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)); tE<L4;t
} _/P"ulNb
for(int i=0;i<nEndPos.length-1;i++) ^J\)cw
{ xLq+njH E
nEndPos = nStartPos[i+1]; {Yv |C)O
} cidS/OH
nEndPos[nEndPos.length-1] = nFileLength; -&@[]/
} 29x "E$e
} CA[k$Sw*
q{n~s=
hTH"jAC+
//启动子线程 >-EoE;s
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; k:`^KtBMl
for(int i=0;i<nStartPos.length;i++) /8J2,8vZ
{ SJIJV6}H
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $(#o)r>_R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kZSe#'R's
nStartPos,nEndPos,i); .oAg (@^6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?W%3>A
fileSplitterFetch.start(); Wb/@~!+i`
} 5j,)}AYO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .J&~u0g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ",Ek| z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", //K]zu
nEndPos = " + nFileLength); !Z<Z"R/
// fileSplitterFetch[nPos.length-1].start(); w[:5uo(
ra$_#HY
u\smQhQGE
//等待子线程结束 [sACPn$f
//int count = 0; {l\v J#r:
//是否结束while循环 kd!f/'E!
boolean breakWhile = false; i|.!*/qF
S#2'Jw
B>YrDJUN
while(!bStop) 9Ni$nZN
{ Ho\K %#u
write_nPos(); e[>(L%QV+
Utility.sleep(500); (J$JIPF
breakWhile = true; 3l5q?"$
2Xe2%{
d=N5cCqq
for(int i=0;i<nStartPos.length;i++) u&2uQ-T0
{ [C P V5\2
if(!fileSplitterFetch.bDownOver) Hagj^8
{ ?8YHz
breakWhile = false; zSDiJ$Xk
break; >d#B149
} ;(VJZ_
} M/Bn^A8@
if(breakWhile) LOR$d^l
break; ^Q2K0'm5
?HZ+fS,-
:%!=Ej.J
//count++; ~A>3k2N/e
//if(count>4) >:KPvq!0
// siteStop(); dRas9g
} }[D[ZLv
NVJvCs)3f
3U1xKF
System.err.println("文件下载结束！"); ^9qncvV
} ;l}TUo
catch(Exception e){e.printStackTrace ();} vJmE}
} [rE,fR
TX*s T
{3 zq.e{
//获得文件长度 c>=[|F{{e
public long getFileSize() 4)Z78H%>
{ %w'@:~0
int nFileLength = -1; S WYiI
try{ nVs0$?}
URL url = new URL(siteInfoBean.getSSiteURL()); evu@uq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kw}J~f2
httpConnection.setRequestProperty("User-Agent","NetFox"); dwB-WF%k
,B!u*
GMB%A
int responseCode=httpConnection.getResponseCode(); yBs
if(responseCode>=400) Il*wVNrZI
{ VGq2ITg9eE
processErrorCode(responseCode); |CStw"Fog
return -2; //-2 represent access is error d=H C;T)
} k@KX=mG<
]5uCs[
6Dw[n
String sHeader; ~;Xdz/
.NwHr6/s*
!oM1
for(int i=1;;i++) }3M\&}=8
{ &d9";V"E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F0Rk[GM
//Utility.log(in.readLine()); WElB,a-RCp
sHeader=httpConnection.getHeaderFieldKey(i); vIz~B2%x
if(sHeader!=null) J}%&;uv
{ wQ4/eQ*
if(sHeader.equals("Content-Length")) M6y:ze
{ "d%":F(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9b()ck-\F#
break; ,v>P05
} =(.HO:#
} 2l8jw:=H
else bWjW_$8
break; ,#D&*
} d}ue/hdw
} @ ;rU#
catch(IOException e){e.printStackTrace ();} /v=MGX@r
catch(Exception e){e.printStackTrace ();} A!goR-J]
`')3}
5I t+ S+a
Utility.log(nFileLength); (Cqhk:F
)[G5qTO
H.!M_aJH
return nFileLength; Sf lHSMFw
} b_cD >A
0u-'{6
Jr 9\j3J{
//保存下载信息（文件指针位置） 6S<J'9sE
private void write_nPos() "aAzG+NM
{ ~{RXc+
try{ zcP_-q]1
output = new DataOutputStream(new FileOutputStream(tmpFile)); lE$X9yIt
output.writeInt(nStartPos.length); 60^dzi!vs
for(int i=0;i<nStartPos.length;i++) F7cv`i?2."
{ N[E t
// output.writeLong(nPos); 80 i<Ij8J
output.writeLong(fileSplitterFetch.nStartPos); ndW??wiM
output.writeLong(fileSplitterFetch.nEndPos); z9'ME
} |;Jcf3e(
output.close(); Rf2;O<
} 'd0]`2tVg4
catch(IOException e){e.printStackTrace ();} u= !?<Q
catch(Exception e){e.printStackTrace ();} &*[T
} h ej
1r|'n aiZ
oT%~)g
//读取保存的下载信息（文件指针位置） F0+u#/#
private void read_nPos() ]"{K5s7
{ iS=}| 8"
try{ 4CfPa6_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }(20MW8rMc
int nCount = input.readInt(); j`='SzVloW
nStartPos = new long[nCount]; WPCaxA+l
nEndPos = new long[nCount]; ~.yt
for(int i=0;i<nStartPos.length;i++) 4^ $
{ l;F3kA
nStartPos = input.readLong(); >/ W:*^g)
nEndPos = input.readLong(); 0rjxWPc
} 7L? ~;;L$
input.close(); {b=]JPE
} 2c_#q1/Z/
catch(IOException e){e.printStackTrace ();} vX/~34o]\
catch(Exception e){e.printStackTrace ();} ?psvhB{O
} UR:cBr
zD7\Gv
kImS'i{A
private void processErrorCode(int nErrorCode) '-S^z"ZrI
{ / ~w\Npf0
System.err.println("Error Code : " + nErrorCode); 5e6]v2 k
} IF$f^$
y]+i.8[
\C~Y
//停止文件下载 kd9hz-*
public void siteStop() d7N}-nsB
{ b P4R
bStop = true; ]k " j
for(int i=0;i<nStartPos.length;i++) i|)<#Ywl
fileSplitterFetch.splitterStop(); ,*}SfCon
_Cj u C`7
AQQeLdTq
} s(r(! FZ
} ]fnc.^{
//负责部分文件的抓取 o!gl :izb
**FileSplitterFetch.java =K-B I
*/ m9a(f>C
package NetFox; Ca0~K42~
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w8%<O^wN,
import java.io.*; }{J<Wzw
import java.net.*; R<a7TkL4?
RxjC sjg
v<HhB.t.
public class FileSplitterFetch extends Thread { /P Qz$e-!Y
(kK6=Mrf
^8ZVB.Fv
String sURL; //File URL J-au{eP^
long nStartPos; //File Snippet Start Position #t>w)`bA-
long nEndPos; //File Snippet End Position GxuFO5wz
int nThreadID; //Thread's ID sFT-aLpL@V
boolean bDownOver = false; //Downing is over R%"wf
boolean bStop = false; //Stop identical *"d"
FileAccessI fileAccessI = null; //File Access interface y.=ur,Nd
_qR1M):yJ
j7?53e
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException hg/G7Ur"
{ KtG|m'\D
this.sURL = sURL; Uw8O"}U8
this.nStartPos = nStart; 4'cdV0]
this.nEndPos = nEnd; t"cGv32b
nThreadID = id; PeEC|&x
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =EA*h_"q9
} W`*S?QGzl@
,JYvfCA
j,Eo/f+j5
public void run() ]bz']`
{ {F+7> X
while(nStartPos < nEndPos && !bStop) b*+Od8r
{ /U4F\pZl
CE=&ZHt9
l&R~I6^E
try{ 5Q;Fwtm
URL url = new URL(sURL); 3P2H!r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Gc^w,n[E
httpConnection.setRequestProperty("User-Agent","NetFox"); NuRxkeEO
String sProperty = "bytes="+nStartPos+"-"; 6FFQoE|n
httpConnection.setRequestProperty("RANGE",sProperty); KB0HM
Utility.log(sProperty); 82nQ]
AcqsXBKd
O(2)A>}
InputStream input = httpConnection.getInputStream(); -NHA{?6r
//logResponseHead(httpConnection); swss#?.se
<5%x3e"7u
jQxv`H
byte[] b = new byte[1024]; sgW*0o
int nRead; {dM18;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) fI9 TzpV
{ "g;^R/sfq
nStartPos += fileAccessI.write(b,0,nRead); b)"bX}
//if(nThreadID == 1) t:B~P,r
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Rf||(KC<
} 7s+3^'
+&6R(7XC
hsr,a{B%$
Utility.log("Thread " + nThreadID + " is over!"); LmE%`qNg
bDownOver = true; 2Dgulx5kGZ
//nPos = fileAccessI.write (b,0,nRead); o?BcpWp
} :s`~m;Y9?
catch(Exception e){e.printStackTrace ();} D[yOFJ~p)
} j qfxQ
} .Zv@iL5
`dO)}}| y
Xxhzzm-B
//打印回应的头信息 00X~/'!
public void logResponseHead(HttpURLConnection con) Wnm?a!j5
{ a NhI<.v
for(int i=1;;i++) 9#Gz2u$
{ e"Kg/*Ji1
String header=con.getHeaderFieldKey(i); `a2%U/U
if(header!=null) SIQ7oxS4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); q$6fb)2I]e
Utility.log(header+" : "+con.getHeaderField(header)); "Qj;pqR
else r%QTUuRXC3
break; cy T,tN
} Eh/B[u7T[
} kcGs2Y_*&
)!M %clm.
\ <b-I
public void splitterStop() }i0(^"SoXZ
{ !A!}j.s
bStop = true; f"My;K$l;
} I<yd=#:n
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++=t|ZS U
} O75^(keW
@AET.qGC
X!#rw= Q
/* v0Ww~4|],
**FileAccess.java *-0tj~)>
*//文件访问(定位，写) s~(!m. R
package NetFox; Hs,pY(l^
import java.io.*; 6%?bl{pNn
r1dP9MT\8
WxO2
public class FileAccessI implements Serializable{ ^~\cx75D
>.'rN>B+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ldqn<wNnI
RandomAccessFile oSavedFile; =*<Cw?Gc
long nPos; Xo^P=uf%
7:iTx;,v
_gDEIoBp
public FileAccessI() throws IOException {6}H}_(]
{ \o}m]v i
this("",0); A9qbE
} 5A^$!q P
3jH-!M5
3,;;C(
public FileAccessI(String sName,long nPos) throws IOException CRXIVver
{ BOqu$f+
oSavedFile = new RandomAccessFile(sName,"rw"); Fb8~2N"3
this.nPos = nPos; wNQhz.>y
oSavedFile.seek(nPos); sv}k_6XgY
} ?VUW.-
2L?jp:$;X
}_,1i3Rip
public synchronized int write(byte[] b,int nStart,int nLen) W%$sA}O
{ %#7NCdk;S
int n = -1; Z|l/6L8
try{ &USKudXmb
oSavedFile.write(b,nStart,nLen); fviq}.
n = nLen; ).IB{+
} NmbA~i
catch(IOException e) vxN,oa{hf
{ p@`]9tLP(K
e.printStackTrace (); Zw4z`x1f
} B+)HDIPa-
G_m$W3 zS
V!^5#A<
return n; :&59N^So|
} VAGQR&T?
,e]|[,r#5
uKOsYN%D
} \Z~|ry0v{d
f&5'1tG
cviPCjM
/* kF,_o/Jc
**SiteInfoBean.java Cf&.hod
*/ qGezmkNFm
package NetFox; J*I G]2'H
O:G5n 5J
ePD~SO9*
public class SiteInfoBean { ! J7ExfEA
&;x*uG
l>t0 H($
private String sSiteURL; //Site's URL GxynLXWo>
private String sFilePath; //Saved File's Path R?Ou=p .
private String sFileName; //Saved File's Name Quts~Q
private int nSplitter; //Count of Splited Downloading File .@`5>_
+9fQ YJBA
E&_q"jJRi
public SiteInfoBean() S}}L& _
{//nSplitter的缺省值为5 W{l{O1,
//default value of nSplitter is 5 7]}2`^9
this("","","",5); Rk$
} N~)RR {$w
+N>z|T<
Ij{ K\{y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) x^XP<R{D
{ 04E S>'@
sSiteURL= sURL; $p)e.ZMgE
sFilePath = sPath; 0Z&ua
sFileName = sName; ZQ)vvD<
this.nSplitter = nSpiltter; :RG=3T[
9cJ1J7y
F`eo3z
} ZP(T=Q
"">{8
IA3m.Vxj ^
public String getSSiteURL() jFH wu*
{ LUfo@R
return sSiteURL; d cG)ql4d
} fpA%:V
.:(T}\]R
\<kQ::o1y
public void setSSiteURL(String value) ,w|Or}h]7
{ hx$bY
sSiteURL = value; 9lR-
} DWXHx
E06)&tF
"wj~KbT}&
public String getSFilePath() pkEx.R)
{ 4%"Df1U
return sFilePath; 0wpGIT!2
} *Kmo1>^
,(v=ZeI
XQI!G_\+C
public void setSFilePath(String value) &S9O:>=*
{ pp1kcrE\M
sFilePath = value; n>L24rL
} 3ahbv%y
5}|bDJ$%_
]wHXrB8vx
public String getSFileName() QqCwyK0
{ Z1N=tL
return sFileName; & oj$h
} kj]m@mS[
D&|HS!
G@8wv J
public void setSFileName(String value) ^"GDaMF
{ fb_q2p} G
sFileName = value; ,wB)hp
} L 4Sa,ZL
@E%fAC
K0^Tg+U($p
public int getNSplitter() rvRIKc|}l
{ {Z_?7J&z
return nSplitter; /=gU
} ,c6c=di
WJBwo%J
H|I.h{:
public void setNSplitter(int nCount) (yv)zg9
{ yGE)EBH
nSplitter = nCount; aBT8mK -.
} Xp?WoC N
} UYkuz
m.&"D> \t
$LHF=tYS
/* n|Gw?@CU7
**Utility.java jUCDf-_ m
*/ (AswV7aGe
package NetFox; .&;:X )
<ql:n
mt]50}eK
public class Utility { XEb+Z7L1
|l673FcJ
TSKR~3D#
public Utility() ,'a[1RN
{ #|;;>YnZ
=g<Y[Fi2
O_^ uLp
} naiy] oY"
{9|S,<9
//线程睡眠 jFGY`9Zw0
public static void sleep(int nSecond) XBN,{
{ y7-daek
try{ )(W%Hmi
Thread.sleep(nSecond); Oi$$vjs2
} 7da~+(yhr
catch(Exception e) Pw/$ }Q9X
{ 6;p"xC-
e.printStackTrace (); wOrpp3I
} E#/vgm=W;
} )mE67{YJh~
4]m?8j) 6b
//日志 'aJm4W&j
public static void log(String sMsg) Z.3*sp0 yv
{ z.0!FUd
System.err.println(sMsg); LhQidvCNJ
} _2rxDd1#.
TM0DR'.
*@[N~:z/
public static void log(int sMsg) R*>EbOuI
{ }`D-]/T8.
System.err.println(sMsg); J%lEyU
} )d7U3i
} g<5G#
QI{<q<
@+(a{%~7y
/* 6M X4h
**TestMethod.java C.Re*;EI,
*/ mFJb9,
package NetFox; nWsR;~pK
~)%DiGW&
P(Z\y^S
public class TestMethod { sT+\ z
$Y<(~E$FX
>&l{_b\k
public TestMethod() ]R6Z(^XT,E
{ ///xx/weblogic60b2_win.exe +8|r_z\A5a
try{ /<it2=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]]lM)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); nQM7@"R
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,7*-%05[\
fileFetch.start(); Nj|~3 *KO
} Uiu9o]n
catch(Exception e){e.printStackTrace ();} IXt cHAgX
Eumdv#Qg
O>sE~~g]?
} Ll'!aar,
]WZi+
.}DL%E`n
public static void main(String[] args) ~.f[K{h8
{ Q2K)Nl >_
new TestMethod(); 31n|ScXv
} Z=CY6Zu7
} C;.+ kE
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