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)); wda';@y5(
} u"+}I,'L
for(int i=0;i<nEndPos.length-1;i++) m5-9yQ=.
{ A3R#z]Ub
nEndPos = nStartPos[i+1]; J^zi2jtV
} 2{oThef[O
nEndPos[nEndPos.length-1] = nFileLength; tT5pggml
} *g$i5!yM'
} :uK btoA
-%m3-xZA
YfDWM7x7,
//启动子线程 ,XB%\[pKe
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; C`K^L=8`{
for(int i=0;i<nStartPos.length;i++) jP=Hf=:$
{ oln<yyDs
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7%d8D>uw8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qX6D1X1_
nStartPos,nEndPos,i); I%;Jpe
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \l,rpVv5m
fileSplitterFetch.start(); 5%i:4sMx *
} <nzN$"%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Oh; Jw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <kc#thL
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =G${[V\
nEndPos = " + nFileLength); .SS<MDcqIt
// fileSplitterFetch[nPos.length-1].start(); r>|-2}{N/
@;)PSp*j
;y1Q6eN
//等待子线程结束 vg\/DbI'
//int count = 0; `_qK&&s
//是否结束while循环 wAF,H8 -DK
boolean breakWhile = false; jRQ+2@n{E
pn%#w*'
aV|9H
while(!bStop) QLo(i
{ \N6\v5vh
write_nPos(); 5Ec/(-F
Utility.sleep(500); q``wt
breakWhile = true; }[!92WS/ee
T|){<
6X_\Ve
for(int i=0;i<nStartPos.length;i++) PHra+NY#A
{ j]5WK_~M
if(!fileSplitterFetch.bDownOver) ZFxLBb:
{ EX "|H.(
breakWhile = false; Vfs$VY2.
break; !:0v{ZQ
} ^[q /Mw
} 7@;">`zvm
if(breakWhile) ^mPPyT,(
break; (03pJV&K
8]"(!i_;)
^&[+H8$
//count++; ")UwkF
//if(count>4) ~[W#/kd1n
// siteStop(); s"~5']8
} N4{nG,Mo]
s] au/T6b
4IsG=7
System.err.println("文件下载结束！"); Fo|xzLm9*|
} jna;0)
catch(Exception e){e.printStackTrace ();} =$^MQ\S0p
} !a-b6Aa
mG2'Y)Sz
E4oz|2!m
//获得文件长度 m&Yi!7@(
public long getFileSize() C/@LZ OEL
{ I.jZ wW!r
int nFileLength = -1; 8l+H"M&|
try{ k*Nr!Z!}
URL url = new URL(siteInfoBean.getSSiteURL()); raUs%Y3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jAhP> t:
httpConnection.setRequestProperty("User-Agent","NetFox"); B6M+mx"G
SoQR#(73HK
(K{5fC
int responseCode=httpConnection.getResponseCode(); vmZ"o9-{#X
if(responseCode>=400) ?dq#e9
{ ?=On%bh
processErrorCode(responseCode); 4<S'
return -2; //-2 represent access is error _elX<o4
} x\\7G^$<h
>lzA]aM$c
+RDJY(Y$
String sHeader; tw K^I6@
\;9W.d1iU
u=NG6G
for(int i=1;;i++) -,#+`>w
{ !{UTD+|=N
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *b|NjwmB
//Utility.log(in.readLine()); Te-Amu
sHeader=httpConnection.getHeaderFieldKey(i); uofr8oL~
if(sHeader!=null) TwahR:T
{ Dd $qQ
if(sHeader.equals("Content-Length")) b>=_*nw9
{ ~^US/"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &"E lm
break; WlwY <)
} 5W? PCOh\
} >FF5x#^&c
else i'HQQWd
break; ;sOsT?)7$
} w4};q%OBj
} 1,t)3;o$
catch(IOException e){e.printStackTrace ();} _M5%V>HO
catch(Exception e){e.printStackTrace ();} YZwaD b
J7$_VP
n! h7
Utility.log(nFileLength); n=sXSxl
1TN}GsAj
a\5FAkI
return nFileLength; {E_{JB~`
} #5ax^p2*~
p~jlx~1-]
&X>7n~@0
//保存下载信息（文件指针位置） ]N)DS+V/
private void write_nPos() ERMa# L
{ `lpz-"EEV
try{ \=2m7v#E
output = new DataOutputStream(new FileOutputStream(tmpFile)); Wch~Yb
output.writeInt(nStartPos.length); CXaWgxlK:a
for(int i=0;i<nStartPos.length;i++) fw-\|fP
{ iLX_T]1
// output.writeLong(nPos); eEw.'B
output.writeLong(fileSplitterFetch.nStartPos); Mt>oI SN&d
output.writeLong(fileSplitterFetch.nEndPos); dJuD|9R
} JAb6zpP
output.close(); J./d!an
} ~}9PuYaD@
catch(IOException e){e.printStackTrace ();} #2p#VQh
catch(Exception e){e.printStackTrace ();} lFG9=Wf
} Y%`SHe7M
tjnPyaJEl
Z*!O:/B
//读取保存的下载信息（文件指针位置） JgfVRqm
private void read_nPos() &)9{HRP
{ hlbvt-C?}"
try{ WrGK\Vw[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); TpfZ>d2
int nCount = input.readInt(); Ty4S~ClO#'
nStartPos = new long[nCount]; WCq /c6 D
nEndPos = new long[nCount]; b~Y%gC)FR
for(int i=0;i<nStartPos.length;i++) D56<fg$
{ N3A<:%s
nStartPos = input.readLong(); z%d#@w0X1
nEndPos = input.readLong(); `#s#it'y
} ~W#sTrK
input.close(); Gwec4D
} @_ygnNn4R
catch(IOException e){e.printStackTrace ();} udk.zk
catch(Exception e){e.printStackTrace ();} s95F#>dr
} {,$rkwW
P }7zE3V
kPxT" " k
private void processErrorCode(int nErrorCode) s|yVAt|=
{ [a1jCo
System.err.println("Error Code : " + nErrorCode); (c\hy53dP
} 2a=sm1?
Rd&9E
kyYLP"oB=
//停止文件下载 +g*k*e>l
public void siteStop() E9fxjI%1
{ ht97s
bStop = true; %/9;ZV
for(int i=0;i<nStartPos.length;i++) R`'1t3p0i
fileSplitterFetch.splitterStop(); \}*k)$r
fC-P.:F#I
dbdM"z4
} $hrIO+
} ub:ly0;t
//负责部分文件的抓取 wD\ZOn_J
**FileSplitterFetch.java Kyg=$^{>G
*/ VDF)zA1V
package NetFox; Bik*b)9y2
*s4\\Wb=
a>mMvc"
import java.io.*; Zl/<w(f_
import java.net.*; *<4Em{rZ5
q?j|K|%
`{K_/Cit
public class FileSplitterFetch extends Thread { oDB`iiBXQ
P1>AOH2yG
JgRYljQi2
String sURL; //File URL k;yw#Af8
long nStartPos; //File Snippet Start Position 9/ovKpY
long nEndPos; //File Snippet End Position R3.*dqo$
int nThreadID; //Thread's ID `8_z!)
boolean bDownOver = false; //Downing is over TYns~X_PR
boolean bStop = false; //Stop identical "h"NW[R
FileAccessI fileAccessI = null; //File Access interface T<b+s#n4
[]kN16F
AIijCL
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException n| !@1sd
{ Z?NW1m()F
this.sURL = sURL; AasZuO_I
this.nStartPos = nStart; `RRE(SiKU
this.nEndPos = nEnd; N!&:rK
nThreadID = id; _RkuBOv@e
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f2I6!_C!+
} myFAKRc
TX8<J>x
cQj-+Tmu
public void run() +/{L#e>
{ H1:be.^YP
while(nStartPos < nEndPos && !bStop) 6i@\5}m=
{ Vy<HA*
xG2F!WeF
'_P\#7$!MV
try{ t~7V{ xk
URL url = new URL(sURL); z;\dL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?`_jFj+<\S
httpConnection.setRequestProperty("User-Agent","NetFox"); yCz|{=7"j
String sProperty = "bytes="+nStartPos+"-"; d4?d4;{
httpConnection.setRequestProperty("RANGE",sProperty); Mz]:}qmFA
Utility.log(sProperty); 5sO@OV\ y
cgu~
h@{_duu
InputStream input = httpConnection.getInputStream(); GwU?wIIj^
//logResponseHead(httpConnection); 9O*_L:4o
8|?LN8rp
&^&zR(o`
byte[] b = new byte[1024]; +UN<Zp7I/
int nRead; ,3i,P(?(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Y.#:HRtgW
{ u+t$l^S
nStartPos += fileAccessI.write(b,0,nRead); {LzH&qu
//if(nThreadID == 1) K0pac6]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sM[I4.A3
} {XurC}#\
BP[|nL
Bf`9V713
Utility.log("Thread " + nThreadID + " is over!"); =WZqQq{
bDownOver = true; w~R`D
//nPos = fileAccessI.write (b,0,nRead); 07g':QU@
} !5@_j,lW(
catch(Exception e){e.printStackTrace ();} Os%n{_#8
} /t<@"BoV
} m#/_x
;TiUpg</_3
pv!oz2w1
//打印回应的头信息 [%A4]QzWh
public void logResponseHead(HttpURLConnection con) `Pn[tuIO
{ U:6W+p8
for(int i=1;;i++) 3voT^o
{ \VMD$zZx
String header=con.getHeaderFieldKey(i); lq:}0<k
if(header!=null) )jrT6x^IB
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t+r:"bb
Utility.log(header+" : "+con.getHeaderField(header)); va|*c22;|
else Q?t^@
break; ?']h%'Q
} F1%vtk;2?
} P>Euq'ajX
DaHZ{T8>d
Pl=]Srw
public void splitterStop() m(iR|Zx
{ _Us*+ 2(4L
bStop = true; A=zPLq{Sb
} )2q~u%9n
_96~rel_P
\vfBrN
} gwd (N
6Si-u
(m[bWdANnW
/* M@1r:4CoKH
**FileAccess.java vR6Bn
*//文件访问(定位，写) x3ERCqTR
package NetFox; 5l-mW0,MK
import java.io.*; 8N%Bn&
J/!cGr(B~
p}b/XnV$~
public class FileAccessI implements Serializable{ pg+[y<B
wu9=N ^x
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 o'<^LYSnB
RandomAccessFile oSavedFile; y7i%W4
long nPos; FSuAjBl0-
iJxQB\x
$QEilf;E
public FileAccessI() throws IOException /%aiEhL
{ Syp"L;H8Em
this("",0); 7r+g8+4
} +z9@:L
1=7jz]t
Hy"x
public FileAccessI(String sName,long nPos) throws IOException ,fIe&zq
{ M~*u;vA/
oSavedFile = new RandomAccessFile(sName,"rw"); |IoB?^_h
this.nPos = nPos; IL/Yc1
oSavedFile.seek(nPos); -F"QEL#
} e pCLM_yA
x.0p%O=`
R1:k23{
public synchronized int write(byte[] b,int nStart,int nLen) if;71ZE
{ >>Ts??
int n = -1; Cp`j/rF
try{ MF3b{|Z
oSavedFile.write(b,nStart,nLen); e^YHJ>@
n = nLen; X2mREt9
} -7uwOr
catch(IOException e) [OTJVpC
{ /N>e&e[35\
e.printStackTrace (); 1T_QX9
} h0oMTiA
]9=h%5Ji>
H`8``#-|@S
return n; qa(>wR"mT
} ,6!rR,0
plu$h-$d
p47S^gW
} &bz:K8c
1pv}]&X
o~FRF0f*VP
/* 'Djm0
**SiteInfoBean.java *tOG*hwdT
*/ GT hL/M
package NetFox; /:6Wzj
C.^Ven
_ ~RpGX
public class SiteInfoBean { CSbI85F
.I VlEG0
3bqC\i^[\m
private String sSiteURL; //Site's URL m+{K^kr[
private String sFilePath; //Saved File's Path =@u 5|:
private String sFileName; //Saved File's Name *?+V65~dW
private int nSplitter; //Count of Splited Downloading File Giq=*D+
5WqXo{S
O?8Ni=]
public SiteInfoBean() Nfe>3uQK
{//nSplitter的缺省值为5 $I#q
//default value of nSplitter is 5 8;y&Pb~)
this("","","",5); rV({4cIe9R
} f\;65k_jq
f"7M^1)h2%
Z34Wbun4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KV|}#<dD
{ xR"M*%{@0
sSiteURL= sURL; =Cv/Y%DN
sFilePath = sPath; o]{uc,
sFileName = sName; PN~@
this.nSplitter = nSpiltter; S.B<pjgt
$qF0ltUQ
t:JI!DR
} [U#72+K
zJM S=r
Sx*oo{Kk%
public String getSSiteURL() "'^4*o9
{ 04J}UE]Ww
return sSiteURL; 2#X4G~>#h
} n\I#CH0V
"M|P+A
#U=X NU}k
public void setSSiteURL(String value) }7{t^>;D
{ ~Au,#7X)
sSiteURL = value; ]fnnZ
} T9 <2A1
&2-L.Xb
,:Vm6u!
public String getSFilePath() d|Gl`BG
{ 5dx&Qu'}ZS
return sFilePath; Fg$3N5*
} o!Ev;'D
e&ANp0|W
RUCPV[{b
public void setSFilePath(String value) (F7_S*
{ iFSJL,QZ3
sFilePath = value; D2YZ9e
} Sz{O2lY
41#w|L \
%or,{mmiM:
public String getSFileName() ,1q_pep~?%
{ _qvK*nE
return sFileName; VhT= l
} in<Rq"L
"+KJop
9/SXs0
public void setSFileName(String value) ej&<GM|
{ -K(fh#<6KO
sFileName = value; K|C^l;M6
} $@\mpwANl
yix'rA-T
:"6q,W
public int getNSplitter() Nf+b"&Zh`
{ $d+DDm1o
return nSplitter; j9qREf9)
} f:zFFpP.j@
,3v+PIcMM+
s#h8%['
public void setNSplitter(int nCount) Q|}aR:4
{ |CgnCUv+
nSplitter = nCount; ]U[X1W+@
} JJV0R}z?TV
} o sbHs$C
bf_I9Z3m
NRnRMY-
/* 0U66y6
**Utility.java )PkNWj6%y
*/ Xf=XBoN|
package NetFox; H-rWDN#
|6J ?8y
4@ILw
public class Utility { |{g+Y
STfyCtS
bLz*A-
public Utility() kH*Pn'
{ 3`hUo5K
>idBS
ezhDcI_T
} [MX;,%;;
^/wfXm
//线程睡眠 s)voII&
public static void sleep(int nSecond) aI zv
{ c_{z(W"
try{ pDPxl?S
Thread.sleep(nSecond); d lH$yub
} iK;dU2h
catch(Exception e) +&tgJ07A
{ Q8p&Ki;i
e.printStackTrace (); U]qav,^[
} PYB+FcR6?n
} Uts"aQ
"wH)mQnd
//日志 HDM<w+ZxX
public static void log(String sMsg) (VvKGh
{ '"pd
System.err.println(sMsg); 3[p_!eoW
} 0uVv<Q~
W#_/ak$uF*
nGZX7Fx5
public static void log(int sMsg) J2GcBzRH
{ )g| BMmB
System.err.println(sMsg); 8B!aO/Km
} :/YO ni1h
} |6biq8|$3V
KHKS$D
I9$c F)zk
/* XXmE+aI
**TestMethod.java m!XI{F@x
*/ "re-@Baw
package NetFox; u#W5`sl
BUUf;Vv
0m[dP
public class TestMethod { \a"Ct'
u]C`6)>
O(2cWQ
public TestMethod() k0?ZYeHC
{ ///xx/weblogic60b2_win.exe Ue5O9;y]u
try{ UIJx*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); x9>\(-uU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); VCNT4m
SiteFileFetch fileFetch = new SiteFileFetch(bean); Mro4`GL
fileFetch.start(); J}spiVM
} ~+D*:7Y_
catch(Exception e){e.printStackTrace ();} ]>##`X
iY[+Ywh
=<f-ob8,
} s}M= oe
Rz%e>)
Z{-Lc68
public static void main(String[] args) wn+FTqj
{ BJjx|VA+
new TestMethod(); ClW'W#*(Y
} 2)iD4G`
} uE_c4Hp
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