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)); PEKXPFN
} KAr5>^<zw
for(int i=0;i<nEndPos.length-1;i++) O+Db#FW
{ raP9rEs
nEndPos = nStartPos[i+1]; -gb@BIV#
} uD4W@*PYr
nEndPos[nEndPos.length-1] = nFileLength; &y3;`A7,
} _*t75e$-
} gHWsKE %
skt9mU
7$L*nf
//启动子线程 K1-3!G
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~>%%kQt
for(int i=0;i<nStartPos.length;i++) gPpk0LZi
{ [XA:pj;rg'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -BrJ5]T>*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @[ '?AsO
nStartPos,nEndPos,i); \&v)#w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8tT/w5
fileSplitterFetch.start(); ge{%B~x
} EhOB+Mc1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c8o2* C$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3HndE~_C&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", A(JgAV1{
nEndPos = " + nFileLength); !3*%-8bp
// fileSplitterFetch[nPos.length-1].start(); R8j\CiV17
~y:?w(GD
*W4~.peoE
//等待子线程结束 [5P1 pkZ
//int count = 0; h& Ezhv2
//是否结束while循环 "!o|^nN,
boolean breakWhile = false; 2 3A)^j
AT"!Ys|
@WzrrCpj
while(!bStop) ((fFe8Rn)q
{ !$,e)89
write_nPos(); Vf$q3X
Utility.sleep(500); zj;KtgcE
breakWhile = true; |OBZSk1jp
6"o@d8>v
YD;"_yH
for(int i=0;i<nStartPos.length;i++) O6\t_.
{ 11-?M
if(!fileSplitterFetch.bDownOver) E@)9'?q
{ Q~)A fa{
breakWhile = false; %T~LK=m
break; 6p~8(-nG
} fSm|anuKZe
} U0dhr;l
if(breakWhile) {&)E$M
break; 24d{ol)
>m`<AynJ
m)xz_Plc
//count++; NS^+n4
//if(count>4) M}!E :bv'
// siteStop(); \7tJ)[0aF
} Wg=4`&F^
x`zE#sD
d)v'K5
System.err.println("文件下载结束！"); 0"xD>ue&
} `&o>7a;
catch(Exception e){e.printStackTrace ();} oJor ]QYK
} M[5fNK&nD
~5wT|d
43o!Vr/S
//获得文件长度 v\Xyz )
public long getFileSize() G:!'hadw
{ FK`M+ j
int nFileLength = -1; :pg]0X;
try{ IM&l%6[).
URL url = new URL(siteInfoBean.getSSiteURL()); {{e+t8J??
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vI+X9C?
httpConnection.setRequestProperty("User-Agent","NetFox"); tLe"i>
G}gmkp]z
eR:!1z_h
int responseCode=httpConnection.getResponseCode(); WRfhxl
if(responseCode>=400) )W$@phY(I
{ {t QZqqdn@
processErrorCode(responseCode); 'n4 iW
return -2; //-2 represent access is error DeRC_ [
} M07==R7
s<fzk1LZ
qb7ur;
String sHeader; PitDk 1T
3q:>NB<
w2o5+G=
for(int i=1;;i++) }C9P--
{ Xmaj7*f>p
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *S{fyYyM
//Utility.log(in.readLine()); -4nSiI
sHeader=httpConnection.getHeaderFieldKey(i); `{W>Dy
if(sHeader!=null) '"o&BmF
{ CxJkT2
if(sHeader.equals("Content-Length")) {{ /-v3n
{ ])uhm)U@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); a;[=bp
break; /;a b"b
} 2g:V_%
} +'QE-#%{=
else =6LF_=}
break; k&SI-jxj
} 6F4OISy%3
} 9a lMC
catch(IOException e){e.printStackTrace ();} UfAN)SE"
catch(Exception e){e.printStackTrace ();} w@"l0gm+u[
a>XlkkX
|\_d^U&`
Utility.log(nFileLength); {|ChwM\x
m03]SF(#3
%q)*8
return nFileLength; O[/l';i
} -P7JaH/Q
yi$Jk}w
La#otuw+?
//保存下载信息（文件指针位置） bQ6<R4
private void write_nPos() FF7
{ UpIt"+d2&
try{ `U[s d*C"
output = new DataOutputStream(new FileOutputStream(tmpFile)); UOAL7
output.writeInt(nStartPos.length); s`Z'5J;S
for(int i=0;i<nStartPos.length;i++) .|Zt&5osI
{ FqpUw<]6s
// output.writeLong(nPos); ri?>@i-9=
output.writeLong(fileSplitterFetch.nStartPos); Zr U9oy&!C
output.writeLong(fileSplitterFetch.nEndPos); Q1?09
} ?YTngIa
output.close(); qS{E+)P
} }HC6m{vH(
catch(IOException e){e.printStackTrace ();} NHjZ`=Js
catch(Exception e){e.printStackTrace ();} e;ej/)no`
} vq&u19iP
~xSAR;8
8kwe._&)
//读取保存的下载信息（文件指针位置） cun&'JOH?U
private void read_nPos() G^Q8B^Lg
{ :xz,PeXo7
try{ 1ehl=WN
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &>]c"?C*
int nCount = input.readInt(); |q:p^;x
nStartPos = new long[nCount]; .3QX*]{
nEndPos = new long[nCount]; !QTfQ69Y0
for(int i=0;i<nStartPos.length;i++) S[zX@3eZV
{ ToVi;
nStartPos = input.readLong(); _'"whZ)2
nEndPos = input.readLong(); ^OWA
} X/l{E4Ex
input.close(); r%^l~PN
} :g`j gn0
catch(IOException e){e.printStackTrace ();} >m-VBo
catch(Exception e){e.printStackTrace ();} #OT8_D
} Jiv%Opo/|
s.p4+KJ
f*ICZM
private void processErrorCode(int nErrorCode) +KzbaBK
{ 5UgxuuP4
System.err.println("Error Code : " + nErrorCode); p]-\\o}
} ?"o7x[
K_" denzT+
_3'FX#xc
//停止文件下载 \69h>h
public void siteStop() ZVin+z
{ R;]z/|8
bStop = true; Uf ?._&:
for(int i=0;i<nStartPos.length;i++) aA|<W g
fileSplitterFetch.splitterStop(); z{N~AaY
ruKm_j#J
`v|w&ty*
} oieJ7\h]m
} Ddr.kXIpo
//负责部分文件的抓取 1j!LK-
**FileSplitterFetch.java t6+c"=P#
*/ oE H""Bd
package NetFox; D\ ;(BB
uSl&d
iiw\
import java.io.*; xRI7_8Jpyn
import java.net.*; !'jZ !NFO
@X?7a]+;8
e` QniTkT
public class FileSplitterFetch extends Thread { g"dq;H
=Lc!L !(,b
U{JD\G8m
String sURL; //File URL S#{jyU9 ]
long nStartPos; //File Snippet Start Position 0{q>'dv
long nEndPos; //File Snippet End Position w1&\heSQ
int nThreadID; //Thread's ID QCD MRh n
boolean bDownOver = false; //Downing is over Tx19\\r
boolean bStop = false; //Stop identical j TyR+#Wn
FileAccessI fileAccessI = null; //File Access interface "?X,);5S
~\oF}7l$
]VkM)< +
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nZbINhls
{ MP3Vo|}3
this.sURL = sURL; yd|roG/
this.nStartPos = nStart; cs]h+yE
this.nEndPos = nEnd; `B A'a" $
nThreadID = id; 44x+2@&1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 JqmxS*_P
} a$AR
CQANex4&\
3n!f'" T
public void run() /=(PMoZu
{ lZr}F.7
while(nStartPos < nEndPos && !bStop) Ym8 V)
{ 2bnYYQ14:
-\9K'8 C
JE*d-
try{ !\}X?Gf
URL url = new URL(sURL); )Ggv_mc h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (k^o[HF
httpConnection.setRequestProperty("User-Agent","NetFox"); \:m1{+l
String sProperty = "bytes="+nStartPos+"-"; 5<>"d :9
httpConnection.setRequestProperty("RANGE",sProperty); Z_h-5VU-
Utility.log(sProperty); I !J'
YW2h#PV6_
:OFs"bC
InputStream input = httpConnection.getInputStream(); t}YT+S
//logResponseHead(httpConnection); *6bO2LO"
2j;9USZ p
,(A $WT@e
byte[] b = new byte[1024]; ZYS]Et[Q
int nRead; o* ~aB_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {ldt/dl~
{ lv>^P>S(O
nStartPos += fileAccessI.write(b,0,nRead); we/sv9v}n
//if(nThreadID == 1) >/4N:=.h
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]5r@`%9
} 2}n7f7[/b
Gsu?m
b+CJRB1
Utility.log("Thread " + nThreadID + " is over!"); pft-.1py
bDownOver = true; !pZ<{|cH
//nPos = fileAccessI.write (b,0,nRead); ?2%;VKN4
} [jv+Of IZ
catch(Exception e){e.printStackTrace ();} ox*>HkV
} neQ~h4U"
} bXi!_'z$
Xp.$FJ1)
K3iQ/j~aq
//打印回应的头信息 W\2 ']7}e
public void logResponseHead(HttpURLConnection con) <L+1 &H
{ P1R5}i
for(int i=1;;i++) Z(XohWe2
{ ?>Ngsp>-P
String header=con.getHeaderFieldKey(i); jU-aa+
if(header!=null) IZLBv2m
//responseHeaders.put(header,httpConnection.getHeaderField(header)); HbRvU}C1
Utility.log(header+" : "+con.getHeaderField(header)); c'>_JlG~
else 9a]{|M9
break; #jh5%@
} }K5okxio
} la}cGZ; p.
Bi2 c5[3
wB bCGU
public void splitterStop() d%UzQ*s
{ d N$,AOT
bStop = true; fDloL
} !TivQB
PXyv);#Q`
9Z21|5
} _RIlGs\.
!,dp/5 V
Y]7503J
/* wBvVY3VQ^
**FileAccess.java )Gm9x]SVl
*//文件访问(定位，写) $H)QUFyC
package NetFox; p="0Y<2l
import java.io.*; `yP`5a/
M!kSt1
|;7mDhj=
public class FileAccessI implements Serializable{ m8;w7S7,j~
M\/hK2J# #
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t>AOF\
RandomAccessFile oSavedFile; 3@qv[yOE
long nPos; d]Y;rqjue
WrSc@j&Ycv
co~NXpqg
public FileAccessI() throws IOException lm 96:S
{ Q`W2\Kod]
this("",0); k qL.ZR
} 3C<G8*4);/
!:m.-TE
0ki- /{;
public FileAccessI(String sName,long nPos) throws IOException vc&v+5Y
{ b _<n]P*)
oSavedFile = new RandomAccessFile(sName,"rw"); i6KB\W2
this.nPos = nPos; SDC'S]{ew
oSavedFile.seek(nPos); DnFzCJ
} N<8\.z5:<
1C8xJ6F
l'/`2Y1
public synchronized int write(byte[] b,int nStart,int nLen) rD~/]y)t
{ Hf@4p'
int n = -1; ":8\2Qp
try{ DtFHh/X
oSavedFile.write(b,nStart,nLen); vMB61 |O
n = nLen; kqm(D#
} K<wFr-z
catch(IOException e) xy]O8>b
{ 7;o:r$08&}
e.printStackTrace (); 7H5VzV
} P*A+k"DU1
fJ[ ^_,O
C[<}eD4bV
return n; +7}^Y}(
} XZb=;tYo
tkT,M,]?9
X7huc*
} "t&=~eOe3
J`U]Ux/L
lG\uJxV
/* s|e.mZk/
**SiteInfoBean.java TvDSs])
*/ }bv+^#
package NetFox; B=TUZ)
1H-Y3G>jN
Qc3d<{7\~
public class SiteInfoBean { T0tX%_6`
bE/|&8
S-S%IdL
private String sSiteURL; //Site's URL Xx{| [2`
private String sFilePath; //Saved File's Path `/PBZnj
private String sFileName; //Saved File's Name bW6| &P}X
private int nSplitter; //Count of Splited Downloading File p>7qyZ8
dn#I,xa`
KVa{;zBwl
public SiteInfoBean() k~8-Eu1
{//nSplitter的缺省值为5 /P*XB%y
//default value of nSplitter is 5 wuH*a3(
this("","","",5); Vc(4d-d5
} !0,q[|m
w0_P9g:
R'k`0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8OZj24*'DS
{ EfEgY|V0
sSiteURL= sURL; KEOk%'c,
sFilePath = sPath; &u2;S?7m
sFileName = sName; teJt.VA7)
this.nSplitter = nSpiltter; :hZM$4
IE`3I#v
UH!(`Z\C
} rtuaU=U
KV_/fa~Ry
Fa%1]R
public String getSSiteURL() YCbvCw$Ob
{ *6/IO&y1a
return sSiteURL; 61S;M8tNv
} #hxYB
Zk=,`sBC
s(=wG|
public void setSSiteURL(String value) A9.TRKb=8
{ 7[1Lh'u
sSiteURL = value; Z_q+Ac{p
} CeYhn\m5K0
1B4Qj`:+0
r^~+<"
public String getSFilePath() ai_ve[A
{ <,M"kF:
return sFilePath; 3(WijtH
} KoERg&fY
9^}&PEl
f7x2"&?vg
public void setSFilePath(String value) !/}3/iU
{ p3M!H2W
sFilePath = value; " @D
} `dZ|Ko%k
h$02#(RHJ
v6*0@/L M
public String getSFileName() uN`/&_$c
{ >jI.$%L$
return sFileName; s)E \
} 3k1e
GKt."[seV
AQ'%}(#0
public void setSFileName(String value) q/ljH_-
{ bT,_=7F
sFileName = value; m Q9dF,
} Cy;UyZ
;XN|dq
8c9HJ9vk
public int getNSplitter() QC+ Z6WS;
{ }Fjbj5w0
return nSplitter; cw<IL
} XKWq{,Ks
I8bM-k):9R
PJ5}c!o[
public void setNSplitter(int nCount) q94;x|63
{ ?%6oM
nSplitter = nCount; 11oNlgY&
} tj13!Cc}e`
} >5FTBe[D
Fl`U{03
ng%[yY
/* dxX`\{E
**Utility.java IJ Jp5[w
*/ hY&Yp^"}]^
package NetFox; ^-"Iwy
mh3S?Uc
h&'|^;FM
public class Utility { GAj%o]}u
;E.]:Ia~
0+CcNY9
public Utility() cUR :a@
{ &>\;4E.O5
ve d]X!
O)q4^AE$
} W![K#r5T
!yd B,S
//线程睡眠 vfkF@^D
public static void sleep(int nSecond) DkWp
{ F!X0Wo=
try{ nCq'=L,m
Thread.sleep(nSecond); Ih.+-!w
} NVMn7H}>
catch(Exception e) ,8 4|qI
{ Q5ASN"_
e.printStackTrace (); e4z~
} MqZ"Js
} _pTcSp3
,iyy2
//日志 0f@+o}i=)
public static void log(String sMsg) :M"+
{ . Vb|le(7
System.err.println(sMsg); F+hV'{|w`
} 6\7c:
pq) =
3;v)f":[
public static void log(int sMsg) j#//U2VdN
{ 0 PYYG
System.err.println(sMsg); z/J?!ee
} "&={E{pQ
} d~<$J9%
O<$w-(
NZ1B#PG,c
/* ClKWf\(ii6
**TestMethod.java }eLApFHEDg
*/ "pO
package NetFox; :tZsSK
Tr?p/9.m
cP?GRMX@}
public class TestMethod { @(#vg\UH
0cmd +`
UCVYO. 9"
public TestMethod() OL\-SQ&
{ ///xx/weblogic60b2_win.exe #mU\8M,
try{ %G!!0V!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F${sEtH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .!4'Y}
SiteFileFetch fileFetch = new SiteFileFetch(bean); r-T1^u
fileFetch.start(); `/WxEu3
} VrW]|jIu*
catch(Exception e){e.printStackTrace ();} *<^C0:i(
~3s?.[}d
__}SHU0R
} "[ S[vkI
7u"Q1n(h/
W"%n5)
public static void main(String[] args) jsAx;Z:QT
{ a?W5~?\9
new TestMethod(); 2(d
} L!JC)p.
} N-l`U(Z~P
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