JAVA处理字符串压缩以及文件压缩

字符串压缩：

之前在做Android客户端开发的时候，需要请求一个字典类型的http请求接口，由于接口json数据过大，达到6M，当时建议后端对接口返回的json数据逻辑进行处理，在服务端将json串压缩，然后在客户端进行解压，最后在将数据显示在客户端。

Java实现字符串压缩API：

压缩算法有多种，我说知道和接触有java I/O自带的zip和gzip两种方式，此次的压缩和解压用到的主要就是GZIPOutputStream和GZIPInputStream类，看一下例子:

字符串压缩代码：

public static String compress(String source) {ByteArrayOutputStream bos = new ByteArrayOutputStream();try {GZIPOutputStream gos = new GZIPOutputStream(bos);gos.write(source.getBytes("ISO-8859-1"));gos.close();return bos.toString("ISO-8859-1");} catch (IOException var3) {System.out.println(var3.getStackTrace().toString());return source;}
}

字符串解压代码：

/***** @Method compress  字符串解压方法* @author source 需要传入待解压的字符串* 返回值   返回解压后的字符串****/public static String uncompress(String source) {if (source != null && source.length() != 0) {try {ByteArrayOutputStream bos = new ByteArrayOutputStream();ByteArrayInputStream bis = new ByteArrayInputStream(source.getBytes("ISO-8859-1"));GZIPInputStream gis = new GZIPInputStream(bis);byte[] data = new byte[1024];for(int len = gis.read(data); len != -1; len = gis.read(data)) {bos.write(data, 0, len);}return bos.toString();} catch (IOException var6) {System.out.println(var6.getStackTrace().toString());return source;}} else {return source;}}

测试代码：

public static void main(String[] args) {// 字符串超过一定的长度  String str = "ggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggfdgfdgf"+ "ggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg"+ "gggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggABCdef123中文~!@#$%^&*()_+{fd}"+ ";/1111111111111111111111111AAAAAAAAAAAJDLFJDLFJDLFJLDFFFFJEIIIIIIIIIIFJJJJJJJJJJJJALLLLLLLLLLLLLLLLLLLLLLdddddddddddddddddfdfdfdfdfdfdd"+ "dddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddessdfrdfdfd"+ "ddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd"+ "ddddddddddddddddddddddddddddddddddddddddddddddddddddddgfgggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggf"+ "ddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd"+ "ddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd"+ "ddddddddddddddddddddddddddddddddddddddddddddggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg" +  "LLppppppppppppppppppppppppppppppppppppppppp===========================------------------------------iiiiiiiiiiiiiiiiiiiiiiiggggggggggggg";//字符串原始长度处理String originalStr = str;System.out.println("原始的字符串长度:" + originalStr.length());//字符串压缩状态处理String compressStr = compress(originalStr);System.out.println("压缩的字符串长度:" + compressStr.length());//字符串解压方法以及测试解压后字符串长度String uncompress = uncompress(compressStr);System.out.println("解压后的字符串长度:" + uncompress.length());//字符串压缩率float rate = (float)compressStr.length() / uncompress.length();System.out.println("字符串压缩率：" + rate);if(originalStr.equals(uncompress)){System.out.println("解压后的字符串和原始的字符串长度一样");}}

控制台打印输出结果：

原始的字符串长度:1474

压缩的字符串长度:136

解压后的字符串长度:1474

字符串压缩率：0.09226594

如图通过调研compress压缩方法将原始字符串压缩，原始字符串的长度为1474个字节，压缩后字符串大小变为136个字节，字符串的压缩率达到91%。

Java代码实现文件压缩与解压：

api说明：

1：添加ZipTools包(主要解决中文路径压缩解压乱码问题)

2：文件压缩需要用到的类 ZipOutputStream(zip文件压缩需要用到的类)

3：ZipEntry 压缩文件的子文件对象，用于保存压缩文件中文件及其文件夹的一个实列

4：ZipFile 压缩文件的实列，用于zip的解压操作

文件压缩相关代码：

 /***** * @Method createZipStream 创建ZIP输出流实例* @param filePath 需要压缩的文件以及路径* @param fileOutPath 生成压缩的文件以及路径* ****/public static void createZipStream(String filePath, String fileOutPath) throws IOException{OutputStream os = new FileOutputStream(fileOutPath);//根据压缩的文件路径创建要输出的文件CheckedOutputStream cos = new CheckedOutputStream(os, new CRC32());//检查输出流，采用crc算法，保证文件的一致性ZipOutputStream zos = new ZipOutputStream(cos);//定义zip文件输出流zos.setEncoding("GBK");//设置编码格式，防止中文乱码File file = new File(filePath);//需要压缩的文件以及文件夹对象compressFile(zos,file);zos.close();cos.close();os.close();System.out.println("压缩文件完成");}/***** @Method compressFile* @param ZipOutputStream zip文件输出流* @param File 要压缩的文件对象****/public static void compressFile(ZipOutputStream zos, File file) throws IOException{String fp = file.getPath().substring(3,file.getPath().length());//去掉盘符if(file.isDirectory()){//如果是文件目录，添加当前文件夹到zip文件流中zos.putNextEntry(new ZipEntry(fp + File.separator));for(File f: file.listFiles()){compressFile(zos, f);}}else{//如果是文件目录，添加当前文件到zip文件流中System.out.println("正在压缩文件:"+file.getPath());zos.putNextEntry(new ZipEntry(fp));InputStream is = new FileInputStream(file.getPath());//用字节方式读取文件BufferedInputStream bis = new BufferedInputStream(is);//创建一个缓存区byte [] b = new byte[1024];//将读取的字节写到zip文件流中while (bis.read(b) != -1) {zos.write(b);}bis.close();is.close();}}测试函数以及返回示例：public static void main(String[] args) throws IOException {createZipStream(filePath,fileOutPath);//      unCompressFile(fileOutPath);}

打印压缩文件过程：

正在压缩文件:D:\MyDrivers\backup\dgsetup.exe

正在压缩文件:D:\MyDrivers\backup\driverlist.mf

正在压缩文件:D:\MyDrivers\backup\Realtek PCIe GBE Family Controller\rt640x64.inf_amd64_98de0ddb0966f29b\rt640x64.inf

正在压缩文件:D:\MyDrivers\backup\Realtek PCIe GBE Family Controller\rt640x64.inf_amd64_98de0ddb0966f29b\rt640x64.PNF

正在压缩文件:D:\MyDrivers\backup\Realtek PCIe GBE Family Controller\rt640x64.inf_amd64_98de0ddb0966f29b\rt640x64.sys

压缩文件完成

文件解压相关函数：

/**** * @Method unCompressFile* @param filePath 需要解压的文件路径****/public static  void unCompressFile(String  filePath) throws IOException{File file = new File(filePath);if(!file.exists()){System.out.println("当前压缩文件不存在");return;}ZipFile zipFile = new ZipFile(file.getPath(),"GBK");for(Enumeration<ZipEntry> enumeration = zipFile.getEntries();enumeration.hasMoreElements();){//循环获取zip文件压缩实例ZipEntry zipEntry = enumeration.nextElement();//获取元素//如果是空文件不解压if(!zipEntry.getName().equals(File.separator)){String path = "D:\\" + zipEntry.getName();System.out.println("文件名:" + path);int len = path.length();//创建解压目录if(path.substring(len - 1, len).equals("\\")){File createFile = new File(path);if(!createFile.exists()){createFile.mkdirs();//如果当前文件不存在，则创建解压目录}}else{//创建解压后的文件OutputStream os = new FileOutputStream(new File(path));BufferedOutputStream bos = new BufferedOutputStream(os);//带缓冲的写出流InputStream is = zipFile.getInputStream(zipEntry);//读取元素BufferedInputStream bis = new BufferedInputStream(is);CheckedInputStream cis = new CheckedInputStream(bis, new CRC32());//检查读取流，用CRC算法检查文件是否一致性byte[] b = new byte[1024];//字节数组，每次读取1024个字节//循环读取解压文件的值,将zip流写入新文件中while (cis.read(b) != -1) {bos.write(b);}cis.close();bis.close();is.close();bos.close();os.close();}}else{System.out.println("目录名:" + zipEntry.getName());}}System.out.println("文件解压结束");}测试解压方法：
public static void main(String[] args) throws IOException {//       createZipStream(filePath,fileOutPath);unCompressFile(fileOutPath);}

打印解压文件结果：

文件名:D:\MyDrivers\backup\

文件名:D:\MyDrivers\update\

文件名:D:\MyDrivers\backup\dgsetup.exe

文件名:D:\MyDrivers\backup\Realtek PCIe GBE Family Controller\rt640x64.inf_amd64_98de0ddb0966f29b\

文件名:D:\MyDrivers\software\disapp\

文件名:D:\MyDrivers\backup\Realtek PCIe GBE Family Controller\rt640x64.inf_amd64_98de0ddb0966f29b\rt640x64.inf

文件名:D:\MyDrivers\backup\Realtek PCIe GBE Family Controller\

文件名:D:\MyDrivers\backup\Realtek PCIe GBE Family Controller\rt640x64.inf_amd64_98de0ddb0966f29b\rt640x64.PNF

文件名:D:\MyDrivers\backup\driverlist.mf

文件名:D:\MyDrivers\

文件名:D:\MyDrivers\backup\Realtek PCIe GBE Family Controller\rt640x64.inf_amd64_98de0ddb0966f29b\rt640x64.sys

文件名:D:\MyDrivers\hotfix\

文件名:D:\MyDrivers\software\

文件解压结束

自己封装的字符串压缩和文件压缩库：

项目目录结构截图如下：

java_zip.jar包是我封装的字符串和文件压缩jar，slf4j-api-1.7.21.jar，slf4j-nop-1.7.2.jar为代码依赖的日志包，ziptools.jar为JavaApi zip防止中文乱码开发的包。

Api演示代码如下：

public static String filePath = "D:/MyDrivers/";public static String fileOutPath = "D:/MyDrivers.zip";//在lib文件中有一个Java_zip.jarpublic static void main(String[] args) {// 字符串超过一定的长度  String str = "ggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggfdgfdgf"+ "ggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg"+ "gggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggABCdef123中文~!@#$%^&*()_+{fd}"+ ";/1111111111111111111111111AAAAAAAAAAAJDLFJDLFJDLFJLDFFFFJEIIIIIIIIIIFJJJJJJJJJJJJALLLLLLLLLLLLLLLLLLLLLLdddddddddddddddddfdfdfdfdfdfdd"+ "dddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddessdfrdfdfd"+ "ddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd"+ "ddddddddddddddddddddddddddddddddddddddddddddddddddddddgfgggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggf"+ "ddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd"+ "ddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd"+ "ddddddddddddddddddddddddddddddddddddddddddddggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg" +  "LLppppppppppppppppppppppppppppppppppppppppp===========================------------------------------iiiiiiiiiiiiiiiiiiiiiiiggggggggggggg";System.out.println("字符串初始长度:" + str.length());String compressstr = GzipUtils.compress(str);System.out.println("压缩后字符串长度:" + compressstr.length());String uncompress = GzipUtils.uncompress(compressstr);System.out.println("解压后字符串长度:" + uncompress.length());//压缩文件
//      ZipUtil.pack(new File(filePath), new File(fileOutPath));//解压文件ZipUtil.unpack(new File(fileOutPath), new File(filePath));

项目Demo地址下载：

https://download.csdn.net/download/zhangmingziliao/10969290