在尝试创建URL时，Java JDK 8中存在异常
在我尝试创建带有嵌套JAR间接寻址的URL时，现在有一个例外 例如，我有以下嵌套jar URL：在尝试创建URL时，Java JDK 8中存在异常,java,url,jar,Java,Url,Jar,在我尝试创建带有嵌套JAR间接寻址的URL时，现在有一个例外 例如，我有以下嵌套jar URL： jar:jar:file:/D://samples/File.zip!/71812_file!/myFile.properties 它是一个带有两个间接地址的嵌套Jar URL 当我尝试执行以下简单行时： URL url = new URL(spec); 我有以下例外： java.net.MalformedURLException: Nested JAR URLs are not support
jar:jar:file:/D://samples/File.zip!/71812_file!/myFile.properties
URL url = new URL(spec);
java.net.MalformedURLException: Nested JAR URLs are not supported
我现在可以做些什么来解决这个问题，新的JDK版本可以吗？好的，所以这里真正的问题是标准Java类加载器不支持嵌套JAR文件，也从来没有支持过嵌套JAR文件。对此，有一个长期存在的功能请求；请参阅 这同样适用于使用
URL.openConnection（）JAR:njar:现在它不再工作了（JDK8_271），但在较旧的JDK8版本中（例如，在我的内存中是92），同样的代码也可以工作 解析URL可能有效。但是
java.net.URLURL.openConnectionJARif ("jar".equalsIgnoreCase(protocol)) {
if (handler instanceof sun.net.www.protocol.jar.Handler) {
// URL.openConnection() would throw a confusing exception
// so generate a better exception here instead.
String s = ((sun.net.www.protocol.jar.Handler) handler).checkNestedProtocol(file);
if (s != null) {
throw new MalformedURLException(s);
}
}
}
嗯，现在我明白了！事实上我已经创建了自己的URLConnection，因为我没有使用url.openConnection代码，这正是您解释的原因（但在此之前，我在尝试创建url时没有出现异常，因此我现在遇到了问题）。我有以下代码：
NestableURLConnection conn = new NestableURLConnection(url);
NestableURLConnection是我创建的自定义URLConnection。我将尝试您的解决方案，这似乎非常合适！我使用的自定义URLConnection与协议处理程序完美配合：
public class NestableURLConnection extends URLConnection {
protected String urlPath;
protected boolean firstEntry = false;
public NestableURLConnection(URL url) {
super(url);
urlPath = url.toString();
}
public NestableURLConnection() {
super(null);
}
public void setURL(URL url) {
this.url = url;
urlPath = url.toString();
}
public NestableURLConnection(URL url, boolean firstEntry) {
this(url);
this.firstEntry = firstEntry;
}
@Override
public void connect() throws IOException {
connected = true;
}
private String getNestedURL() throws IOException {
int sep = urlPath.indexOf("!/");
int start = urlPath.indexOf(':') + 1;
for (int i = start, end = urlPath.indexOf("/") - 1; (i = urlPath.indexOf(":", i)) < end;) {
int cursep = urlPath.indexOf("!/", sep + 2);
if (cursep < 0) {
break;
}
sep = cursep;
++i;
}
return urlPath.substring(start, sep);
}
@Override
public InputStream getInputStream() throws IOException {
int start = urlPath.indexOf(':') + 1;
if (start > urlPath.length() || urlPath.charAt(start) == '/') {
return url.openStream();
}
if (FileUtilities.useFileOrHTTPProtocol(urlPath)) {
return url.openStream();
}
int sep = urlPath.indexOf("!/");
if (sep < 0) {
throw new MalformedURLException("Missing separator " + urlPath);
}
String nestedURL = getNestedURL();
sep = urlPath.indexOf(nestedURL) + nestedURL.length();
int nextSep = urlPath.indexOf("!/", sep + 2);
// Use the default Java openStream() for a file scheme.
InputStream inputStream;
ZipEntry inputZipEntry;
boolean isKnownProtocol = FileUtilities.useFileOrHTTPProtocol(nestedURL);
if (!isKnownProtocol || (firstEntry)) {
if (firstEntry) {
nestedURL = urlPath;
} else {
if (!nestedURL.contains("!/")) {
nestedURL = "file:" + nestedURL.substring(4);
}
}
inputStream = createInputStream(nestedURL);
} else {
String entry = nextSep < 0 ? urlPath.substring(sep + 2) : urlPath.substring(sep + 2, nextSep);
sep = nextSep;
nextSep = urlPath.indexOf("!/", sep + 2);
// Go directly to the right entry in the zip file
final ZipFile zipFile = new ZipFile(FileUtilities.replaceEscapedSequences(nestedURL.substring(5)));
inputZipEntry = zipFile.getEntry(entry);
InputStream zipEntryInputStream = inputZipEntry == null ? null : zipFile.getInputStream(inputZipEntry);
if (zipEntryInputStream == null) {
zipFile.close();
// return null instead of throwing an Exception if the URL does not exist
return null;
}
inputStream = new FilterInputStream(zipEntryInputStream) {
@Override
public void close() throws IOException {
super.close();
zipFile.close();
}
};
}
// Loop over the archive paths.
LOOP:
while (sep > 0) {
// The entry name to be matched.
String entry = nextSep < 0 ? urlPath.substring(sep + 2) : urlPath.substring(sep + 2, nextSep);
// Wrap the input stream as a zip stream to scan it's contents for a match.
// Don't use try-with-resources here because we only want to close it if there is an internal IOException
ZipInputStream zipInputStream = new ZipInputStream(inputStream);
while (zipInputStream.available() >= 0) {
ZipEntry zipEntry = zipInputStream.getNextEntry();
if (zipEntry == null) {
break;
} else if (firstEntry) {
inputZipEntry = zipEntry;
inputStream = zipInputStream;
sep = -1;
continue LOOP;
} else if (entry.equals(zipEntry.getName())) {
inputZipEntry = zipEntry;
inputStream = zipInputStream;
// Skip to the next archive path and continue the loop.
sep = nextSep;
nextSep = urlPath.indexOf("!/", sep + 2);
continue LOOP;
}
}
throw new IOException("Archive entry not found " + urlPath);
}
return inputStream;
}
private InputStream createInputStream(String nestedURL) throws IOException {
return new URL(nestedURL).openStream();
}
@Override
public OutputStream getOutputStream() throws IOException {
return null;
}
公共类NestableURLConnection扩展了URLConnection{
受保护的字符串路径；
受保护的布尔值firstEntry=false；
公共嵌套URL连接（URL）{
超级链接（url）；
urlPath=url.toString（）；
}
公共NestableURLConnection（）{
超级（空）；
}
公共无效设置URL（URL）{
this.url=url；
urlPath=url.toString（）；
}
公共NestableURLConnection（URL，布尔值firstEntry）{
此（url）；
this.firstEntry=firstEntry；
}
@凌驾
public void connect（）引发IOException{
连接=真；
}
私有字符串getNestedURL（）引发IOException{
int sep=urlPath.indexOf（！/”；
int start=urlPath.indexOf（“：”）+1；
对于（int i=start，end=urlPath.indexOf（“/”）-1；（i=urlPath.indexOf（“：”，i））urlPath.length（）| | urlPath.charAt（开始）=='/'））{
返回url.openStream（）；
}
if（FileUtilities.useFileOrHTTPProtocol（urlPath））{
返回url.openStream（）；
}
int sep=urlPath.indexOf（！/”；
如果（sep<0）{
抛出新的MalformedURLException（“缺少分隔符”+urlPath）；
}
字符串nestedURL=getNestedURL（）；
sep=urlPath.indexOf（nestedURL）+nestedURL.length（）；
int-nextSep=urlPath.indexOf（“！/”，sep+2）；
//对文件方案使用默认的Java openStream（）。
输入流输入流；
Zippentry输入Zippentry；
布尔值isKnownProtocol=FileUtilities.useFileOrHTTPProtocol（nestedURL）；
如果（！isKnownProtocol | | |（第一项））{
如果（首次输入）{
nestedURL=urlPath；
}否则{
如果（！nestedURL.contains（！/”）{
nestedURL=“文件：”+nestedURL.substring（4）；
}
}
inputStream=createInputStream（nestedURL）；
}否则{
String entry=nextSep<0？urlPath.substring（sep+2）：urlPath.substring（sep+2，nextSep）；
sep=nextSep；
nextSep=urlPath.indexOf（“！/”，sep+2）；
//直接转到zip文件中的正确条目
final ZipFile ZipFile=新的ZipFile（FileUtilities.replaceScapedSequences（nestedURL.substring（5））；
inputZipEntry=zipFile.getEntry（条目）；
InputStream ZipPentryInputStream=InputZipPentry==null？null:zipFile.getInputStream（InputZipPentry）；
if（zipEntryInputStream==null）{
zipFile.close（）；
//如果URL不存在，则返回null而不是引发异常
返回null；
}
inputStream=新过滤器inputStream（zipEntryInputStream）{
@凌驾
public void close（）引发IOException{
super.close（）；
zipFile.close（）；
}
};
}
//在归档路径上循环。
循环：
而（9月>0日）{
//要匹配的条目名称。
String entry=nextSep<0？urlPath.substring（sep+2）：urlPath.substring（sep+2，nextSep）；
//将输入流包装为zip流，以扫描其内容以查找匹配项。
//这里不要使用try with resources，因为我们只想在出现内部IOException时关闭它
ZipInputStream ZipInputStream=新的ZipInputStream（inputStream）；
而（zipInputStream.available（）>=0）{
ZipEntry-ZipEntry=zipInputStream.getNextEntry（）；
if（zipEntry==null）{
public class NestableURLConnection extends URLConnection {
protected String urlPath;
protected boolean firstEntry = false;
public NestableURLConnection(URL url) {
super(url);
urlPath = url.toString();
}
public NestableURLConnection() {
super(null);
}
public void setURL(URL url) {
this.url = url;
urlPath = url.toString();
}
public NestableURLConnection(URL url, boolean firstEntry) {
this(url);
this.firstEntry = firstEntry;
}
@Override
public void connect() throws IOException {
connected = true;
}
private String getNestedURL() throws IOException {
int sep = urlPath.indexOf("!/");
int start = urlPath.indexOf(':') + 1;
for (int i = start, end = urlPath.indexOf("/") - 1; (i = urlPath.indexOf(":", i)) < end;) {
int cursep = urlPath.indexOf("!/", sep + 2);
if (cursep < 0) {
break;
}
sep = cursep;
++i;
}
return urlPath.substring(start, sep);
}
@Override
public InputStream getInputStream() throws IOException {
int start = urlPath.indexOf(':') + 1;
if (start > urlPath.length() || urlPath.charAt(start) == '/') {
return url.openStream();
}
if (FileUtilities.useFileOrHTTPProtocol(urlPath)) {
return url.openStream();
}
int sep = urlPath.indexOf("!/");
if (sep < 0) {
throw new MalformedURLException("Missing separator " + urlPath);
}
String nestedURL = getNestedURL();
sep = urlPath.indexOf(nestedURL) + nestedURL.length();
int nextSep = urlPath.indexOf("!/", sep + 2);
// Use the default Java openStream() for a file scheme.
InputStream inputStream;
ZipEntry inputZipEntry;
boolean isKnownProtocol = FileUtilities.useFileOrHTTPProtocol(nestedURL);
if (!isKnownProtocol || (firstEntry)) {
if (firstEntry) {
nestedURL = urlPath;
} else {
if (!nestedURL.contains("!/")) {
nestedURL = "file:" + nestedURL.substring(4);
}
}
inputStream = createInputStream(nestedURL);
} else {
String entry = nextSep < 0 ? urlPath.substring(sep + 2) : urlPath.substring(sep + 2, nextSep);
sep = nextSep;
nextSep = urlPath.indexOf("!/", sep + 2);
// Go directly to the right entry in the zip file
final ZipFile zipFile = new ZipFile(FileUtilities.replaceEscapedSequences(nestedURL.substring(5)));
inputZipEntry = zipFile.getEntry(entry);
InputStream zipEntryInputStream = inputZipEntry == null ? null : zipFile.getInputStream(inputZipEntry);
if (zipEntryInputStream == null) {
zipFile.close();
// return null instead of throwing an Exception if the URL does not exist
return null;
}
inputStream = new FilterInputStream(zipEntryInputStream) {
@Override
public void close() throws IOException {
super.close();
zipFile.close();
}
};
}
// Loop over the archive paths.
LOOP:
while (sep > 0) {
// The entry name to be matched.
String entry = nextSep < 0 ? urlPath.substring(sep + 2) : urlPath.substring(sep + 2, nextSep);
// Wrap the input stream as a zip stream to scan it's contents for a match.
// Don't use try-with-resources here because we only want to close it if there is an internal IOException
ZipInputStream zipInputStream = new ZipInputStream(inputStream);
while (zipInputStream.available() >= 0) {
ZipEntry zipEntry = zipInputStream.getNextEntry();
if (zipEntry == null) {
break;
} else if (firstEntry) {
inputZipEntry = zipEntry;
inputStream = zipInputStream;
sep = -1;
continue LOOP;
} else if (entry.equals(zipEntry.getName())) {
inputZipEntry = zipEntry;
inputStream = zipInputStream;
// Skip to the next archive path and continue the loop.
sep = nextSep;
nextSep = urlPath.indexOf("!/", sep + 2);
continue LOOP;
}
}
throw new IOException("Archive entry not found " + urlPath);
}
return inputStream;
}
private InputStream createInputStream(String nestedURL) throws IOException {
return new URL(nestedURL).openStream();
}
@Override
public OutputStream getOutputStream() throws IOException {
return null;
}