blocks|key|335748|text|看看新的Java+7+-+nio2+package吧。你所需要的就是里面。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|335749|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.oracle.com/javase/tutorial/essential/io/fileio.html^0|4|L|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

Have a look in new <a href="http://docs.oracle.com/javase/tutorial/essential/io/fileio.html" rel="nofollow">Java 7 - nio2 package</a>. All you need is inside.

blocks|key|552207|text|我推荐阅读data+structures，尤其是trees。在Java中，您可以通过创建一个引用其他节点的节点类来表示这些节点。例如：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|552208|public+class+Node+{
++++private+Node[]+children;
++++/*+snip+other+fields+*/
++++public+boolean+isFile()+{
+++++++++return+children.count+==+0;
++++}
}|code-block|syntax|javascript|552209|显然，你可以按你喜欢的方式存储你的节点引用--数组或集合将使用非二叉树。|552210|给定您的文件列表，您可以读取这些文件并填充您的树结构。|552211|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/Data_structure|1|http://en.wikipedia.org/wiki/Tree_%2528data_structure%2529^0|5|F|0|O|5|1|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@$A|X|B|Y|1|Z]|$A|10|B|11|1|12]]|C|$]]|$1|D|3|E|5|F|7|13|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|14|8|@]|9|@]|C|$]]|$1|K|3|L|5|6|7|15|8|@]|9|@]|C|$]]|$1|M|3|-4|5|6|7|16|8|@]|9|@]|C|$]]]|N|$O|$5|P|Q|R|C|$S|T]]|U|$5|P|Q|R|C|$S|V]]]]

I would recommend reading up on <a href="http://en.wikipedia.org/wiki/Data_structure" rel="nofollow">data structures</a>, particularly <a href="http://en.wikipedia.org/wiki/Tree_%28data_structure%29" rel="nofollow">trees</a>. In Java, you can represent these by creating a node class that has references to other nodes. For example:

<pre><code>public class Node {
 private Node[] children;
 /* snip other fields */
 public boolean isFile() {
 return children.count == 0;
 }
}
</code></pre>

Obviously, you can store your node references anyway you like- arrays or collections will work with non-binary trees.

Given your list of files, you can read these and populate your tree structure.

blocks|key|552274|text|似乎您可以调整Trie+/+Radix+Trie或Binary+Search+Tree来在这两种情况下工作。您可以扩充Trie以将“文件夹”存储为内部节点(而不是像常规Trie中那样的字符)，或者可以扩充二叉搜索树以将“文件夹”存储为内部节点(只要它们实现可比较的接口)，并将“文件”存储为叶节点。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|552275|我对这些结构的实现链接在上面的文本中。|552276|entityMap|0|LINK|mutability|MUTABLE|url|http://code.google.com/p/java-algorithms-implementation/source/browse/src/com/jwetherell/algorithms/data_structures/Trie.java|1|http://code.google.com/p/java-algorithms-implementation/source/browse/src/com/jwetherell/algorithms/data_structures/RadixTrie.java|2|http://code.google.com/p/java-algorithms-implementation/source/browse/src/com/jwetherell/algorithms/data_structures/BinarySearchTree.java^0|7|4|0|E|A|1|P|I|2|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@$A|S|B|T|1|U]|$A|V|B|W|1|X]|$A|Y|B|Z|1|10]]|C|$]]|$1|D|3|E|5|6|7|11|8|@]|9|@]|C|$]]|$1|F|3|-4|5|6|7|12|8|@]|9|@]|C|$]]]|G|$H|$5|I|J|K|C|$L|M]]|N|$5|I|J|K|C|$L|O]]|P|$5|I|J|K|C|$L|Q]]]]

Seems like you could adapt either a <a href="http://code.google.com/p/java-algorithms-implementation/source/browse/src/com/jwetherell/algorithms/data_structures/Trie.java" rel="nofollow">Trie</a> / <a href="http://code.google.com/p/java-algorithms-implementation/source/browse/src/com/jwetherell/algorithms/data_structures/RadixTrie.java" rel="nofollow">Radix Trie</a> or a <a href="http://code.google.com/p/java-algorithms-implementation/source/browse/src/com/jwetherell/algorithms/data_structures/BinarySearchTree.java" rel="nofollow">Binary Search Tree</a> to work in either situation. You could augment a Trie to store "folders" as the inner nodes (instead of characters like in a regular Trie) or you could augment a Binary Search Tree to store "folders" as inner nodes (as long as they implement a comparable interface) and "files" as leaf nodes.

My implementation of those structures are linked in the text above.

blocks|key|335907|text|谢谢你的回答。我完成了我的工作实现。我认为我需要改进它，以便在向树结构添加元素时使用更多的缓存来更好地工作。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|335908|正如我所说的，我需要的是一种结构，它允许我对FS进行“虚拟”的rappresentation。|335909|MXMTree.java|335910|public+class+MXMTree+{

++++MXMNode+root;
++++MXMNode+commonRoot;

++++public+MXMTree(+MXMNode+root+)+{
++++++++this.root+=+root;
++++++++commonRoot+=+null;
++++}

++++public+void+addElement(+String+elementValue+)+{+
++++++++String[]+list+=+elementValue.split("/");

++++++++//+latest+element+of+the+list+is+the+filename.extrension
++++++++root.addElement(root.incrementalPath,+list);

++++}

++++public+void+printTree()+{
++++++++//I+move+the+tree+common+root+to+the+current+common+root+because+I+don't+mind+about+initial+folder
++++++++//that+has+only+1+child+(and+no+leaf)
++++++++getCommonRoot();
++++++++commonRoot.printNode(0);
++++}

++++public+MXMNode+getCommonRoot()+{
++++++++if+(+commonRoot+!=+null)
++++++++++++return+commonRoot;
++++++++else+{
++++++++++++MXMNode+current+=+root;
++++++++++++while+(+current.leafs.size()+<=+0+)+{
++++++++++++++++current+=+current.childs.get(0);
++++++++++++}
++++++++++++commonRoot+=+current;
++++++++++++return+commonRoot;
++++++++}

++++}


}|code-block|syntax|javascript|335911|MXMNode.java|335912|import+java.util.ArrayList;
import+java.util.Arrays;
import+java.util.List;


public+class+MXMNode+{

++++List<MXMNode>+childs;
++++List<MXMNode>+leafs;
++++String+data;
++++String+incrementalPath;

++++public+MXMNode(+String+nodeValue,+String+incrementalPath+)+{
++++++++childs+=+new+ArrayList<MXMNode>();
++++++++leafs+=+new+ArrayList<MXMNode>();
++++++++data+=+nodeValue;
++++++++this.+incrementalPath+=+incrementalPath;
++++}

++++public+boolean+isLeaf()+{
++++++++return+childs.isEmpty()+&&+leafs.isEmpty();
++++}

++++public+void+addElement(String+currentPath,+String[]+list)+{

++++++++//Avoid+first+element+that+can+be+an+empty+string+if+you+split+a+string+that+has+a+starting+slash+as+/sd/card/
++++++++while(+list[0]+==+null+%7C%7C+list[0].equals("")+)
++++++++++++list+=+Arrays.copyOfRange(list,+1,+list.length);

++++++++MXMNode+currentChild+=+new+MXMNode(list[0],+currentPath%2B"/"%2Blist[0]);
++++++++if+(+list.length+==+1+)+{
++++++++++++leafs.add(+currentChild+);
++++++++++++return;
++++++++}+else+{
++++++++++++int+index+=+childs.indexOf(+currentChild+);
++++++++++++if+(+index+==+-1+)+{
++++++++++++++++childs.add(+currentChild+);
++++++++++++++++currentChild.addElement(currentChild.incrementalPath,+Arrays.copyOfRange(list,+1,+list.length));
++++++++++++}+else+{
++++++++++++++++MXMNode+nextChild+=+childs.get(index);
++++++++++++++++nextChild.addElement(currentChild.incrementalPath,+Arrays.copyOfRange(list,+1,+list.length));
++++++++++++}
++++++++}
++++}

++++@Override
++++public+boolean+equals(Object+obj)+{
++++++++MXMNode+cmpObj+=+(MXMNode)obj;
++++++++return+incrementalPath.equals(+cmpObj.incrementalPath+)+&&+data.equals(+cmpObj.data+);
++++}

++++public+void+printNode(+int+increment+)+{
++++++++for+(int+i+=+0;+i+<+increment;+i%2B%2B)+{
++++++++++++System.out.print("+");
++++++++}
++++++++System.out.println(incrementalPath+%2B+(isLeaf()+?+"+->+"+%2B+data+:+"")++);
++++++++for(+MXMNode+n:+childs)
++++++++++++n.printNode(increment%2B2);
++++++++for(+MXMNode+n:+leafs)
++++++++++++n.printNode(increment%2B2);
++++}

++++@Override
++++public+String+toString()+{
++++++++return+data;
++++}


}|335913|测试代码的Test.java|335914|public+class+Test+{

++++/**
+++++*+@param+args
+++++*/
++++public+static+void+main(String[]+args)+{

++++++++String+slist[]+=+new+String[]+{+
++++++++++++++++"/mnt/sdcard/folder1/a/b/file1.file",+
++++++++++++++++"/mnt/sdcard/folder1/a/b/file2.file",+
++++++++++++++++"/mnt/sdcard/folder1/a/b/file3.file",+
++++++++++++++++"/mnt/sdcard/folder1/a/b/file4.file",
++++++++++++++++"/mnt/sdcard/folder1/a/b/file5.file",+
++++++++++++++++"/mnt/sdcard/folder1/e/c/file6.file",+
++++++++++++++++"/mnt/sdcard/folder2/d/file7.file",+
++++++++++++++++"/mnt/sdcard/folder2/d/file8.file",+
++++++++++++++++"/mnt/sdcard/file9.file"+
++++++++};

++++++++MXMTree+tree+=+new+MXMTree(new+MXMNode("root",+"root"));
++++++++for+(String+data+:+slist)+{
++++++++++++tree.addElement(data);
++++++++}

++++++++tree.printTree();
++++}

}|335915|如果你对改进有什么好的建议，请告诉我:)|335916|entityMap^0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|X|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|Y|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|Z|8|@]|9|@]|A|$I|J]]|$1|K|3|L|5|6|7|10|8|@]|9|@]|A|$]]|$1|M|3|N|5|H|7|11|8|@]|9|@]|A|$I|J]]|$1|O|3|P|5|6|7|12|8|@]|9|@]|A|$]]|$1|Q|3|R|5|H|7|13|8|@]|9|@]|A|$I|J]]|$1|S|3|T|5|6|7|14|8|@]|9|@]|A|$]]|$1|U|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|V|$]]

Thank you for all your answer. I made my working implementation.
I think that I will need to improve it in order to make it works better with more caching in adding element to the tree structure.

As I said what I was needing was a structure that allow me to have a "virtual" rappresentation of a FS.

MXMTree.java

<pre><code>public class MXMTree {

 MXMNode root;
 MXMNode commonRoot;

 public MXMTree( MXMNode root ) {
 this.root = root;
 commonRoot = null;
 }

 public void addElement( String elementValue ) { 
 String[] list = elementValue.split("/");

 // latest element of the list is the filename.extrension
 root.addElement(root.incrementalPath, list);

 }

 public void printTree() {
 //I move the tree common root to the current common root because I don't mind about initial folder
 //that has only 1 child (and no leaf)
 getCommonRoot();
 commonRoot.printNode(0);
 }

 public MXMNode getCommonRoot() {
 if ( commonRoot != null)
 return commonRoot;
 else {
 MXMNode current = root;
 while ( current.leafs.size() &lt;= 0 ) {
 current = current.childs.get(0);
 }
 commonRoot = current;
 return commonRoot;
 }

 }


}
</code></pre>

MXMNode.java

<pre><code>import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;


public class MXMNode {

 List&lt;MXMNode&gt; childs;
 List&lt;MXMNode&gt; leafs;
 String data;
 String incrementalPath;

 public MXMNode( String nodeValue, String incrementalPath ) {
 childs = new ArrayList&lt;MXMNode&gt;();
 leafs = new ArrayList&lt;MXMNode&gt;();
 data = nodeValue;
 this. incrementalPath = incrementalPath;
 }

 public boolean isLeaf() {
 return childs.isEmpty() &amp;&amp; leafs.isEmpty();
 }

 public void addElement(String currentPath, String[] list) {

 //Avoid first element that can be an empty string if you split a string that has a starting slash as /sd/card/
 while( list[0] == null || list[0].equals("") )
 list = Arrays.copyOfRange(list, 1, list.length);

 MXMNode currentChild = new MXMNode(list[0], currentPath+"/"+list[0]);
 if ( list.length == 1 ) {
 leafs.add( currentChild );
 return;
 } else {
 int index = childs.indexOf( currentChild );
 if ( index == -1 ) {
 childs.add( currentChild );
 currentChild.addElement(currentChild.incrementalPath, Arrays.copyOfRange(list, 1, list.length));
 } else {
 MXMNode nextChild = childs.get(index);
 nextChild.addElement(currentChild.incrementalPath, Arrays.copyOfRange(list, 1, list.length));
 }
 }
 }

 @Override
 public boolean equals(Object obj) {
 MXMNode cmpObj = (MXMNode)obj;
 return incrementalPath.equals( cmpObj.incrementalPath ) &amp;&amp; data.equals( cmpObj.data );
 }

 public void printNode( int increment ) {
 for (int i = 0; i &lt; increment; i++) {
 System.out.print(" ");
 }
 System.out.println(incrementalPath + (isLeaf() ? " -&gt; " + data : "") );
 for( MXMNode n: childs)
 n.printNode(increment+2);
 for( MXMNode n: leafs)
 n.printNode(increment+2);
 }

 @Override
 public String toString() {
 return data;
 }


}
</code></pre>

Test.java for test code

<pre><code>public class Test {

 /**
 * @param args
 */
 public static void main(String[] args) {

 String slist[] = new String[] { 
 "/mnt/sdcard/folder1/a/b/file1.file", 
 "/mnt/sdcard/folder1/a/b/file2.file", 
 "/mnt/sdcard/folder1/a/b/file3.file", 
 "/mnt/sdcard/folder1/a/b/file4.file",
 "/mnt/sdcard/folder1/a/b/file5.file", 
 "/mnt/sdcard/folder1/e/c/file6.file", 
 "/mnt/sdcard/folder2/d/file7.file", 
 "/mnt/sdcard/folder2/d/file8.file", 
 "/mnt/sdcard/file9.file" 
 };

 MXMTree tree = new MXMTree(new MXMNode("root", "root"));
 for (String data : slist) {
 tree.addElement(data);
 }

 tree.printTree();
 }

}
</code></pre>

Please tell me if you have some good advice about improvments :)

I've a list of paths like this 

<pre><code>/mnt/sdcard/folder1/a/b/file1
/mnt/sdcard/folder1/a/b/file2
/mnt/sdcard/folder1/a/b/file3
/mnt/sdcard/folder1/a/b/file4
/mnt/sdcard/folder1/a/b/file5
/mnt/sdcard/folder1/e/c/file6
/mnt/sdcard/folder2/d/file7
/mnt/sdcard/folder2/d/file8
/mnt/sdcard/file9
</code></pre>

So from this list of paths (Stings) I need to crete a Java Tree structure that has folders as nodes and files as leaf (there wont be empty folders as leaf).

What I need I think is the add method where I pass to them a String (path of the file) and it add it to the correct place in the tree creating correct nodes (Folder) if they are not already there

This tree structure will need me to get list of nodes when I'm on node and list of leafs (but I think this will be a normal features for trees)

I will always have Strings as paths and not real file or folders.
Is there something ready to use or a source code to start?

Thank you very much.

Java Tree to represent filesystem (files/dir) from list of paths

Java

我有一个这样的路径列表/mnt/sdcard/folder1/a/b/file1/mnt/sdcard/folder1/a/b/file2/mnt/sdcard/folder1/a/b/file3/mnt/sdcard/folder1/a/b/file4/mnt/sdcard/folder1/a/b/file5/mnt...

问表示路径列表中的文件系统(files/dir)的Java树
EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问表示路径列表中的文件系统(files/dir)的Java树EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问表示路径列表中的文件系统(files/dir)的Java树
EN