賦值不是表達式，在此上下文中只允許使用表達式 - 將Java轉換為Kotlin時出錯

Question

我有很好的托管代碼和Java項目。 但我需要在Kotlin開發另一個項目。 所以，我在Kotlin盡可能地轉換了所有代碼。 但是有ZipFileManager.kt代碼用於壓縮/解壓縮文件。

這是代碼（ Kotlin ）：

object ZipFileManager {

    private val BUFFER_SIZE = 6 * 1024

    @Throws(IOException::class)
    fun zip(files: Array<String>, zipFile: String) {
        var origin: BufferedInputStream? = null
        val out = ZipOutputStream(BufferedOutputStream(FileOutputStream(zipFile)))
        try {
            val data = ByteArray(BUFFER_SIZE)

            for (file in files) {
                val fi = FileInputStream(file)
                origin = BufferedInputStream(fi, BUFFER_SIZE)
                try {
                    val entry = ZipEntry(file.substring(file.lastIndexOf("/") + 1))
                    out.putNextEntry(entry)
                    var count: Int
                    while ((count = origin.read(data, 0, BUFFER_SIZE)) != -1)     {
                        out.write(data, 0, count)
                    }
                } finally {
                    origin.close()
                }
            }
        } finally {
            out.close()
        }
    }

    fun unzip(zipFileUrl: String, fileLocation: String) {
        try {
            val f = File(fileLocation)
            if (!f.isDirectory) {
                f.mkdirs()
            }
            ZipInputStream(FileInputStream(zipFileUrl)).use { zin ->
                var ze: ZipEntry? = null
                while ((ze = zin.nextEntry) != null) {
                    //                    Log.e("UnZipFILE", "Unzipping....");
                    val path = fileLocation + ze!!.name

                    if (ze.isDirectory) {
                        val unzipFile = File(path)
                        if (!unzipFile.isDirectory) {
                            unzipFile.mkdirs()
                        }
                    } else {
                        FileOutputStream(path, false).use { fout ->
                            val buffer = ByteArray(1024)
                            var read: Int
                            while ((read = zin.read(buffer)) != -1) {
                                fout.write(buffer, 0, read)
                            }
                            zin.closeEntry()
                        }
                    }
                }
            }
        } catch (e: Exception) {
            e.printStackTrace()
            Log.e("UnZipException", Log.getStackTraceString(e))
        }

    }
}

所以，我正在嘗試通過此代碼，但它顯示編譯時錯誤，如：

Assignments are not expressions, and only expressions are allowed in this context中Assignments are not expressions, and only expressions are allowed in this context在行中的fun zip中while ((count = origin.read(data, 0, BUFFER_SIZE)) != -1)

while ((ze = zin.nextEntry) != null)和行while ((read = zin.read(buffer)) != -1)的行處給出另一個相同的編譯時錯誤。

所以，我的大問題是在Kotlin使用此代碼。 那么，任何身體都可以幫助誰知道Kotlin以及如何在Kotlin使用這種類型的循環結構？

如果有人想看到我也有Java代碼：

public class ZipFileManager {

    private static int BUFFER_SIZE = 6 * 1024;

    public static void zip(String[] files, String zipFile) throws IOException {
        BufferedInputStream origin = null;
        ZipOutputStream out = new ZipOutputStream(new BufferedOutputStream(new FileOutputStream(zipFile)));
        try {
            byte data[] = new byte[BUFFER_SIZE];

            for (String file : files) {
                FileInputStream fi = new FileInputStream(file);
                origin = new BufferedInputStream(fi, BUFFER_SIZE);
                try {
                    ZipEntry entry = new ZipEntry(file.substring(file.lastIndexOf("/") + 1));
                    out.putNextEntry(entry);
                    int count;
                    while ((count = origin.read(data, 0, BUFFER_SIZE)) != -1) {
                        out.write(data, 0, count);
                    }
                } finally {
                    origin.close();
                }
            }
        } finally {
            out.close();
        }
    }

    public static void unzip(String zipFileUrl, String fileLocation) {
        try {
            File f = new File(fileLocation);
            if (!f.isDirectory()) {
                f.mkdirs();
            }
            try (ZipInputStream zin = new ZipInputStream(new FileInputStream(zipFileUrl))) {
                ZipEntry ze = null;
                while ((ze = zin.getNextEntry()) != null) {
//                    Log.e("UnZipFILE", "Unzipping....");
                    String path = fileLocation + ze.getName();

                    if (ze.isDirectory()) {
                        File unzipFile = new File(path);
                        if (!unzipFile.isDirectory()) {
                            unzipFile.mkdirs();
                        }
                    } else {
                        try (FileOutputStream fout = new FileOutputStream(path, false)) {
                            byte[] buffer = new byte[1024];
                            int read;
                            while ((read = zin.read(buffer)) != -1) {
                                fout.write(buffer, 0, read);
                            }
                            zin.closeEntry();
                        }
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
            Log.e("UnZipException", Log.getStackTraceString(e));
        }
    }
}

我也嘗試管理循環：

do {
    ze = zin.nextEntry
} while (ze != null)

但是文件沒有正確解壓縮或破壞。 所以，如果有任何機構有想法管理這種類型的循環，那將非常有幫助。

Answer 1

我正在將您的Java代碼轉換為Kotlin

我之前遇到過這個問題。 Assignments are not expressions, and only expressions are allowed in this context

在這里使用此代碼是您的解決方案

object ZipFileManager {

private val BUFFER_SIZE = 6 * 1024
@Throws(IOException::class)
fun zip(files: Array<String>, zipFile: String) {
    var origin: BufferedInputStream? = null
    val out = ZipOutputStream(BufferedOutputStream(FileOutputStream(zipFile)))
    try {
        val data = ByteArray(BUFFER_SIZE)

        for (file in files) {
            val fi = FileInputStream(file)
            origin = BufferedInputStream(fi, BUFFER_SIZE)
            try {
                val entry = ZipEntry(file.substring(file.lastIndexOf("/") + 1))
                out.putNextEntry(entry)
                var count: Int= origin.read(data, 0, BUFFER_SIZE);
                while (count != -1) {
                    out.write(data, 0, count)
                    count = origin.read(data, 0, BUFFER_SIZE)
                }
            } finally {
                origin.close()
            }
        }
    } finally {
        out.close()
    }
}

fun unzip(zipFileUrl: String, fileLocation: String) {
    try {
        val f = File(fileLocation)
        if (!f.isDirectory) {
            f.mkdirs()
        }
        ZipInputStream(FileInputStream(zipFileUrl)).use { zin ->
            var ze: ZipEntry? = null
            ze = zin.nextEntry
            while (ze != null) {
                //                    Log.e("UnZipFILE", "Unzipping....");
                val path = fileLocation + ze!!.name

                if (ze.isDirectory) {
                    val unzipFile = File(path)
                    if (!unzipFile.isDirectory) {
                        unzipFile.mkdirs()
                    }
                } else {
                    FileOutputStream(path, false).use { fout ->
                        val buffer = ByteArray(1024)
                        var read: Int= zin.read(buffer)
                        while (read != -1) {
                            fout.write(buffer, 0, read)
                            read = zin.read(buffer)
                        }
                        zin.closeEntry()
                    }
                }
                ze = zin.nextEntry
            }
        }
    } catch (e: Exception) {
        e.printStackTrace()
        Log.e("UnZipException", Log.getStackTraceString(e))
    }
  }
}