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)); ^]a#7/]o
} }0X:F`Y-
for(int i=0;i<nEndPos.length-1;i++) "0cID3A$
{ ek}a}.3 {
nEndPos = nStartPos[i+1]; Wu_kx2h
} 9)gC6IiW
nEndPos[nEndPos.length-1] = nFileLength; LG1r]2
} \8 h;K>=h
} eK!V );
IuRmEL_Q_
[ zEUH:9D
//启动子线程 )_i qAqkS
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?Vdia:
for(int i=0;i<nStartPos.length;i++) YGPy@-,E
{ 5wh|=**/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (C@~3!AVa
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), dOoKLry
nStartPos,nEndPos,i); -cSP_1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hijgF@
fileSplitterFetch.start(); GrAujc5|
} vOc 9ZE
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '_/Bp4i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fmiz,$O4?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", x>*Drm 7
nEndPos = " + nFileLength); qASqscO
// fileSplitterFetch[nPos.length-1].start(); uec!RKE
x\s|n{
m:WyuU<
//等待子线程结束 ,eZ1uBI?
//int count = 0; D*F4it.
//是否结束while循环 D6Goa(!9d
boolean breakWhile = false; eQD)$d_5
Y>EzTV
-!N&OZ+R
while(!bStop) 0Emr<n
{ q"<acqK
write_nPos(); F>-B3x
Utility.sleep(500); .G)(0z("s
breakWhile = true; -:Ia^{YN
'=G|Sq^aO
f/Hm{<BY
for(int i=0;i<nStartPos.length;i++) /`6ZAom9
{ "gne_Ye.
if(!fileSplitterFetch.bDownOver) g)_e]&
{ |*'cF-lp6v
breakWhile = false; MF'$~gxo
break; t$xY #:
} ghX|3lI\q
} krC{ed
if(breakWhile) Y<Xz wro0
break; r]l!WRn
W81E!RyP`
OZTPOz.
//count++; l#H#+*F
//if(count>4) E gal4
// siteStop(); ""1^k2fj
} CFqJ/''
p Wt) A
;+<&8.=,)
System.err.println("文件下载结束！"); 1!1beR]
} &b?LP]
catch(Exception e){e.printStackTrace ();} ALNc'MW!
} -Gw$#!
1QU:?_\6@t
<X7FMNr[
//获得文件长度 5K<5kHpvJ{
public long getFileSize() ni6{pK4Wqm
{ zSSB>D
int nFileLength = -1; ?I[8'
try{ .Y3pS/VI
URL url = new URL(siteInfoBean.getSSiteURL()); z(fAnn T?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +S R+x/?z
httpConnection.setRequestProperty("User-Agent","NetFox"); z[cyA.
f~dd3m('
@Q^P{
int responseCode=httpConnection.getResponseCode(); 9XRZ$j}L
if(responseCode>=400) N^pJS6cJkl
{ <oWB0%
processErrorCode(responseCode); DWID$w
return -2; //-2 represent access is error &/uu)v
} t@R ?Rgu3
-GqT7`:(H4
ltgc:&=|@
String sHeader; *r=:y{!Yd
%c [F;ug
BwBm[jtP
for(int i=1;;i++) YQpSlCCo 3
{ h~p>re
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7G\\{
//Utility.log(in.readLine()); )EL!D%<A
sHeader=httpConnection.getHeaderFieldKey(i); >layJt
if(sHeader!=null) +> WM[o^I
{ =Uj-^qcE
if(sHeader.equals("Content-Length")) "v`
{ zj/!In
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~5 *5
break; wQiX<)O
} #SX8=f`K5
} rN%F) q#
else 7hi"6,
break; AN24Sf'`
} K)-m*#H&uw
} xw3YK!$sIF
catch(IOException e){e.printStackTrace ();} 6X\ 2GC9
catch(Exception e){e.printStackTrace ();} 7\9>a
{qmdm`V[
o.'g]Q<}UB
Utility.log(nFileLength); L W;heO"
{O,{c\
Uv?|G%cD-
return nFileLength; sL@U
} sPpsq
V hk_
TzntO9P+
//保存下载信息（文件指针位置） 0%Z]h?EYy|
private void write_nPos() u&9 r2R959
{ ]\xy\\b/`
try{ ]_8qn'7
output = new DataOutputStream(new FileOutputStream(tmpFile)); i@B[ eta
output.writeInt(nStartPos.length); q-`RI*1]
for(int i=0;i<nStartPos.length;i++) KrXdnY8
{ Ai/b\:V9S
// output.writeLong(nPos); wo3wtx
output.writeLong(fileSplitterFetch.nStartPos); pFm=y#!t
output.writeLong(fileSplitterFetch.nEndPos); $ KRI'4
} y8 KX<2s1
output.close(); r.T<j.\
} c1_5, 1U'
catch(IOException e){e.printStackTrace ();} ;]w<&C!=
catch(Exception e){e.printStackTrace ();} ]a!xUg!S
} 1|?05<8
oXDN+4ge
J%jB?2 1:o
//读取保存的下载信息（文件指针位置） c= x,ijY "
private void read_nPos() qt3PXqR7:
{ %rF?dvb;?
try{ {XWZ<OjG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k~/>b~.c
int nCount = input.readInt(); UTSL
nStartPos = new long[nCount]; J8"[6vId~
nEndPos = new long[nCount]; 1=nUW":
for(int i=0;i<nStartPos.length;i++) 0V{(Ru.O
{ .(X lg-H,
nStartPos = input.readLong(); ]/!<PF
nEndPos = input.readLong(); 1$2D O
} X5]TY]
input.close(); \y88d4zX
} Fk6x<^Q<w
catch(IOException e){e.printStackTrace ();} 8UMFq
catch(Exception e){e.printStackTrace ();} *5wu
} e{A9r@p!
+MB!B9M@
[F*4EGB
private void processErrorCode(int nErrorCode) [ G e=kFB
{ s (0*
System.err.println("Error Code : " + nErrorCode); 1O!/g
} DEw8*MN
s%!`kWVJ.
/%I7Vc
//停止文件下载 V=X:=
public void siteStop() ; h`0ir4[A
{ qA:#iJ8w
bStop = true; O0:)X)b
for(int i=0;i<nStartPos.length;i++) ~-#yOu ,w
fileSplitterFetch.splitterStop(); k`{@pt.
yCXrVN:`,
O$g_@B0E1
} ZKz,|+X0G
} ?6k}ii!c
//负责部分文件的抓取 -@F fU2
**FileSplitterFetch.java `?y<>m*
*/ -3&G"hfK
package NetFox; M^7MU}5w
rFZrYm
`$YP<CJeq
import java.io.*; jr /lk
import java.net.*; $v`afd y
O Lc}_
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public class FileSplitterFetch extends Thread { jS!`2li?{
`' 153M]
s3 ;DG
String sURL; //File URL e*
long nStartPos; //File Snippet Start Position om3`[r[{
long nEndPos; //File Snippet End Position }%-t+Tf,
int nThreadID; //Thread's ID ;@nFVy>U
boolean bDownOver = false; //Downing is over $LHa?3
boolean bStop = false; //Stop identical ]O TH"*j
FileAccessI fileAccessI = null; //File Access interface G\;}w
TS"D]Txs
EQe5JFR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException E"|4Y(G
{ $2MAZGJV
this.sURL = sURL; '>k{tPi.
this.nStartPos = nStart; Dw2Q 'E
this.nEndPos = nEnd; \@~UDP]7
nThreadID = id; (5<^p&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ==H$zmK
} ZCVl5R(mZ
M|[ZpM+
W><dYy=z5
public void run() +-a&2J;J'
{ ,SScf98,j
while(nStartPos < nEndPos && !bStop) u=&Bmn_
{ D%7kBfCb
"GgK,d}%
0F)Y[{h<
try{ :o=[Zp~B4d
URL url = new URL(sURL); m"NZ;*d'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |nB2X;K5~
httpConnection.setRequestProperty("User-Agent","NetFox"); \DpXs[1
String sProperty = "bytes="+nStartPos+"-"; 8hGp?Ihu
httpConnection.setRequestProperty("RANGE",sProperty); u3Ua>A-
Utility.log(sProperty); &+u$96
x# 0(CcKK
GV* B$
InputStream input = httpConnection.getInputStream(); G=(F-U;*
//logResponseHead(httpConnection); rj<r6
*s<FEF
!|hv49!H
byte[] b = new byte[1024]; 2?#IwT'
int nRead; nJlrBf_Kj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rE EWCt
{ hQvSh\p
nStartPos += fileAccessI.write(b,0,nRead); "^yTH/m
//if(nThreadID == 1) g*TAaUs|n
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6;k#|-GU&
} $s$z"<
hC=9%u{r?
V07e29w
Utility.log("Thread " + nThreadID + " is over!"); '*|Wi}0R
bDownOver = true; 4l560Fb'U
//nPos = fileAccessI.write (b,0,nRead); L@XhgQ
} b&. o9PV"
catch(Exception e){e.printStackTrace ();} /X{:~*.z
} `XS6t)!ik
} UJ<eF/KSmG
~Qeyh^wo
+2!F6"hP
//打印回应的头信息 Tt<Ry'Z$3
public void logResponseHead(HttpURLConnection con) ](vOH#E
{ 1^TOTY
for(int i=1;;i++) .|;`qUo
{ x~rIr#o
String header=con.getHeaderFieldKey(i); }mzM'9JH
if(header!=null) tgKmCI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); TeSF
Utility.log(header+" : "+con.getHeaderField(header)); |/5j0
else HI*xk
break; |]w0ytL>(2
} {=VauF
} :%~+&qS
76(-!Z@=J
TU&gj1
public void splitterStop() 17 Hdj
{ q4C$-W%rj
bStop = true; HNu/b)-Rb
} <p;cR` %uE
t 5g@t0$
wK!4:]rhG
} 18jI6$DY
7;ZSeQyC
+pURF&Pr
/* p(fYpD
**FileAccess.java S;[9 hI+
*//文件访问(定位，写) (hEqh nnm`
package NetFox; ?kMG!stgp}
import java.io.*; iqW T<WY
Ew~piuj
bsO78a~=P
public class FileAccessI implements Serializable{ Ii_X^)IL(
fH-V!QYGF
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 BrcT`MM[(=
RandomAccessFile oSavedFile; I"eXoqh
long nPos; rZm|7A)i
h(*!s`1
{ AdPC?R`
public FileAccessI() throws IOException tG+ E'OP
{ )o-rg
this("",0); j?K]0j;
} `VM@-;@w
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,{!~rSq-l
public FileAccessI(String sName,long nPos) throws IOException Z<T%:F
{ /"Ws3.p
oSavedFile = new RandomAccessFile(sName,"rw"); q^ lx03
this.nPos = nPos; WB<_AIt+
oSavedFile.seek(nPos); ?]+{2&&$
} v0&E!4q*'
AX!YB'm-
g&I/b/A
public synchronized int write(byte[] b,int nStart,int nLen) [xXa3W
{ ="hh=x.5J
int n = -1; 8T6.Zhv
try{ bR"hl? &c
oSavedFile.write(b,nStart,nLen); p}_n :a
n = nLen; ~Q}JC3f>
} xFvDKW)_X7
catch(IOException e) 7m3|2Qv
{ T>,3V:X
e.printStackTrace (); +MU|XT_5|6
} aUUr&yf_L
;dgxeP;mp
# Un>g4>Rh
return n; 1D159NLB
} 3}V`]B#a
X;25G
IMjz#|c
} GAG=4g
QwPLy O
.4DX/~F
/* DdJ>1504
**SiteInfoBean.java Wm!lWQu7
*/ RQiGKz5
package NetFox; ,w&8 &wj
zG)XB*c
j}}:&>;
public class SiteInfoBean { |eH>55 b
e%.Xya#\
Hg$t,\j
private String sSiteURL; //Site's URL NGZEUtj
private String sFilePath; //Saved File's Path R+,eXjz"
private String sFileName; //Saved File's Name m:U.ao6
private int nSplitter; //Count of Splited Downloading File gw[\7
`@?f@p$(B
<,/k"Y=
public SiteInfoBean() 9ReH@5_bGM
{//nSplitter的缺省值为5 Sz4G,c
//default value of nSplitter is 5 g_'F(An
this("","","",5); r,F~Vwa}
} yM}b
R(_UR)G0 @
<Th)&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {v{qPYNyh
{ "f/91gIzm'
sSiteURL= sURL; }NX9"}/
sFilePath = sPath; n/*BK;
sFileName = sName; /Xa_Xg7
this.nSplitter = nSpiltter; ^Qrezl&
.u[hK
e_mUO"
} 7u8HcHl
c *<"&
44;ZX$HL
public String getSSiteURL() ` O;+N"v
{ X]up5tk~
return sSiteURL; ukM11LD5x
} 'wh2787
5m2`$y-nb
fT)u`voE,
public void setSSiteURL(String value) ia=eFWt.
{ i$MYR @
sSiteURL = value; Th1/Bxb:
} 15PFnk6E|
JBX#U@k>I
{|)u).n|
public String getSFilePath() }py6H[
{ 9e^HTUFbG
return sFilePath; $x_6 .AOZ,
} *]uo/g
ch2Qk8
H(f~B<7q
public void setSFilePath(String value) rzmd`)g
{ (pY'v/a-
sFilePath = value; w#V{'{DKp
} nT UKA
)nJo\HFXv
% H"A%
public String getSFileName() 1O" Mo
{ yL =*yC
return sFileName; -"*UICd
} YbS$D
r0 %WGMk2
A4!IbJD,0
public void setSFileName(String value) ^H]q[XFR
{ )C>4?)
sFileName = value; ^(,qkq'u D
} L0ZgxG3:g
%C&HR2
`LD#fg*
public int getNSplitter() WSA;p=_
{ P_:A%T
return nSplitter; dOm`p W^
} Z.9?u;
aDJ\%
ziFg+i%s
public void setNSplitter(int nCount) B^4D`0G[4
{ Yt^<^l77D
nSplitter = nCount; ym*,X@Qg^
} (#zSVtZ
} Rx';P/F0C
R7'a/
n<Vq@=9AE
/* WxNPAJ6YH
**Utility.java ?~G D^F
*/ _Ju@<V$
package NetFox; z'cK,psq(
I'"b3]DXG
Z<7FF}i
public class Utility { j@OGl&'^-
\5g7_3,3W
%;5AF8#c
public Utility() OyTEd5\3
{ lZyxJDZ A
t- Rp_2t
?Bg<74
} ` oBlv
REd"}zDI
//线程睡眠 ?QzA;8H
public static void sleep(int nSecond) Z#8O)GK
{ YyI4T/0s_
try{ b"`Vn,
Thread.sleep(nSecond); :mwNkT2et
} qw]:oh&G
catch(Exception e) T<!&6,N A
{ [c6I/U=-
e.printStackTrace (); yc|j]?
} eUiJl6^x
} )ZkQWiP-
x --buO
//日志 Q~/TqG U
public static void log(String sMsg) P\"|b\O1
{ Kv**(~FNnH
System.err.println(sMsg); WU}?8\?U%
} \Qa6mt2h
^QX3p,Y
WM8 Ce0E
public static void log(int sMsg) _)4YxmK%
{ t?[|oz:v
System.err.println(sMsg); [Tha j
} /.leY$
} 99T_y`df
nxzdg5A(w
C^uH]WO
/* P#`Mg@.
**TestMethod.java <8yv(
*/ +-=o16*{ !
package NetFox; p h[ ^ve
3U#z {%
\/8 I6a=
public class TestMethod { ]6wo]nV[P
eQBR*@x
I+ZK \?Rs
public TestMethod() I`%\ "bF@
{ ///xx/weblogic60b2_win.exe a<CN2e_Z
try{ 7%aaqQ1T
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #q2cVN1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); YyR)2j1O
SiteFileFetch fileFetch = new SiteFileFetch(bean); EC6&#)g;CO
fileFetch.start(); Lb# e
} #&+0hS
catch(Exception e){e.printStackTrace ();} 0>#or$:6E
x Bn+-V
Qz*!jwg
} H ]BH
Yh%a7K
zo*YPDEm"
public static void main(String[] args) %vPs38Fks
{ y#\jc4F_a
new TestMethod(); $Iuf(J-5[
} p"9a`/
} yRQR@
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