http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ZkJYPXdn?
} jF\J+:5M
for(int i=0;i<nEndPos.length-1;i++) I!;#Nk>
{ ,e ~@
nEndPos = nStartPos[i+1]; [T.BK:
} .baS mfc
nEndPos[nEndPos.length-1] = nFileLength; i%~4>k
} :>[;XT<
} 5)yQrS !{:
tU%-tlU9?
^m
//启动子线程 EO;f`s)t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fxQN
for(int i=0;i<nStartPos.length;i++) ?7cF_Zvve
{ j}?O
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }>:x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /.\$%bua
nStartPos,nEndPos,i); khb Gyg%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X3:-+]6,d
fileSplitterFetch.start(); j]"Yzt~u
} jz$)*Kdi*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -< 7KW0CA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); R?Q@)POW
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +*Cg2`
nEndPos = " + nFileLength); 8<t?o'9I
// fileSplitterFetch[nPos.length-1].start(); K`@GNT&
eb)S<%R/
`C`_2y8
//等待子线程结束 h<9h2
//int count = 0; h(I~HZ[K&T
//是否结束while循环 T]nZ3EZ
boolean breakWhile = false; 3X{=*wvt
)(&g\
X!n-nms
while(!bStop) Kk~0jP_B9
{ Qko}rd_M
write_nPos(); f#l/N%VoBZ
Utility.sleep(500); PL8eM]XS
breakWhile = true; 'B"kUh%3$5
d& @KGJ
~`MGXd"o
for(int i=0;i<nStartPos.length;i++) jK&kQ
{ x]k^JPX
if(!fileSplitterFetch.bDownOver) IrXC/?^h
{ n\ma5"n0=\
breakWhile = false; F,e_`
break; I/GZ
} %f@VOSs
} &,fBg6A%
if(breakWhile) Z$,1Tk"O/s
break; SF;;4og
8jjJ/Mz`
fj 19U9R
//count++; r&\}E+
//if(count>4) E<a~ `e
// siteStop(); KTk%Np
} WZCX&ui
{ >Y<!
Ckvm3r\i2
System.err.println("文件下载结束！"); mB#`{|1[
} ;X\>oV3#
catch(Exception e){e.printStackTrace ();} Vd|5JA}<"
} X63DBF4A
o"v> BhpC
$<]y.nr|CX
//获得文件长度 D;<Qm,[
public long getFileSize() _qmBPUx
{ ~]A';xH&
int nFileLength = -1; 2u6N';jgZ
try{ DnaG$a<
URL url = new URL(siteInfoBean.getSSiteURL()); /v;g v[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }{Lf 4|8
httpConnection.setRequestProperty("User-Agent","NetFox"); -b(:kAwStk
[/*854
"aP>}5<h
int responseCode=httpConnection.getResponseCode(); E+"INX7
if(responseCode>=400) sj`9O-?49
{ (>>pla^
processErrorCode(responseCode); T_,LK7D
return -2; //-2 represent access is error A A<9XC
} ;oULtQ
-NZj:N
:M ix*NCf
String sHeader; Qkk~{OuC
_?@>S7-
vUgLWd
for(int i=1;;i++) {TdKS
{ 6yTL7@V|B
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tZU"Ud
//Utility.log(in.readLine()); A@_F ;4X
sHeader=httpConnection.getHeaderFieldKey(i); Z[AJat@H
if(sHeader!=null) E] t:_v
{ 4lb3quY$Us
if(sHeader.equals("Content-Length")) rg_-gZl8&z
{ ^=D77 jS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _ZD)#?
break; +B_q? 6pR
} Roy`HU ;0a
} rQ*'2Zf'<
else Q_6./.GQ
break; P}&7G-
} C3bZ3vcW$
} ?GD{}f33
catch(IOException e){e.printStackTrace ();} 5HL JkOV5
catch(Exception e){e.printStackTrace ();} h:#
>}O1lsjW:z
YIfPE{,
Utility.log(nFileLength); v2EM| Q xp
{)ZbOq2
\fU{$
return nFileLength; x7Ly,
} zmf5!77
Lvv`_
w*#k&N[X
//保存下载信息（文件指针位置） x;Dr40wD@y
private void write_nPos() u/y`M]17
{ #&r^~>,#L-
try{ AWQwpaj-
output = new DataOutputStream(new FileOutputStream(tmpFile)); +VDl"Hx
output.writeInt(nStartPos.length); 9qwVBu ;
for(int i=0;i<nStartPos.length;i++) -1S+fUkiK/
{ wXXv0OzK
// output.writeLong(nPos); BIbcm,YQ
output.writeLong(fileSplitterFetch.nStartPos); uTP=kgYqJ
output.writeLong(fileSplitterFetch.nEndPos); jDgiH}
} ^bL.|vB
output.close(); eiP>?8
} )@1_Dm@0b
catch(IOException e){e.printStackTrace ();} pwd7I
catch(Exception e){e.printStackTrace ();} 0gO2^m)W
} kZ`60X%wE
_4zlEo-.gU
|KU>+4= @
//读取保存的下载信息（文件指针位置） Zf]d'oW{/
private void read_nPos() TDtk'=;
{ Lkk'y})/
try{ yn!LJT[~2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;n7k_K#0z!
int nCount = input.readInt(); %>xW_5;Z
nStartPos = new long[nCount]; &E {/s
nEndPos = new long[nCount]; 6$)Yqg`X
for(int i=0;i<nStartPos.length;i++) L V33vy
{ ;c:vzF~Q
nStartPos = input.readLong(); 0[PPVr:
nEndPos = input.readLong(); fgn*3 pg
} kt X(\Hf!
input.close(); xE;fM\7pu
} o0s+ roiD
catch(IOException e){e.printStackTrace ();} X_Y$-I$qd
catch(Exception e){e.printStackTrace ();} ,!%[CpM3
} $3Wl~ G}
X[NsdD?w1+
kfm8F8sxl
private void processErrorCode(int nErrorCode) jW2z3.w
{ pl q$t/.U;
System.err.println("Error Code : " + nErrorCode); WF*2^iWJ
} OYG8%L
7gD$Q
W1r-uR
//停止文件下载 @U5+1Hjc
public void siteStop() _jU6[y|XLh
{ cQgmRHZ]
bStop = true; H0tjN&O_
for(int i=0;i<nStartPos.length;i++) )u\"xxcV
fileSplitterFetch.splitterStop(); <&l3bL
A8c'CMEm
4X#>;
} Pm+H!x,
} z56W5g2
//负责部分文件的抓取 *tz"T-6O
**FileSplitterFetch.java _Mq@58q'
*/ .HZYSY:X
package NetFox; x*BfRj
1K^/@^
6<]&T lS]
import java.io.*; <MvFAuAT
import java.net.*; f_D1zU^
Q(Vc/
]jY->NsA]
public class FileSplitterFetch extends Thread { M9bb,`X>Q
l4R:_Z<
{*jkx,|
String sURL; //File URL v8 6ls[lzu
long nStartPos; //File Snippet Start Position z ; :E~;
long nEndPos; //File Snippet End Position zFB$^)v"<
int nThreadID; //Thread's ID z<^HohT
boolean bDownOver = false; //Downing is over tBrd+}e2*
boolean bStop = false; //Stop identical Q9%N>h9
FileAccessI fileAccessI = null; //File Access interface VD36ce9
]>R`]U9*O
^!pagt^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _6=6 b!hD
{ .%WbXs
this.sURL = sURL; ^Y #?@
this.nStartPos = nStart; 0qJ(3N
this.nEndPos = nEnd; 0p Lb<&
nThreadID = id; Q$kSK+ q!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,"j|0Q
} .O1g'%
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t&0n"4$d'
public void run() A[oi?.D
{ 5f}63as
while(nStartPos < nEndPos && !bStop) G_42ckLq
{ 2+"#
@*%5"~F
@zd)]O]xH?
try{ dBobVT'
URL url = new URL(sURL); ;zSh9H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O;qS3
httpConnection.setRequestProperty("User-Agent","NetFox"); H1hj` '\"<
String sProperty = "bytes="+nStartPos+"-"; ym(r;mj!
httpConnection.setRequestProperty("RANGE",sProperty); o5Pq>Y2T
Utility.log(sProperty); uo 7AU3\
HpNf f0c
k*z)AR
InputStream input = httpConnection.getInputStream(); \P{VJ^)0
//logResponseHead(httpConnection); H~||]_q|
[0MVsc=
Ae`K9
byte[] b = new byte[1024]; s'} oVx]
int nRead; gtCd#t'(V
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `n5)oU2q
{ !n)2HDYhx,
nStartPos += fileAccessI.write(b,0,nRead); /7P4[~vw
//if(nThreadID == 1) eW7;yH
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "V?U^L>SF
} \i`/k(
q'K=Ly+
HK:?Y[ebs
Utility.log("Thread " + nThreadID + " is over!"); T:na\y/{j
bDownOver = true; f>p;Jh{2fn
//nPos = fileAccessI.write (b,0,nRead); =P0~=UP
} bhuA,}
catch(Exception e){e.printStackTrace ();} J,+| Fb
} G.T}^xHmL
} 0%'&s)#
^(UL$cQ>
'H*S-d6V
//打印回应的头信息 6AZ/whn#
public void logResponseHead(HttpURLConnection con) Pfi '+I`s
{ AbLOq@lrK
for(int i=1;;i++) ;znIY&Z
{ tM{t'WU
String header=con.getHeaderFieldKey(i); -- _,;
if(header!=null) ZHw)N&Qn
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _Y}(v((;
Utility.log(header+" : "+con.getHeaderField(header)); e[R364K
else #XC\=pZX
break; ">CjnF2>R
} q|gG{9
} [gH vI
=<a`G3SY!
W~dS8B=<
public void splitterStop() j6IWdqXe
{ Et`z7Q*e
bStop = true; }@a_x,O/x}
} #.FtPR
f4`=yj*
uN6TV*]:
} Wl::tgU
P) GBuW
\t^q@}~0Wz
/* ]hv4EL(zi
**FileAccess.java `){*JPl
*//文件访问(定位，写) mv<z%y?Oj
package NetFox; gt'0B-;W
import java.io.*; i(L;1 `
obaJT"1
\gj@O5rGP
public class FileAccessI implements Serializable{ }2V|B4
3x'BMAA+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *Swb40L^
RandomAccessFile oSavedFile; b/5;377_
long nPos; /-G;#Wm
~G5)ya-
<\2,7K{{+;
public FileAccessI() throws IOException H4^-MSw
{ X^fMt]
this("",0); }MXZ
} yv4hH4Io
",`fGu )
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public FileAccessI(String sName,long nPos) throws IOException jIAl7aoY
{ ZqS'xN:k
oSavedFile = new RandomAccessFile(sName,"rw"); X#gZgz ='
this.nPos = nPos; !t~S.`vF
oSavedFile.seek(nPos); 3vNoD
} |2{y'?,
Mq6.!j
.CrahV1G
public synchronized int write(byte[] b,int nStart,int nLen) :m^eNS6:
{ C!RxMccTh
int n = -1; GwW!Q|tVz=
try{ im4V6 f;%
oSavedFile.write(b,nStart,nLen); YX!%R]c%
n = nLen; }T4"#'`
} ##1[/D(
catch(IOException e) MP;7u%
{ Dr,{V6^
e.printStackTrace (); Fgt/A#`fz
} v[35C]gS
u|O5ZV-cd
2+ >.Z.pX
return n; Yz\z Qj
} jJ|u!a
3DMfR ofg
VX2bC(E'%
} vr=iG xD
7GWPsaPn
IkL|bV3E0
/* O^F%ssF8
**SiteInfoBean.java AEOo]b*&d
*/ Aj SIM.
package NetFox; ~*THL0]~
,?<jue/bd
OUnt?[U\
public class SiteInfoBean { o&fAnpia=
76mQ$ze
{C|#<}1
private String sSiteURL; //Site's URL ZMy7z|
private String sFilePath; //Saved File's Path zSj.Y{J
private String sFileName; //Saved File's Name nWmc
private int nSplitter; //Count of Splited Downloading File tjuW+5O
!$qNugLg
p,$1%/m
public SiteInfoBean() {cq; SH
{//nSplitter的缺省值为5 :$dGcX}
//default value of nSplitter is 5 E3_EXz9h
this("","","",5); j?[fpN$
} V,*YM
}!lLA4XRr
[$OD+@~A2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2,E&}a|;b
{ Pm%ZzU
sSiteURL= sURL; h,rGa\X~0
sFilePath = sPath; kIP~XV~
sFileName = sName; b ]1SuL
this.nSplitter = nSpiltter; _I3j7f,V
9\R:J"X
2AzF@Pi^z
} .LN&EfMenF
+, p
L8TT54fM
public String getSSiteURL() u}qfwVX Z
{ DIkD6n?V
return sSiteURL; :sk7`7v
} %:YON,1b=7
p_!Y:\a5
E9!IGci
public void setSSiteURL(String value) ofj7$se
{ g@`14U/|
sSiteURL = value; K3!|k(jt
} M)Vz9,
TM[Z~n(wt
Ep.,2H
public String getSFilePath() #xm<|s
{ Cdotl$'
return sFilePath; _ZC4O&fL
} D0~WK stl
?b^VEp.;}
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public void setSFilePath(String value) TB*g$*
{ 1CFrV=d
sFilePath = value; toX4kmC
} `m`jX|`
*x)WF;(]g
M5: f^
public String getSFileName() k_-=:(Z
{ lVARe3#
return sFileName; 2:&8FdU
} i8Yl1nF
7==Uz?}C
ipw_AC~
public void setSFileName(String value) aVO5zR./)
{ ]J~37 35]
sFileName = value; s~IOc%3
} N 2L/A
G0^23j
Y^2`)':
public int getNSplitter() {!o-y=
{ Qh? E*9
return nSplitter; p%]*I?
} de[c3!#1d
4ME8NEE
C!Y|k.`p
public void setNSplitter(int nCount) {{tH$j?Q
{ G>YJ3p7
nSplitter = nCount; DSizr4R
} *;,=x<
} !})/x~~e
@zT.&1;`
n-}:D<\7
/* yodJGGAzk
**Utility.java 4+$<G/K
*/ ;=5V)1~i1;
package NetFox; NQ'^z
B5 C]4
?0DCjh8We
public class Utility { #fk)Y1
/h0-qW
ie 2X.#
public Utility() 5w@ ;B
{ DcQ^V4_
oZA|IF8U0
A0V"5syY
} wkdd&Nw;
F$ZWQ9&5U0
//线程睡眠 PxfeU2^{0
public static void sleep(int nSecond) SL hki)|
{ y$r9Y!?s
try{ U^+9l?ol
Thread.sleep(nSecond); ?"{+m
} ga4 gH>4
catch(Exception e) 83412@&
{ )XnG.T{0|
e.printStackTrace (); HsR#dp+s~
} @1*lmFq'kV
} ,b-wo
k]qZOO}
//日志 ,au64sH
public static void log(String sMsg) &VY;Al
{ 9(|[okB
System.err.println(sMsg); kZU8s'C
} `]LaX&u
>BrxJw#M
E&{*{u4
public static void log(int sMsg) `yP-,lA$
{ "f!*%SR: 1
System.err.println(sMsg); c72Oy+#
} q-o=lU"
} #_2V@F+,
$\81WsL'
Eh!%NeO
/* AU^Wy|i5Q
**TestMethod.java ~H@':Mms.h
*/ yz9`1R2c
package NetFox; KfG%#2\G_
_8 vxb
bjm`u3 A
public class TestMethod { \#LKsQa
,*E%D_
J}._v\Q7P
public TestMethod() @tEVgyN
{ ///xx/weblogic60b2_win.exe E;VBoN [
try{ ;FMK>%Zq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); thipfS
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %f6l"~y
SiteFileFetch fileFetch = new SiteFileFetch(bean); w?jmi~6
fileFetch.start(); 7z<!2
} /nv1.c)k
catch(Exception e){e.printStackTrace ();} reu[}k~
IH\k_Yf#u
iBp 71x65
} P^rSpS9
E0xUEAO
$rFv(Qc^=
public static void main(String[] args) 9'8OGCN
{ By3dRiM=,2
new TestMethod(); F|xXMpC.f
} @h>#cwhU
} zHb<YpU
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