Java example source code file (ZipFile.c)

This example Java source code file (ZipFile.c) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

bufsize, deflated, jnicall, jniexport, jnu_newstringplatform, jnu_throwoutofmemoryerror, maxname, null, open_delete, open_read, stored, throwzipexception, win32, zip_getentry

The ZipFile.c Java example source code

/*
 * Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * Native method support for java.util.zip.ZipFile
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <assert.h>
#include "jlong.h"
#include "jvm.h"
#include "jni.h"
#include "jni_util.h"
#include "zip_util.h"
#ifdef WIN32
#include "io_util_md.h"
#else
#include "io_util.h"
#endif

#include "java_util_zip_ZipFile.h"
#include "java_util_jar_JarFile.h"

#define DEFLATED 8
#define STORED 0

static jfieldID jzfileID;

static int OPEN_READ = java_util_zip_ZipFile_OPEN_READ;
static int OPEN_DELETE = java_util_zip_ZipFile_OPEN_DELETE;

JNIEXPORT void JNICALL
Java_java_util_zip_ZipFile_initIDs(JNIEnv *env, jclass cls)
{
    jzfileID = (*env)->GetFieldID(env, cls, "jzfile", "J");
    assert(jzfileID != 0);
}

static void
ThrowZipException(JNIEnv *env, const char *msg)
{
    jstring s = NULL;
    jobject x;

    if (msg != NULL) {
        s = JNU_NewStringPlatform(env, msg);
    }
    x = JNU_NewObjectByName(env,
                            "java/util/zip/ZipException",
                            "(Ljava/lang/String;)V", s);
    if (x != NULL) {
        (*env)->Throw(env, x);
    }
}

JNIEXPORT jlong JNICALL
Java_java_util_zip_ZipFile_open(JNIEnv *env, jclass cls, jstring name,
                                        jint mode, jlong lastModified,
                                        jboolean usemmap)
{
    const char *path = JNU_GetStringPlatformChars(env, name, 0);
    char *msg = 0;
    jlong result = 0;
    int flag = 0;
    jzfile *zip = 0;

    if (mode & OPEN_READ) flag |= O_RDONLY;
    if (mode & OPEN_DELETE) flag |= JVM_O_DELETE;

    if (path != 0) {
        zip = ZIP_Get_From_Cache(path, &msg, lastModified);
        if (zip == 0 && msg == 0) {
            ZFILE zfd = 0;
#ifdef WIN32
            zfd = winFileHandleOpen(env, name, flag);
            if (zfd == -1) {
                /* Exception already pending. */
                goto finally;
            }
#else
            zfd = JVM_Open(path, flag, 0);
            if (zfd < 0) {
                throwFileNotFoundException(env, name);
                goto finally;
            }
#endif
            zip = ZIP_Put_In_Cache0(path, zfd, &msg, lastModified, usemmap);
        }

        if (zip != 0) {
            result = ptr_to_jlong(zip);
        } else if (msg != 0) {
            ThrowZipException(env, msg);
            free(msg);
        } else if (errno == ENOMEM) {
            JNU_ThrowOutOfMemoryError(env, 0);
        } else {
            ThrowZipException(env, "error in opening zip file");
        }
finally:
        JNU_ReleaseStringPlatformChars(env, name, path);
    }
    return result;
}

JNIEXPORT jint JNICALL
Java_java_util_zip_ZipFile_getTotal(JNIEnv *env, jclass cls, jlong zfile)
{
    jzfile *zip = jlong_to_ptr(zfile);

    return zip->total;
}

JNIEXPORT jboolean JNICALL
Java_java_util_zip_ZipFile_startsWithLOC(JNIEnv *env, jclass cls, jlong zfile)
{
    jzfile *zip = jlong_to_ptr(zfile);

    return zip->locsig;
}

JNIEXPORT void JNICALL
Java_java_util_zip_ZipFile_close(JNIEnv *env, jclass cls, jlong zfile)
{
    ZIP_Close(jlong_to_ptr(zfile));
}

JNIEXPORT jlong JNICALL
Java_java_util_zip_ZipFile_getEntry(JNIEnv *env, jclass cls, jlong zfile,
                                    jbyteArray name, jboolean addSlash)
{
#define MAXNAME 1024
    jzfile *zip = jlong_to_ptr(zfile);
    jsize ulen = (*env)->GetArrayLength(env, name);
    char buf[MAXNAME+2], *path;
    jzentry *ze;

    if (ulen > MAXNAME) {
        path = malloc(ulen + 2);
        if (path == 0) {
            JNU_ThrowOutOfMemoryError(env, 0);
            return 0;
        }
    } else {
        path = buf;
    }
    (*env)->GetByteArrayRegion(env, name, 0, ulen, (jbyte *)path);
    path[ulen] = '\0';
    if (addSlash == JNI_FALSE) {
        ze = ZIP_GetEntry(zip, path, 0);
    } else {
        ze = ZIP_GetEntry(zip, path, (jint)ulen);
    }
    if (path != buf) {
        free(path);
    }
    return ptr_to_jlong(ze);
}

JNIEXPORT void JNICALL
Java_java_util_zip_ZipFile_freeEntry(JNIEnv *env, jclass cls, jlong zfile,
                                    jlong zentry)
{
    jzfile *zip = jlong_to_ptr(zfile);
    jzentry *ze = jlong_to_ptr(zentry);
    ZIP_FreeEntry(zip, ze);
}

JNIEXPORT jlong JNICALL
Java_java_util_zip_ZipFile_getNextEntry(JNIEnv *env, jclass cls, jlong zfile,
                                        jint n)
{
    jzentry *ze = ZIP_GetNextEntry(jlong_to_ptr(zfile), n);
    return ptr_to_jlong(ze);
}

JNIEXPORT jint JNICALL
Java_java_util_zip_ZipFile_getEntryMethod(JNIEnv *env, jclass cls, jlong zentry)
{
    jzentry *ze = jlong_to_ptr(zentry);
    return ze->csize != 0 ? DEFLATED : STORED;
}

JNIEXPORT jint JNICALL
Java_java_util_zip_ZipFile_getEntryFlag(JNIEnv *env, jclass cls, jlong zentry)
{
    jzentry *ze = jlong_to_ptr(zentry);
    return ze->flag;
}

JNIEXPORT jlong JNICALL
Java_java_util_zip_ZipFile_getEntryCSize(JNIEnv *env, jclass cls, jlong zentry)
{
    jzentry *ze = jlong_to_ptr(zentry);
    return ze->csize != 0 ? ze->csize : ze->size;
}

JNIEXPORT jlong JNICALL
Java_java_util_zip_ZipFile_getEntrySize(JNIEnv *env, jclass cls, jlong zentry)
{
    jzentry *ze = jlong_to_ptr(zentry);
    return ze->size;
}

JNIEXPORT jlong JNICALL
Java_java_util_zip_ZipFile_getEntryTime(JNIEnv *env, jclass cls, jlong zentry)
{
    jzentry *ze = jlong_to_ptr(zentry);
    return (jlong)ze->time & 0xffffffffUL;
}

JNIEXPORT jlong JNICALL
Java_java_util_zip_ZipFile_getEntryCrc(JNIEnv *env, jclass cls, jlong zentry)
{
    jzentry *ze = jlong_to_ptr(zentry);
    return (jlong)ze->crc & 0xffffffffUL;
}

JNIEXPORT jbyteArray JNICALL
Java_java_util_zip_ZipFile_getCommentBytes(JNIEnv *env,
                                           jclass cls,
                                           jlong zfile)
{
    jzfile *zip = jlong_to_ptr(zfile);
    jbyteArray jba = NULL;

    if (zip->comment != NULL) {
        if ((jba = (*env)->NewByteArray(env, zip->clen)) == NULL)
            return NULL;
        (*env)->SetByteArrayRegion(env, jba, 0, zip->clen, (jbyte*)zip->comment);
    }
    return jba;
}

JNIEXPORT jbyteArray JNICALL
Java_java_util_zip_ZipFile_getEntryBytes(JNIEnv *env,
                                         jclass cls,
                                         jlong zentry, jint type)
{
    jzentry *ze = jlong_to_ptr(zentry);
    int len = 0;
    jbyteArray jba = NULL;
    switch (type) {
    case java_util_zip_ZipFile_JZENTRY_NAME:
        if (ze->name != 0) {
            len = (int)strlen(ze->name);
            if (len == 0 || (jba = (*env)->NewByteArray(env, len)) == NULL)
                break;
            (*env)->SetByteArrayRegion(env, jba, 0, len, (jbyte *)ze->name);
        }
        break;
    case java_util_zip_ZipFile_JZENTRY_EXTRA:
        if (ze->extra != 0) {
            unsigned char *bp = (unsigned char *)&ze->extra[0];
            len = (bp[0] | (bp[1] << 8));
            if (len <= 0 || (jba = (*env)->NewByteArray(env, len)) == NULL)
                break;
            (*env)->SetByteArrayRegion(env, jba, 0, len, &ze->extra[2]);
        }
        break;
    case java_util_zip_ZipFile_JZENTRY_COMMENT:
        if (ze->comment != 0) {
            len = (int)strlen(ze->comment);
            if (len == 0 || (jba = (*env)->NewByteArray(env, len)) == NULL)
                break;
            (*env)->SetByteArrayRegion(env, jba, 0, len, (jbyte*)ze->comment);
        }
        break;
    }
    return jba;
}

JNIEXPORT jint JNICALL
Java_java_util_zip_ZipFile_read(JNIEnv *env, jclass cls, jlong zfile,
                                jlong zentry, jlong pos, jbyteArray bytes,
                                jint off, jint len)
{
    jzfile *zip = jlong_to_ptr(zfile);
    char *msg;

#define BUFSIZE 8192
    /* copy via tmp stack buffer: */
    jbyte buf[BUFSIZE];

    if (len > BUFSIZE) {
        len = BUFSIZE;
    }

    ZIP_Lock(zip);
    len = ZIP_Read(zip, jlong_to_ptr(zentry), pos, buf, len);
    msg = zip->msg;
    ZIP_Unlock(zip);
    if (len != -1) {
        (*env)->SetByteArrayRegion(env, bytes, off, len, buf);
    }

    if (len == -1) {
        if (msg != 0) {
            ThrowZipException(env, msg);
        } else {
            char errmsg[128];
            sprintf(errmsg, "errno: %d, error: %s\n",
                    errno, "Error reading ZIP file");
            JNU_ThrowIOExceptionWithLastError(env, errmsg);
        }
    }

    return len;
}

/*
 * Returns an array of strings representing the names of all entries
 * that begin with "META-INF/" (case ignored). This native method is
 * used in JarFile as an optimization when looking up manifest and
 * signature file entries. Returns null if no entries were found.
 */
JNIEXPORT jobjectArray JNICALL
Java_java_util_jar_JarFile_getMetaInfEntryNames(JNIEnv *env, jobject obj)
{
    jlong zfile = (*env)->GetLongField(env, obj, jzfileID);
    jzfile *zip;
    int i, count;
    jobjectArray result = 0;

    if (zfile == 0) {
        JNU_ThrowByName(env,
                        "java/lang/IllegalStateException", "zip file closed");
        return NULL;
    }
    zip = jlong_to_ptr(zfile);

    /* count the number of valid ZIP metanames */
    count = 0;
    if (zip->metanames != 0) {
        for (i = 0; i < zip->metacount; i++) {
            if (zip->metanames[i] != 0) {
                count++;
            }
        }
    }

    /* If some names were found then build array of java strings */
    if (count > 0) {
        jclass cls = (*env)->FindClass(env, "java/lang/String");
        result = (*env)->NewObjectArray(env, count, cls, 0);
        if (result != 0) {
            for (i = 0; i < count; i++) {
                jstring str = (*env)->NewStringUTF(env, zip->metanames[i]);
                if (str == 0) {
                    break;
                }
                (*env)->SetObjectArrayElement(env, result, i, str);
                (*env)->DeleteLocalRef(env, str);
            }
        }
    }
    return result;
}

JNIEXPORT jstring JNICALL
Java_java_util_zip_ZipFile_getZipMessage(JNIEnv *env, jclass cls, jlong zfile)
{
    jzfile *zip = jlong_to_ptr(zfile);
    char *msg = zip->msg;
    if (msg == NULL) {
        return NULL;
    }
    return JNU_NewStringPlatform(env, msg);
}