在BlackBerry Java应用中压缩文件

Question

Does anyone know how to zip a file using ZipOutputStream ?

try {
    // Creating Zip Streams
    FileConnection path = (FileConnection) Connector.open(
            "file:///SDCard/BlackBerry/documents/" + "status.zip",
            Connector.READ_WRITE);

    if (!path.exists()) {
        path.create();
    }
    ZipOutputStream zinstream = new ZipOutputStream(
            path.openOutputStream());

    // Adding Entries
    FileConnection jsonfile = (FileConnection) Connector.open(
            "file:///SDCard/BlackBerry/documents/" + "status.json",
            Connector.READ_WRITE);
    if (!jsonfile.exists()) {
        jsonfile.create();
    }
    int fileSize = (int) jsonfile.fileSize();
    if (fileSize > -1) {
        byte[] data = new byte[fileSize];
        InputStream input = jsonfile.openInputStream();
        input.read(data);

        ZipEntry entry = new ZipEntry(jsonfile.getName());
        zinstream.putNextEntry(entry);
        // zinstream.write(buf);
        // ZipEntry entry = null;

        path.setWritable(true);
        OutputStream out = path.openOutputStream();

        int len;
        while ((len = input.read(data)) != -1) {
            out.write(data, 0, len);
            out.flush();
            out.close();
            zinstream.close();
            content = "FILE EXIST" + entry;
        }

        jsonfile.close();
        path.close();
    }
} catch (...) {
    ...
}

Answer 1

The data should be written to the ZipOutputStream zinstream instead of to a new OutputStream out .

Its also important to close the ZipEntry entry after writing is done.

FileConnection path = (FileConnection) Connector.open(
        "file:///SDCard/BlackBerry/documents/" + "status.zip",
        Connector.READ_WRITE);

if (!path.exists()) {
    path.create();
}
ZipOutputStream zinstream = new ZipOutputStream(path.openOutputStream());

// Adding Entries
FileConnection jsonfile = (FileConnection) Connector.open(
        "file:///SDCard/BlackBerry/documents/" + "status.json",
        Connector.READ_WRITE);
if (!jsonfile.exists()) {
    jsonfile.create();
}
int fileSize = (int) jsonfile.fileSize();
if (fileSize > -1) {
    InputStream input = jsonfile.openInputStream();
    byte[] data = new byte[1024];

    ZipEntry entry = new ZipEntry(jsonfile.getName());
    zinstream.putNextEntry(entry);

    int len;
    while ((len = input.read(data)) > 0) {
        zinstream.write(data, 0, len);
    }
    zinstream.closeEntry();
}
jsonfile.close();
zinstream.close();
path.close();

Answer 2

BlackBerry uses the J2ME API which does not have all of the J2SE classes, such as the ZipOutputStream and ZipEntry and related classes. There are some classes such as ZLibOutputStream which may help, but that is just the byte-level compression and you'll end up having to implement the actual PKZIP container yourself (unless there is a third-party library out there that can do this for you).