.charAt(number));
}
return sb.toString();
}
# 利用Apache commons的DigestUtils工具类
String password1 = DigestUtils.md5Hex(stu1.name+stu1.password+stu1.email);
System.out.println(password1);
# 反复加盐
String password1 = DigestUtils.md5Hex(stu1.name+stu1.password+stu1.email);
DigestUtils.md5Hex(DigestUtils.md5Hex("774"+password1+"@@__"));
public class Main {
public static void main(String[] args) throws Exception {
// 创建一个MessageDigest实例:
MessageDigest md = MessageDigest.getInstance("SHA-1");
// 反复调用update输入数据:
md.update("Hello".getBytes("UTF-8"));
md.update("World".getBytes("UTF-8"));
byte[] result = md.digest(); // 20 bytes: db8ac1c259eb89d4a131b253bacfca5f319d54f2
System.out.println(new BigInteger(1, result).toString(16));
}
}
# 控制台
db8ac1c259eb89d4a131b253bacfca5f319d54f2
public class Test1 {
public static void main(String[] args) throws Exception {
// 创建一个MessageDigest实例:
MessageDigest md = MessageDigest.getInstance("SHA-256");
// 反复调用update输入数据:
md.update("Hello".getBytes("UTF-8"));
md.update("World".getBytes("UTF-8"));
byte[] result = md.digest(); // 20 bytes: db8ac1c259eb89d4a131b253bacfca5f319d54f2
System.out.println(new BigInteger(1, result).toString(16));
}
}
# 控制台
872e4e50ce9990d8b041330c47c9ddd11bec6b503ae9386a99da8584e9bb12c4
public class Test1 {
public static void main(String[] args) throws Exception {
// 创建一个MessageDigest实例:
MessageDigest md = MessageDigest.getInstance("SHA-512");
// 反复调用update输入数据:
md.update("Hello".getBytes("UTF-8"));
md.update("World".getBytes("UTF-8"));
byte[] result = md.digest(); // 20 bytes: db8ac1c259eb89d4a131b253bacfca5f319d54f2
System.out.println(new BigInteger(1, result).toString(16));
}
}
# 控制台
8ae6ae71a75d3fb2e0225deeb004faf95d816a0a58093eb4cb5a3aa0f197050d7a4dc0a2d5c6fbae5fb5b0d536a0a9e6b686369fa57a027687c3630321547596
