Java压缩字符串的方法收集

说明：

1、一般来说要实现压缩，那么返回方式一般是用byte[]数组。

2、研究发现byte[]数组在转成可读的String时，大小会还原回原来的。

3、如果采用压缩之后不可读的String时，互相转换大小会变小，唯一缺点就是转出的String不可读，需要再次解码之后才可读。

4、对于压缩一般最近常听的应该就是gzip这些。

实现一：

/*** * 压缩GZip * * @param data * @return */ public static byte[] gZip(byte[] data) { byte[] b = null; try { ByteArrayOutputStream bos = new ByteArrayOutputStream(); GZIPOutputStream gzip = new GZIPOutputStream(bos); gzip.write(data); gzip.finish(); gzip.close(); b = bos.toByteArray(); bos.close(); } catch (Exception ex) { ex.printStackTrace(); } return b; } /*** * 解压GZip * * @param data * @return */ public static byte[] unGZip(byte[] data) { byte[] b = null; try { ByteArrayInputStream bis = new ByteArrayInputStream(data); GZIPInputStream gzip = new GZIPInputStream(bis); byte[] buf = new byte[1024]; int num = -1; ByteArrayOutputStream baos = new ByteArrayOutputStream(); while ((num = gzip.read(buf, 0, buf.length)) != -1) { baos.write(buf, 0, num); } b = baos.toByteArray(); baos.flush(); baos.close(); gzip.close(); bis.close(); } catch (Exception ex) { ex.printStackTrace(); } return b; } /*** * 压缩Zip * * @param data * @return */ public static byte[] zip(byte[] data) { byte[] b = null; try { ByteArrayOutputStream bos = new ByteArrayOutputStream(); ZipOutputStream zip = new ZipOutputStream(bos); ZipEntry entry = new ZipEntry("zip"); entry.setSize(data.length); zip.putNextEntry(entry); zip.write(data); zip.closeEntry(); zip.close(); b = bos.toByteArray(); bos.close(); } catch (Exception ex) { ex.printStackTrace(); } return b; } /*** * 解压Zip * * @param data * @return */ public static byte[] unZip(byte[] data) { byte[] b = null; try { ByteArrayInputStream bis = new ByteArrayInputStream(data); ZipInputStream zip = new ZipInputStream(bis); while (zip.getNextEntry() != null) { byte[] buf = new byte[1024]; int num = -1; ByteArrayOutputStream baos = new ByteArrayOutputStream(); while ((num = zip.read(buf, 0, buf.length)) != -1) { baos.write(buf, 0, num); } b = baos.toByteArray(); baos.flush(); baos.close(); } zip.close(); bis.close(); } catch (Exception ex) { ex.printStackTrace(); } return b; } /*** * 压缩BZip2 * * @param data * @return */ public static byte[] bZip2(byte[] data) { byte[] b = null; try { ByteArrayOutputStream bos = new ByteArrayOutputStream(); CBZip2OutputStream bzip2 = new CBZip2OutputStream(bos); bzip2.write(data); bzip2.flush(); bzip2.close(); b = bos.toByteArray(); bos.close(); } catch (Exception ex) { ex.printStackTrace(); } return b; } /*** * 解压BZip2 * * @param data * @return */ public static byte[] unBZip2(byte[] data) { byte[] b = null; try { ByteArrayInputStream bis = new ByteArrayInputStream(data); CBZip2InputStream bzip2 = new CBZip2InputStream(bis); byte[] buf = new byte[1024]; int num = -1; ByteArrayOutputStream baos = new ByteArrayOutputStream(); while ((num = bzip2.read(buf, 0, buf.length)) != -1) { baos.write(buf, 0, num); } b = baos.toByteArray(); baos.flush(); baos.close(); bzip2.close(); bis.close(); } catch (Exception ex) { ex.printStackTrace(); } return b; } /** * 把字节数组转换成16进制字符串 * * @param bArray * @return */ public static String bytesToHexString(byte[] bArray) { StringBuffer sb = new StringBuffer(bArray.length); String sTemp; for (int i = 0; i < bArray.length; i++) { sTemp = Integer.toHexString(0xFF & bArray[i]); if (sTemp.length() < 2) sb.append(0); sb.append(sTemp.toUpperCase()); } return sb.toString(); } /** *jzlib 压缩数据 * * @param object * @return * @throws IOException */ public static byte[] jzlib(byte[] object) { byte[] data = null; try { ByteArrayOutputStream out = new ByteArrayOutputStream(); ZOutputStream zOut = new ZOutputStream(out, JZlib.Z_DEFAULT_COMPRESSION); DataOutputStream objOut = new DataOutputStream(zOut); objOut.write(object); objOut.flush(); zOut.close(); data = out.toByteArray(); out.close(); } catch (IOException e) { e.printStackTrace(); } return data; } /** *jzLib压缩的数据 * * @param object * @return * @throws IOException */ public static byte[] unjzlib(byte[] object) { byte[] data = null; try { ByteArrayInputStream in = new ByteArrayInputStream(object); ZInputStream zIn = new ZInputStream(in); byte[] buf = new byte[1024]; int num = -1; ByteArrayOutputStream baos = new ByteArrayOutputStream(); while ((num = zIn.read(buf, 0, buf.length)) != -1) { baos.write(buf, 0, num); } data = baos.toByteArray(); baos.flush(); baos.close(); zIn.close(); in.close(); } catch (IOException e) { e.printStackTrace(); } return data; } public static void main(String[] args) { String s = "this is a test"; byte[] b1 = zip(s.getBytes()); System.out.println("zip:" + bytesToHexString(b1)); byte[] b2 = unZip(b1); System.out.println("unZip:" + new String(b2)); byte[] b3 = bZip2(s.getBytes()); System.out.println("bZip2:" + bytesToHexString(b3)); byte[] b4 = unBZip2(b3); System.out.println("unBZip2:" + new String(b4)); byte[] b5 = gZip(s.getBytes()); System.out.println("bZip2:" + bytesToHexString(b5)); byte[] b6 = unGZip(b5); System.out.println("unBZip2:" + new String(b6)); byte[] b7 = jzlib(s.getBytes()); System.out.println("jzlib:" + bytesToHexString(b7)); byte[] b8 = unjzlib(b7); System.out.println("unjzlib:" + new String(b8)); } }

实现二：

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 ZipUtil { // 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(); } // 测试方法 public static void main(String[] args) throws IOException { System.out.println(ZipUtil.uncompress(ZipUtil.compress("中国China"))); } }

实现三：

import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.util.zip.ZipEntry; import java.util.zip.ZipInputStream; import java.util.zip.ZipOutputStream; public class StringCompress { public static final byte[] compress(String paramString) { if (paramString == null) return null; ByteArrayOutputStream byteArrayOutputStream = null; ZipOutputStream zipOutputStream = null; byte[] arrayOfByte; try { byteArrayOutputStream = new ByteArrayOutputStream(); zipOutputStream = new ZipOutputStream(byteArrayOutputStream); zipOutputStream.putNextEntry(new ZipEntry("0")); zipOutputStream.write(paramString.getBytes()); zipOutputStream.closeEntry(); arrayOfByte = byteArrayOutputStream.toByteArray(); } catch (IOException localIOException5) { arrayOfByte = null; } finally { if (zipOutputStream != null) try { zipOutputStream.close(); } catch (IOException localIOException6) { } if (byteArrayOutputStream != null) try { byteArrayOutputStream.close(); } catch (IOException localIOException7) { } } return arrayOfByte; } @SuppressWarnings("unused") public static final String decompress(byte[] paramArrayOfByte) { if (paramArrayOfByte == null) return null; ByteArrayOutputStream byteArrayOutputStream = null; ByteArrayInputStream byteArrayInputStream = null; ZipInputStream zipInputStream = null; String str; try { byteArrayOutputStream = new ByteArrayOutputStream(); byteArrayInputStream = new ByteArrayInputStream(paramArrayOfByte); zipInputStream = new ZipInputStream(byteArrayInputStream); ZipEntry localZipEntry = zipInputStream.getNextEntry(); byte[] arrayOfByte = new byte[1024]; int i = -1; while ((i = zipInputStream.read(arrayOfByte)) != -1) byteArrayOutputStream.write(arrayOfByte, 0, i); str = byteArrayOutputStream.toString(); } catch (IOException localIOException7) { str = null; } finally { if (zipInputStream != null) try { zipInputStream.close(); } catch (IOException localIOException8) { } if (byteArrayInputStream != null) try { byteArrayInputStream.close(); } catch (IOException localIOException9) { } if (byteArrayOutputStream != null) try { byteArrayOutputStream.close(); } catch (IOException localIOException10) { } } return str; } } 

 

参考：

https://www.cnblogs.com/dongzhongwei/p/5964758.html（以上内容部分转自此篇文章）

http://www.blogjava.net/fastunit/archive/2008/04/25/195932.html（以上内容部分转自此篇文章）

http://blog.csdn.net/xyw591238/article/details/51720016（以上内容部分转自此篇文章）