If you use the compression toolkit that comes with Java to implement the function of decompressing files to the specified folder, because the zip provided by jdk can only be processed in UTF-8 format, and the file name in Windows system is encoded in GBK, so if It is to unzip a zip package containing the Chinese file name, and it will report an illegal parameter exception. Therefore, to implement decompression, you must deflaterOutputStream.java, InflaterInputStream.java, ZipConstants.java, ZipEntry.java, ZipInputStream.java, and ZipOutputStream.java. The relevant classes are modified, and the process is as follows:
Since J2SE 1.4, the Java compiler no longer supports importing classes or interfaces for unnamed package names, so in the Java project you create, you must create a new package that you define yourself. The format of the package naming is generally in the reverse order of the school domain name +Own network name, such as cn.edu.xidian.crytoll.
Create a new DeflaterOutputStream class in the package, the code is as follows:
DeflaterOutputStream.java:
The code copy is as follows:
package cn.edu.xdian.crytoll;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.zip.Deflater;
/**
* This class implements an output stream filter for compressing data in
* the "deflate" compression format. It is also used as the basis for other
* types of compression filters, such as GZIPOutputStream.
*
* @see Deflater
* @version 1.36, 03/13/06
* @author David Connelly
*/
public
class DeflaterOutputStream extends FilterOutputStream {
/**
* Compressor for this stream.
*/
protected Deflater def;
/**
* Output buffer for writing compressed data.
*/
protected byte[] buf;
/**
* Indicates that the stream has been closed.
*/
private boolean closed = false;
/**
* Creates a new output stream with the specified compressor and
* buffer size.
* @param out the output stream
* @param def the compressor ("deflater")
* @param size the output buffer size
* @exception IllegalArgumentException if size is <= 0
*/
public DeflaterOutputStream(OutputStream out, Deflater def, int size) {
super(out);
if (out == null || def == null) {
throw new NullPointerException();
} else if (size <= 0) {
throw new IllegalArgumentException("buffer size <= 0");
}
this.def = def;
buf = new byte[size];
}
/**
* Creates a new output stream with the specified compressor and
* a default buffer size.
* @param out the output stream
* @param def the compressor ("deflater")
*/
public DeflaterOutputStream(OutputStream out, Deflater def) {
this(out, def, 512);
}
boolean usesDefaultDeflater = false;
/**
* Creates a new output stream with a default compressor and buffer size.
* @param out the output stream
*/
public DeflaterOutputStream(OutputStream out) {
this(out, new Deflater());
usesDefaultDeflater = true;
}
/**
* Writes a byte to the compressed output stream. This method will
* block until the byte can be written.
* @param b the byte to be written
* @exception IOException if an I/O error has occurred
*/
public void write(int b) throws IOException {
byte[] buf = new byte[1];
buf[0] = (byte)(b & 0xff);
write(buf, 0, 1);
}
/**
* Writes an array of bytes to the compressed output stream. This
* method will block until all the bytes are written.
* @param b the data to be written
* @param off the start offset of the data
* @param len the length of the data
* @exception IOException if an I/O error has occurred
*/
public void write(byte[] b, int off, int len) throws IOException {
if (def.finished()) {
throw new IOException("write beyond end of stream");
}
if ((off | len | (off + len) | (b.length - (off + len))) < 0) {
throw new IndexOutOfBoundsException();
} else if (len == 0) {
return;
}
if (!def.finished()) {
// Deflate no more than stride bytes at a time. This avoids
// excess copying in deflateBytes (see Deflater.c)
int stride = buf.length;
for (int i = 0; i < len; i+= stride) {
def.setInput(b, off + i, Math.min(stride, len - i));
while (!def.needsInput()) {
deflate();
}
}
}
}
/**
* Finishes writing compressed data to the output stream without closing
* the underlying stream. Use this method when applying multiple filters
* in succession to the same output stream.
* @exception IOException if an I/O error has occurred
*/
public void finish() throws IOException {
if (!def.finished()) {
def.finish();
while (!def.finished()) {
deflate();
}
}
}
/**
* Writes remaining compressed data to the output stream and closes the
* underlying stream.
* @exception IOException if an I/O error has occurred
*/
public void close() throws IOException {
if (!closed) {
finish();
if (usesDefaultDeflater)
def.end();
out.close();
closed = true;
}
}
/**
* Writes next block of compressed data to the output stream.
* @throws IOException if an I/O error has occurred
*/
protected void deflate() throws IOException {
int len = def.deflate(buf, 0, buf.length);
if (len > 0) {
out.write(buf, 0, len);
}
}
}