Java ZipInputStream不'；t报告*实际*（即压缩）字节读取

爱这个网站！我的问题如下：

我正在读取一个从HTTP“PUT”请求通过网络发送的zip文件。请求头告诉我内容长度是（比如）1Mb。以下代码创建ZipInputStream，并将zip内容保存到当前目录中的文件中：

ZipInputStream zis = new ZipInputStream(inputStream);
ZipEntry ze;
long totalBytesRead = 0;
while ((ze = zis.getNextEntry()) != null) {
    BufferedOutputStream outStream = new BufferedOutputStream(new FileOutputStream(ze.getName()));
    byte[] buffer = new byte[4096];
    int i;
    while ((i = zis.read(buffer)) != -1) {
        totalBytesRead+=i;
        outStream.write(buffer,0,i);
    } 
    outStream.close();
}
inputStream.close();

说到做到，totalBytesRead大约等于1.5Mb（取决于文件的压缩程度，可能是任意大小！）。我想知道的是，是否有办法找出从原始

inputStream

读取的实际字节数？

ze.getSize（）

和

ze.getCompressedSize（）

为每个压缩条目返回-1（即它不知道）。我需要这个信息作为进度条，以显示传输的zip文件已从网络上读取了多少字节

建议？我是否应该将ZipInputStream子类化，并尝试找出它从包装的InputStream中读取的字节数

---

提前谢谢

当然，这似乎是合理的

基本上有两种选择：读取所有字节，存储它们（在内存或文件中），计算它们的数量，然后解压缩它们；或者在他们进来的时候数一数。前者似乎效率低下，而后者需要

InputStream

的子类，该子类能够计算读取的字节数。我想不出标准库中有哪一个，但实现可能就存在于此——那么，编写自己的实现就很容易了

import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * 
 */

/**
 * @author clint
 * 
 */
public class ByteCountingInputStream extends FilterInputStream {

  public int totalRead = 0;

  /**
   * @param in
   */
  protected ByteCountingInputStream(InputStream in) {
    super(in);
    // TODO Auto-generated constructor stub
  }

  /* (non-Javadoc)
   * @see java.io.FilterInputStream#read()
   */
  @Override
  public int read() throws IOException {
    int ret = super.read();
    totalRead++;
    return ret;
  }

  /* (non-Javadoc)
   * @see java.io.FilterInputStream#read(byte[], int, int)
   */
  @Override
  public int read(byte[] b, int off, int len) throws IOException {
    int ret = super.read(b, off, len);
    totalRead += ret;
    return ret;
  }

  /* (non-Javadoc)
   * @see java.io.FilterInputStream#read(byte[])
   */
  @Override
  public int read(byte[] b) throws IOException {
    int ret = super.read(b);
    totalRead += ret;
    return ret;
  }

  /* (non-Javadoc)
   * @see java.io.FilterInputStream#skip(long)
   */
  @Override
  public long skip(long n) throws IOException {
    //What to do?
    return super.skip(n);
  }

  /**
   * @return the totalRead
   */
  protected int getTotalRead() {
    return this.totalRead;
  }

}

这是介于两者之间的

ZipInputStream zis = new ZipInputStream(new ByteCountingInputStream(inputStream));

---

谢谢你们两位！我刚刚完全按照克林特的建议完成了制作

import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;

public class CountingInputStream extends FilterInputStream {

    private long totalBytes = 0;

    protected CountingInputStream(InputStream in) {
        super(in);
    }

    public int getTotalBytesRead() {
        return totalBytes;
    }

    @Override
    public int read() throws IOException {
        int byteValue = super.read();
        if (byteValue != -1) totalBytes++;
        return byteValue;
    }

    @Override
    public int read(byte[] b) throws IOException {
        int bytesRead = super.read(b);
        if (bytesRead != -1) totalBytes+=bytesRead;
        return bytesRead;
    }

    @Override
    public int read(byte[] b, int off, int len) throws IOException {
        int bytesRead = super.read(b,off,len);
        if (bytesRead != -1) totalBytes+=bytesRead;
        return bytesRead;
    }
}

现在我想知道我该给谁打个“勾号”给

---

再次感谢

我就是这么做的。。。不需要覆盖任何内容

ZipInputStream zis = new ZipInputStream(inputStream);
ZipEntry ze;
int totalBytes = inputStream.available();
int totalBytesRead = 0;
while ((ze = zis.getNextEntry()) != null) {
    totalBytesRead = totalBytes - inputStream.available();
    BufferedOutputStream outStream = new BufferedOutputStream(new FileOutputStream(ze.getName()));
    byte[] buffer = new byte[4096];
    int i;
    while ((i = zis.read(buffer)) != -1) {
        outStream.write(buffer,0,i);
    } 
    outStream.close();
}
inputStream.close();

---

为什么构造函数受保护？在当前条目数据达到EOF后返回0，否则始终返回1。程序不应依赖此方法返回可以在不阻塞的情况下读取的实际字节数。