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)); ,$]q2aL
} N93E;B
for(int i=0;i<nEndPos.length-1;i++) _tk5?9Ykn
{ vck$@3*
nEndPos = nStartPos[i+1]; ) G{v>Z,
} 3XnXQ/({
nEndPos[nEndPos.length-1] = nFileLength; UIl_&|
} TUaK:*x*
} [:QMnJ
(*RybKoaA
l(5-Cr
//启动子线程 ;Wa{q.)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &~%@QC/
for(int i=0;i<nStartPos.length;i++) N>R%0m<e
{ ie(7m|.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (<l2 ^H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), v'!Ntk
nStartPos,nEndPos,i); 3+-(;>>\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q]wM/7
fileSplitterFetch.start(); wuzz%9;@B
} XNUqZ-M:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RFJ;hh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); FZ9<Q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^kr)U8
nEndPos = " + nFileLength); W/>?1+r.Z
// fileSplitterFetch[nPos.length-1].start(); iy]}1((hR
$3TTHS o
i .N1Cvp&
//等待子线程结束 7fay:_
//int count = 0; $vBU}~l7
//是否结束while循环 (L>[,YO9
boolean breakWhile = false; UTQKlwPa
9+QrTO
5E!m! nBZ
while(!bStop) B`scuLl3
{ ]M(mq`K
write_nPos(); sZ"U=6R
Utility.sleep(500); [kOA+\v
breakWhile = true; /[? F1Q
~vGtNMQg
`z_7[$\~
for(int i=0;i<nStartPos.length;i++) EKPTDKut
{ ;J(,F:N
if(!fileSplitterFetch.bDownOver) rcZ SC3
{ eeU$uR
breakWhile = false; jw[BtRW
break; XKX,7
} 4Aew )
} n^\;*1%$c@
if(breakWhile) &=Zg0Q
break; />Vx*^u8Hz
HY4E
F2$bUY
//count++; <%D"eD
//if(count>4) X`n0b<
// siteStop(); b0b9#9x
} qffSq](D.
f_!`~`04
L~{Vt~H9"
System.err.println("文件下载结束！"); &H&P)Px*_
} k|3(dXLG
catch(Exception e){e.printStackTrace ();} o#P3lz
} {p|%hhTK%
/:` i%E
WKl'
//获得文件长度 kqW<e[
public long getFileSize() 6b70w @P!
{ huJq#5?
int nFileLength = -1; Sz|CreFK16
try{ +.]}f}Y
URL url = new URL(siteInfoBean.getSSiteURL()); G}#/`]o!K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +MZO%4
httpConnection.setRequestProperty("User-Agent","NetFox"); qW~R-g]
cIvYfgIo9
e=l5j"gq
int responseCode=httpConnection.getResponseCode(); ~H|LWCU)K8
if(responseCode>=400) RLz`aBT
{ ZQ9oZHUm
processErrorCode(responseCode); _S2^;n?
return -2; //-2 represent access is error h ^h-pd
} GR ?u?-
U|7Qw|I7
|3:=qpT-
String sHeader; 8I\eromG
$U1kP?pR
Ws*PMK.0
for(int i=1;;i++) < }wAP_y
{ n [Xzo}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ik5jwfz
//Utility.log(in.readLine()); s#4ew}
sHeader=httpConnection.getHeaderFieldKey(i); Zng` oFD
if(sHeader!=null) O;0<^M/0G
{ U`9\P2D`/
if(sHeader.equals("Content-Length")) GHJ=-9{YL
{ < mK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); '?G[T28
break; ,(0XsBL
} [k~+(.2I
} oT)VOkFq
else [du>ff
break; '<D`:srV
} B~;LBgpp
} `Kc %S^C'
catch(IOException e){e.printStackTrace ();} [Ht."VxR
catch(Exception e){e.printStackTrace ();} FPMSaN P
2Z`$
Uaj`
Utility.log(nFileLength); 2]NAs9aZ
+%#MrNM'
\8*,&ak%
return nFileLength; ,AbKxT f2
} :@>br+S
9U<)_E<y
SZ2q}[o`R
//保存下载信息（文件指针位置） }C{}oLz
private void write_nPos() Q)6wkY+!
{ d0A\#H_&
try{ \ ~LU 'j
output = new DataOutputStream(new FileOutputStream(tmpFile)); Iq0 #A5U%
output.writeInt(nStartPos.length); 9{%g-u\
for(int i=0;i<nStartPos.length;i++) L.0} UXd
{ :Q r7:$S^
// output.writeLong(nPos); P"=UI$HN
output.writeLong(fileSplitterFetch.nStartPos); bN4&\d*u#
output.writeLong(fileSplitterFetch.nEndPos); KBr5bcm4u
} Wt+y-ES
output.close(); LA+$_U"Jk
} 2rj/wakd
catch(IOException e){e.printStackTrace ();} R)d99j^"
catch(Exception e){e.printStackTrace ();} )qyx|D
} ~f=6?5.wa
dx13vZ3[U
g;-+7ViIr
//读取保存的下载信息（文件指针位置） G{f`K^
private void read_nPos() g2aT`=&Z
{ n.a=K2H:V
try{ nrS[7~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,dZ H$
int nCount = input.readInt(); (]}x[F9l
nStartPos = new long[nCount]; cPx~|,)l
nEndPos = new long[nCount]; \L9?69B~
for(int i=0;i<nStartPos.length;i++) V8nz-DL{
{ nG},v%
nStartPos = input.readLong(); :n+y/6*
nEndPos = input.readLong(); B15O,sL&W
} @7Rt4}g
input.close(); ?+ -/';
} FI`nRFq)C
catch(IOException e){e.printStackTrace ();} (pE\nuA\
catch(Exception e){e.printStackTrace ();} 7TV>6i+7
} %;<k(5bhGJ
J\xz^%p
ycrh5*g
private void processErrorCode(int nErrorCode) )'j_D<
{ )l!J$X+R
System.err.println("Error Code : " + nErrorCode); h{W$ fZc<
} Y|m_qB^_
qD(fYOX{C
rysP)e
//停止文件下载 )e|$K= D
public void siteStop() k+WO &g*|
{ *#Lsjk~_-
bStop = true; G>=9gSLM
for(int i=0;i<nStartPos.length;i++) s<Ex"+
fileSplitterFetch.splitterStop(); ReI=4Jq11
N?a1sdR
P&[Ft)`
} :jk)(=^
} ~{7zm"jN
//负责部分文件的抓取 'ZGT`'ri
**FileSplitterFetch.java hF{x')(#l
*/ jU]]:S4xD/
package NetFox; `P^u:
{k_ PMl0G
o%V @D'w
import java.io.*; [!J @a
import java.net.*; Q? <-`7
&TP:yA[
L,C? gd@"
public class FileSplitterFetch extends Thread { xta}4:d-Y
X+dR<GN+YX
;g: U[cE
String sURL; //File URL 'A@qg^e:`
long nStartPos; //File Snippet Start Position }g>dn
long nEndPos; //File Snippet End Position HF&h
int nThreadID; //Thread's ID KjFZ
boolean bDownOver = false; //Downing is over ig{A[7qN
boolean bStop = false; //Stop identical iUeV5cB
FileAccessI fileAccessI = null; //File Access interface --in+
C2+{U
?(5o@Xq
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U6c)"^\
{ gt =j5
this.sURL = sURL; XGE 2J
this.nStartPos = nStart; xb4Pt`x)rS
this.nEndPos = nEnd; ]> nPqL
nThreadID = id; |MTpU@`p5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ruZYehu1W
} uSABh^
pT("2:)x
V*6l6-y~Ih
public void run() l;XU#6{
{ $Cz1C
while(nStartPos < nEndPos && !bStop) 42b.7E
{ &u+yM D
0M$#95n
2wB.S_4"-<
try{ Mam8\
URL url = new URL(sURL); OD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vC{h2A
httpConnection.setRequestProperty("User-Agent","NetFox"); \ V[;t-
String sProperty = "bytes="+nStartPos+"-"; \@Ee9C13
httpConnection.setRequestProperty("RANGE",sProperty); p&i.)/
Utility.log(sProperty); J"%8:pL
%==G+S{
N7e`6d!
InputStream input = httpConnection.getInputStream(); ~gu=x&{
//logResponseHead(httpConnection); I*^5'N'
44\!PYf7
6N9 c<JC
byte[] b = new byte[1024]; b->eg 8|
int nRead; W*YxBn4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) lemVP'cn
{ pTcbq
nStartPos += fileAccessI.write(b,0,nRead); *-?Wcz
//if(nThreadID == 1) 3.Ji5~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Yuwc$Qp)
} 7#~4{rjg
|w=Ec#)t4
S-isL4D.Z
Utility.log("Thread " + nThreadID + " is over!"); gzVtxDh
bDownOver = true; S4L-/<s[*
//nPos = fileAccessI.write (b,0,nRead); DW1@<X
} <(fdHQD!7>
catch(Exception e){e.printStackTrace ();} Xl#Dw bx
} Wu4ot0SZ
} 25aNC;J
d2RnQA
SXQ@;=]xV
//打印回应的头信息 "Owct(9
public void logResponseHead(HttpURLConnection con) rVUUH!
{ 0yn[L3x7
for(int i=1;;i++) n%F-cw
{ py]KTRzy
String header=con.getHeaderFieldKey(i); lwVk(l Z
if(header!=null) i*X{^A73"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Y^QKp"
Utility.log(header+" : "+con.getHeaderField(header)); As0 B\
else E[S? b=^
break; Iha[Gu
} ;xfO16fNk
} 3FFaEl
(@+h5@J[`I
1hR (N
public void splitterStop() Y!Drb-U?;
{ -^yXLa;D
bStop = true; kB8 Mi
} N*Yy&[
2R~6<W+&:>
ndr)3tuYu
} s8^~NX(xdy
88 {1mA,v
fO6[!M(
/* xPt*CB
**FileAccess.java 7skljw(
*//文件访问(定位，写) ZT6V/MD7T.
package NetFox; 0x\2#i
import java.io.*; 7!pLK&_
(qUK7$
3 -tO;GKb
public class FileAccessI implements Serializable{ :V-k'hm &
69Nw/$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 80|onP\L
RandomAccessFile oSavedFile; [9OSpq
long nPos; (VyA6a8
8"x9#kyU<3
(_K_`5d;QI
public FileAccessI() throws IOException 6a*83G,k
{ kae2 73"
this("",0); ?mMW*ico
} vs+QbI6>-
-j&Vtr
.Rvf/-e
public FileAccessI(String sName,long nPos) throws IOException }S*/b1
{ ZZ("-#?
oSavedFile = new RandomAccessFile(sName,"rw"); #F!Kxks
this.nPos = nPos; fz3lR2~G
oSavedFile.seek(nPos); {(}yG_Q]!
} *hF^fxLbl
09d9S`cS\
<#y*h8IZ@t
public synchronized int write(byte[] b,int nStart,int nLen) wX0l?xdI
{ _8^0!,j
int n = -1; Q ]"jD#F
try{ =2%VZE7Vm
oSavedFile.write(b,nStart,nLen); $eBQH
n = nLen; v5T`K=qC
} \,R!S/R#
catch(IOException e) MU1E_"Z)
{ ;'}'5nO=$
e.printStackTrace (); !"E-\cc'
} (9]6bd
zT7"VbP
(~&w-w3
return n; BqB|Fo
} Ns<?b;aK
q jz3<`7-
d;=u
} !^iwQ55e2A
_{$fA6C
4&{!M _
/* &s8<6P7
**SiteInfoBean.java #byJqy&e
*/ ?v4E<iXs
package NetFox; K(VW%hV1
d2~l4IL)~
_R^y\1Qu
public class SiteInfoBean { ARF\fF|<2
1k[GuG%/K
6{=_718l`
private String sSiteURL; //Site's URL vk'rA{x
private String sFilePath; //Saved File's Path 8eJE>g1J
private String sFileName; //Saved File's Name ,q#2:b<E
private int nSplitter; //Count of Splited Downloading File l^W uS|G[
MQ`%``
HCj>,^<h
public SiteInfoBean() mI"D(bx\
{//nSplitter的缺省值为5 ` 1+%}}!$u
//default value of nSplitter is 5 VRbQdiZ{
this("","","",5); [b/o$zR
} Yw)Fbt^
-bS)=L
&RO7{,`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) '#D8*OP^
{ Y:psZ
sSiteURL= sURL; I^_NC&m
sFilePath = sPath; ()\jCNLT
sFileName = sName; 9I.^LZ"
this.nSplitter = nSpiltter; yMxTfR
TH4\HY9qa?
(0L=AxH
} 68e[:wf
"^Rv#
YQd:M%$
public String getSSiteURL() wL3,g2-L
{ $a(`ve|
return sSiteURL; 1~\M!SQ)
} |m;L?)F<
ER^QV(IvP8
>o/95xk2
public void setSSiteURL(String value) e |V]
{ %tmp
sSiteURL = value; (3;@^S4&w
} zzIr2so
~<)vKk
#xT!E:W'
public String getSFilePath() }x:f%Z5h
{ gXy-Mpzp
return sFilePath; gU;&$
} ss iokLE
V.=lGhi
b>11h
public void setSFilePath(String value) ;ME)Og
{ LFf`K)q
sFilePath = value; QyGnDomQ
} ;Vu5p#,O<M
RMP9y$~3pU
(9C<K<
public String getSFileName() Kat&U19YH
{ 42+#<U7T
return sFileName; A.En+-[\
} QDTNx!WL
Kq)MTlP0g
I#G0, &Gv
public void setSFileName(String value) Eu,`7iQ?(
{ pqR\>d0
sFileName = value; 3BQ!qO17^d
} Q5a)}6-5
yI3kvh
BRv x[u
public int getNSplitter() T .n4TmF
{ 1^G{tlA-
return nSplitter; eQDX:b
} 3EK9,:<Cf
u2iXJmM*
s'\$t
public void setNSplitter(int nCount) (gXN%rsY
{ Vba.uKNjk
nSplitter = nCount; (zcLx;N
} M(Zc^P}N
} I#rubAl
_$s> c!t,#
IV`%V+ f
/* D(]E/k@;~
**Utility.java & ,hr8
*/ YY5!_k
package NetFox; y~ rXl
`T&jPA9eY
z(13~38+
public class Utility { wvby?MhPY
z rfUQO
O7G"sT1Dv
public Utility() kcuzB+
{ 7h9U{4r: M
19UN*g3(
y1f:?L-z
} 1;F`c`0<
vVxD!EL
//线程睡眠 s1j{x&OSq
public static void sleep(int nSecond) g(E"4M@t!
{ t^tmz PWA
try{ gm"#:< )
Thread.sleep(nSecond); b #fTAC;<
} Ea $aUORm
catch(Exception e) (eWPis[
{ 23]Y<->Eu<
e.printStackTrace (); OFU/gaO~
} {KL5GowH
} , X{>
Zu*K-ep"
//日志 sW@krBxMv
public static void log(String sMsg) 6<76H
{ ~NcQ1.
System.err.println(sMsg); #]Y>KX2HG
} mN_Z7n;^eh
/RnTQ4
#FxPj-3(ix
public static void log(int sMsg) jM)C4ii.-$
{ <n"C,
System.err.println(sMsg); Nf41ZT~
} \;X+X,M
} 5\fCd|
zg)sd1@
x2Lq=zwJ
/* &HZmQ>!R D
**TestMethod.java RO(TvZ0pE
*/ D<$XyP
package NetFox; /iaf ^ >
C~% 1w%nn
~a9W3b4j
public class TestMethod { T1WWK'
*iA4:EIP
]e?x# <S
public TestMethod() -V.d?A4"
{ ///xx/weblogic60b2_win.exe !D^c3d
try{ `{v?6:G:Q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); BqK(DH^9N
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8jlLUG:g
SiteFileFetch fileFetch = new SiteFileFetch(bean); yY).mxRN
fileFetch.start(); ;E^K.6
} ZJW[?V\5=
catch(Exception e){e.printStackTrace ();} >/$Fh:R-
/#NYi,<{X
W!Gdf^Yy<
} (.Y/
rh*sbZ68>E
1Tp/MV/>
public static void main(String[] args) $g9**b@
{ oPf)be| #
new TestMethod(); KL,/2(
} _*M42<wcO
} g`^X#-!(
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