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)); up>c$jJ
} asHxL!
for(int i=0;i<nEndPos.length-1;i++) 30>3 !Xqa
{ *`_{
nEndPos = nStartPos[i+1]; ZfrVjUB
} IQZ#-)[T"
nEndPos[nEndPos.length-1] = nFileLength; 83%)/_&
} y5r4+2B
} |`TgX@,#9
QnQOm""
M_g?<rK
//启动子线程 Ep9W-n?}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "]K>j'^Zs<
for(int i=0;i<nStartPos.length;i++) MN^Aw9U
{ Dre2J<QL
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z2_6??tS/c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $5x ,6[&
nStartPos,nEndPos,i); ryB}b1`D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '2^7-3_1
fileSplitterFetch.start(); >P6BW
} PHOP%hI$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0k)rc$eDF+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Q7Iw[=;\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yAL[[
nEndPos = " + nFileLength); GZI`jS"lU
// fileSplitterFetch[nPos.length-1].start(); 'k;rH!R
wX >*H
#$1Z
//等待子线程结束 ~5FW[_
//int count = 0; 4}+/F}TbJ5
//是否结束while循环 Od f[*
boolean breakWhile = false; .p0Clr!
HY)-/
v~QHMg
while(!bStop) HK`I\,K
{ ZKHG!`X0
write_nPos(); J'$>Gk]
Utility.sleep(500); @)o^uU T
breakWhile = true; !?c|XdjZ
8Nu=^[qwQM
^nbnbU4'
for(int i=0;i<nStartPos.length;i++) iQDx{m3]
{ V"c 6Kdtd
if(!fileSplitterFetch.bDownOver) Z}$TKO*u
{ )W/;=K
breakWhile = false; /1Ue?)g
break; ck?YI]q|
} okbQ<{9
} DC{>TC[p1k
if(breakWhile) rj(T~d4
break; }gJ(DbnV
T5a*z}L5
h1'\:N`
//count++; pe^u$YE
//if(count>4) PRHCrHs
// siteStop(); Fu!RhsW5j
} CHe>OreiS
d3=KTTi\
sI{ M
System.err.println("文件下载结束！"); 0$,SF3K
} ZK>WW
catch(Exception e){e.printStackTrace ();} y;s`P.
} B95B|tU>.
tH-C8Qxy
,^uEYT}j
//获得文件长度 ]]zPq<b2
public long getFileSize() z^T`x_mF
{ IiG6<|d8H
int nFileLength = -1; Lhqz\o
try{ )wT-8o
URL url = new URL(siteInfoBean.getSSiteURL()); :j+ ZI3@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z11O F
httpConnection.setRequestProperty("User-Agent","NetFox"); r-:Uz\gM
J+`VujWT
|`.([2
int responseCode=httpConnection.getResponseCode(); B)0i:"q
if(responseCode>=400) {{QELfH2
{ O#F4WWF
processErrorCode(responseCode); j KoG7HH
return -2; //-2 represent access is error V$ps>
} Z<vKQ4G
tCdqh-
ZpnxecJUJ
String sHeader; Za1QC;7
K*~0"F>"0
H'
for(int i=1;;i++) 3f,hw5R
{ ljb7oA3cP4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [PDNwh0g5
//Utility.log(in.readLine()); Q\ 0cvmU
sHeader=httpConnection.getHeaderFieldKey(i); p>4-s, W
if(sHeader!=null) dw*_(ys
{ XCBL}pNkR
if(sHeader.equals("Content-Length")) >Wv;R2|
{ A<??T[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h2XfC.f
break; 7eAX*Kgt<_
} NfjE`
} !6*"(
else sG F aL
break; ee^{hQi
} i%0ur}p
} :51/29}
catch(IOException e){e.printStackTrace ();} V6@o]*
catch(Exception e){e.printStackTrace ();} K1M%!JKh)x
TA4!$7b$
E>D_V@,/
Utility.log(nFileLength); uC(V
%-1O.Q|f
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return nFileLength; .oeX"6K
} oU.R2\Q
kZmpu?P
l4uMG]m
//保存下载信息（文件指针位置） NgP&.39U
private void write_nPos() 2QyV%wz
{ {#@W)4)cA
try{ "i[@P)
output = new DataOutputStream(new FileOutputStream(tmpFile)); RO'7\xvn
output.writeInt(nStartPos.length); }E50>g
for(int i=0;i<nStartPos.length;i++) heV=)8
{ ;z$(nhJ
// output.writeLong(nPos); hvsWs.;L'
output.writeLong(fileSplitterFetch.nStartPos); a6)BqlJ
output.writeLong(fileSplitterFetch.nEndPos); GkQpELO:
} ?iWi
output.close(); Ju1D =b
} @~"h62=] -
catch(IOException e){e.printStackTrace ();} j~[z2tV
catch(Exception e){e.printStackTrace ();} H[U!%Z
} 3cK I
0tT(W^ho g
2{H@(Vgpbr
//读取保存的下载信息（文件指针位置） Dv5D~on{
private void read_nPos() i#vYyVr[
{ gc-@"wI?
try{ G}b]w~ML~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Lh!J >
int nCount = input.readInt(); YUtC.TR1
nStartPos = new long[nCount]; RC7]'4o
nEndPos = new long[nCount]; T[UN@^DP(
for(int i=0;i<nStartPos.length;i++) svcK?^ HTe
{ 5YeM%%-S
nStartPos = input.readLong(); BBwy,\o#
nEndPos = input.readLong(); 3KlbP
} gd`!tRcNY
input.close(); i:Y^{\Z?V
} +M\`#i\g>
catch(IOException e){e.printStackTrace ();} iJ1"at
catch(Exception e){e.printStackTrace ();} 3TeY%5iVt
} vqDu(6!2
(MxQ+D\
MOQ*]fV:
private void processErrorCode(int nErrorCode) v$?+MNks
{ | *2w5iR
System.err.println("Error Code : " + nErrorCode); "n(hfz0y%
} $P/~rZ@M@
Vc\MV0lr
rWa2pO
//停止文件下载 W$hx,VEy`
public void siteStop() &=] ~0$
{ N8F~8lTi
bStop = true; v&DI`xn~
for(int i=0;i<nStartPos.length;i++) ]hk
fileSplitterFetch.splitterStop(); )rxX+k+b/
K*K,}W&}
D#cyOrzy
} u8&Z!p\
} lb4Pcdj
//负责部分文件的抓取 ~=M7 3U#
**FileSplitterFetch.java SJb&m-
*/ . qO@Q=
package NetFox; 2_HNhW
B~MU^|v
n8~N$tDU
import java.io.*; +" .X )avF
import java.net.*; !Xf5e*1IS
[=6]+V83M
y\4L{GlBM
public class FileSplitterFetch extends Thread { s~ a"4~f
f-vCm 5f
Dp,L/1GQ8
String sURL; //File URL 89pEfl j2
long nStartPos; //File Snippet Start Position %g{X?
long nEndPos; //File Snippet End Position h7G"G"
int nThreadID; //Thread's ID _|kxY'_[8
boolean bDownOver = false; //Downing is over J=9FRC
boolean bStop = false; //Stop identical P{kur} T
FileAccessI fileAccessI = null; //File Access interface >JHryS.j$4
:~&~y-14
h\fjBDU^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^ Edfv5
{ X5zDpi|Dq
this.sURL = sURL; n{n52][J]
this.nStartPos = nStart; 36}?dRw#p
this.nEndPos = nEnd; o4G?nvK-
nThreadID = id; CGW.I$u
fileAccessI = new FileAccessI(sName,nStartPos);//定位 lA| 5E?
} oK6tTK
(-UYB9s
[+2[`K c]
public void run() KKja/p
{ aL+ o /
while(nStartPos < nEndPos && !bStop) T0wW<_jh
{ HJ=:8:
_<n~n]%
ZCMw3]*
try{ W,V:R
URL url = new URL(sURL); c69C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lk/n}bx
httpConnection.setRequestProperty("User-Agent","NetFox"); q6McGHT
String sProperty = "bytes="+nStartPos+"-"; &N2N6&Ta/
httpConnection.setRequestProperty("RANGE",sProperty); ;#g"(
Utility.log(sProperty); (9''MlGd%
Q|S.R1L^
\FQRNj?'_
InputStream input = httpConnection.getInputStream(); jFQQ`O V
//logResponseHead(httpConnection); 2V- 16Q'%
Z3"%`*Tmq-
(5$!MUS~9
byte[] b = new byte[1024]; EU2$f
int nRead; |7'df&CA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *v;2PP[^
{ -u6bAQ
nStartPos += fileAccessI.write(b,0,nRead); $O&b``
//if(nThreadID == 1) 9&-dTayIz
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zqimR#u
} cvn@/qBq*t
B nFwlw
1{)5<!9!l
Utility.log("Thread " + nThreadID + " is over!"); K[I=6
bDownOver = true; N]>=p.#j
//nPos = fileAccessI.write (b,0,nRead); zGb|)A~,
} F+YZE[h%
catch(Exception e){e.printStackTrace ();} f',Op1o
} \j@OZ
} 1!xQ=DU"
,Xu-@br{
xgwY@'GN
//打印回应的头信息 b1(T4w6
public void logResponseHead(HttpURLConnection con) >!eAM )
{ [^WC lRF
for(int i=1;;i++) Fco`^kql.D
{ {{$Nqn,pH
String header=con.getHeaderFieldKey(i); %0S3V[4I
if(header!=null) tURu0`](
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5bRJS70M
Utility.log(header+" : "+con.getHeaderField(header)); m~iXl,r
else ]J1dtN=
break; VQc_|z_s
} \\iQEy<i
} &PR5q7
rN<0 R`4sE
R3 -n>V5o
public void splitterStop() lUOF4U&r
{ [T8WThs
bStop = true; F%@A6'c
} E-T)*`e
u4t7Ie*Q
@:oXN]+ _
} >nJ\BPx
b)6D_Az7c
%R}qg6dL
/* , Rk9N
**FileAccess.java ax"+0L{
*//文件访问(定位，写) ^=GC3% J
package NetFox; 0!4Ts3qn1
import java.io.*; LK{*sHi$
sQYkQ81
:NhO2L
public class FileAccessI implements Serializable{ -WY<zJ
7o7)0l9!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ew>XrT=Zm
RandomAccessFile oSavedFile; ()Y~Q(5ji
long nPos; z 9vInf@M
vk}n,ecl
OSRp0G20k\
public FileAccessI() throws IOException dcDyK!zz"
{ GB23\Yv
this("",0); Ow+GS{-q
} GoJ.&aH $
KI.q@zO6|
6/f7<
public FileAccessI(String sName,long nPos) throws IOException k9<;woOBO
{ 35h8O,Y
oSavedFile = new RandomAccessFile(sName,"rw"); 'F/~o1\.
this.nPos = nPos; 5VfyU8)7X
oSavedFile.seek(nPos); {0L1X6eg
} `xKp%9
T.])diuvj-
6Pz4\uE=
public synchronized int write(byte[] b,int nStart,int nLen) n7zm>&
{ R"-mKT}
int n = -1; ^PDJ0k/u1
try{ zG }@0
oSavedFile.write(b,nStart,nLen); ?qmRbDI
n = nLen; "H=6j)Cb
} 0CWvYC%e
catch(IOException e) 1XrO~W\=
{ e2AX0(
e.printStackTrace (); 5Y.)("1f}f
} kDEXN
x,'(5*
&u]8IEv}u
return n; } +TORR?
} 6O7'!@@
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IQAZuN"<
} 4svBzZdr
HCIU!4rH
|hKDvH
/* 7!$Q;A
**SiteInfoBean.java WQx?[tW(U
*/ c/:b.>W
package NetFox; ~Zun&b)S
5-FQMXgThc
2Sle#nw3
public class SiteInfoBean { sZ3KT&
hXcyoZ8
OyU5DoDz1
private String sSiteURL; //Site's URL ?so=;gh
private String sFilePath; //Saved File's Path mu\6z_e
private String sFileName; //Saved File's Name ]V[q(-Jk
private int nSplitter; //Count of Splited Downloading File o$wEEz*4
7z%L*z8V
C>ICu*PW
public SiteInfoBean() ~Z-Vs
{//nSplitter的缺省值为5 j:Xq1f6a
//default value of nSplitter is 5 Ja|5 @
this("","","",5); ;"xfOzQ
} \Q {m9fE
_jvxc'6
[xK3F+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B+$%*%b
{ E7WK (
sSiteURL= sURL; >Ifr [
sFilePath = sPath; I:E`PZ
sFileName = sName; MH =%-S
this.nSplitter = nSpiltter; FDv<\2+ c
X1:V<,}"
aFl;BhM
} k6;?)~.
aH yx_B
Hf%@3X
public String getSSiteURL() k)i3
{ W6^5YH%
return sSiteURL; ISzqEi
} $6#CqWhI
L,HhbTRca
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public void setSSiteURL(String value) #{6{TFx\
{ /RG:W0=K
sSiteURL = value; zZ:>do\2
} |sa]F5
'g">LQ~a+
):P?
public String getSFilePath() # ncRb
{ l.(v^3:X
return sFilePath; *o]L|Vu
} #"}JdBn
|+{)_?
?'IP4z;y
public void setSFilePath(String value) M5i%jZk
{ [ieI;OG;
sFilePath = value; 5v[*:0p'
} 0!D4pvlt
{k(g]#pP
hMa]B*o/-
public String getSFileName() y>S.?H:P
{ W}nlRbN?
return sFileName; 50"pbzW
} dSLU>E3g
B=U 3
y3vdUauOn
public void setSFileName(String value) dR K?~1
{ bes<qy
sFileName = value; 4M^=nae
} oxr#7Ei0d
yyR0]NzYUD
pk>^?MO
public int getNSplitter() &`h{iK7
{ !'Ak&j1:`
return nSplitter; ''|W9!
} f<GhkDPm>?
Yh7rU?Gj
|O3q@
public void setNSplitter(int nCount) 8aZ=?_gvT
{ cv8L-Z>x.=
nSplitter = nCount; 2v:]tj
} Pi=+/}
} ;$HftG>B
.28<tEf
Z~GL5]S
/* +20G>y=+
**Utility.java RXNn[A4xfY
*/ fAF1"4f
package NetFox; S2E8Gq9
GeI-\F7b
Cwr~HY
public class Utility { XWnVgY s
5CuuG<0
X3(tuqmi
public Utility() a,Sw4yJ!Q
{ =NpYFKmMhV
FW.7'7G@n
z Eq GD2"
} 57aXQ8u{
\1d(9jR
//线程睡眠 ~W*FCG#E
public static void sleep(int nSecond) =pr`'
{ "7U4'Y:E
try{ 1f%1*L0>@
Thread.sleep(nSecond); [2>yYr s_=
} z__EYh
catch(Exception e) 4Xgg%@C
{ >1s* at/h
e.printStackTrace (); >/{@C
} 9K.Vb1&
} 1Vsz4P"O $
A_V]yP
//日志 ]E7F/O/.
public static void log(String sMsg) 3^IpE];+:u
{ B{/R: Hm
System.err.println(sMsg); 8Pfb~&X^Ws
} Y5f1lUT
Q}`0W[a ~
@>u}eB>Kn
public static void log(int sMsg) ,NOsFO-`<
{ ~Io7]
System.err.println(sMsg); j_/>A=OD
} *lYVY)L
} -^K"ZP1
Amp#GR1CA
y?rPlA_
/* $:BKzHmg
**TestMethod.java l~1Oef#y
*/ &]g}u5J!=
package NetFox; -O1>|y2rU
26e]`]!SU
UG'Q]S#!
public class TestMethod { i% w3/m
8k2?}/+
F7 5#*
public TestMethod() ?e`^P
{ ///xx/weblogic60b2_win.exe rTM}})81
try{ hmvfw:Nq4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Sw:7pByjI
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &[_g6OL
SiteFileFetch fileFetch = new SiteFileFetch(bean); Jk&3%^P{m
fileFetch.start(); G"klu
} grS:j+_M2m
catch(Exception e){e.printStackTrace ();} Mh~q//
Vl5`U'^qx
b v G/|U
} oin$-i|Xp!
<x@}01~
YO#M/%^j
public static void main(String[] args) =w;F<M|Y
{ :Uz|3gq
new TestMethod(); \O}E7-
} g=39C>
} &?W0mW(
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