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)); 9U~sRj=D
} $|r p5D6
for(int i=0;i<nEndPos.length-1;i++) !x1ivP
{ s+XDtO
nEndPos = nStartPos[i+1]; hZNAI
} UqZ#mKi
nEndPos[nEndPos.length-1] = nFileLength; MuQ'L=iJ
} Yq0=4#_
} K44j-Ypb
9!|+GIjn
@mId{w z
//启动子线程 MyJG2C#R
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6pY<,7t0
for(int i=0;i<nStartPos.length;i++) wQ/Z:
{ 088"7 s
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u3@v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e&J_uG
nStartPos,nEndPos,i); qI#ow_lL#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uV+.(sjH
fileSplitterFetch.start(); %t<ba[9F
} UV8K$n<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), = ~^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MJ0UZxnl
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (YH/#n1"{
nEndPos = " + nFileLength); (GI]Uyn
// fileSplitterFetch[nPos.length-1].start(); Y+'522er
gtV*`g
3&z.m/
//等待子线程结束 rE&+fSBD
//int count = 0; >*cg K}!@
//是否结束while循环 =Frbhh57
boolean breakWhile = false; p$*;>YKO
zaoC
Wx-vWWx*Q
while(!bStop) eGh7,wngH
{ d65t"U
write_nPos(); hpOUz%
Utility.sleep(500); "[BDa}Il
breakWhile = true; ('VHL!
' 5%`[&
A/#Xr
for(int i=0;i<nStartPos.length;i++) sCE2 F_xjL
{ -!b@\=
if(!fileSplitterFetch.bDownOver) @CU~3Md*
{ y:3d`E4Xw
breakWhile = false; [Y=X^"PF
break; '4}c1F1T_
} <UMT:`h1MZ
} 37QXML
if(breakWhile) c/\$AJV.H
break; {IpIQ-@l
u t4+c0
ZT'Sw%U:
//count++; X0"f>.Lg
//if(count>4) hpVu
// siteStop(); 7yK1Q_XY>
} 8${Yu
`Ufv,_n
Vdz(\-}ao
System.err.println("文件下载结束！"); GxR, 3
} {BlKVsQ
catch(Exception e){e.printStackTrace ();} U\\nSU
} ,@'M'S
xFY< ns
~1yMw.04V
//获得文件长度 tuiQk=[c
public long getFileSize() !(wH}ti
{ 11Hf)]M
int nFileLength = -1; tSvklI
try{ =!cI@TI
URL url = new URL(siteInfoBean.getSSiteURL()); t|Ipxk.)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p!~{<s]
httpConnection.setRequestProperty("User-Agent","NetFox"); "=BO,see9
Y4B<]C4
%Fg}"=f1
int responseCode=httpConnection.getResponseCode(); g}]EIv{
if(responseCode>=400) XN=Cq*3}
{ U~w g'
processErrorCode(responseCode); MN22#G4j^w
return -2; //-2 represent access is error m*^|9*dIC
} ]O;Hlty(g
n_Ka+Y<
a}w%k
String sHeader; OLdD3OI
u70-HFI@
v8`)h<:W?
for(int i=1;;i++) "n3i(sZ
{ ;5.o;|w?!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6!3Jr
//Utility.log(in.readLine()); aumXidbS
sHeader=httpConnection.getHeaderFieldKey(i); o,sw[
if(sHeader!=null) T"GuE[?a
{ /@H2m\vBX
if(sHeader.equals("Content-Length")) joN}N}U
{ $.z~bmH"D
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +HK)A%QI
break; yeCR{{B/'
} <9s=K\-
} f2#9E+IQ
else R "&(Ae?LR
break; ($oO, c'z
} 4P>tGO&*x
} Uq,M\V\
catch(IOException e){e.printStackTrace ();} $pT%7jV}
catch(Exception e){e.printStackTrace ();} <}E^r_NvD
IFX|"3[$
] _/d
Utility.log(nFileLength); m7XJe[O
Qjj:r~l
Qn7l-:`?
return nFileLength; |m%M$^sZ}
} &E{5k{Y
6rnehv!p
@x@w<e%
//保存下载信息（文件指针位置） PSdH9ea
private void write_nPos() r]{fjw(~
{ mF>CH]k3
try{ FNDLqf!j
output = new DataOutputStream(new FileOutputStream(tmpFile)); sQA{[l!aj
output.writeInt(nStartPos.length); {1GW,T!#
for(int i=0;i<nStartPos.length;i++) %;0w2W
{ fxDY:l
// output.writeLong(nPos); 3_atv'I
output.writeLong(fileSplitterFetch.nStartPos); 4Pljyq:
output.writeLong(fileSplitterFetch.nEndPos); <(JsB'TK
} n/"T7Y\2
output.close(); 6Upg\(
} wE75HE`gW
catch(IOException e){e.printStackTrace ();} v`hv5wQ
catch(Exception e){e.printStackTrace ();} SPV'0* Z
} r2T?LO0N{
LoG@(g&)
=&fBmV
//读取保存的下载信息（文件指针位置） F_~-o,\
private void read_nPos() 33kI#45s
{ Yf:utCvv
try{ O#7ldF(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2t { Cpw
int nCount = input.readInt(); s8|#sHT
nStartPos = new long[nCount]; A*pihBo7
nEndPos = new long[nCount]; e>t9\vN#bx
for(int i=0;i<nStartPos.length;i++) N,ik&NIWy
{ FZ>*<&
nStartPos = input.readLong(); JMOP/]%D
nEndPos = input.readLong(); 7/vr!tbL`p
} ?E2k]y6<
input.close(); ^BM/K&7^
} %:o@IRTRU
catch(IOException e){e.printStackTrace ();} ](0Vm_es
catch(Exception e){e.printStackTrace ();} x#0C+cU
} 2al~`
>V(2Ke Y
) Q=G&
private void processErrorCode(int nErrorCode) GxZQ{ \
{ *vhm
System.err.println("Error Code : " + nErrorCode); LbR/it'}
} RQ,(?I*8\
>`NY[Mn
!E_uQ?/w]Z
//停止文件下载 z K8#gif@
public void siteStop() ~DZ;l/&Mz7
{ LO61J_J<
bStop = true; YLd 5
for(int i=0;i<nStartPos.length;i++) d L%E0o
fileSplitterFetch.splitterStop(); Xy*X4JJh^
\ b9,>
na']{a1K
} A?}OOjA
} k7{fkl9|#
//负责部分文件的抓取 ga^<_;5<
**FileSplitterFetch.java *gz{:}NX
*/ xN"KSQpu
package NetFox; \Di~DN1
<vt^=QA'
($(1KE
import java.io.*; *vAOUqX`x
import java.net.*; g&0GO:F`
4_.k Q"'DH
K[sM)_I
public class FileSplitterFetch extends Thread { ?XOeMI
T%a]3
j|G-9E
String sURL; //File URL 'fAD Dh}
long nStartPos; //File Snippet Start Position a3c4#'c|D
long nEndPos; //File Snippet End Position nnGA_7-t
int nThreadID; //Thread's ID .`'SL''c
boolean bDownOver = false; //Downing is over T4!]^_t^
boolean bStop = false; //Stop identical NuO>zAu
FileAccessI fileAccessI = null; //File Access interface <uTsXv
3X!~*_iC
$Qy(ed
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8]?1gDS|9O
{ 2FVKgyV
this.sURL = sURL; h5F'eur
this.nStartPos = nStart; }ZmdX^xB
this.nEndPos = nEnd; Y|VzeJC
nThreadID = id; (Z"Xp{u
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~$\j$/A8/
} 1UM]$$:i
.V.N^8(:a
d}o1 j
public void run() `f'q/
{ 78QFaN$
while(nStartPos < nEndPos && !bStop) oM7^h3R
{ |(P;2q4>
CLkVe
Z],"<[E
try{ _5m }g!
URL url = new URL(sURL); 8&UuwZ6i-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <aHt6s'
httpConnection.setRequestProperty("User-Agent","NetFox"); \34|9#*z-
String sProperty = "bytes="+nStartPos+"-"; 2@&|hd=-
httpConnection.setRequestProperty("RANGE",sProperty); nIi_4=Z
Utility.log(sProperty); QNJG}Upl
'9/kDkt!
%@&)t?/=
InputStream input = httpConnection.getInputStream(); Q~@8t"P
//logResponseHead(httpConnection); ?0(B;[xEJ
O^xt
nDOIE)#
byte[] b = new byte[1024]; oPbD9
int nRead; rODKM-7+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \fKE~61
{ `P5"5N\h
nStartPos += fileAccessI.write(b,0,nRead); .~U9*5d
//if(nThreadID == 1) LuqaGy}>-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IB6]Wj
} ;?o C=c
/< :;^B
"QF083$
Utility.log("Thread " + nThreadID + " is over!"); ;dFe >`~
bDownOver = true; VxFy[rP
//nPos = fileAccessI.write (b,0,nRead); ``<1Lo@
} ^"l$p,P+
catch(Exception e){e.printStackTrace ();} Qm.kXlsDI
} 0\#Q;Z2
} % *G)*n
lewDR"0Kx
'AAY!{>
//打印回应的头信息 f5a](&
public void logResponseHead(HttpURLConnection con) Xp~]kRm9
{ 9vbh5xX
for(int i=1;;i++) 7xc<vl#:q7
{ Xdq, =;
String header=con.getHeaderFieldKey(i); *YtNt5u
if(header!=null) B~NC
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~/U0S.C
Utility.log(header+" : "+con.getHeaderField(header)); dc>y7$2
else itF+6wv~
break; ?W n(ciO
} *02( J
} W*<]`U_.
<C$<(Dw5
jyGVbno`
public void splitterStop() 2 QmUg
{ ]p!J]YV ]0
bStop = true; i4I0oRp
} MP,*W}@
2jW>uk4/i
{Pb^Lf >
} Flxo%g};
`0^i #
*jK))|%
/* i-?zwVmn
**FileAccess.java @;6}xO2
*//文件访问(定位，写) cWc)sb
package NetFox; $P(nh'\
import java.io.*; #FB>}:L{h*
[!&k?.*;<
)!d1<p3
public class FileAccessI implements Serializable{ %d0S-.
aHC;p=RQ\A
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .e"Qv*[^
RandomAccessFile oSavedFile; (g m^o{
long nPos; X^Y9T`mQ}
^I{]Um:
kMl<
public FileAccessI() throws IOException $t$f1?
{ =.E(p)fz
this("",0); [bv@qBL
} 9@Sb! 9h
%20-^&zZ
n6G&^Oj
public FileAccessI(String sName,long nPos) throws IOException =BS'oBn^6
{ ;n!X% S<z*
oSavedFile = new RandomAccessFile(sName,"rw"); F?} *ovy
this.nPos = nPos; udGGDH
oSavedFile.seek(nPos); zt2-w/[Q
} g&TCff
z,|%? 1
rhTk}2@h
public synchronized int write(byte[] b,int nStart,int nLen) !|h2&tH
{ {,FeNf46
int n = -1; " B{0-H+
try{ 4p8jV*:@{
oSavedFile.write(b,nStart,nLen); f*vk1dS:*3
n = nLen; mzB#O;3=
} pqN[G=0
catch(IOException e) <88}+j
{ |u;BAb
e.printStackTrace (); )95yV;n
} 2U'JzE^Do
:5M}Iz7
M5kHD]b
return n; ^3|$wB=
} bM^A9BxD
\a2oM$PX
GFdJFQio
} sK-|xU.
jL+}F/~r
S1juAV=
/* hav?mnVJ
**SiteInfoBean.java 0^.4eX:E_
*/ +N$7=oGC
package NetFox; /v)!m&6]>
}r~l72 `
'Y{ux>
public class SiteInfoBean { wT~;tOw~
,DuZMGg
s<_LcQbt{
private String sSiteURL; //Site's URL [RFK-E
private String sFilePath; //Saved File's Path M(zY[O
private String sFileName; //Saved File's Name SE9u2Jk
private int nSplitter; //Count of Splited Downloading File qm8n7Z/
C.)&FW2F_
Bb[e[,ah
public SiteInfoBean() &9dr+o-(~
{//nSplitter的缺省值为5 y2"S\%7$h
//default value of nSplitter is 5 z!C4>,
this("","","",5); ^xw [d}0S
} e1^{
Gx_`|I{P
x";.gjI |g
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) a]Da`$T
{ uM)9b*Vbo
sSiteURL= sURL; n+\Cw`'<H
sFilePath = sPath; 1X"H6j[w
sFileName = sName; ^$+f3Z'
this.nSplitter = nSpiltter; |@L &yg,x
*_/eAi/WG
@EP{VV
} .cT$h?+jyl
*CY6 a
CDwIq>0j
public String getSSiteURL() '"]>`=R
{ 0?Tk*X
return sSiteURL; o%^k T&
} }Q r0T
2}`Vc{\
g1 Wtu*K3
public void setSSiteURL(String value) yp2'KES>
{ TQ\wHJ
sSiteURL = value; fFZ`rPb
} ,gL)~6!A
N 1f~K.e\
.H(}[eG_
public String getSFilePath() oF b mz*
{ _ U8OIXN
return sFilePath; Z_V&IQo-7
} gc2|V6(
vgQhdtt
OU.9 #|qU
public void setSFilePath(String value) fyg~KF}
{ &pMlt7
sFilePath = value; snTJe[^d
} IJ_'w[k
Pvg
}Cmj(k`~
public String getSFileName() g?A5'o&Yu
{ Sp`fh7d.(
return sFileName; iZ.&q 6
} kf^-m/
|Y8Mk2,s
0'%+X|
public void setSFileName(String value) cfC;eRgq~
{ g3|Y$/J7P
sFileName = value; ^E<~zO=Z
} )0n29
#}t1
M89-*1
public int getNSplitter() ?`T6CRZhr
{ >xU72l#5
return nSplitter; lN)Y
} vA2,&%jw
xu"94y+
0XR;5kd%
public void setNSplitter(int nCount) Wp7@
{ P$(WdVG
nSplitter = nCount; D,GPn%Wqi
} <r7qq$
} e"o6C\c
M\y~0uZ
HoIKx_
/* J:~[j
**Utility.java p-Rm,xyL%
*/ -VreBKn
package NetFox; 3lLW'g&=
XUQW;H
oieQ2>lYh
public class Utility { Y>78h2AU
BYr_Lz|T
J:g<RZZ1
public Utility() Z/NGv
{ 1C}pv{0:&
%2Xus9;k#
X]zCTY=l
} ')P2O\YS
j'#jnP*P
//线程睡眠 \'s$ZN$k
public static void sleep(int nSecond) xJ=ZQ)&]
{ _gPVmGG
try{ 8u:v:>D.'
Thread.sleep(nSecond); as\<nPT{Fj
} ^(dGO)/
catch(Exception e) E'&OOEMN-
{ nl)_`8=
e.printStackTrace (); "q9~C
} WIEx '{
} a%MzNH
@O}IrC!bf
//日志 $tDCS
public static void log(String sMsg) _XY`UZ
{ <K DH
System.err.println(sMsg); Nl=m'4@`
} ]=?X*,'
5T$9'5V7
0\\ueMj
public static void log(int sMsg) {2}tPT[a(
{ zqHpT^B?
System.err.println(sMsg); 629~Uc6]
} 9atjK4+o
} Z;j/K
||{T5E-.F
5YTb7M
/* zmy4tsmX
**TestMethod.java 0v_6cYA
*/ 8X}^~e
package NetFox; 45Nv_4s
g:3d<CS
msA' 5>
public class TestMethod { Ax5mP8S
iX8h2l
a' IX yj
public TestMethod() 71k!k&Im
{ ///xx/weblogic60b2_win.exe )CC?vV
try{ IZ4W_NN
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); H$NP1^5!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %+AS0 JhB
SiteFileFetch fileFetch = new SiteFileFetch(bean); T7>48eH
fileFetch.start(); +8LM~voB
} ,~?A,9?%:
catch(Exception e){e.printStackTrace ();} J-t=1
eVqM=%Q
MuDFdbtR
} io1S9a(y
\]Y\P~n
l 8O"w&
public static void main(String[] args) :3111}>c
{ -kG3k> by_
new TestMethod(); MxM](ew~7
} dIoF~8V
} l?3vNa FeR
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