一個簡單的遞歸程序,它讀取給定目錄下所有文件,然后以樹型的方式在屏幕上打印出來.昨天斷斷續(xù)續(xù)得花了1個多小時寫出來
讀取文件
package
?test;
import
?java.io.
*
;
import
?java.util.
*
;
/**?*/
/**
?*???Put?files?into?a?tree
?*?
*/
public
?
class
?ReadFilesAndBuiltTree?
{
????
????
static
?
class
?Node
{
????????
private
?Node?father;
????????
private
?List?children;
????????
private
?File?data;
????????
public
?Node()
{
????????????children?
=
?
new
?Vector();
????????}
????????
public
?File?getData()?
{
????????????
return
?data;
????????}
????????
public
?
void
?addChild(Node?c)
{
????????????
this
.getChildren().add(c);
????????}
????????
public
?
void
?setData(File?data)?
{
????????????
this
.data?
=
?data;
????????}
????????
public
?List?getChildren()?
{
????????????
return
?children;
????????}
????????
public
?
void
?setChildren(List?children)?
{
????????????
this
.children?
=
?children;
????????}
????????
public
?Node?getFather()?
{
????????????
return
?father;
????????}
????????
public
?
void
?setFather(Node?father)?
{
????????????
this
.father?
=
?father;
????????}
????????
public
?
boolean
?hasChildren()
{
????????????
return
?children.size()
>
0
;
????????}
????????
public
?Node?getChile(
int
?index)
{
????????????
return
?(Node)children.get(index);
????????}
????????
public
?Node?getChild(String?fname)
{
????????????Iterator?i?
=
?getChildren().iterator();
????????????
while
(i.hasNext())
{
????????????????Node?bn?
=
?(Node)i.next();
????????????????String?n?
=
?
????????????????????bn.getData().getName();
????????????????
if
(n.equals(fname))
return
?bn;
????????????}
????????????
return
?
null
;
????????}
????????
public
?List?getDirChildren()
{
????????????List?c?
=
?
new
?Vector();
????????????
for
(
int
?i?
=
?
0
?;?i?
<
children.size();i
++
)
{
????????????????Node?n?
=
?(Node)children.get(i);
????????????????
if
(
??????????????????n.getData().isDirectory()????????
????????????????)c.add(n);
????????????}
????????????
return
?c;
????????}
????????
public
?List?getFileChildren()
{
????????????List?c?
=
?
new
?Vector();
????????????
for
(
int
?i?
=
?
0
?;?i?
<
children.size();i
++
)
{
????????????????Node?n?
=
?(Node)children.get(i);
????????????????
if
(
??????????????????
!
n.getData().isDirectory()????????
????????????????)c.add(n);
????????????}
????????????
return
?c;
????????}
????}
????
????
private
?ReadFilesAndBuiltTree()
{}
????
????
public
?
static
?Node?getTree(File?rootDir)
{
????????Node?r?
=
?
new
?Node();
????????r.setData(rootDir);
????????
return
?
new
?ReadFilesAndBuiltTree().builtTree(r);
????}
????
????
private
?Node?builtTree(Node?root)
{
????????
if
(
!
root.getData().isDirectory())
return
?root;
????????File?f?
=
?root.getData();
????????File[]?fs?
=
?f.listFiles();
????????
for
(
int
?i?
=
?
0
?;?i?
<
?fs.length?;?i
++
?)
{
????????????File?ff?
=
?fs[i];
????????????Node?n?
=
?
new
?Node();
????????????n.setData(ff);
????????????n.setFather(root);
????????????root.addChild(builtTree(n));
????????}
????????
return
?root;
????}
????
????
public
?
static
?
void
?main(String[]?args)
throws
?Exception
{
????????Node?root?
=
?getTree(
new
?File(ShowFileDir.ROOT_DIR));
????????Node?cn?
=
?root.getChild(
"
maps
"
);
????????System.out.println(cn.getChildren().size());
????}
????
}
輸出文件
package?test;
import?java.io.File;
import?java.util.Iterator;
import?java.util.List;
import?test.ReadFilesAndBuiltTree.Node;
/**?*//**
?*??Print?the?tree?to?screen
?*?*/
public?class?ShowFileDir?{
????
????public?static?String?ROOT_DIR?=?"E:/y音樂";
????
????public?ShowFileDir(){
????}
????
????public?void?printNodes(){
???????Node?root?=?ReadFilesAndBuiltTree.getTree(new?File(ROOT_DIR));
???????printNode(root,0);
????}
????
????private?void?printNode(Node?root,int?depth){
????????if(!root.hasChildren())return;
????????pd(root.getData().getName(),depth);
????????pindent(++depth);
????????List?l?=?root.getFileChildren();
????????pc(l,depth);
????????l?=?root.getDirChildren();
????????for(int?i?=?0?;?i?<?l.size()?;?i++){
????????????Node?c?=?(Node)l.get(i);
????????????printNode(c,depth);
????????}
????}
????
//?Screen?methods????
????private?void?pc(List?l,int?count){
????????Iterator?i?=?l.iterator();
????????while(i.hasNext()){
????????????Node?n?=?(Node)i.next();
????????????pp(count);
????????????p("+"+n.getData().getName()+"\n");
????????}
????}
????
????private?void?pd(String?t,int?depth){
????????String?spc?=?"";
????????for(int?i?=?0;?i<?depth;?i++)spc+="-";
????????p(spc+"+"+t+"\n");
????}
????
????private?void?pindent(int?depth){
????????String?spc?=?"";
????????for(int?i?=?0;?i<?depth;?i++)spc+="?";
????????System.out.println(spc+"|");
????}
????
????private?void?pp(int?count){
????????for(int?i?=?0?;?i?<?count?;?i++)p("?");
????}
????
????private?void?p(String?s){System.out.print(s);}
????
????public?static?void?main(String[]?args)throws?Exception{
????????ShowFileDir?sfd?=?new?ShowFileDir();
????????sfd.printNodes();
????}
}
2個類,一個負(fù)責(zé)讀.一個負(fù)責(zé)寫.
輸出結(jié)果:
+y音樂
?|
-+歐美
? |
? +WeAreTheWorld.txt
? +WeAreTheWorld.wmv
? +WhereAreYou!.txt
? +jeanny_3.mp3
? +blood-upon-the-risers.mp3
? +Broken Down Angel.txt
? +Love Hurts.txt
? +Broken Down Angle.mp3
? +Love Hurts.mp3
? +Celien Dion - God Bless America.mp3
? +SS閃電部隊在前進(jìn).mp3
? +The_Sun_Is_Burning_Simon_and_Garfunkel.mp3
? +vitas.-.opera02.rm
? +chivas we could be together.wma
? +綠色椅子.mp3
? +come away with me-norah jones.wma
? +the sound of silence.mp3
--+live from new york city,1967-simon&garfunkel
?? |
?? +a church is burning.mp3
?? +a hazy shade of winter.mp3
?? +a most peculiar.mp3
?? +a poem on the underground wall.mp3
?? +anji.mp3
?? +benedictus.mp3
?? +blessed.mp3
?? +for emily,whenever I may find her.mp3
?? +he was my brother.mp3
?? +howeward bound.mp3
?? +I am a rock.mp3
?? +leaves that are green.mp3
?? +richard cory.mp3
?? +sparrow.mp3
?? +the 59th street bridge song.mp3
?? +the dangling conversation.mp3
?? +the sound of silence.mp3
?? +wednesday morning,3A.M.mp3
?? +you don't know where your interest lies.mp3
-+其他
? |
? +StarCraft - Techno Mix.mp3
? +牽手.mp3
? +螢火蟲 .mp3
? +njsw.mp3
? +zeldaN64.rar
這是算法系列的第一篇,下一個準(zhǔn)備寫動態(tài)規(guī)劃的.