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)); <<F#Al
} #k? Rl
for(int i=0;i<nEndPos.length-1;i++) _YF~DU
{ N,v4SIC@
nEndPos = nStartPos[i+1]; *;A I0
} Q]X0O10
nEndPos[nEndPos.length-1] = nFileLength; 48,Aq*JFw
} SPKen}g
} ?m-kpW8
Y68`B"3
9HMW!DSK`
//启动子线程 mY"DYYR>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; lSP{9L6
for(int i=0;i<nStartPos.length;i++) d5<@WI:wz
{ *UVjN_na5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7O5`&Z'-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $4.mRS97g
nStartPos,nEndPos,i); 4eb<SNi
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JtYc'%OF
fileSplitterFetch.start(); dIv/.x/V
} 6GzmzhX4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E\!:MCL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %8iA0t+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", y$@d%U*rW^
nEndPos = " + nFileLength); qmUq9bV
// fileSplitterFetch[nPos.length-1].start(); 9_IR%bm
}D.?O,ue
?#]K54?
//等待子线程结束 wP3PI.g-g
//int count = 0; @~6A9Fr
//是否结束while循环 5xW)nEV
boolean breakWhile = false; N>i1TM2
]*a)'k_@[
sQW$P9s c
while(!bStop) &H\$O.?f
{ [o&Vr\.$
write_nPos(); A?Jm59{w
Utility.sleep(500); b7fP)nb695
breakWhile = true; u#=Yv|9
2L.UEAt
Q6?+#}
for(int i=0;i<nStartPos.length;i++) g#FqjE|mx
{ uF5d ]{Qt
if(!fileSplitterFetch.bDownOver) 2^Gl;3
{ ;@K,>$ur-
breakWhile = false; G[u_Uu=>
break; Q(m} Sr4
} G8|[.n
} AG)N^yd
if(breakWhile) [:$j<}UmB
break; "hz(A.THi
s<0yQ-=.?N
Vja' :i
//count++; FVLXq0<Cj
//if(count>4) L]0+u\(
// siteStop(); IDBhhv3ak
} >>krH'79
Y5LESZWo
l1`Zp9I
System.err.println("文件下载结束！"); 6, ag\
} <Xw 6m$fr:
catch(Exception e){e.printStackTrace ();} ;}K1c+m!5V
} aq"E@fb
rBs7,h
D+rDgrv
//获得文件长度 GSV,
public long getFileSize() #Q6wv/"Ub
{ S6}_Z
int nFileLength = -1; S}e*~^1J
try{ Wf_aEW&n
URL url = new URL(siteInfoBean.getSSiteURL()); ,: w~-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [K13Jy+
httpConnection.setRequestProperty("User-Agent","NetFox"); O89<IXk
g2C-)*'{yh
`ZN@L<I6
int responseCode=httpConnection.getResponseCode(); =Z/'|;Vd_x
if(responseCode>=400) +YT/od1t7
{ 6N.mSnp
processErrorCode(responseCode); =pWpHbB.
return -2; //-2 represent access is error /0SG
} &{&lCBN
H*|Bukgt/M
&.kg8|s{
String sHeader; t,N-|
.5L/<
s5|LD'o!
for(int i=1;;i++) wO} 3i6
{ L3q)j\ls
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "r cPJX
//Utility.log(in.readLine()); <)Kjf/x
sHeader=httpConnection.getHeaderFieldKey(i); T'XAcH
if(sHeader!=null) (#c5Q&
{ &\sg~
if(sHeader.equals("Content-Length")) H?40yu2m5
{ O,qR$#l
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); iBJ*6orz
break; *sJx0<!M}
} F&lc8
} #2yOqUO\
else nIph[Vs-Z
break; ygpC1nN
} d;lp^K M
} tP!sOvQ:
catch(IOException e){e.printStackTrace ();} j K[VEhs
catch(Exception e){e.printStackTrace ();} a-!"m
y#AY+ >
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Utility.log(nFileLength); w])~m1yW
>4M_jC.
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return nFileLength; >;xEzc!W3*
} rF~q"9
.U5+PQN
Zz?+,-$_*&
//保存下载信息（文件指针位置） }WI24|`zM
private void write_nPos() *B:{g>0
{ 7M;Y#=sR
try{ 8x,;B_Zu
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^fK8~g;rB
output.writeInt(nStartPos.length); ~w]1QHA'f
for(int i=0;i<nStartPos.length;i++) ,eUMSg~P.7
{ 5tq$SF42X
// output.writeLong(nPos); MiRH i<g0
output.writeLong(fileSplitterFetch.nStartPos); \TMRS(
output.writeLong(fileSplitterFetch.nEndPos); ;t?pyFT2Z
} Ur&: Rr
output.close(); 8QC:ro
} iT^lk'?{O
catch(IOException e){e.printStackTrace ();} P#ru-0DD
catch(Exception e){e.printStackTrace ();} y_$^Po
} L6 _Sc-sU
;k/0N~
P\zi:]h[Gh
//读取保存的下载信息（文件指针位置） 7KM!\"PM
private void read_nPos() _IlL'c5
{ =:"@YD^a4
try{ &u=FLp5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); svo^#V~h'
int nCount = input.readInt(); ;prp6(c
nStartPos = new long[nCount]; `}Q;2 F
nEndPos = new long[nCount]; +#B%YK|LR
for(int i=0;i<nStartPos.length;i++) A5H[g`&
{ !uO|T'u0a
nStartPos = input.readLong(); *c3o&-ke9
nEndPos = input.readLong(); 9oq(5BG,
} cQ+,F2
input.close(); '!1lK
} p$9N}}/c
catch(IOException e){e.printStackTrace ();} ~o # NOfYi
catch(Exception e){e.printStackTrace ();} K4RjGSaF
} ;( 2uQ#Y
V;:A&
b/5~VY*T
private void processErrorCode(int nErrorCode) > %Y#(_~a
{ ;QEGr|(
System.err.println("Error Code : " + nErrorCode); .FMF0r>l
} T@vVff
uo%O\}#u9
\pPq]k
//停止文件下载 T2(+HI2
public void siteStop() ]iNSa{G
{ v#/,,)m
bStop = true; lJYv2EZ
for(int i=0;i<nStartPos.length;i++) \uPT-M*
fileSplitterFetch.splitterStop(); 6|jE3rHw
3t_5Xacj
X*Q7Yu
} w^p2XlQ<
} }Ql;%7
//负责部分文件的抓取 Ahwu'mgnC
**FileSplitterFetch.java 9n%W-R.
*/ ljf9L:L
package NetFox; ]g)%yuox9F
ovfw_
\@F{Q-
import java.io.*; X|q0m3jt
import java.net.*; ftH 0aI
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?PQiVL
public class FileSplitterFetch extends Thread { 0y ;gi3W
c`jTdVD
:8QG$Ua1
String sURL; //File URL H{$yy)@F
long nStartPos; //File Snippet Start Position "1nd~ BBOw
long nEndPos; //File Snippet End Position j68Gz5;j
int nThreadID; //Thread's ID hs*:!&E
boolean bDownOver = false; //Downing is over {Y/
boolean bStop = false; //Stop identical < 1r.p<s
FileAccessI fileAccessI = null; //File Access interface r-0 7!A
){(cRB$
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]E3g8?L
{ ;kFp)*i
this.sURL = sURL; 23fAc"@ B
this.nStartPos = nStart; #,9|Hr%
this.nEndPos = nEnd; WUV Q_<i+
nThreadID = id; M<L<mP}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 i@;a%$5
} D"WkD j"M
v|'N|k l
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public void run() .5z|g@ 6
{ ZuhT \l
while(nStartPos < nEndPos && !bStop) 97g-*K
{ Q:LuRE!t
Umd!j,
S:j0&*
try{ *Xo f;)Z^
URL url = new URL(sURL); ";xEuX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b$eJH
httpConnection.setRequestProperty("User-Agent","NetFox"); IpP0|:}
String sProperty = "bytes="+nStartPos+"-"; d^Wh-U
httpConnection.setRequestProperty("RANGE",sProperty); bpILiC
Utility.log(sProperty); N?Z?g_a8
!6%mt}h
%In"Kh*
InputStream input = httpConnection.getInputStream(); h=tY 5]8
//logResponseHead(httpConnection); E}GSii%S
th<]L<BP/
M#p,Z F
byte[] b = new byte[1024]; 'GyPl
int nRead; yUG5'<lX
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $5o<Mj
{ s [!SG`&
nStartPos += fileAccessI.write(b,0,nRead); j AE0$u~.
//if(nThreadID == 1) ,jWd?-NH
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X>4`{x`
} 9..k/cH
a]k&$
{3Rax5Ty
Utility.log("Thread " + nThreadID + " is over!"); ^/uGcz|.
bDownOver = true; 5a&wM
//nPos = fileAccessI.write (b,0,nRead); y{sA["
} R pbl)
catch(Exception e){e.printStackTrace ();} R;yAqr29
} E6gEP0b
} *LVM}| f
"10VN*)J}
cmeyCyV*
//打印回应的头信息 aFym&n\
public void logResponseHead(HttpURLConnection con) ..:V3]-D
{ S#9SAX [
for(int i=1;;i++) [:'n+D=T3M
{ C"{on%
String header=con.getHeaderFieldKey(i); ( A)wcB
if(header!=null) *J=ol
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1`t?5|s>
Utility.log(header+" : "+con.getHeaderField(header)); NZuFxJ-`
else THp `!l
break; v\eBL&WK
} 8iNAs#s
} \2,18E
(AYS>8O&
1sjn_fPz
public void splitterStop() U!5*V9T~J
{ (n/1:'
bStop = true; )8SP$
} {+:XVT_+
&>{>k<z
sdWl5 "
} :ct+.#
j1<1D@UO
{p 0'Lc<3n
/* B>ZPn6?y
**FileAccess.java A&F4;>dms
*//文件访问(定位，写) Y zS*p~|
package NetFox; Oy&'zigJ
import java.io.*; E2IVR]C2^
q1Sm#_7
JWL J<z
public class FileAccessI implements Serializable{ gxM8IQ
"~<~b2Y"5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 O:)IRB3
RandomAccessFile oSavedFile; ~S6{VK.
long nPos; njMy&$6a##
~P_kr'o
]Qr8wa>Z
public FileAccessI() throws IOException ]LTc)[5Zj
{ <h=M Rw,l
this("",0); ?<'W~Rm6n
} RHVv}N0
'.yWL
6sl<Z=E#
public FileAccessI(String sName,long nPos) throws IOException VWy:U#;+8
{ lg>AWTW[
oSavedFile = new RandomAccessFile(sName,"rw"); lM*O+k
this.nPos = nPos; 2H[aY%1T
oSavedFile.seek(nPos); zDyeAxh4
} xUi!|c
QJWES%m`
9Oyi:2A
public synchronized int write(byte[] b,int nStart,int nLen) ]4mj 1g&C
{ ->I{ :#
int n = -1; I%919
try{ 3 ?F@jEQk
oSavedFile.write(b,nStart,nLen); >-lL-%N_
n = nLen; H$amt^|zQ4
} !h>$bm
catch(IOException e) p,\bez
{ {K4t8T]
e.printStackTrace (); [E (M(w':
} X-#mv|3
Ko)T>8:
T zYgH
return n; NB5B$q_'#
} -_DiD^UcXn
;}~Bv<#
}]+}Tipd
} >5Oy^u6Ly
$Wzv$4;
[KI`e
/* /%9p9$kFot
**SiteInfoBean.java AdOAh y2H
*/ *9Js:z7I
package NetFox; #4 &N0IG
1r& ?J.z25
C$G88hesn
public class SiteInfoBean { ' 5 qL
B4Af
\w[ZY$/
private String sSiteURL; //Site's URL Z?c=t-yqp
private String sFilePath; //Saved File's Path X1[R*a/p
private String sFileName; //Saved File's Name 1vK(^u[
private int nSplitter; //Count of Splited Downloading File `Mn{bd
NvHy'
sk6|_
public SiteInfoBean() ,tF" 4|#
{//nSplitter的缺省值为5 ^%$W S,
//default value of nSplitter is 5 soQzIx
this("","","",5); (Zn3-t*
} q\y#
Y_3YO2K]
k;AiG8jb
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V'f5-E0
{ Qn)[1v
sSiteURL= sURL; 1fhK{9#
sFilePath = sPath; \BcJDdL
sFileName = sName; ]AA*f_!
this.nSplitter = nSpiltter; r]EZ)qp^@
X:-bAu}D
Y1_6\zpA
} lPQ Ut!xI
\]#;!6ge
ySK Yqt z
public String getSSiteURL() pF*~)e
{ OjlB0
return sSiteURL; 27YLg c
} xVz -_z
u:H 3.5)%
}V#9tWW
public void setSSiteURL(String value) }%ZG>LG5J
{ 0/00W6r0
sSiteURL = value; (9 z.IH7}k
} UNcJ=
3g#=sd!0O@
=']};
public String getSFilePath() ]G o~]7(5|
{ l)rvh#D
return sFilePath; awSS..g}L
} z0Z\d
t"bPKFRy9E
b}*@=X=4o
public void setSFilePath(String value) ))69a
{ ])ALAAIc-
sFilePath = value; GE8D3V;*V
} {L-aXe{
a(43]d&
$h]Y<&('G
public String getSFileName() uZ`d&CEh
{ xBE RCO^
return sFileName; UFIAgNKl
} )bCG]OM7<
Rw ao5l=x
>&Ui*
public void setSFileName(String value) -}qGb}F8!
{ bR8 HGH28
sFileName = value; z2nUul(2
} v!{'23`87
7~l
;aK !eD$
public int getNSplitter() u388Wj
{ gQpD]p%k
return nSplitter; mA] 84zO
} +?5Uy*$
hzuMTKH9
ND55`KT4
public void setNSplitter(int nCount) cH*/zNp
{ N4` 9TN7
nSplitter = nCount; &(uF&-PwO4
} o )nT
} wp]7Lx?F
D_19sN@0m
N}x/&e
/* kG;eOp16R
**Utility.java ^2;(2s
*/ pW3)Y5/D
package NetFox; @a.6?.<L
3e!Yu.q:
peTO-x^a-
public class Utility { n"<GJ.{
jQ_|z@OV
5nxS+`Pn.)
public Utility() N9JgV,`
{ Xx y Bg!R
& L.PU@
_^xh1=Qr}n
} |p8"9jN@}c
{sfmWVp
//线程睡眠 il>x!)?o
public static void sleep(int nSecond) 4<3?al&
{ i^s`6:rNu
try{ ghJ,s|lH
Thread.sleep(nSecond); 9?l?G GmQ
} (4{ C7
catch(Exception e) srChY&h?<
{ ll<9f)
e.printStackTrace (); z7t'6Fy9'
} =@1R ozt
} ;*)fO?TG)
e0|_Z])D
//日志 UP~WP@0F
public static void log(String sMsg) 1hMX(N&|
{ =~W0~lxX
System.err.println(sMsg); `r'0"V
} RP|>&I
/:Z~"Q*r
_8NEwwhc
public static void log(int sMsg) ;1R?9JN"
{ GEe 0@q#YA
System.err.println(sMsg); m_E[bDON
} ,3J`ftCV
} R!_8jD:$
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V$-~%7@>;9
/* 1|l)gfcP
**TestMethod.java 2Pem%HE~P
*/ oXQ<9t1(
package NetFox; x#:BE
M~ i+F0
Q2[prrk%j
public class TestMethod { Hlt8al3
4(Cd
wzDk{4U
public TestMethod() 20.-;jK
{ ///xx/weblogic60b2_win.exe ySixYt
try{ y;{^Ln4{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >2|[EZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]e@0T{!
SiteFileFetch fileFetch = new SiteFileFetch(bean); !e:iB7<
fileFetch.start(); ]M+VSU
} Z92iil;t
catch(Exception e){e.printStackTrace ();} ~|r'2V*
7|+|\7l#
,TKs/-_?
} [w&#+h-q
O2`oe4."vd
JGk3b=K
public static void main(String[] args) f.aB?\"f6
{ Uw2,o|=O
new TestMethod(); |b$>68:
} F}6DB*
} wDT>">&d
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