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)); tW~kn9glZ
} gpyio1V>
for(int i=0;i<nEndPos.length-1;i++) dBA&NW07
{ FR6 W-L
nEndPos = nStartPos[i+1]; d1_kw A2y
} (hOD
nEndPos[nEndPos.length-1] = nFileLength; J>#hu3&UOQ
} 4G:~|N.{p
} 'y!qrmMRr
Q\s+w){f%
&I=o1F2B)
//启动子线程 oU,8?(}'~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5uG^`H@X
for(int i=0;i<nStartPos.length;i++) e46`"}r
{ Zgh~7Z/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xO:h[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {,uSDIOj$
nStartPos,nEndPos,i); #Pk{emYW
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jc?zX8>Ae:
fileSplitterFetch.start(); nygGI_[l
} l8(9?!C
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DqY"N]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6<@+J
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", C3^3<
nEndPos = " + nFileLength); ShVR{gIs
// fileSplitterFetch[nPos.length-1].start(); Q3& ?28
):4)8@]5M
}~&0<8m
//等待子线程结束 \C~6 '
//int count = 0; ^L.I9a#]
//是否结束while循环 O[$X36z
boolean breakWhile = false; z-K};l9y
GIYdI#0RC
8IL5:7H8
while(!bStop) :9L}jz
{ ; Yc\O:Qq
write_nPos(); ^m D$#
Utility.sleep(500); xe6V7Wi/Tt
breakWhile = true; nm\f$K>Pg
/|NyO+Io
A #SO}c
for(int i=0;i<nStartPos.length;i++) B!`.,3
{ 'HfI~wN
if(!fileSplitterFetch.bDownOver) ":T"Y;
{ "Ltp]nCR
breakWhile = false; xzz@Wc^_
break; IeChz d
} \Qv:7;?
} tMU10=d
if(breakWhile) 0Z((cI\J
break; tculG|/
uCW}q.@4
Q$'\_zV
//count++; JSh'iYJ.
//if(count>4) b;;y|H
// siteStop(); S=< ]u
} p+Bvfn
;1,#rTs
y&4im;X0
System.err.println("文件下载结束！"); &SZAe/3+
} |%X_<Cpk
catch(Exception e){e.printStackTrace ();} xXV15%&
} 1Ogtzf
|`wJ {-
[A!=Hv_$
//获得文件长度 @*T8>
public long getFileSize() xU.Ymq& 5
{ \q-["W34
int nFileLength = -1; J{EK}'
try{ _cfAJ)8=
URL url = new URL(siteInfoBean.getSSiteURL()); ]%Whtj.,x7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L(`q3>iC4.
httpConnection.setRequestProperty("User-Agent","NetFox"); CS"k0V44}
|@>Zc5MY$
\gZjq]3
int responseCode=httpConnection.getResponseCode(); -Xgup,}?
if(responseCode>=400) _{i-.;K
{ g;3<oI/P
processErrorCode(responseCode); q*J-ii
return -2; //-2 represent access is error t&bE/i_T
} | qf8y
uUG&At
6ozBU^n
String sHeader; TU8K\;l]
/z,+W9`
v[y|E;B
for(int i=1;;i++) W.b?~
{ Lr(wS {
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >\!>CuU
//Utility.log(in.readLine()); $0E_4#kwB
sHeader=httpConnection.getHeaderFieldKey(i); PmE2T\{s!
if(sHeader!=null) fm%-wUgj
{ RE:$c!E!
if(sHeader.equals("Content-Length")) _RzcMX
{ Ed~2Qr\65
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); EabZ7zFoN
break; fL1EQ)
} bPdbKi{j@
} 5/{gY{
else cvf#^Cu
break; vV9q5Bj:
} }h)[>I(
} Q|}Pc>ae
catch(IOException e){e.printStackTrace ();} AU +2'
catch(Exception e){e.printStackTrace ();} w,FOq?j^k
r5?qz<WW~
%sLij*
Utility.log(nFileLength); $r=Ud >
$.@)4Nu!_
8.Ty ,7Z
return nFileLength; rx#\Dc}
} ~FV Z0%+,
C[O \aW
='cr@[~i
//保存下载信息（文件指针位置） Et+N4w
private void write_nPos() x~tG[Y2F?
{ <4Jo1
try{ yVM 1W"Q
output = new DataOutputStream(new FileOutputStream(tmpFile)); [sY>ac
output.writeInt(nStartPos.length); ATU 2\Y
for(int i=0;i<nStartPos.length;i++) 8W"~>7/>D
{ ` 0k
// output.writeLong(nPos); `?VB)
output.writeLong(fileSplitterFetch.nStartPos); n'JwT! A
output.writeLong(fileSplitterFetch.nEndPos); 9c1n
} )S|}de/a2
output.close(); 'N0/;k0ax
} *Gm%Dn
catch(IOException e){e.printStackTrace ();} /tf}8d
catch(Exception e){e.printStackTrace ();} Ee##:I[z
} :R<n{%~
#$Z|)i]w
P~:W+!@5v
//读取保存的下载信息（文件指针位置） fV_(P_C
private void read_nPos() l 49)Cv/
{ %97IXrE
try{ U&/Jh^Yy
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -~ `5kO~
int nCount = input.readInt(); GjA;o3(
nStartPos = new long[nCount]; VWG#v#o
nEndPos = new long[nCount]; K{HRjNda#
for(int i=0;i<nStartPos.length;i++) 81/Bn!
{ l\*}
nStartPos = input.readLong(); W]n%$a
nEndPos = input.readLong(); %u43Pj
} .Lp0_R@
input.close(); t_WNEZW7f
} >'8.>f
catch(IOException e){e.printStackTrace ();} lBL;aTzo
catch(Exception e){e.printStackTrace ();} h8O[xca/~
} -rlxxLT+
Y'Jb@l`$-
6pQ#Zg()vp
private void processErrorCode(int nErrorCode) 'd1E~A
{ 9+SeG\Th
System.err.println("Error Code : " + nErrorCode); `96:Z-!}
} z8= Gc$w!
U\ y?P:yy
HH2*12e
//停止文件下载 +?(2-RBd
public void siteStop() yc4mWB~gyU
{ oWo"`"P
bStop = true; M0x5s@
for(int i=0;i<nStartPos.length;i++) xK0VWi
fileSplitterFetch.splitterStop(); gV!Eotq
Hv<%_t_/
f| 3`8JU
} VE6T&fz`
} _d]w)YMO
//负责部分文件的抓取 jfS?#;T)
**FileSplitterFetch.java <2ffcBv
*/ 7~eo^/PbS
package NetFox; #d*mG =
r['T.yo
\%EZg
import java.io.*; o]}b#U8S
import java.net.*; 4G@vO{$
%7O`]ik:
=1^Ru*G
public class FileSplitterFetch extends Thread { r1-?mMSU&
. %tc7`k8
.ymR%X_k
String sURL; //File URL <jw`"L[D
long nStartPos; //File Snippet Start Position Vs8os+
long nEndPos; //File Snippet End Position X&^t 8
int nThreadID; //Thread's ID k^]+I%?Q
boolean bDownOver = false; //Downing is over _xAdvr' W
boolean bStop = false; //Stop identical =a?l@dI]
FileAccessI fileAccessI = null; //File Access interface vp4!p~C{
X||oiqbY
.+ai dWd
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException EZIMp8^
{ 2*Z~JM
this.sURL = sURL; 8_Y{7;<ey
this.nStartPos = nStart; VV?+q)
this.nEndPos = nEnd; \0(QO8.
nThreadID = id; tV*g1)'zX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5^GUuFt5m
} `8xe2=Ub
WsJ3zZc
Bu>srX9f
public void run() #?!)-Q%
{ lx U}HM
while(nStartPos < nEndPos && !bStop) e0j*e7$
{ g?^o++
1-r1hZ-
7,j}]
try{ qK.8^{b
URL url = new URL(sURL); 7I^(vQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %OfaBv&
httpConnection.setRequestProperty("User-Agent","NetFox"); 2!7wGXm~U
String sProperty = "bytes="+nStartPos+"-"; _s|C0Pt
httpConnection.setRequestProperty("RANGE",sProperty); tE3!;
Utility.log(sProperty); E:&=A 4%
_D$|lk-
BGLJ>zkq
InputStream input = httpConnection.getInputStream(); 4FGcCE3
//logResponseHead(httpConnection); r<UZ\d -
V. =!^0'A
&=<x&4H+
byte[] b = new byte[1024]; IObGmc
int nRead; Q;)[~p
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T.`EDluG
{ c:>&Bg&,6T
nStartPos += fileAccessI.write(b,0,nRead); LUHj3H
//if(nThreadID == 1) ,l&Dt,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dE.R$SM
} &h`s:Y
!-U5d9!
3RXq/E
Utility.log("Thread " + nThreadID + " is over!"); k9.@S
bDownOver = true; FU;Tv).
//nPos = fileAccessI.write (b,0,nRead); Eu l,1yR
} r[q-O&2&
catch(Exception e){e.printStackTrace ();} :+bQPzL
} vfK^^S
} HIk5Q'ek
pBL,kqYNA>
r0+lH:G*q
//打印回应的头信息 vCb3Ra~L`
public void logResponseHead(HttpURLConnection con) 8uP,#D<wZ
{ Cf91#%:cN
for(int i=1;;i++) r.lH@}i%n
{ `J'xVq#O
String header=con.getHeaderFieldKey(i); FWq+'GkSV
if(header!=null) I+rHb< P%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P%8 Gaa=
Utility.log(header+" : "+con.getHeaderField(header)); :rk=(=@8`
else 3%bCv_6B
break; cV\(Z6u
} =ps3=D
} 9E'fM
(+`pEDD{X
` .|JTm[
public void splitterStop() Oh3AbpTT
{ 3k.{gAZKh
bStop = true; qjFz}6
} Dt%Gv0
i,r O3Jn
{_&'tXL
} )r3}9J
[=7=zV;}4
ELfcZfJ
/* &_Ze@Ir-
**FileAccess.java >Akrbmh5
*//文件访问(定位，写) -^LUa]"E
package NetFox; `Fnl<C<
import java.io.*; a8ya5EO
U_i%@{
7#d>a=$h
public class FileAccessI implements Serializable{ d` %8qLIW
r<VZEbm)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 XtY!fo*
RandomAccessFile oSavedFile; +Ysm6n '
long nPos; cq lA"Eof
yHhx- `
H'KCIqo
public FileAccessI() throws IOException mApn[)?tv
{ I@Cq<:+(3
this("",0); G"k.sRKu
} p]h;M
@Wgd(Ezd
^*sDJ #
public FileAccessI(String sName,long nPos) throws IOException YnM&t ;TX
{ X$*MxMNs
oSavedFile = new RandomAccessFile(sName,"rw"); `9;0Y
this.nPos = nPos; A*+pGQ
oSavedFile.seek(nPos); mJ+M|#Ox
} +cH,2^&
y8*MNw
d}D%%noIu
public synchronized int write(byte[] b,int nStart,int nLen) (=A61]yB
{ LR:PSgy
int n = -1; $Lj~ge3#
try{ 6HroKu
oSavedFile.write(b,nStart,nLen); w8=&rzr8
n = nLen; r]q;>\T'
} o<h2]TN
catch(IOException e) ^}SP,lg'
{ SjosbdD
e.printStackTrace (); Wd`*<+t]
} 6=cfr; BH2
v~8CpC
}K.Rv(m
return n; $>JfLSyC
} 7MWd(n-
[}Q_T.4)E
1Kjqs)p^
} QhhL_vP
ai7R@~O:_k
w"`Zf7a{/
/* r` B(ucE
**SiteInfoBean.java HNJR&U t
*/ uTShz3
package NetFox; LC1WVK/
K`=9"v'f+
4s s 4O
public class SiteInfoBean { a(J@]X>'
^h$^j
6"Ze%:AZZ
private String sSiteURL; //Site's URL ZZ>"LH
private String sFilePath; //Saved File's Path E2xK GK
private String sFileName; //Saved File's Name hW!2C6
private int nSplitter; //Count of Splited Downloading File /0swrt.
Vp7d
2Z-[x9t
public SiteInfoBean() u`.3\Geh
{//nSplitter的缺省值为5 Y{Ff I+
//default value of nSplitter is 5 3'Hz,qP
this("","","",5); Dm@h'*
} XU`ly3!
1{ H=The
zviTGhA
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) iT;Ld $!{f
{ VFrp7;z43
sSiteURL= sURL; p,V%wGM
sFilePath = sPath; '3w%K+eJY
sFileName = sName; #bJp)&LO
this.nSplitter = nSpiltter; ~,_@|,)
eslvg#Q
r$1b=m,0d
} =r)LG,w212
Q:j~ kutS|
C B`7KK
public String getSSiteURL() EJP]E)
{ E/hT/BOPK
return sSiteURL; x=Aq5*A0
} g[R4/]K^$
UGlHe7
1 0zw}1x
public void setSSiteURL(String value) (Hmm^MV)
{ 3GNcnb
sSiteURL = value; jXVvVv
} M}j[{wW3
q9H\ $
=W;e9 6#
public String getSFilePath() ,N_/J4Us
{ U{KnjoS
return sFilePath; Y]=k"]:%
} &qK:LHhj
F\hVunPVx
mlCBstt{
public void setSFilePath(String value) }OhSCH'o6
{ H2oxD$s
sFilePath = value; J>k 6`gw
} Fc80HK5R
x N7sFSV@
AN6Q~%,
public String getSFileName() 2X[oge0@
{ AAs&P+;
return sFileName; S*>T%#F6Uo
} wx[m-\
8MI8~
)#8g<]q
public void setSFileName(String value) Bu&9J(J1
{ @tPr\F
sFileName = value; DRR)mQBb
} 4;W{#jk
Cl9rJ oT
~ +>ehU
public int getNSplitter() ?pfr^ !@$
{ ;2\6U;
return nSplitter; "/RMIS K[;
} TTFs|T6`q
GB^`A
9PACXW0
public void setNSplitter(int nCount) +t%2V?
{ W7b m}JHn
nSplitter = nCount; p}h.2)PO
} +&S6se4
} ;1PJS_@rX
|6b~c{bt
zRD-[Z/-
/* uSRhIKy
**Utility.java ,OubKcNg
*/ r8eJ&-Yi{Z
package NetFox; &Jb\}c}
=EMB~i
[:#K_EI5%
public class Utility { hmd3W`8D
G%: 3.:E"
GVJ||0D
public Utility() Fz,jnV9=j
{ >(ip-R
Q8AAu&te7
~=iH*AQR
} <{bxOr+
(g/A uL
//线程睡眠 N'9T*&o+
public static void sleep(int nSecond) ;*<R~HJt
{ vg[3\!8z[
try{ cPuXye
Thread.sleep(nSecond); ) c\Y!vS
} +llb{~ZN
catch(Exception e) T\bP8D
{ :,aY|2si
e.printStackTrace (); !|xB>d q?
} `3i>e<m~
} ;]Q6K9.d8
(~zu4^9w
//日志 :M6v<Kg{;
public static void log(String sMsg) j\~,Gtn>Z
{ qc @cdi
System.err.println(sMsg); wCNn/%C
} r5S/lp+Y+N
mLZ1u\7W
pN5kcvQ
public static void log(int sMsg) ,GYQ,9:
{ >lUPOc
System.err.println(sMsg); Lo!hyQ)
} 3;BIwb_
} N~8H\
^_Hf}8H7]
2@6@|jRG
/* }`<&l
**TestMethod.java D/."0 #q
*/ "x=\mA#`
package NetFox; w/nohZF6H
_Pqq*
1$vGQ
public class TestMethod { 6(`N!]e*L
yqq1a o
JpfA+r
public TestMethod() F*PhV|XU
{ ///xx/weblogic60b2_win.exe M<w.q|P
try{ W7!gD
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J#Hh4Kc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V)<>W_g
SiteFileFetch fileFetch = new SiteFileFetch(bean); [G|.
fileFetch.start(); n]IF`kYQV
} ?CQE6ch
catch(Exception e){e.printStackTrace ();} 3s!6rT_=)d
bu _ @>`S
>6o <Q
} Z\IM~-
lw9jk`7^
'lZlfS:Z8
public static void main(String[] args) D j9aTO
{ 8/aJ4w[A
new TestMethod(); /(BS<A
} #Zm`*s`
} TRi#
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