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)); Xy%p"b<
} b%cF
for(int i=0;i<nEndPos.length-1;i++) ws^4?O
{ %c[V
nEndPos = nStartPos[i+1]; r1fGJv1!o
} aM4k *|H?
nEndPos[nEndPos.length-1] = nFileLength; D-N8<:cA
} h,"4SSL
} 2k<;R':
}%D^8>S
<oz!H[!
//启动子线程 z3uW)GQ.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }pJwj
for(int i=0;i<nStartPos.length;i++) jv&!Kw.Ug
{ H*9~yT'Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /a6Xa&(B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "*})3['n
nStartPos,nEndPos,i); V\6]n2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yV^s,P1
fileSplitterFetch.start(); |.wEm;Bz
} a@R]X5[O
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p0pWzwTG3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); qpXWi &g
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U)3DQ6T99
nEndPos = " + nFileLength); Gm\/Y:U
// fileSplitterFetch[nPos.length-1].start(); -ig6w.%lk
>a}f{\Q
f^VP/rdg
//等待子线程结束 S%`0'lzzj
//int count = 0; <^$<#Kd
//是否结束while循环 uIZWO.OdU
boolean breakWhile = false; *E{2J:`
!>1@HH?I\/
#UbF9})q
while(!bStop) H#ncM~y*
{ :^(>YAyHj^
write_nPos(); [}&Sxgv
Utility.sleep(500); l<);s
breakWhile = true; o^ XtU5SVq
%HJK;
xt*u4%
for(int i=0;i<nStartPos.length;i++) *BR^U$,e
{ f;b[w
if(!fileSplitterFetch.bDownOver) AF%@VLf
{ Qubp9C#r
breakWhile = false; l'eyq}&
break; Jkek-m
} Hhh0T>gi
} uS^Ipxe\
if(breakWhile) /3{b%0Aa
break; Ih"XV
q|),`.eh\
O6OP =K!t:
//count++; y`=]T>X&x
//if(count>4) 8e(\%bX
// siteStop(); rh^mJUh
} r >nG@A
aca=yDs2
9B9(8PVG
System.err.println("文件下载结束！"); tdu$pC6
} c??mL4$'N
catch(Exception e){e.printStackTrace ();} S.f5v8
} _D+J!f^
X)% A6M
q?8| [.
//获得文件长度 {Ja!~N;3
public long getFileSize() wY_)y
{ zld#qG6
int nFileLength = -1; Uw7h=UQh
try{ G2T|RT$_K
URL url = new URL(siteInfoBean.getSSiteURL()); %xyou:~0zs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _BP&n
httpConnection.setRequestProperty("User-Agent","NetFox"); ]@u6HH~^
_+E5T*dk
=aTv! 8</
int responseCode=httpConnection.getResponseCode(); av|g}xnj
if(responseCode>=400) [wzb<"kW
{ \r+8qC[,
processErrorCode(responseCode); e0,|Wm
return -2; //-2 represent access is error "9Q40w\
} #^A*
|3KLk?2
O*FUTZd(J
String sHeader; @/ohg0
LF& z
GVYkJ0,
for(int i=1;;i++) YF>m$?;
{ M,\:<kNI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )u`[6,d
//Utility.log(in.readLine()); z)r=+ -
sHeader=httpConnection.getHeaderFieldKey(i); YOmM=X+'H
if(sHeader!=null) I!Z_[M
{ -^hWM}F
if(sHeader.equals("Content-Length")) 7%|~>
{ P 'od`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^Xq 6:
break; x#xFh0CA
} GQUe!G9
} (<xfCH F5
else lHPd"3HDK
break; aGtf z)
} po2!
} Sp;G'*g
catch(IOException e){e.printStackTrace ();} OX?\<),
catch(Exception e){e.printStackTrace ();} 6"J? #
tnN.:%mZ
|es?;s'
Utility.log(nFileLength); eoG$.M"
ZJzt~ H
qGB{7-ru
return nFileLength; 7`zHX&-W
} RbP6F*f
_M`--.{\O[
QLvHQtzwX
//保存下载信息（文件指针位置） v,-HU&/*B
private void write_nPos() %^4CSh
{ !h23cj+V
try{ x7!L{(E3
output = new DataOutputStream(new FileOutputStream(tmpFile)); kwo3`b
output.writeInt(nStartPos.length); %InA+5s`
for(int i=0;i<nStartPos.length;i++) .*Ct bGw
{ -$cmG4
// output.writeLong(nPos); #*K}IBz
output.writeLong(fileSplitterFetch.nStartPos); 7byK{{/z
output.writeLong(fileSplitterFetch.nEndPos); z"-u95H
} 8pIP
output.close(); ?mFv0_!O
} =hC,@R>;
catch(IOException e){e.printStackTrace ();} IEsEdw]aZE
catch(Exception e){e.printStackTrace ();} -.u]GeMy
} bnq;)>&
DEG[Z7Ju
Zw5Ni Xj
//读取保存的下载信息（文件指针位置） dJeNbVd
private void read_nPos() `.~N4+SP
{ !;Yg/'vD-
try{ A+ZK4]xb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "GMBjT8
int nCount = input.readInt(); |:nOp(A\*
nStartPos = new long[nCount]; 1PVtxL?1P
nEndPos = new long[nCount]; CrC^1K
for(int i=0;i<nStartPos.length;i++) 9kN}c<o
{ A&.WH?p
nStartPos = input.readLong(); Fq~yL!#!
nEndPos = input.readLong(); %GjM(;Tk
} %p^wZtm
input.close(); F\JM\{&F
} g]<4&)~
catch(IOException e){e.printStackTrace ();} 591>rh)
catch(Exception e){e.printStackTrace ();} ^ =bu(L
} =9y[1t
E4`N-3
jSh5!6O
private void processErrorCode(int nErrorCode) Vwg|K|
{ 1an^1!
System.err.println("Error Code : " + nErrorCode); r?+%?$
} ck ]Do!h
>Wm`v.-
#I{h\x><?
//停止文件下载 @Lpq~ 1eZB
public void siteStop() mXRB7k
{ /\ y?Y
bStop = true; tvkb~
for(int i=0;i<nStartPos.length;i++) YIn',]p:
fileSplitterFetch.splitterStop(); 8##-EN;ag
iEVb"w059
C]O(T2l{l
} rHC>z7+z.
} 3 R=,1<
//负责部分文件的抓取 UldXYtGe
**FileSplitterFetch.java 5A)2} D]
*/ yh Yb'GK
package NetFox; wj*,U~syB
A;;fACF8e
r@72|:,
import java.io.*; L"E7#}
import java.net.*; p#ol*m5wE
(7mAt3n k
)JDs\fUE
public class FileSplitterFetch extends Thread { u!!Y=!y*<
`>7;!
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String sURL; //File URL o1-m1<ft
long nStartPos; //File Snippet Start Position TTeH`
long nEndPos; //File Snippet End Position 3C?f(J}
int nThreadID; //Thread's ID MuYk};f
boolean bDownOver = false; //Downing is over )#BMTKA^
boolean bStop = false; //Stop identical :=}US}H$
FileAccessI fileAccessI = null; //File Access interface nG,A@/N
~xA-V4.
<>dT64R|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3VsW@SG7N
{ bV(Y`g
this.sURL = sURL; G<At_YS
this.nStartPos = nStart; @E;=*9ek{u
this.nEndPos = nEnd; Y#!UPhg<
nThreadID = id; &R[ Mc-2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4~k\j
} 8e*,jH3
-9%:ilX~
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public void run() \.C+ue
{ Z8# (kmBdB
while(nStartPos < nEndPos && !bStop) SFB~ ->db
{ VeGL)
1_o],?Q
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try{ iWRH{mK
URL url = new URL(sURL); GS0;bI4ay
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a;rdQ>
httpConnection.setRequestProperty("User-Agent","NetFox"); b1^vd@(lx
String sProperty = "bytes="+nStartPos+"-"; JI?rL
httpConnection.setRequestProperty("RANGE",sProperty); ^M3~^lV
Utility.log(sProperty); DQNnNsP:M-
o]+z)5zC
~"!] 3C,L
InputStream input = httpConnection.getInputStream(); Wl;.%.]>
//logResponseHead(httpConnection); D!Q">6_"z
TkE 8D n
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byte[] b = new byte[1024]; vqnw#U4`
int nRead; {G|,\O1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +1Vjw'P
{ |M>eEE*F<
nStartPos += fileAccessI.write(b,0,nRead); `k=bL"T>\
//if(nThreadID == 1) wHsYF`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l]@&D#3ZM
} RSr %n1
&K[_J
&J55P]7w
Utility.log("Thread " + nThreadID + " is over!"); ji1viv
bDownOver = true; K)-U1JE7
//nPos = fileAccessI.write (b,0,nRead); =7-9[{
} ;6gDV`Twy
catch(Exception e){e.printStackTrace ();} -mC0+}h
} X- pqw~$
} 9!f/aI
wQv'8A_}
DamCF
//打印回应的头信息 FjK3 .>'
public void logResponseHead(HttpURLConnection con) Dakoqke
{ H70LhN
for(int i=1;;i++) ,%n\=
{ ~;Ov-^tp
String header=con.getHeaderFieldKey(i); BsBK@+ZyI
if(header!=null) wDcj,:h`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?bPRxR
Utility.log(header+" : "+con.getHeaderField(header)); EM]s/LD@%
else wkP#Z"A0~
break; i7]4W
} ,pqGX3
} kV?y0J.
W^fuScG)c
Ks=>K(V6
public void splitterStop() HuB<k3#sPy
{ :r%P.60H X
bStop = true; UH]l9Aq$P
} dOqOw M.y
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z."a.>fPaO
} , 3,gG"
pcau}5 .
5:O-tgig.
/* W)9K`hM6
**FileAccess.java }xBc0gr
*//文件访问(定位，写) eK.e|z|
package NetFox; /3;4#:Kkw
import java.io.*; Xg<*@4RD8
i%ZW3MrY~
TftHwe):V
public class FileAccessI implements Serializable{ HU%o6cw
XID<(HBA"!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 k9$K}
RandomAccessFile oSavedFile; h]og*(
long nPos; C3< m7h
x\F,SEj
K3m]%m2\
public FileAccessI() throws IOException uIcn{RZ_z
{ u`y><w4i
this("",0); wB.Nn/p
} NLS%Sq
/V8}eZ97
^\\Tx*#i
public FileAccessI(String sName,long nPos) throws IOException 1&^MfP}
{ /J04^6
oSavedFile = new RandomAccessFile(sName,"rw"); VUVaaOmO
this.nPos = nPos; D<8HZ%o
oSavedFile.seek(nPos); &C_'p{G
} A]YVs
4!+pc-}-
^&bRX4pYo
public synchronized int write(byte[] b,int nStart,int nLen) Xv<B1
{ fRy^Q_~,
int n = -1; hGd<<\
try{ .u:81I=w(
oSavedFile.write(b,nStart,nLen); N-I5X2
n = nLen; .mDM[e@'
} A;/-u<f
catch(IOException e) w4W_iaU
{ B*4}GPQ
e.printStackTrace (); v-yde>(
} Y2d;E.DH8
w;k):;$
si&S%4(
return n; tjGd )
} mjWU0Gh%*
66.5QD0
G 16!eDMt
} kqce[hgs<
2zVJvn7
ogL EtqT
/* M9y<t'
**SiteInfoBean.java ]4R[<<hd
*/ R,9[hNHWGs
package NetFox; z"+Mrew
M7ers|&{
Ga#:P F0
public class SiteInfoBean { S,<EEtXQ
TjQvAkT
TF 'U
private String sSiteURL; //Site's URL ]UH`Pdlt
private String sFilePath; //Saved File's Path n|b5? 3
private String sFileName; //Saved File's Name ZO4*sIw%
private int nSplitter; //Count of Splited Downloading File 6oLwfTy
O!Oumw,$
EhO|~A*R
public SiteInfoBean() |1ST=O7.LH
{//nSplitter的缺省值为5 ]8T |f
//default value of nSplitter is 5 VQ0fS!5'
this("","","",5); AX= 1b,s
} NzU,va N
zo[[>MA
+T=(6dr
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1j:Wh
{ zN{K5<7o
sSiteURL= sURL; ;Ra+=z}>
sFilePath = sPath; UTf9S>HS
sFileName = sName; 3,]gEE3
this.nSplitter = nSpiltter; Ya;9]k8,
`.T}=j|
d3W0-INL
} ~BDu$
`ORECg)
$Bj;D=d@V
public String getSSiteURL() 4#5:~M }
{ NvHJ3>"%
return sSiteURL; ^Ve<>b
} TYlbU<
o99pHW(E
59zENUYl
public void setSSiteURL(String value) jMbC Y07v
{ CBDG./
sSiteURL = value; m8SA6Y\
} RPIyO
ZxlAk+<]
cwm_nQKk
public String getSFilePath() vk>b#%1{
{ {q<03d~9|G
return sFilePath; uA$<\fnz
} 0vVV%,v
6<N5_1
Dk+&X-]6x5
public void setSFilePath(String value) Q2A7mGN
{ @JvPx0
sFilePath = value; &AlJ "N|
} "wlt> SU
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n.sbr
public String getSFileName() ,R$u?c0>'&
{ PG8^.)]M
return sFileName; 4;HJ;0-ps
} R(-<BtM!-
k^ YO%_
]c&<zeX,
public void setSFileName(String value) }hYZ" A~
{ 0QvT
sFileName = value; })w*m
} sP-^~ pp
w=|GJ0
%lX%8Z$v
public int getNSplitter() =CL} $_
{ s;1]tD
return nSplitter; p-%|P]&
} xr7+$:>a
h(qQsxIOhS
Y-'78BJk
public void setNSplitter(int nCount) &QG6!`fK}3
{ U:MPgtwe
nSplitter = nCount; n!6Z]\8~$
} wnTV|^Q
} % aUsOB-RV
,-+"^>
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/* Dfd-^N!
**Utility.java PyA&ZkX>
*/ g~BoFc.V2~
package NetFox; :L_BG)dM
p'sc0@}_O
2Bk$ lx7
public class Utility { l;sy0S"DO]
eUl/o1~mXa
_SACqamo5s
public Utility() "lNzGi-H
{ ^E6d`2w-
mR8W]'gl.L
- }!H3]tr
} )2DQ>cm
\([WH!7
//线程睡眠 +,50qN:%[
public static void sleep(int nSecond) WZ!WxX>zO
{ -[OXSaf6
try{ W>M~Sk$v
Thread.sleep(nSecond); \V2,pi8'v
} M=xQ=j?
catch(Exception e) Dml*T(WM>
{ s cdtWA
e.printStackTrace (); *2}O-e
} *n(> ^
} !3oKmL5
l{ex?
//日志 XT,#g-oi
public static void log(String sMsg) nK3k]gLc{
{ h{lDxOH*
System.err.println(sMsg); ?zq+jLyo
} D\^WXY5e%y
*QM~O'WhD
U-0#0}_
public static void log(int sMsg) ,jy*1Hjd
{ xx*2?i
System.err.println(sMsg); 8*g ^o\M
} oK+ WF
} /?"8-0d
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<-UOISyf
/* ?p[O%_Xf
**TestMethod.java 92dF`sv
*/ /T0nLp`gi
package NetFox; LF*Q!
~9D~7UR
'ul\Q`N3
public class TestMethod { SC#sax4N!=
+c206.
H L<s@kEZ
public TestMethod() S"snB/
{ ///xx/weblogic60b2_win.exe Gie@JX
try{ MM{_Ur7Q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); h3u1K>R)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [A~G-
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6R}j-1 <n
fileFetch.start(); $%c{06Oq(
} |bZM/U=
catch(Exception e){e.printStackTrace ();} H D/5!d
#y"=Cz=1u7
J/D|4fC
} CfT/R/L
`T!#@&+
8zQfY^/{M
public static void main(String[] args) I#A2)V0P)
{ NVIWWX9?
new TestMethod(); 2BB<mv K4
} +p:Y=>bTj
} {_ V0
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