我有一段代码，其中ZipInputStream被转换为byte[]，但我不知道如何将其转换为InputStream。
private void convertStream(String encoding, ZipInputStream in) throws IOException,
UnsupportedEncodingException
{
final int BUFFER = 1;
@SuppressWarnings("unused")
int count = 0;
byte data[] = new byte[BUFFER];
while ((count = in.read(data, 0, BUFFER)) != -1)
{
// How can I convert data to InputStream here ?
}
}
ZipInputStream是InputStream的子类。
http://download.oracle.com/javase/6/docs/api/java/util/zip/ZipInputStream.html
以下是我解决这个问题的方法。现在我可以将ZipInputStream中的单个文件作为InputStream存储到内存中。
private InputStream convertZipInputStreamToInputStream(ZipInputStream in, ZipEntry entry, String encoding) throws IOException
{
final int BUFFER = 2048;
int count = 0;
byte data[] = new byte[BUFFER];
ByteArrayOutputStream out = new ByteArrayOutputStream();
while ((count = in.read(data, 0, BUFFER)) != -1) {
out.write(data);
}
InputStream is = new ByteArrayInputStream(out.toByteArray());
return is;
}
out 流中使用 out.write(data) 添加额外的数据。正确的方式应该是 out.write(data, 0, count)。当问题就在这里时，我浪费了很多时间在代码中找问题。请参考此答案：https://stackoverflow.com/a/19473853/7630458。 - 11tprivate static void testZip() {
ZipInputStream zipStream = null;
byte buff[] = new byte[16384];
int readBytes;
try {
FileInputStream fis = new FileInputStream("./test.zip");
zipStream = new ZipInputStream(fis);
ZipEntry ze;
while((ze = zipStream.getNextEntry()) != null) {
if(ze.isDirectory()) {
System.out.println("Folder : "+ze.getName());
continue;//no need to extract
}
System.out.println("Extracting file "+ze.getName());
//at this moment zipStream pointing to the beginning of current ZipEntry, e.g. archived file
//saving file
FileOutputStream outFile = new FileOutputStream(ze.getName());
while((readBytes = zipStream.read(buff)) != -1) {
outFile.write(buff, 0, readBytes);
}
outFile.close();
}
} catch (Exception e) {
System.err.println("Error processing zip file : "+e.getMessage());
} finally {
if(zipStream != null)
try {
zipStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
以下代码对于 FileOutputStream 对象在我的环境下有效：
try (ZipInputStream zin = new ZipInputStream(response.getInputStream())) {
for (ZipEntry zipEntry = zin.getNextEntry(); zipEntry != null; zipEntry = zin.getNextEntry()) {
File f = new File(dir, zipEntry.getName());
try (FileOutputStream fout = new FileOutputStream(f)) {
int len;
byte[] buffer = new byte[1024];
while ((len = zin.read(buffer)) > 0) {
fout.write(buffer, 0, len);
}
zin.closeEntry();
}
}
}
ZipInputStream 允许直接读取 ZIP 内容：使用 getNextEntry() 进行迭代，直到找到要读取的条目，然后从 ZipInputStream 中读取即可。
如果您不仅想读取 ZIP 内容，而且需要在传递到下一步之前对流应用其他转换，则可以使用 PipedInputStream 和 PipedOutputStream。其思路类似于以下代码（根据记忆编写，可能无法编译）：
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
public abstract class FilterThread extends Thread {
private InputStream unfiltered;
public void setUnfilteredStream(InputStream unfiltered) {
this.unfiltered = unfiltered;
}
private OutputStream threadOutput;
public void setThreadOutputStream(OutputStream threadOutput) {
this.threadOutput = threadOutput;
}
// read from unfiltered stream, filter and write to thread output stream
public abstract void run();
}
...
public InputStream getFilteredStream(InputStream unfiltered, FilterThread filter) {
PipedInputStream filteredInputStream = new PipedInputStream();
PipedOutputStream threadOutputStream = new PipedOutputStream(filteredInputStream);
filter.setUnfilteredStream(unfiltered);
filter.setThreadOuptut(threadOutputStream);
filter.start();
return filteredInputStream;
}
...
public void clientCode() {
...
ZipInputStream zis = ...;// get ZIP stream
FilterThread filter = ...; // assign your implementation of FilterThread that transforms your ZipInputStream
InputStream filteredZipInputStream = getFilteredStream(zis, filter);
...
}
邮政编码很简单，但是我在将ZipInputStream作为InputStream返回时遇到了问题。由于某些原因，压缩包中包含的某些文件丢失了一些字符。下面是我的解决方案，目前它一直在工作。
private Map<String, InputStream> getFilesFromZip(final DataHandler dhZ,
String operation) throws ServiceFault
{
Map<String, InputStream> fileEntries = new HashMap<String, InputStream>();
try
{
DataSource dsZ = dhZ.getDataSource();
ZipInputStream zipIsZ = new ZipInputStream(dhZ.getDataSource()
.getInputStream());
try
{
ZipEntry entry;
while ((entry = zipIsZ.getNextEntry()) != null)
{
if (!entry.isDirectory())
{
Path p = Paths.get(entry.toString());
fileEntries.put(p.getFileName().toString(),
convertZipInputStreamToInputStream(zipIsZ));
}
}
}
finally
{
zipIsZ.close();
}
}
catch (final Exception e)
{
faultLocal(LOGGER, e, operation);
}
return fileEntries;
}
private InputStream convertZipInputStreamToInputStream(
final ZipInputStream in) throws IOException
{
ByteArrayOutputStream out = new ByteArrayOutputStream();
IOUtils.copy(in, out);
InputStream is = new ByteArrayInputStream(out.toByteArray());
return is;
}