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)); \OVtvJV]
} `R8&(kQ
for(int i=0;i<nEndPos.length-1;i++) IB[$~sGe
{ Pn">fWRCx
nEndPos = nStartPos[i+1]; \6SjJ]o>
} )Q =>7%ZA
nEndPos[nEndPos.length-1] = nFileLength; Yu3S3aRE
} H"l4b4)N\
} rvd$4l^
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%|(c?`2|
//启动子线程 < v]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; p 4>ThpX
for(int i=0;i<nStartPos.length;i++) "g^i%
{ zk8)!Af
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w7?fJ")
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $C\ETQ@
nStartPos,nEndPos,i); P+hcj p*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~/`/r%1/J
fileSplitterFetch.start(); &su'znLV
} mfQ#n!{ZH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vNGE]+QX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~#*C,4m
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !|&|%x6@
nEndPos = " + nFileLength); ^)gyKl:E'
// fileSplitterFetch[nPos.length-1].start(); 8mreHa
o2ggHZe/=@
Bxm,?=h
//等待子线程结束 (CxA5u1|l
//int count = 0; :uo1QavO@,
//是否结束while循环 $gBQ5Wd
boolean breakWhile = false; R}=5:)%w
?ZRF]\dP]
p5fr}#en
while(!bStop) lWId 0eNS
{ eA4:]A"
write_nPos(); +Ua|0>?
Utility.sleep(500); F$?Ab\#B
breakWhile = true; vAUt~X"
13!@LbC
}~I!'J#)
for(int i=0;i<nStartPos.length;i++) lln"c
{ z5fE<=<X_W
if(!fileSplitterFetch.bDownOver) njy2pDC@
{ :jl*Y-mM
breakWhile = false; C:J;'[,S
break; XA2Ld
} NZq-%bE
} ccuGM WG*
if(breakWhile) .c"nDCFVR
break; QF"7.~~2
9b+jT{Tg
]^~}/@
//count++; 2nB99L{6
//if(count>4) FbE/x$;~O
// siteStop(); u-TT;k'
} JnBUW"
SN{+ Pk
&$~fz":1!
System.err.println("文件下载结束！"); C 5.3[
} lhN@,q
catch(Exception e){e.printStackTrace ();} V*4Z.3/E5
} 3^o(\=-JX
k6Kc{kY
fc9;ZX7
//获得文件长度 8v"rM >[
public long getFileSize() ebk>e*
{ EU?qLj':
int nFileLength = -1; {[oNUzcd
try{ qk(Eyp
URL url = new URL(siteInfoBean.getSSiteURL()); \3 SY2g8+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?gE=hh
httpConnection.setRequestProperty("User-Agent","NetFox"); RPz[3y
D|LO!,=b
OM\J4"YV$
int responseCode=httpConnection.getResponseCode(); b{A[\ "
if(responseCode>=400) J6Z[c*W
{ \]tBwa
processErrorCode(responseCode); @k?vbq
return -2; //-2 represent access is error r6m^~Wq!}
} }e[ E
x%B_v^^^
v"bWVc~H
String sHeader; T`bYidA
a('0l2e<u9
&GP(yj]
for(int i=1;;i++) iE~!?N|a3
{ -N45ni87
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w+br)
//Utility.log(in.readLine()); DB'0
sHeader=httpConnection.getHeaderFieldKey(i); E`IXBI
if(sHeader!=null) KUI{Z I
{ v ccH(T
if(sHeader.equals("Content-Length")) t%=7v)IOE
{ E=sh^Q(A
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); TjW!-s?S
break; OdzeHpH3g
} Cy~IB [
} |p|Zv H
else s.2f'i+
break; 2@|`Ugjptl
} ?XBdBR_"^
} -/Q5?0z
catch(IOException e){e.printStackTrace ();} pHeG{<^
catch(Exception e){e.printStackTrace ();} VdHT3r
iGW|j>N
Y <6|z3
Utility.log(nFileLength); R|st<P
U4!bW
#"gt&t9Q
return nFileLength; "<CM'R
} }.&nEi`
;2f=d_/x
mxv?PP
//保存下载信息（文件指针位置） }je<^]a
private void write_nPos() jl,gqMn"V
{ /;`H )
try{ DzZF*ylQ5P
output = new DataOutputStream(new FileOutputStream(tmpFile)); uF7vba$
output.writeInt(nStartPos.length); &`^(dO9
for(int i=0;i<nStartPos.length;i++) @.t +
{ BlVHP8/b
// output.writeLong(nPos); o=m5AUe?J
output.writeLong(fileSplitterFetch.nStartPos); 7)rQf{q7
output.writeLong(fileSplitterFetch.nEndPos); W5R/Ub@g
} ng1E'c]0@
output.close(); k<9,Ypa
} "-4|HA
catch(IOException e){e.printStackTrace ();} tr0b#4
catch(Exception e){e.printStackTrace ();} H,7='n7"
} %BI8m|6
;d?BVe?
?%O>]s
//读取保存的下载信息（文件指针位置） -)V0D,r$[
private void read_nPos() BZeEZ2"
{ Y+-yIMt$r
try{ o|xf2k
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S^QEctXU
int nCount = input.readInt(); q\fbrv%I4
nStartPos = new long[nCount]; JX59n%$@
nEndPos = new long[nCount]; K9<8FSn
for(int i=0;i<nStartPos.length;i++) pS?D~0Nb
{ (XZ[-M7
nStartPos = input.readLong(); 7e<=(\(yl
nEndPos = input.readLong(); *p{p.%Qs:
} odP<S.
input.close(); o@Ye_aM~?Y
} TegdB|y7O
catch(IOException e){e.printStackTrace ();} Jf^3nBZ
catch(Exception e){e.printStackTrace ();} )."ob=m
} Pf;OYWST
nW=6nCyvo
x;mw?B[
private void processErrorCode(int nErrorCode) xdSMYH{2A
{ z g7Q`
System.err.println("Error Code : " + nErrorCode); YD4I2'E
} a*M|_&MH*
%['NPs%B
(hc!!:N~q
//停止文件下载 N_%@_$3G]
public void siteStop() '(]Wtx%9"
{ Wv4$Lgr
bStop = true; NEBhVh
for(int i=0;i<nStartPos.length;i++) Qf:e;1F!
fileSplitterFetch.splitterStop(); ][ $UN
Y>$5j}K
e~vO
} +)c<s3OCE
} q;K]NP-_p
//负责部分文件的抓取 (B#FLoK
**FileSplitterFetch.java R@\fqNq
*/ dle\}Sy=
package NetFox; gwaSgV$z
]OpGD5jZ
KloX.y)q
import java.io.*; wSR|uh
import java.net.*; 49FP&NgK
igu1s}F
{4+/0\
public class FileSplitterFetch extends Thread { '/GB8L
tQ}GTqk
Ana[>wSZO@
String sURL; //File URL -@AhJY.
long nStartPos; //File Snippet Start Position F}Zg3#
long nEndPos; //File Snippet End Position =Uk#7U"P
int nThreadID; //Thread's ID <$A,|m
boolean bDownOver = false; //Downing is over >MYxj}I4{z
boolean bStop = false; //Stop identical ^B.Z3Y
FileAccessI fileAccessI = null; //File Access interface FK BRJ5O
p\zqZ=s
FBE|pG7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +Xg:*b9So
{ 7FwtBO
this.sURL = sURL; ".jO2GO^
this.nStartPos = nStart; Sct
this.nEndPos = nEnd; WsTIdr36x
nThreadID = id; F=F84_+K
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ww|fqx?
} ^!tX+`,6^
9Qyc!s`
N[@~q~v
public void run() L|[i<s;
{ Od.@G~
while(nStartPos < nEndPos && !bStop) 5Sl"1HL
{ -zECxHjx
P$'PB*5d|
GW {tZaB
try{ CC^D4]ug
URL url = new URL(sURL); MJX ny4n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .#y#u={{l
httpConnection.setRequestProperty("User-Agent","NetFox"); C b'|
String sProperty = "bytes="+nStartPos+"-"; \BBs;z[/
httpConnection.setRequestProperty("RANGE",sProperty); 05F/&+V
Utility.log(sProperty); c:Czu
W2`3 p
B1X&O d
InputStream input = httpConnection.getInputStream(); ]MCH]/
//logResponseHead(httpConnection); U<Oc&S{]*
Vg62HZ |
J_F\cM
byte[] b = new byte[1024]; E+y_te^+b
int nRead; {GtX:v#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) j*>]HNo&
{ +.djC3^:
nStartPos += fileAccessI.write(b,0,nRead); x)80:A}
//if(nThreadID == 1) .i\FK@2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]Mq-67
} H[w';u[%
/ 0$!.
'&Ur(axs
Utility.log("Thread " + nThreadID + " is over!"); `U0XvWPr[
bDownOver = true; tnpEfi-
//nPos = fileAccessI.write (b,0,nRead); IV~)BW leT
} Z6B$\Q5Od
catch(Exception e){e.printStackTrace ();} R1JD{
} ~v&Q\>'
} +PPQ"#1pS
}^I36$\
o4: e1
//打印回应的头信息 @Mg&T$
public void logResponseHead(HttpURLConnection con) ](I||JJa9f
{ G{?`4=K
for(int i=1;;i++) 0%xb):Ctw
{ 9T;>gm
String header=con.getHeaderFieldKey(i); dLqBu~*
if(header!=null) @oY+b!L
//responseHeaders.put(header,httpConnection.getHeaderField(header)); bV:<%l]
Utility.log(header+" : "+con.getHeaderField(header)); Jd `Qa+
else U:x;4
break; NxJnU<g-
} h_-4Q"fb(
} wv3*o10_w8
^vm6JWwN0B
"E<+idoz
public void splitterStop() v2gk1a&
{ !4v>|tq!
bStop = true; Ot.v%D`e 5
} g mWwlkf9
= y^5PjN
o(}%b8 K
} C D6N8n]
RKrNmD*rk*
zWPX
/* DhxS@/
**FileAccess.java `JV(ae0
*//文件访问(定位，写) FzOWM7+\
package NetFox; ;E{jn4B'
import java.io.*; }72\Aw5
d&G]k!|\
o]V.6Ge-
public class FileAccessI implements Serializable{ &g}P)xr
{Zw;<1{E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z3[J sE%
RandomAccessFile oSavedFile; 1tO96t^d%
long nPos; v?8i;[
PcbhylKd
+*Wlj8
public FileAccessI() throws IOException lA4-ZQ2Zp[
{ .~ uKr^%
this("",0); (z;lNl(*C
} 1mHS -oI9J
}.s%J\ckx
Q(A$ >A
public FileAccessI(String sName,long nPos) throws IOException Dl~(NLM
{ `3? HQ2n
oSavedFile = new RandomAccessFile(sName,"rw"); gdSqG2/&
this.nPos = nPos; >+<b_q|P
oSavedFile.seek(nPos); ^?]-Q*w3Qs
} a/s5Oit2'X
&kvmLOI
vx7=I\1
public synchronized int write(byte[] b,int nStart,int nLen) ic}TiTK
{ o6w8Y/VPu
int n = -1; zrSYLG
try{ L[:AUe
oSavedFile.write(b,nStart,nLen); [&P@0Fn
n = nLen; vaQsG6q[
} rF}Q(<Y86
catch(IOException e) U<F|A!Fg
{ 6.tA$#6HP
e.printStackTrace (); gT=pO`a
} )sQ/$gJ
RIUJX{?
NKEmY-f;
return n; 4V{&[ Z
} "{+2Q
y(iq
->OVNmCB`+
} nT01B1/<]
%hmRh~/&
&=S:I!9;;
/* k(7Q\JKE
**SiteInfoBean.java H_XspiB@
*/ /? d)01
package NetFox; g/68& M
gREk,4DAv
'Qg!ww7O
public class SiteInfoBean { g-!
*@^@7`W
K:XP;#OsP
private String sSiteURL; //Site's URL [;yH.wn#5
private String sFilePath; //Saved File's Path V=fh;p
private String sFileName; //Saved File's Name AB3OG*C9
private int nSplitter; //Count of Splited Downloading File 8kcMgCO
yaG:}=.3
,?jc0L.'r]
public SiteInfoBean() B1FJAKI);
{//nSplitter的缺省值为5 +-),E.
//default value of nSplitter is 5 Odw'Ua
this("","","",5); Wj!+ E{y<r
} IYtiX
F#L1~\7
%2b^t*CQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )l! /7WKY
{ 1_!?wMo:f
sSiteURL= sURL; fD(r/~Vu
sFilePath = sPath; x%k@&d;z
sFileName = sName; Vh;|qF 9
this.nSplitter = nSpiltter; vm;%713#1
}%PK %/ zI
o_b3G
} rZ n@i
F_-xp1|
mT-[I<
public String getSSiteURL() $aU.M3
{ JvvN>bg
return sSiteURL; 7BINqVS&
} F7j/Zuj
tw.GBR
(_@]-
public void setSSiteURL(String value) cK\ u
{ |,=^P`#%
sSiteURL = value; LjGZp"&{
} 1,h:|
X=1o$:7
MCEHv}W
public String getSFilePath() =#pYd~
{ PCL ;Z
return sFilePath; $v#`2S(7
} &L+.5i
G!B:>P|\l
m44a HBwId
public void setSFilePath(String value) ^$% Sg//
{ (y6}xOa(
sFilePath = value; ^Lc\{,m
} _[E+D0A
1|w@f&W"
k]$oir
public String getSFileName() +ansN~3
{ =+mb@#="m
return sFileName; } )Lz%Z
} 7$g$p&,VX
w1-P6cf
/i27F2NQm
public void setSFileName(String value) Nc4;2~XwRp
{ J]Z~.f="
sFileName = value; &)+H''JY
} JN9>nC!Zy_
[mjie1j/<
#|,cy,v4
public int getNSplitter() |LbAW/9a
{ vC@^B)5gb
return nSplitter; *{+{h;p
} #O;JV}y
rq!*unJ
a9p:k ]{
public void setNSplitter(int nCount) ! #! MTk
{ 6YNL4HE?
nSplitter = nCount; qF`6l(
} YI7M%B9Lj
} Mth:V45G|
ti%RE:*
_h#I}uJ~
/* TvDC4tm-:
**Utility.java kD;pj3o&"2
*/ `vOL3`P
package NetFox; sfr+W-7kx
M+VWAh#uD
>L!c} Ku
public class Utility { 7XyCl&Dc:
pk.\IKlG]
^5Lk}<utw
public Utility() n6WKk+
{ 8aWEl%
h ':ZF
EmcLW74
} !YjxCx
7CuZ7!>$
//线程睡眠 ZGR5"el!
public static void sleep(int nSecond) f4Y)GO<R]
{ 4%ooJi|)
try{ xR3$sA2
Thread.sleep(nSecond); Ws`ndR
} /qIl)+M
catch(Exception e) rq8 d}wj
{ YVDFcN9v
e.printStackTrace (); >god++,o
} ]nB|8k=J
} \298SH(!7
; iia?f1
//日志 /o m++DxV
public static void log(String sMsg) RhHm[aN
{ U3V5Jor#
System.err.println(sMsg); 1F`jptVQ\G
} Px=@Tw N,
6^'BTd
qJdlZW<
public static void log(int sMsg) )'U0n`=
{ A/'po_'uy
System.err.println(sMsg); ySmbX
} .nrllVG%`
} v}Ju2}IK
18Y#=uH}
@0@ZlHwM
/* sg^|dS{3D
**TestMethod.java Wvr{l
*/ s b;q)Rh
package NetFox; ?![[la+f
P7.bn
&R%'s1]o
public class TestMethod { W/ Q*NB
OA[e}Vn
]c7X~y
public TestMethod() g5@g_~ g
{ ///xx/weblogic60b2_win.exe vW=L{8zu
try{ 2Ckx.m&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); HTOr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &2`p#riAS
SiteFileFetch fileFetch = new SiteFileFetch(bean); rtj`FH??11
fileFetch.start(); \]u;NbC]
} (*9.GyK
catch(Exception e){e.printStackTrace ();} _2!8,MX
VWE>w|'
;[Mvk6^'R
} h0rPMd(K
8XB[CbO
^'V :T Y
public static void main(String[] args) T[bCY 6
{ ~_D.&-xUF
new TestMethod(); ?@.v*'qR
} Jo\P,-\(
} h<Aq|*
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