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)); p `oB._ R
} ,lCFe0>k!=
for(int i=0;i<nEndPos.length-1;i++) +c]D2@ctG
{ S~z$=IiB
nEndPos = nStartPos[i+1]; Y -BZV |
} KvPLA{
nEndPos[nEndPos.length-1] = nFileLength; H^B,b!5i
} xV`)?hEXFh
} hms Aim9i
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*.$ov<E.
//启动子线程 &j'k9C2p
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; kMzDmgoxNg
for(int i=0;i<nStartPos.length;i++) * kL>9
{ k_^ 4NU
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p8s%bPjK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }7%ol&<@
nStartPos,nEndPos,i); # NK{]H$fd
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |tY6+T}
fileSplitterFetch.start(); S:2 xm8 i
} ]t17= Lr?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1G(wESe
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2,|@a\H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", G'HLnx}Yi
nEndPos = " + nFileLength); GXv2B%i8
// fileSplitterFetch[nPos.length-1].start(); h52+f
Pa; *%7
Cx) N;x
//等待子线程结束 `x L@%
//int count = 0; 2mx }bj8
//是否结束while循环 &&}c R:U,
boolean breakWhile = false; Pqvj0zUo$
EO",|V-
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while(!bStop) S]&i<V1qX
{ Jx&+e,OST
write_nPos(); x41t=E](
Utility.sleep(500); "1P2`Ep;
breakWhile = true; _ -ec(w~/
(d <pxx
-%VFC^'5
for(int i=0;i<nStartPos.length;i++) k]TJL9Q
{ tJGPkeA
if(!fileSplitterFetch.bDownOver) N7s9"i
{ k[1[Y{n.
breakWhile = false; O1]XoUH<
break; 9 771D
} aO<H!hK
} cwUor}<|
if(breakWhile) !VfVpi+-
break; )pey7-P7g5
`AdHyE
ybB<AkYc
//count++; d?CU+=A&|
//if(count>4) DEv,!8
// siteStop(); }u5J<*:bZ
} 7w0=i Z>K
,.gI'YPQC
4x/u$Ixzh=
System.err.println("文件下载结束！"); H/G;hk
} 3bugVJ93
catch(Exception e){e.printStackTrace ();} )4+uM'2%
} ."q8 YaW
@6b;sv1W
6& 9q6IIy
//获得文件长度 ?N%5c%oF
public long getFileSize() mvtuV`
{ }4>#s$.2
int nFileLength = -1; Z\$!:
try{ 61TL]S8
URL url = new URL(siteInfoBean.getSSiteURL()); S7hfwu&7F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ! }awlv;
httpConnection.setRequestProperty("User-Agent","NetFox"); h/l?,7KHI
N4_V
W?@+LQa??
int responseCode=httpConnection.getResponseCode(); YGq-AB
if(responseCode>=400) tkix@Q!;\
{ 9+>%U~U<
processErrorCode(responseCode); KEr?&e
return -2; //-2 represent access is error k.F(*kh
} IZ_ B $mo
9l7 youZ]
Q[Tbdc%1EG
String sHeader; VqB9^qJ]!
&cx]7:;
w?c~be$
for(int i=1;;i++) 4_Rv}Yd
{ k1WyV_3
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]0p*EB=C*
//Utility.log(in.readLine()); 23UXOY0BW
sHeader=httpConnection.getHeaderFieldKey(i); vf_pEkx*wD
if(sHeader!=null) @]{:juD~
{ bNz2Uo!0K
if(sHeader.equals("Content-Length")) _ID =]NJ_
{ /^Lo@672
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,PyPRPk
break; 6HR*)*>z_
} ]h&?^L<.
} z:W1(/W~
else QjUojHz%Z
break; ;W#/;C _h
} '#8;bU
} 7)3cq}]O
catch(IOException e){e.printStackTrace ();} c6pGy%T-
catch(Exception e){e.printStackTrace ();} S4X['0rX!
7otqGE\2
["?WVXCF8|
Utility.log(nFileLength); fm,:8%
V=H}Ecd
2HvzMo-4
return nFileLength; OBp/:]
} %O&C\{J
p$%g$K
PYYO-Twg
//保存下载信息（文件指针位置） _:;j)J0
private void write_nPos() - e"XEot~
{ 1HNX6
try{ z0&I>PG^
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]r1C
output.writeInt(nStartPos.length); W.U|mNJ$
for(int i=0;i<nStartPos.length;i++) \~q cYp
{ o!t1EPJE*
// output.writeLong(nPos); -wV0Nv(V8
output.writeLong(fileSplitterFetch.nStartPos); wZUR
output.writeLong(fileSplitterFetch.nEndPos); 3H47 vm(`
} [ w1"
output.close(); \8X8NCM
} 32V,25 (`5
catch(IOException e){e.printStackTrace ();} FwGMrJW
catch(Exception e){e.printStackTrace ();} c'6$`nC
} F1o"H/:n
NBZ>xp[U
jk}m
//读取保存的下载信息（文件指针位置） #8jH_bi
private void read_nPos() >pl*2M&
{ oE4hGt5x{
try{ 7dU7cc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0=J69Yd
int nCount = input.readInt(); k-vxKrjZ/
nStartPos = new long[nCount]; ;R?9|:7
nEndPos = new long[nCount]; |tS~\_O/
for(int i=0;i<nStartPos.length;i++) r\66]u[
{ ?|9$o/Q}
nStartPos = input.readLong(); /L"&'~
nEndPos = input.readLong(); ;42D+q=s
} ;w}5:3+
input.close(); KBFAV&
} DWH)<\?
catch(IOException e){e.printStackTrace ();} Uyyw'Ni
catch(Exception e){e.printStackTrace ();} k||DcwO
} J#W>%2"s
&hYjQ&n
)Z 3fytY
private void processErrorCode(int nErrorCode) t|zLR
{ 6Gs,-Kb:
System.err.println("Error Code : " + nErrorCode); Cx/duodp
} ^5~[G%G4
S.OGLLprp
$T0|zPK5
//停止文件下载 $rC`)"t
public void siteStop() ]g;K_>@
{ W}1h~rNy
bStop = true; h@D4~(r
for(int i=0;i<nStartPos.length;i++) 9?W38EF
fileSplitterFetch.splitterStop(); ;nJCd1H
)FqE8oN-
-Q8pWtt
} 4[&6yHJ^
} ",rA
//负责部分文件的抓取 u$[T8UqF
**FileSplitterFetch.java ),6Z1 K1
*/ c$'UfW
package NetFox; *WgP+"h
{:enoV"
6A/|XwfE/v
import java.io.*; K~WwV8c9;
import java.net.*; Ja#idF[V
/qL&)24
qQ6NxhQo
public class FileSplitterFetch extends Thread { 9aC>gye!
|T"{q
\ca4X{x
String sURL; //File URL E%-&!%_>D@
long nStartPos; //File Snippet Start Position BWX&5""
long nEndPos; //File Snippet End Position <s#}`R.#2
int nThreadID; //Thread's ID ;@d<*
boolean bDownOver = false; //Downing is over ZdHWSfO)O
boolean bStop = false; //Stop identical 5y"yd6O]O5
FileAccessI fileAccessI = null; //File Access interface MJXm7<(
aV(*BE/@F
lv ^=g
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I/)dXk~
{ /HDX[R
this.sURL = sURL; {+t'XkA
this.nStartPos = nStart; ~ab"q%
this.nEndPos = nEnd; oci-[CI,
nThreadID = id; <ZrZSt+<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 M=N`&m\
} "5jZS6A]
sinG $=
l>&)_:\
public void run() a4: PufS
{ *G~c6BZ
while(nStartPos < nEndPos && !bStop) d*>M<6b-
{ n(f&uV_):
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:({lXGc}4?
try{ p-;]O~^
URL url = new URL(sURL); 65J'uN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x{ZVq 4
httpConnection.setRequestProperty("User-Agent","NetFox"); uX0wg
String sProperty = "bytes="+nStartPos+"-"; cdIy[ 1
httpConnection.setRequestProperty("RANGE",sProperty); xSOL4
Utility.log(sProperty); {@, L
@,aL'2G
$~~=SOd0
InputStream input = httpConnection.getInputStream(); 3.d=1|E
//logResponseHead(httpConnection); ,.}PZL
uV 6f~cQ
cW GU?cv}
byte[] b = new byte[1024]; 3iEcLhe"4
int nRead; ) L{Tn8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {U(h]'
{ $uLzC]
nStartPos += fileAccessI.write(b,0,nRead); tc,7yo\".
//if(nThreadID == 1) QX]tD4OH
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (I~,&aBr
} m#;:%.Rm
MA-$aN_(
"?9fL#8f*!
Utility.log("Thread " + nThreadID + " is over!"); $qrr]U
bDownOver = true; sy@k3wQ
//nPos = fileAccessI.write (b,0,nRead); Vd1K{rH#
} y?unI~4tC
catch(Exception e){e.printStackTrace ();} 7T2W%JT-,
} "+Qh,fTt
} #/jHnRrQ
q2<J`G(tZ
2.lnT{
//打印回应的头信息 F9+d7 Y$
public void logResponseHead(HttpURLConnection con) vo(?[[
{ X)&Z{ V>
for(int i=1;;i++) wRiP5U,
{ iN{TTy
String header=con.getHeaderFieldKey(i); h.Dk>H_G
if(header!=null) r?+u}uH
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `Ys })Pl
Utility.log(header+" : "+con.getHeaderField(header)); ~fUSmc
else R$3JbR.
break; p.}[!!m P
} p4AXQuOP
} e-K8K+7
q-3KF
<|`@K|N
public void splitterStop() RYhdf
{ Em]T.'y
bStop = true; !KlSw,&=.6
} CM#EA"9
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`i:0dVs
} 7lj-Z~1
7S7!
Y}#^n7*w~
/* f:Ja
**FileAccess.java 'q^Gg;c>+
*//文件访问(定位，写) D8#q.OR]
package NetFox; &Egn`QU
import java.io.*; %7@H7^s}9
jbGH3 L
E0hp%:
public class FileAccessI implements Serializable{ .5ycO
*h%G4M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 KN`z68c4L
RandomAccessFile oSavedFile; Q+Fw =Xw
long nPos; ppD~xg]
A X#!9-m3
U`Ag|R
public FileAccessI() throws IOException A-u5
{ =iQm_g
this("",0); 0EB'!
} X]*/]Xx
.0-m=3mp2
ykeUS zz2
public FileAccessI(String sName,long nPos) throws IOException H44&u](8{
{ ,+BgY4OY
oSavedFile = new RandomAccessFile(sName,"rw"); c>!J@[,
this.nPos = nPos; -:>#w`H
oSavedFile.seek(nPos); 7EO&:b]
} DnFl*T>
q{ 1U
}\{1`$*~
public synchronized int write(byte[] b,int nStart,int nLen) vTEkh0Ys
{ .%<&W1
int n = -1; 4~Pto f@
try{ Ft rw3OxN
oSavedFile.write(b,nStart,nLen); C941@I
n = nLen; 5gEfhZQ
} I}v#r8'!
catch(IOException e) h3IkOh4|h
{ `4q}D-'TF8
e.printStackTrace (); kZ}u
} PPO<{
g DG m32
NGs9Jke2
return n; oI~Qo*4eh
} zs:7!
j1C.#-P[
wg.fo:Q
} {wXN kq
$:N "*
|P7f^0idk
/* o)=VPUe
**SiteInfoBean.java EI.Pk>ZIm
*/ =*}Mymhk(
package NetFox; +|<&#b0Xd
aF"Z!HD
Hc%\9{zH
public class SiteInfoBean { =M#?*e
-b}S3<15@
X4G55]D$>
private String sSiteURL; //Site's URL %Nl(Y@dD*
private String sFilePath; //Saved File's Path 26VdRy{[
private String sFileName; //Saved File's Name 2H+DT-hK
private int nSplitter; //Count of Splited Downloading File :t S"sM
WGluY>C;
ee^_Dh4
public SiteInfoBean() :*'?Ac ?
{//nSplitter的缺省值为5 :+Ax3
//default value of nSplitter is 5 gtGKV
this("","","",5); aQ:f"0fL
} )o</gt)
z 2VCK@0
32LB*zc
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <&%1pZ/6.
{ %,cFX[D/)
sSiteURL= sURL; A<5`[<x$
sFilePath = sPath; yaLW(@
sFileName = sName; xBfe8lor
this.nSplitter = nSpiltter; LC\:xia{X
J8BT%
:_a]T-GL
} /B\-DP3K
tB=D&L3
4`P2FnJ?
public String getSSiteURL() O)JUY*&I5
{ gNN" H#=2
return sSiteURL; sg"D;b:X
} Z"|P(]A
9Pp|d"6]y
M6*{#Y?
public void setSSiteURL(String value) tZCe?n]
{ ~yH>Ko9F}
sSiteURL = value; [Um4\QvUx
} H!.D2J
%e7(HfW-U
L(n/uQ :
public String getSFilePath() kok^4VV
{ H"rzRd;S
return sFilePath; /+t[,
} &:I +]G/W
'b?.\Bm;
|z]2KjF&w-
public void setSFilePath(String value) n_n|^4w
{ @IY?DO
sFilePath = value; xhkWKB/7
} Rw\C0'
_+04M)q0
}t%>_
public String getSFileName() _d| 62VS
{ 7(~H77
return sFileName; kTZx-7~
} m?VRX.>
<h_P+ nz
:sVHY2x
public void setSFileName(String value) 'cF%4F
{ MhI)7jj`mt
sFileName = value; IqCCfsf4
} W_,;eyo
,ANK3n\
}t51U0b%
public int getNSplitter() l \^nC2
{ <VaMUm<2
return nSplitter; %|(?!w7
} {rvbo1t
t0J5v;
LJ(n?/z%
public void setNSplitter(int nCount) 6=,#9C9
{ V9E6W*IE
nSplitter = nCount; Lkl|4L
} 1.0!H.>q
} }S vw,c
.y7)XLC
"?SOBA!vy
/* U7"BlT!V\
**Utility.java H : T N
*/ xeHb89GnoQ
package NetFox; F%#*U82
!-5S8b
3K#mF7)a
public class Utility { IjDT'p_
crNjI`%tw
_MdZDhtm
public Utility() xEiX<lguyN
{ Sc'c$/
II-$WJy
B8UZ9I$n
} 27a*H1iQ
m@Ip^]9ry
//线程睡眠 fNqmTRu
public static void sleep(int nSecond) 7SK3
{ P*SCHe'
try{ (H8C\%g:
Thread.sleep(nSecond); 1O9p YW5J
} qqe2,X?
catch(Exception e) o3F|#op
{ R#/?AD&
e.printStackTrace (); e$Bf[F#;-
} :6W^ S/pf
} {M@@)27gW
kPO6gdwq$
//日志 `.>k)=F&
public static void log(String sMsg) L%WME8PB
{ afY_9g!\
System.err.println(sMsg); *^D@l%av;
} |}M0,AS
SH vaV[C
;vJ\]T ml
public static void log(int sMsg) 2Io6s'
{ v\%B
System.err.println(sMsg); o9ctJf=qn
} %GX uuE}mX
} RVkU+7
';b3Mm #
Z cm<Fw
/* JY2/YDJ
**TestMethod.java }Kj Ju;
*/ W-z90k4Z5
package NetFox; zj>aaY
*#1y6^
tyEPU^PM
public class TestMethod { I/On3"U%
SE^j=1
c~^CKgr~R9
public TestMethod() H|;*_
{ ///xx/weblogic60b2_win.exe 5{13V*<
try{ <&5m N
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }!%JYG^!D
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C,A!tj7@
SiteFileFetch fileFetch = new SiteFileFetch(bean); &|.hkR2k
fileFetch.start(); E dn[cH7
} yB,{#nM>8
catch(Exception e){e.printStackTrace ();} FxCZRo&
PS=e\(6QC
#wenX$UTh3
} UvxSMD:A
'qL5$zG
!K3})& w
public static void main(String[] args) r{\BbUnf)
{ ?;|@T ty%
new TestMethod(); wG1y,u'
} ;} lT
} KVB0IXZC~
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