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)); lf-.c$.>
} 6.]~7n
for(int i=0;i<nEndPos.length-1;i++) 'd N1~Pa
{ #w''WOk@ZG
nEndPos = nStartPos[i+1]; H^'%$F?Ss
} G ]h
nEndPos[nEndPos.length-1] = nFileLength; F:jNv3W1
} X+Sqw5rH
} 2D:/.9= 8v
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//启动子线程 Fx!D:.)/G
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; MsIR~
for(int i=0;i<nStartPos.length;i++) E{)X ;kN=
{ k{r<S|PK0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;=joQWNDm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !Ge;f/@
nStartPos,nEndPos,i); S:{xx`6K
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4V9BmVS|Th
fileSplitterFetch.start(); 9 m8KDB[N
} Ko&4{}/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 29=ob("
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +o@:8!IM1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", r0nnmy]{d
nEndPos = " + nFileLength); @q!T,({kx
// fileSplitterFetch[nPos.length-1].start(); zsuqRM "
|[~S&
zHKP$k8
//等待子线程结束 p"P+8"`
//int count = 0; ^U?Ac=
//是否结束while循环 F;_c x
boolean breakWhile = false; m=n79]b:N
;%0kzIvP
bj`GGxzOb
while(!bStop) KC"S06
{ Rk5#5R n
write_nPos(); b~UWFX#U
Utility.sleep(500); E-1u_7
breakWhile = true; yR~$i3Z*
~0+<-T
g}R#0gkdk}
for(int i=0;i<nStartPos.length;i++) WZ`i\s1#
{ }8AH/
if(!fileSplitterFetch.bDownOver) PK|qiu-O&*
{ 4IW fp&Q!
breakWhile = false; ?Sh"%x
break; HY_>sD
} _<]0hC
} p8XvfM
if(breakWhile) +-b'+mF
break; 6|lsG6uf
sCJ|U6Q-
9_==C"F
//count++; ;HAvor=?
//if(count>4) #yIHr&'oX
// siteStop(); :@5{*o
} 7Cp/{l;d
3~R,)fO;
X*MK(aV3
System.err.println("文件下载结束！"); f6J]=9jU
} EKO'S+~
catch(Exception e){e.printStackTrace ();} "c} en[
} 0t7)x8c
=c 9nC;C
59$PWfi-\
//获得文件长度 x0)=jp '
public long getFileSize() ~-NSIV:f
{ &x B^
int nFileLength = -1; L8n?F#q
try{ QuMv1)n
URL url = new URL(siteInfoBean.getSSiteURL()); Y,L[0%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~$>JYJj
httpConnection.setRequestProperty("User-Agent","NetFox"); @f"[*7Q`/
Z&?4<-@6\p
J~J+CGT~2
int responseCode=httpConnection.getResponseCode(); Y=|20Y\K
if(responseCode>=400) 1P"{TMd?
{ W;T0_=
processErrorCode(responseCode); wO.d;SK
return -2; //-2 represent access is error 7bbFUUUG"
} PX?%}~ v
9;I%Dv
CAviP61T
String sHeader; E@otV6Wk[@
|AE{rvP{@
@D*PO-s9
for(int i=1;;i++) ud(0}[
{ pam9wfP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |15!D
//Utility.log(in.readLine()); iku*\,6W
sHeader=httpConnection.getHeaderFieldKey(i); Gjq7@F'
if(sHeader!=null) LCS.C(n,
{ '_7rooU9
if(sHeader.equals("Content-Length")) 'Q=)-
{ 8EkzSe
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); P@GU2[1
break; EKcPJ\7
} b{-"GqMO
} !oXFDC3k
else k4<28
break; Q|+ a
} >&e=0@?+G
} Nz3+yxv1
catch(IOException e){e.printStackTrace ();} [*It' J^
catch(Exception e){e.printStackTrace ();} 55ec23m
N;YFr
fsK=]~<g
Utility.log(nFileLength); {5 pK8
@",#'eC"
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return nFileLength; R=a4zVQ
} 6^J[SQ6P
;{HDz$
0U/[hG"DKN
//保存下载信息（文件指针位置） KyT=:f V
private void write_nPos() Q5dqn"?
{ a;KdkykG
try{ JW><&hY$"
output = new DataOutputStream(new FileOutputStream(tmpFile)); oLR/\Y(
output.writeInt(nStartPos.length); NTX0vQG
for(int i=0;i<nStartPos.length;i++) kl~/tbf
{ jK/FzD0-
// output.writeLong(nPos); "|J6*s
output.writeLong(fileSplitterFetch.nStartPos); 4yqYs>
output.writeLong(fileSplitterFetch.nEndPos); XP!m]\E&I
} {E(2.'d
output.close(); #r"|%nOfY
} h4KMhr
catch(IOException e){e.printStackTrace ();} 2DsP "q79k
catch(Exception e){e.printStackTrace ();} ?5ZvvAi
} &0[L2x}7
Opf)TAl{
~a3u['B
//读取保存的下载信息（文件指针位置） ~vpF|4Zn5
private void read_nPos() *2~WP'~PQd
{ mE{QTZS
try{ H[s+.&^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); GTfM *b
int nCount = input.readInt(); C4PT(cezR
nStartPos = new long[nCount]; #6#n4`%ER
nEndPos = new long[nCount]; R!/JZ@au<
for(int i=0;i<nStartPos.length;i++) 4P)#\$d:
{ ? .SiT5
nStartPos = input.readLong(); ]D5Maid+
nEndPos = input.readLong(); d>I)_05t
} NTZ3Np`
input.close(); kq(><T
} F~E)w5?\O
catch(IOException e){e.printStackTrace ();} 1Zp/EYWa{
catch(Exception e){e.printStackTrace ();} E <j=5|0t
} 6J JA"] `
:ln|n6X
Z R=[@Oi
private void processErrorCode(int nErrorCode) 2uT6M%OC
{ UE5,Ml~X
System.err.println("Error Code : " + nErrorCode); ";&PtLe
} YwY?tOxBe
0e#PN@
Z/:yYSq
//停止文件下载 E Lq1
public void siteStop() ;c]O*\/
{ k0PwAt)65
bStop = true; "v wLj:
for(int i=0;i<nStartPos.length;i++) $ eL-fg
fileSplitterFetch.splitterStop(); 1TA!9cz0Z
G8w@C
mYJ8O$
} +PsR*T
} 7;'UC','
//负责部分文件的抓取 ZGX"Vn|YL
**FileSplitterFetch.java ,#;`f=aqTG
*/ oF+yh!~mM
package NetFox; UJp'v_hN
2P'Vp7f6 Y
!WGQ34R{
import java.io.*; S/pU|zV[
import java.net.*; TBJ?8W(
X1}M_h%
<W3p!
public class FileSplitterFetch extends Thread { 7z, $
OA9P"*
91&=UUkK?
String sURL; //File URL MTl @#M
long nStartPos; //File Snippet Start Position ^)Y3V-@t
long nEndPos; //File Snippet End Position &Q"vXs6Gt
int nThreadID; //Thread's ID v+sF0 j\P
boolean bDownOver = false; //Downing is over n{<@-6
boolean bStop = false; //Stop identical AIQ {^:
FileAccessI fileAccessI = null; //File Access interface {U3jJ#K
\pK&gdw
?Q=(?yR0]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException am.d^'
{ ;}S_PnwC@
this.sURL = sURL; k 75 p
this.nStartPos = nStart; 6 mLC{X[
this.nEndPos = nEnd; {P?DkUO}
nThreadID = id; O{byMV{Ou
fileAccessI = new FileAccessI(sName,nStartPos);//定位 uw8g%
} q0>9T
`l?MmIJ
e'G3\h}#
public void run() I;_T_m4.q
{ \j)c?1*$
while(nStartPos < nEndPos && !bStop) $$4flfx
{ BIx*(
8,+T[S
|mWSS'7fI
try{ j+AZ!$E
URL url = new URL(sURL); k)F!gV#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); twldwuN
httpConnection.setRequestProperty("User-Agent","NetFox"); " @""
String sProperty = "bytes="+nStartPos+"-"; ^qC.bv]&
httpConnection.setRequestProperty("RANGE",sProperty); 75R4[C6T
Utility.log(sProperty); og+Vrd
h \`(
oui0:Vy<
InputStream input = httpConnection.getInputStream(); UBQtD|m\
//logResponseHead(httpConnection); MMaS
.':17 $c`H
c"`HKfL
byte[] b = new byte[1024]; uW[AnQ1w
int nRead; Z9% u,Cb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Pk5\v0vkg
{ :Zq?V`+M
nStartPos += fileAccessI.write(b,0,nRead); }/NjZ*u
//if(nThreadID == 1) u\xrC\Ka
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e>!]_B1ad
} Wx;%W"a
g0/R\
ZZ!6O/M
Utility.log("Thread " + nThreadID + " is over!"); #vy[v22
bDownOver = true; KU+u.J
//nPos = fileAccessI.write (b,0,nRead); l&] %APL
} MB>4Y]rtU
catch(Exception e){e.printStackTrace ();} +ZE"pA^C
} y\iECdPU
} zKYN5|17
5>1c4u`x
F)'_,.?0
//打印回应的头信息 i+I.>L/S
public void logResponseHead(HttpURLConnection con) }L{GwiDMDl
{ =.m/X>
for(int i=1;;i++) srImk6YD
{ #z_.!E
String header=con.getHeaderFieldKey(i); bccf4EyQ Y
if(header!=null) UiK)m:NU
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8r,0Qic2K
Utility.log(header+" : "+con.getHeaderField(header)); OaN"6Ge#
else ^eRbp?H*T
break; [["eK9}0
} ]4*E:
} e*D,2>o
|N^8zo :
;uZq_^?:9&
public void splitterStop() %_5?/H@%3z
{ V%M@zd?u.
bStop = true; Iz#jR2:yn
} -=1>t3~\
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\Y:zg3q*
} ] TZ/=Id
(h@~0S
*a(GG
/* [Q8vS;.
**FileAccess.java G&6`?1k
*//文件访问(定位，写) /W}"/W9
package NetFox; K7qR
import java.io.*; PEKXPFN
{ueDwnZ
6TQ[2%X'
public class FileAccessI implements Serializable{ vsq |m5
+f^|Yi
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 gd]k3XN$f
RandomAccessFile oSavedFile; -gb@BIV#
long nPos; ^v3J ld
!.|A}8nK
te>Op 1R
public FileAccessI() throws IOException x+Ly,9nc$
{ RtaMrG=D
this("",0); \:Hh'-77q
} 3Z}m5f`t
mI;\ UOh'
q{q;X{
public FileAccessI(String sName,long nPos) throws IOException H,!yG5yF
{ K1-3!G
oSavedFile = new RandomAccessFile(sName,"rw"); sa"!ckh
this.nPos = nPos; ~Bt>Y
oSavedFile.seek(nPos); )o::~ eu
} ~!Rf5QA85
b|.<rV'BTt
B-$ps=G+z
public synchronized int write(byte[] b,int nStart,int nLen) }qhND-9#@
{ OR10IS
int n = -1; |Yi_|']#
try{ &c= 3BEh
oSavedFile.write(b,nStart,nLen); 4%jQHOZ
n = nLen; cm>+f^4?n
} ~^g*cA t}
catch(IOException e) %W2 o`W$
{ S)^eHuXPI
e.printStackTrace (); Gx%f&H~Z^
} ch/DBu
O3p<7`K<4
-}>H3hr
return n; > mP([]
} AD'c#CT
hi ),PfAV
]vCs9* |B
} GkdxwuRw
X&%;(`
gYw=Z_z
/* $j0<ef!
**SiteInfoBean.java 6s:
*/ q:,ck@-4
package NetFox; P`n"E8"ab<
55Ye7P-d
-wnBdL
public class SiteInfoBean { PW*[(VX
2$joM`j$
ZP4y35&%y
private String sSiteURL; //Site's URL rWuqlx#
private String sFilePath; //Saved File's Path 1z8fhE iiE
private String sFileName; //Saved File's Name l27J
private int nSplitter; //Count of Splited Downloading File Lyjp
- SCFWc
Ec!R3+
public SiteInfoBean() *,XT;h$'>
{//nSplitter的缺省值为5 [ldx_+xa:E
//default value of nSplitter is 5 Ehtb`Ms
this("","","",5); |OBZSk1jp
} <d3a
"A}2iI
;.d{$SO
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0(|36;x
{ )KN]"<jB
sSiteURL= sURL; h]^= y.Q
sFilePath = sPath; =#?=Lh
sFileName = sName; E@)9'?q
this.nSplitter = nSpiltter; r 4+%9)
-lI6!a^
$w! v
} t&(\A,ch%
N6/;p]|
0F[+rh"x
public String getSSiteURL() SMHQh.O?5
{ {mB &xz:b
return sSiteURL; ;#dzw!+Y
} #D8u#8Dz
'n"n;
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public void setSSiteURL(String value) >m`<AynJ
{ !4fT<V(
sSiteURL = value; Y^}c+)t
} WeS$$:ro
P<R'S
@@+BPLl
public String getSFilePath() )9V8&,
{ 8FT@TUFb
return sFilePath; ZTi KU)
} '<hgc
fzjZiBK@
[hKt4]R
public void setSFilePath(String value) Znh)m
{ 0"xD>ue&
sFilePath = value; _!E/em
} d/`d:g
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wO*x0$
public String getSFileName() w?A6S-z
{ p!p:LSk"/b
return sFileName; ,Zs*07!$f
} 4k=LVu]Kcr
43o!Vr/S
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public void setSFileName(String value) tp3 !6I6
{ Z oQPvs7_
sFileName = value; G:!'hadw
} |Ht~o(]&&/
fTV}IP
?8@EBPpC
public int getNSplitter() kk7M$)>d
{ E'F87P^>
return nSplitter; 4j-%I7
} s7na!A[
oD7^9=#
_[ufH*
public void setNSplitter(int nCount) >$N ?\\#
{ 2vX!j!_
nSplitter = nCount; 5$"IUq*
} T Ue=Yj
} `>skcvkm
rsC^Re:*jr
f-a+&DB9
/* {t QZqqdn@
**Utility.java 5jK9cF$>
*/ f!+G1z}iA
package NetFox; ]sV) '-
M07==R7
ev%}\^Vl[
public class Utility { 8/+x1,S%
#)EVi7UP
j\@osjUu
public Utility() 'mU7N<Q$qQ
{ ,L9ioYbp
C:<TJ
}|(v0]
} X,i^OM_
s N|7
//线程睡眠 ~<Sb:Izld
public static void sleep(int nSecond) tk,Vp3p
{ \TTt!"aK
try{ x"n)y1y
Thread.sleep(nSecond); &{H LYxh
} <&p0:S7
catch(Exception e) _q1E4z
{ "o>gX'm*
e.printStackTrace (); 56^#x
} !Di*y$`}b
} wA7^
%LeZd}v
//日志 ])uhm)U@
public static void log(String sMsg) ;`-@L
{ k<!xOg
System.err.println(sMsg); xE%sPWbj
} )NL_))\
29AWg(9?aS
LKe~
public static void log(int sMsg) t{RdqAF
{ S|v")6
System.err.println(sMsg); k1Thjt
} g|PRk9
} S 0L"5B@
0dKi25J
xRPUGGv
/* ]J>{ZL
**TestMethod.java `u7"s'
*/ iP^o]4[c
package NetFox; \rY<DxtOq
K"U[OZC`
@Zov&01
public class TestMethod { -iJ @K
,CA3Q.y>|
]\Q9j7}37+
public TestMethod() <\C/;
{ ///xx/weblogic60b2_win.exe }qn@8}
try{ i*-L_!cc:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |>L|7>J{<d
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); QvjOOc@k~n
SiteFileFetch fileFetch = new SiteFileFetch(bean); y(uE
fileFetch.start(); ej&ZE n
} La#otuw+?
catch(Exception e){e.printStackTrace ();} STY\c5
:r,o-D
^t#W?rxp&
} ?RVY%s;g
6Om)e=gU/
t;e+WZkV
public static void main(String[] args) T.kQ] h2ZG
{ 6e.?L
new TestMethod(); VLO!hA#
} +9d]([Lx
} Y] "_}
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