ZIP压缩和解压字符串

时间:2024-08-23 23:05:50

由于ZIP压缩会产生头信息, 所以当字符串长度没有达到一定规模的时候, 压缩后的长度可能比原来的还长

 // 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 { //测试字符串
String str="%5B%7B%22lastUpdateTime%22%3A%222011-10-28+9%3A39%3A41%22%2C%22smsList%22%3A%5B%7B%22liveState%22%3A%221"; System.out.println("原长度:"+str.length()); System.out.println("压缩后:"+ZipUtil.compress(str).length()); System.out.println("解压缩:"+ZipUtil.uncompress(ZipUtil.compress(str)));
}
}