long getSize()

描述 (Description)

java.util.zip.ZipEntry.getSize()方法返回条目数据的未压缩大小，如果未知，则返回-1。

声明 (Declaration)

以下是java.util.zip.ZipEntry.getSize()方法的声明。public long getSize()

返回值 (Returns)

条目数据的未压缩大小，如果未知则为-1。

先决条件

在D:》 test 》目录中创建一个文件Hello.txt，其中包含以下内容。This is an example.

例子 (Example)

以下示例显示了java.util.zip.ZipEntry.getSize()方法的用法。package com.iowiki;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.util.Date;

import java.util.Enumeration;

import java.util.zip.Adler32;

import java.util.zip.CheckedOutputStream;

import java.util.zip.ZipEntry;

import java.util.zip.ZipFile;

import java.util.zip.ZipOutputStream;

public class ZipEntryDemo {

private static String SOURCE_FILE = "D:\\test\\Hello.txt";

private static String TARGET_FILE = "D:\\test\\Hello.zip";

public static void main(String[] args) {

try {

createZipFile();

readZipFile();

} catch(IOException ioe) {

System.out.println("IOException : " + ioe);

}

}

private static void createZipFile() throws IOException{

FileOutputStream fout = new FileOutputStream(TARGET_FILE);

CheckedOutputStream checksum = new CheckedOutputStream(fout, new Adler32());

ZipOutputStream zout = new ZipOutputStream(checksum);

FileInputStream fin = new FileInputStream(SOURCE_FILE);

ZipEntry zipEntry = new ZipEntry(SOURCE_FILE);

zout.putNextEntry(zipEntry);

int length;

byte[] buffer = new byte[1024];

while((length = fin.read(buffer)) > 0) {

zout.write(buffer, 0, length);

}

zout.closeEntry();

fin.close();

zout.close();

}

private static void readZipFile() throws IOException{

final ZipFile file = new ZipFile(TARGET_FILE);

System.out.println("Iterating over zip file : " + TARGET_FILE);

try {

final Enumeration extends ZipEntry> entries = file.entries();

while (entries.hasMoreElements()) {

final ZipEntry entry = entries.nextElement();

System.out.printf("File: %s Size %d Modified on %TD %n",

entry.getName(), entry.getSize(),

new Date(entry.getTime()));

extractFile(entry, file.getInputStream(entry));

}

System.out.printf("Zip file %s extracted successfully.", SOURCE_FILE);

}

finally {

file.close();

}

}

private static void extractFile(final ZipEntry entry, InputStream is)

throws IOException {

FileOutputStream fos = null;

try {

fos = new FileOutputStream(entry.getName());

final byte[] buf = new byte[1024];

int read = 0;

int length;

while ((length = is.read(buf, 0, buf.length)) >= 0) {

fos.write(buf, 0, length);

}

} catch (IOException ioex) {

fos.close();

}

}

}

让我们编译并运行上面的程序，这将产生以下结果 -Iterating over zip file : D:\test\Hello.zip

File: D:\test\Hello.txt Size 19 Modified on 05/20/17

Zip file D:\test\Hello.txt extracted successfully.