blocks|key|1371375|text|是。它适用于除bootstrap类加载器加载的类以外的所有类。另一种确定方法是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1371376|Class+klass+=+String.class;
URL+location+=+klass.getResource('/'+%2B+klass.getName().replace('.',+'/')+%2B+".class");|code-block|syntax|javascript|1371377|正如notnoop所指出的，klass.getResource()方法返回类文件本身的位置。例如：|offset|length|style|CODE|1371378|jar:file:/jdk/jre/lib/rt.jar!/java/lang/String.class
file:/projects/classes/pkg/MyClass$1.class|1371379|getProtectionDomain().getCodeSource().getLocation()方法返回jar文件或类的位置|1371380|file:/Users/home/java/libs/ejb3-persistence-1.0.2.GA.jar
file:/projects/classes|1371381|entityMap^0|0|0|E|J|0|0|0|1F|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@$I|X|J|Y|K|L]]|9|@]|A|$]]|$1|M|3|N|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|10|8|@$I|11|J|12|K|L]]|9|@]|A|$]]|$1|Q|3|R|5|D|7|13|8|@]|9|@]|A|$E|F]]|$1|S|3|-4|5|6|7|14|8|@]|9|@]|A|$]]]|T|$]]

Yes. It works for all classes except classes loaded by bootstrap classloader. The other way to determine is:

<pre><code>Class klass = String.class;
URL location = klass.getResource('/' + klass.getName().replace('.', '/') + ".class");
</code></pre>

As notnoop pointed out <code>klass.getResource()</code> method returns the location of the class file itself. For example: 

<pre><code>jar:file:/jdk/jre/lib/rt.jar!/java/lang/String.class
file:/projects/classes/pkg/MyClass$1.class
</code></pre>

The <code>getProtectionDomain().getCodeSource().getLocation()</code> method returns the location of the jar file or CLASSPATH 

<pre><code>file:/Users/home/java/libs/ejb3-persistence-1.0.2.GA.jar
file:/projects/classes
</code></pre>

blocks|key|1156398|text|从Lombok+Patcher+LiveInjector.java中检出LiveInjector.findPathJar()。请注意，在特殊情况下，文件实际上不在jar中，您可能想要更改这种情况。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1156399|/**
+*+If+the+provided+class+has+been+loaded+from+a+jar+file+that+is+on+the+local+file+system,+will+find+the+absolute+path+to+that+jar+file.
+*+
+*+@param+context+The+jar+file+that+contained+the+class+file+that+represents+this+class+will+be+found.+Specify+{@code+null}+to+let+{@code+LiveInjector}
+*++++++++++++++++find+its+own+jar.
+*+@throws+IllegalStateException+If+the+specified+class+was+loaded+from+a+directory+or+in+some+other+way+(such+as+via+HTTP,+from+a+database,+or+some
+*+++++++++++++++++++++++++++++++other+custom+classloading+device).
+*/
public+static+String+findPathJar(Class<?>+context)+throws+IllegalStateException+{
++++if+(context+==+null)+context+=+LiveInjector.class;
++++String+rawName+=+context.getName();
++++String+classFileName;
++++/*+rawName+is+something+like+package.name.ContainingClass$ClassName.+We+need+to+turn+this+into+ContainingClass$ClassName.class.+*/+{
++++++++int+idx+=+rawName.lastIndexOf('.');
++++++++classFileName+=+(idx+==+-1+?+rawName+:+rawName.substring(idx%2B1))+%2B+".class";
++++}

++++String+uri+=+context.getResource(classFileName).toString();
++++if+(uri.startsWith("file:"))+throw+new+IllegalStateException("This+class+has+been+loaded+from+a+directory+and+not+from+a+jar+file.");
++++if+(!uri.startsWith("jar:file:"))+{
++++++++int+idx+=+uri.indexOf(':');
++++++++String+protocol+=+idx+==+-1+?+"(unknown)"+:+uri.substring(0,+idx);
++++++++throw+new+IllegalStateException("This+class+has+been+loaded+remotely+via+the+"+%2B+protocol+%2B
++++++++++++++++"+protocol.+Only+loading+from+a+jar+on+the+local+file+system+is+supported.");
++++}

++++int+idx+=+uri.indexOf('!');
++++//As+far+as+I+know,+the+if+statement+below+can't+ever+trigger,+so+it's+more+of+a+sanity+check+thing.
++++if+(idx+==+-1)+throw+new+IllegalStateException("You+appear+to+have+loaded+this+class+from+a+local+jar+file,+but+I+can't+make+sense+of+the+URL!");

++++try+{
++++++++String+fileName+=+URLDecoder.decode(uri.substring("jar:file:".length(),+idx),+Charset.defaultCharset().name());
++++++++return+new+File(fileName).getAbsolutePath();
++++}+catch+(UnsupportedEncodingException+e)+{
++++++++throw+new+InternalError("default+charset+doesn't+exist.+Your+VM+is+borked.");
++++}
}|code-block|syntax|javascript|1156400|entityMap|0|LINK|mutability|MUTABLE|url|http://github.com/rzwitserloot/lombok.patcher/blob/master/src/lombok/patcher/inject/LiveInjector.java^0|G|H|10|Q|1|W|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]]|D|@$9|X|A|Y|1|Z]]|E|$]]|$1|F|3|G|5|H|7|10|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|L|$M|$5|N|O|P|E|$Q|R]]]]

Checkout the <code>LiveInjector.findPathJar()</code> from <a href="http://github.com/rzwitserloot/lombok.patcher/blob/master/src/lombok/patcher/inject/LiveInjector.java" rel="noreferrer">Lombok Patcher <code>LiveInjector.java</code></a>. Note that it special cases where the file doesn't actually live in a jar, and you might want to change that.

<pre><code>/**
 * If the provided class has been loaded from a jar file that is on the local file system, will find the absolute path to that jar file.
 * 
 * @param context The jar file that contained the class file that represents this class will be found. Specify {@code null} to let {@code LiveInjector}
 * find its own jar.
 * @throws IllegalStateException If the specified class was loaded from a directory or in some other way (such as via HTTP, from a database, or some
 * other custom classloading device).
 */
public static String findPathJar(Class&lt;?&gt; context) throws IllegalStateException {
 if (context == null) context = LiveInjector.class;
 String rawName = context.getName();
 String classFileName;
 /* rawName is something like package.name.ContainingClass$ClassName. We need to turn this into ContainingClass$ClassName.class. */ {
 int idx = rawName.lastIndexOf('.');
 classFileName = (idx == -1 ? rawName : rawName.substring(idx+1)) + ".class";
 }

 String uri = context.getResource(classFileName).toString();
 if (uri.startsWith("file:")) throw new IllegalStateException("This class has been loaded from a directory and not from a jar file.");
 if (!uri.startsWith("jar:file:")) {
 int idx = uri.indexOf(':');
 String protocol = idx == -1 ? "(unknown)" : uri.substring(0, idx);
 throw new IllegalStateException("This class has been loaded remotely via the " + protocol +
 " protocol. Only loading from a jar on the local file system is supported.");
 }

 int idx = uri.indexOf('!');
 //As far as I know, the if statement below can't ever trigger, so it's more of a sanity check thing.
 if (idx == -1) throw new IllegalStateException("You appear to have loaded this class from a local jar file, but I can't make sense of the URL!");

 try {
 String fileName = URLDecoder.decode(uri.substring("jar:file:".length(), idx), Charset.defaultCharset().name());
 return new File(fileName).getAbsolutePath();
 } catch (UnsupportedEncodingException e) {
 throw new InternalError("default charset doesn't exist. Your VM is borked.");
 }
}
</code></pre>

blocks|key|1371445|text|private+String+resourceLookup(String+lookupResourceName)+{



++++try+{

++++++++if+(lookupResourceName+==+null+%7C%7C+lookupResourceName.length()==0)+{
++++++++++++return+"";
++++++++}
++++++++//+"/java/lang/String.class"

++++++++//+Check+if+entered+data+was+in+java+class+name+format
++++++++if+(lookupResourceName.indexOf("/")==-1)+{
++++++++++++lookupResourceName+=+lookupResourceName.replaceAll("[.]",+"/");
++++++++++++lookupResourceName+=++"/"+%2B+lookupResourceName+%2B+".class";
++++++++}

++++++++URL+url+=+this.getClass().getResource(lookupResourceName);
++++++++if+(url+==+null)+{
++++++++++++return("Unable+to+locate+resource+"%2B+lookupResourceName);

++++++++}

++++++++String+resourceUrl+=+url.toExternalForm();

++++++++Pattern+pattern+=
++++++++++++Pattern.compile("(zip:%7Cjar:file:/)(.*)!/(.*)",+Pattern.CASE_INSENSITIVE);

++++++++String+jarFilename+=+null;
++++++++String+resourceFilename+=+null;
++++++++Matcher+m+=+pattern.matcher(resourceUrl);
++++++++if+(m.find())+{
++++++++++++jarFilename+=+m.group(2);
++++++++++++resourceFilename+=+m.group(3);
++++++++}+else+{
++++++++++++return+"Unable+to+parse+URL:+"%2B+resourceUrl;

++++++++}

++++++++if+(!jarFilename.startsWith("C:")+){
++++++++++jarFilename+=+"/"%2BjarFilename;++//+make+absolute+path+on+Linux
++++++++}

++++++++File+file+=+new+File(jarFilename);
++++++++Long+jarSize=null;
++++++++Date+jarDate=null;
++++++++Long+resourceSize=null;
++++++++Date+resourceDate=null;
++++++++if+(file.exists()+&&+file.isFile())+{

++++++++++++jarSize+=+file.length();
++++++++++++jarDate+=+new+Date(file.lastModified());

++++++++++++try+{
++++++++++++++++JarFile+jarFile+=+new+JarFile(file,+false);
++++++++++++++++ZipEntry+entry+=+jarFile.getEntry(resourceFilename);
++++++++++++++++resourceSize+=+entry.getSize();
++++++++++++++++resourceDate+=+new+Date(entry.getTime());
++++++++++++}+catch+(Throwable+e)+{
++++++++++++++++return+("Unable+to+open+JAR"+%2B+jarFilename+%2B+"+++"%2BresourceUrl+%2B"\n"%2Be.getMessage());

++++++++++++}

+++++++++++return+"\nresource:+"%2BresourceFilename%2B"\njar:+"%2BjarFilename+%2B+"++\nJarSize:+"+%2BjarSize%2B"++\nJarDate:+"+%2BjarDate.toString()%2B"++\nresourceSize:+"+%2BresourceSize%2B"++\nresourceDate:+"+%2BresourceDate.toString()%2B"\n";


++++++++}+else+{
++++++++++++return("Unable+to+load+jar:"+%2B+jarFilename%2B+"++\nUrl:+"+%2BresourceUrl);

++++++++}
++++}+catch+(Exception+e){
++++++++return+e.getMessage();
++++}


}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1371446|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>private String resourceLookup(String lookupResourceName) {



 try {

 if (lookupResourceName == null || lookupResourceName.length()==0) {
 return "";
 }
 // "/java/lang/String.class"

 // Check if entered data was in java class name format
 if (lookupResourceName.indexOf("/")==-1) {
 lookupResourceName = lookupResourceName.replaceAll("[.]", "/");
 lookupResourceName = "/" + lookupResourceName + ".class";
 }

 URL url = this.getClass().getResource(lookupResourceName);
 if (url == null) {
 return("Unable to locate resource "+ lookupResourceName);

 }

 String resourceUrl = url.toExternalForm();

 Pattern pattern =
 Pattern.compile("(zip:|jar:file:/)(.*)!/(.*)", Pattern.CASE_INSENSITIVE);

 String jarFilename = null;
 String resourceFilename = null;
 Matcher m = pattern.matcher(resourceUrl);
 if (m.find()) {
 jarFilename = m.group(2);
 resourceFilename = m.group(3);
 } else {
 return "Unable to parse URL: "+ resourceUrl;

 }

 if (!jarFilename.startsWith("C:") ){
 jarFilename = "/"+jarFilename; // make absolute path on Linux
 }

 File file = new File(jarFilename);
 Long jarSize=null;
 Date jarDate=null;
 Long resourceSize=null;
 Date resourceDate=null;
 if (file.exists() &amp;&amp; file.isFile()) {

 jarSize = file.length();
 jarDate = new Date(file.lastModified());

 try {
 JarFile jarFile = new JarFile(file, false);
 ZipEntry entry = jarFile.getEntry(resourceFilename);
 resourceSize = entry.getSize();
 resourceDate = new Date(entry.getTime());
 } catch (Throwable e) {
 return ("Unable to open JAR" + jarFilename + " "+resourceUrl +"\n"+e.getMessage());

 }

 return "\nresource: "+resourceFilename+"\njar: "+jarFilename + " \nJarSize: " +jarSize+" \nJarDate: " +jarDate.toString()+" \nresourceSize: " +resourceSize+" \nresourceDate: " +resourceDate.toString()+"\n";


 } else {
 return("Unable to load jar:" + jarFilename+ " \nUrl: " +resourceUrl);

 }
 } catch (Exception e){
 return e.getMessage();
 }


}
</code></pre>

blocks|key|1156454|text|使用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1156455|String+path+=+<Any+of+your+class+within+the+jar>.class.getProtectionDomain().getCodeSource().getLocation().getPath();+|code-block|syntax|javascript|1156456|如果包含多个条目，则执行一些子字符串操作。|1156457|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Use

<pre><code>String path = &lt;Any of your class within the jar&gt;.class.getProtectionDomain().getCodeSource().getLocation().getPath(); 
</code></pre>

If this contains multiple entries then do some substring operation.

blocks|key|1156509|text|在Linux中，我使用一个小脚本来帮助我找到一个类可以在find+-exec中使用的jar。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1156510|findclass.sh|1156511|unzip+-l+"$1"+2>/dev/null+%7C+grep+$2+>/dev/null+2>&1+&&+echo+"$1"|code-block|syntax|javascript|1156512|基本上，由于jars是压缩的，unzip+-l将打印类资源的列表，因此您必须将.转换为/。您可以使用tr在脚本中执行替换，但在调用脚本时自己执行也不会太麻烦。|1156513|这个想法是在类路径的根上使用find来定位所有jars，然后在所有找到的jars上运行findclass.sh来查找匹配项。|1156514|它不能处理多个目录，但是如果你仔细选择根目录，你可以让它工作。|1156515|现在，找出哪个jar包含org.apache.commons.lang3.RandomUtils类，用来解封您的项目(...)：|1156516|$+find+~/.m2/repository/+-type+f+-name+'*.jar'+-exec+findclass.sh+{}+org/apache/commons/lang3/RandomUtils+\;

.m2/repository/org/apache/commons/commons-lang3/3.7/commons-lang3-3.7.jar
.m2/repository/org/apache/commons/commons-lang3/3.6/commons-lang3-3.6.jar
.m2/repository/org/apache/commons/commons-lang3/3.6/commons-lang3-3.6-sources.jar
$|1156517|entityMap^0|S|A|0|0|C|0|0|F|8|13|1|17|1|1E|2|0|E|4|17|C|0|0|C|10|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|11|8|@$9|12|A|13|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|14|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|15|8|@$9|16|A|17|B|C]|$9|18|A|19|B|C]|$9|1A|A|1B|B|C]|$9|1C|A|1D|B|C]]|D|@]|E|$]]|$1|O|3|P|5|6|7|1E|8|@$9|1F|A|1G|B|C]|$9|1H|A|1I|B|C]]|D|@]|E|$]]|$1|Q|3|R|5|6|7|1J|8|@]|D|@]|E|$]]|$1|S|3|T|5|6|7|1K|8|@$9|1L|A|1M|B|C]]|D|@]|E|$]]|$1|U|3|V|5|J|7|1N|8|@]|D|@]|E|$K|L]]|$1|W|3|-4|5|6|7|1O|8|@]|D|@]|E|$]]]|X|$]]

With Linux, I'm using a small script to help me find in which jar a class lies that can be used in a <code>find -exec</code>:
<code>findclass.sh</code>:
<pre><code>unzip -l &quot;$1&quot; 2&gt;/dev/null | grep $2 &gt;/dev/null 2&gt;&amp;1 &amp;&amp; echo &quot;$1&quot;
</code></pre>
Basically, as jars are zip, <code>unzip -l</code> will print the list of class resources, so you'll have to convert <code>.</code> to <code>/</code>. You could perform the replacement in the script with a <code>tr</code>, but it's not too much trouble to do it yourself when calling the script.
The, the idea is to use <code>find</code> on the root of your classpath to locate all jars, then runs <code>findclass.sh</code> on all found jars to look for a match.
It doesn't handle multi-directories, but if you carefully choose the root you can get it to work.
Now, find which jar contains class <code>org.apache.commons.lang3.RandomUtils</code> to you un-mavenize your project (...):
<pre><code>$ find ~/.m2/repository/ -type f -name '*.jar' -exec findclass.sh {} org/apache/commons/lang3/RandomUtils \;

.m2/repository/org/apache/commons/commons-lang3/3.7/commons-lang3-3.7.jar
.m2/repository/org/apache/commons/commons-lang3/3.6/commons-lang3-3.6.jar
.m2/repository/org/apache/commons/commons-lang3/3.6/commons-lang3-3.6-sources.jar
$
</code></pre>

I am not in front of an IDE right now, just looking at the API specs.

<pre><code>CodeSource src = MyClass.class.getProtectionDomain().getCodeSource();
if (src != null) {
 URL jar = src.getLocation();
}
</code></pre>

I want to determine which JAR file a class is from. Is this the way to do it?

Determine which JAR file a class is from

Linux

我现在并没有站在IDE的前面，只是在看API规范。CodeSource src = MyClass.class.getProtectionDomain().getCodeSource();if (src != null) {    URL jar = src.getLocation();}我想确定一个类来自哪个JAR文...

问确定类来自哪个JAR文件
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