java字符串压缩解压示例
java字符串压缩解压示例
发布时间:2016-12-28 来源:查字典编辑
摘要:我测试的字符串是JQuery源码。明文长度:78082压缩后:26566加密长度:54746再压缩:41647---------------...

我测试的字符串是JQuery源码。

明文长度:78082

压缩后:26566

加密长度:54746

再压缩:41647

-----------------------------

密文长度:41647

解压缩:54746

解密后:26566

再解压:78082

-----------------------------

比对成功

Des需要Jar:sun.misc.BASE64Decoder.jar

Test

复制代码 代码如下:

public static void main(String[] args) throws Exception {

String cont = "";

String cont2=jm(yjy(cont));

if(cont.equals(cont2)){

System.out.println("比对成功");

}else{

System.out.println("比对失败");

}

}

public static String yjy(String cont) throws Exception {

System.out.println("明文长度:" + cont.length());

// 第一次压缩

cont = ZipUtil2.compress(cont);

System.out.println("压缩后:" + cont.length());

// 第一次加密

cont = DesUtil.encrypt(cont, DesUtil.PWD_KEY);

System.out.println("加密长度:" + cont.length());

// 第二次压缩

cont = ZipUtil2.compress(cont);

System.out.println("再压缩:" + cont.length());

return cont;

}

public static String jm(String cont) throws Exception {

System.out.println("-----------------------------");

System.out.println("密文长度:" + cont.length());

// 第一次解压缩

cont = ZipUtil2.uncompress(cont);

System.out.println("解压缩:" + cont.length());

// 第一次解密

cont = DesUtil.decrypt(cont, DesUtil.PWD_KEY);

System.out.println("解密后:" + cont.length());

// 第二次解压缩

cont = ZipUtil2.uncompress(cont);

System.out.println("再解压:" + cont.length());

return cont;

}

DesUtil

复制代码 代码如下:

import java.io.IOException;

import java.security.SecureRandom;

import javax.crypto.Cipher;

import javax.crypto.SecretKey;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.DESKeySpec;

import Decoder.BASE64Decoder;

import Decoder.BASE64Encoder;

public class DesUtil {

private final static String DES = "DES";

public final static String PWD_KEY = "MZTHPWDJM";

public final static String ID_KEY = "MZTHIDJM";

public static void main(String[] args) throws Exception {

String data = "xkajsdasdk'al;ks'dl;kasl;d";

System.err.println("加密:"+encrypt(data, PWD_KEY));

System.err.println("解密:" +decrypt(encrypt(data, PWD_KEY), PWD_KEY));

}

/**

* Description 根据键值进行加密

*

* @param data

* @param key

* 加密键byte数组

* @return

* @throws Exception

*/

public static String encrypt(String data, String key) throws Exception {

byte[] bt = encrypt(data.getBytes(), key.getBytes());

String strs = new BASE64Encoder().encode(bt);

return strs;

}

/**

* Description 根据键值进行解密

*

* @param data

* @param key

* 加密键byte数组

* @return

* @throws IOException

* @throws Exception

*/

public static String decrypt(String data, String key) throws IOException,

Exception {

if (data == null)

return null;

BASE64Decoder decoder = new BASE64Decoder();

byte[] buf = decoder.decodeBuffer(data);

byte[] bt = decrypt(buf, key.getBytes());

return new String(bt);

}

/**

* Description 根据键值进行加密

*

* @param data

* @param key

* 加密键byte数组

* @return

* @throws Exception

*/

private static byte[] encrypt(byte[] data, byte[] key) throws Exception {

// 生成一个可信任的随机数源

SecureRandom sr = new SecureRandom();

// 从原始密钥数据创建DESKeySpec对象

DESKeySpec dks = new DESKeySpec(key);

// 创建一个密钥工厂,然后用它把DESKeySpec转换成SecretKey对象

SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);

SecretKey securekey = keyFactory.generateSecret(dks);

// Cipher对象实际完成加密操作

Cipher cipher = Cipher.getInstance(DES);

// 用密钥初始化Cipher对象

cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);

return cipher.doFinal(data);

}

/**

* Description 根据键值进行解密

*

* @param data

* @param key

* 加密键byte数组

* @return

* @throws Exception

*/

private static byte[] decrypt(byte[] data, byte[] key) throws Exception {

// 生成一个可信任的随机数源

SecureRandom sr = new SecureRandom();

// 从原始密钥数据创建DESKeySpec对象

DESKeySpec dks = new DESKeySpec(key);

// 创建一个密钥工厂,然后用它把DESKeySpec转换成SecretKey对象

SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);

SecretKey securekey = keyFactory.generateSecret(dks);

// Cipher对象实际完成解密操作

Cipher cipher = Cipher.getInstance(DES);

// 用密钥初始化Cipher对象

cipher.init(Cipher.DECRYPT_MODE, securekey, sr);

return cipher.doFinal(data);

}

}

ZipUtil2

.

复制代码 代码如下:

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.util.zip.GZIPInputStream;

import java.util.zip.GZIPOutputStream;

// 将一个字符串按照zip方式压缩和解压缩

public class ZipUtil2 {

// 测试方法

public static void main(String[] args) throws IOException {

// 测试字符串

String str = "";

System.out.println("原长度:" + str.length());

System.out.println("压缩后:" + ZipUtil2.compress(str).length());

System.out

.println("解压缩:" + ZipUtil2.uncompress(ZipUtil2.compress(str)));

}

// 压缩

public static String compress(String str) throws IOException {

if (str == null || str.length() == 0) {

return str;

}

ByteArrayOutputStream out = new ByteArrayOutputStream();

GZIPOutputStream gzip = new GZIPOutputStream(out);

gzip.write(str.getBytes());

gzip.close();

return out.toString("ISO-8859-1");

}

// 解压缩

public static String uncompress(String str) throws IOException {

if (str == null || str.length() == 0) {

return str;

}

ByteArrayOutputStream out = new ByteArrayOutputStream();

ByteArrayInputStream in = new ByteArrayInputStream(

str.getBytes("ISO-8859-1"));

GZIPInputStream gunzip = new GZIPInputStream(in);

byte[] buffer = new byte[256];

int n;

while ((n = gunzip.read(buffer)) >= 0) {

out.write(buffer, 0, n);

}

// toString()使用平台默认编码,也可以显式的指定如toString("GBK")

return out.toString();

}

}

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