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)); RtxAIMzh?
} ]SL+ZT
for(int i=0;i<nEndPos.length-1;i++) /:BC<]s
{ Uvi@HB HJ
nEndPos = nStartPos[i+1]; n>:e8KVM;
} qPUACuF'
nEndPos[nEndPos.length-1] = nFileLength; : 4lR`%
} cFJZ|Ld
} rW~G'
,If"4C!w
,,IK}
//启动子线程 'cIFbjJ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _U*1D*kLI[
for(int i=0;i<nStartPos.length;i++) 6 !fq658
{ N>P" $
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f4dHOH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), prIJjy-F
nStartPos,nEndPos,i); Oq3t-omXS
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !^1oH**
fileSplitterFetch.start(); @^-f+o
} }095U(@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ov\%*z2=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Q'ib7R;V,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Zw/??Tq b
nEndPos = " + nFileLength); {+kWK;1
// fileSplitterFetch[nPos.length-1].start(); L+lye Ir'
AGVipI #
aK,\e/Oo
//等待子线程结束 $SniQ
//int count = 0; >%_i#|dE>
//是否结束while循环 ]i `~J
boolean breakWhile = false; rXe+#`m2
eB,@oo%
Tn38]UL
while(!bStop) Nii5},
{ Ur""&@
write_nPos(); z!~{3M
Utility.sleep(500); }y*rO(cu7G
breakWhile = true; ?iaO6HD
Na.e1A&?j
[f$pq5f='
for(int i=0;i<nStartPos.length;i++) &mA{_|>
{ z^%`sUgP
if(!fileSplitterFetch.bDownOver) RcI0n"Gi_
{ %V!!S#W
breakWhile = false; :O;uP_r9
break; IY(;:#l
} SQuW`EHBgs
} RT9%E/m
if(breakWhile) j2n 4; m
break; 3}.OSt'=
!#WJ(zSq
X%B2xQM5
//count++; @XKVdtG
//if(count>4) 3);Wgh6
// siteStop(); Ftud6
} 'sI @es
f_QZql
HNfd[#gV
System.err.println("文件下载结束！"); GMob&0l8_
} )f%Q7
catch(Exception e){e.printStackTrace ();} l~*d0E-$
} Y3'dV)
Vt4,?"
2-"`%rE
//获得文件长度 w/CD-
public long getFileSize() 9v}vCg
{ %BRll
int nFileLength = -1; 6b4]dvl_
try{ L7.LFWq$S
URL url = new URL(siteInfoBean.getSSiteURL()); <>=abgg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); twPD'X!r
httpConnection.setRequestProperty("User-Agent","NetFox"); TiI3<.a!
.ldBl
piPV&ytI
int responseCode=httpConnection.getResponseCode(); Jqt|'G3
if(responseCode>=400) 8.' THLI
{ `SYq/6$VEH
processErrorCode(responseCode); 7)Bizlf
return -2; //-2 represent access is error I{u+=0^Y
} o7:"Sl2AD
^c>ROpic
AiV1 vD`
String sHeader; X,+N/nku
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"I[uD)$
for(int i=1;;i++) {_J1m&/
{ NUX2{8gs
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [\ppKC
//Utility.log(in.readLine()); JB!KOzw
sHeader=httpConnection.getHeaderFieldKey(i); 'jU;.vZex
if(sHeader!=null) \YF'qWB
{ fu`|@S
if(sHeader.equals("Content-Length")) brt`oR
{ Cqw`K P
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J`A )WsKkb
break; xgB-m[Xi
} 'C1yqkIa`
} xO'xZ%cUI
else j|(bdTZY:
break; `[.4SIah
} o}lA\A
} Ns`:=
catch(IOException e){e.printStackTrace ();} ^g N?Io
catch(Exception e){e.printStackTrace ();} s!K9-qZl<
)%(H'omvl
@)Sd3xw[
Utility.log(nFileLength); @>hXh +!2h
>U[YSsFt6
je~gk6}Y
return nFileLength; JztSP?
} T#R*]
<o&\/uO~H
qu0dWgK
//保存下载信息（文件指针位置） q8fnUK?i
private void write_nPos() G!m;J8#m(
{ `v1~nNoY
try{ ndB*^nT
output = new DataOutputStream(new FileOutputStream(tmpFile)); >U'gQS?\]
output.writeInt(nStartPos.length); ~px)Jd
for(int i=0;i<nStartPos.length;i++) WzO[-csy
{ V]A*' ke/
// output.writeLong(nPos); 1ba* U~OEg
output.writeLong(fileSplitterFetch.nStartPos); ?O#,|\v?]
output.writeLong(fileSplitterFetch.nEndPos); V']1j
} u-#J!Z<T8
output.close(); -Mufo.Jz1o
} a6.0$'
catch(IOException e){e.printStackTrace ();} PsoW:t
catch(Exception e){e.printStackTrace ();} Z <vTr6?
} 3gU*,K7
23[XmBf
C*,PH!$k
//读取保存的下载信息（文件指针位置） _8nT$!\\
private void read_nPos() +h?z7ZY^
{ _f~m&="T!
try{ e.pq6D5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i?pC[Ao-_
int nCount = input.readInt(); Z%O>|ozpq
nStartPos = new long[nCount]; wDS(zG
nEndPos = new long[nCount]; ( G#W6
for(int i=0;i<nStartPos.length;i++) ^6I8a"
{ Q?TXM1Bp
nStartPos = input.readLong(); ^B7C8YP
nEndPos = input.readLong(); P0^7hSo
} \KPwh]0
input.close(); )Aa h
} qx\P(dOUf
catch(IOException e){e.printStackTrace ();} *%`jcF
catch(Exception e){e.printStackTrace ();} Hs6}~d
} B#;0{
[}bPkD
7FD.3/
private void processErrorCode(int nErrorCode) p*S;4+>#
{ Z:s:NvFX
System.err.println("Error Code : " + nErrorCode); Pi:=0,"XOp
} xSoXf0zq:
`tZ`a
/QCyA%y
//停止文件下载 H@hHEzO
public void siteStop() Qp]-4%^Vz
{ 1brKs-z
bStop = true; ZRo-=/1
for(int i=0;i<nStartPos.length;i++) 2k3yf_N
fileSplitterFetch.splitterStop(); meNz0ve
+zn207.`
@&M$oI$4*
} O/2Jz
} i7(\i2_P
//负责部分文件的抓取 vAp?Zl?g
**FileSplitterFetch.java uA2-&smw
*/ f$^+;j
package NetFox; [?Ub =sp
j>t*k!db
-S%)2(f^
import java.io.*; *<nfA}
import java.net.*; v\?J$Hdd
Ffp<|2T2_
z ''-AH,
public class FileSplitterFetch extends Thread { SR\F2@u
P",E/beV
{Lm%zdk*k
String sURL; //File URL ;NzS;C'
long nStartPos; //File Snippet Start Position trC+Etc
long nEndPos; //File Snippet End Position y()Si\9v
int nThreadID; //Thread's ID E)7ODRVbl
boolean bDownOver = false; //Downing is over Co#_Cyxg=9
boolean bStop = false; //Stop identical #yVMC;J?W
FileAccessI fileAccessI = null; //File Access interface &BDdJwE
2r|!:^'?W
qEbzF#a-:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException k_<8SG+`
{ #XlE_XD
this.sURL = sURL; `2Oh0{x0*O
this.nStartPos = nStart; @UidQX"b
this.nEndPos = nEnd; {<3>^ o|"
nThreadID = id; ;Jrk#7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Yi+~}YP.E(
} ep3iI77/
]\t+zF>&Y
{Qla4U
public void run() #Qp.O@e
{ pD>^Dfd
while(nStartPos < nEndPos && !bStop) d@72z r
{ ^BFD -p
0fTEb%z8
!bi}9w
try{ 9k@`{+wmZ
URL url = new URL(sURL); on q~wEr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cOr@dUSL
httpConnection.setRequestProperty("User-Agent","NetFox"); SAEV "
String sProperty = "bytes="+nStartPos+"-"; 32sb$|eQq
httpConnection.setRequestProperty("RANGE",sProperty); KVrK:W--p
Utility.log(sProperty); mTW@E#)n
`1[GY){?)
bu2'JIDR
InputStream input = httpConnection.getInputStream(); t[ZumQ@HC
//logResponseHead(httpConnection); !F|iL
k5@_8Rc
dIR6dI
byte[] b = new byte[1024]; #`0iN+qh
int nRead; 7o4 vf~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rGe^$!QB
{ ^{W#ut>IN
nStartPos += fileAccessI.write(b,0,nRead); :tA|g
//if(nThreadID == 1) Um$a9S8b&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ymsqJ
} Mwdw7MZ"S
69v[*InSd
]cv|A^
Utility.log("Thread " + nThreadID + " is over!"); E+&]96*Lby
bDownOver = true; ewn/@;E
//nPos = fileAccessI.write (b,0,nRead); |UO1vA@
} 2.K"+%
catch(Exception e){e.printStackTrace ();} {mp;^/O`er
} H5N(MihT
} JqdNO:8
n>dM OQb
"p\XaClpz
//打印回应的头信息 >)N}V'9
public void logResponseHead(HttpURLConnection con) Lz VvUVk
{ RhJL`>W`
for(int i=1;;i++) 2,>q(M6,EA
{ qKL_1 ~
String header=con.getHeaderFieldKey(i); Hf/2KYZ
if(header!=null) lE54RX}e4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?ExfxR!~
Utility.log(header+" : "+con.getHeaderField(header)); \\D~Yg\#
else A*h)p@3t<
break; [^gSWU
} bz~-uHC
} _l?5GLl_F$
f-\l<o(
Zv=p0xH
public void splitterStop() ]'aGoR
{ -BV&u(
bStop = true; 7#,+Q(2
} (WW,]#^
"gCSbMq(Vq
B(MO!GNg=
} nDvny0^a
>NwrJSx
u%O^hcfb
/* fxLhVJ"b
**FileAccess.java `,(1'
*//文件访问(定位，写) %;9eh'
package NetFox; ZUyM:$
import java.io.*; zYOPE 6E
n20H{TA
e<^tY0rR&
public class FileAccessI implements Serializable{ 0nAeeVz|
Iw"?%k\U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }}qR~.[
RandomAccessFile oSavedFile; 8IC((
long nPos; >t8eVMMa
r/Pg,si
+V|]:{3W
public FileAccessI() throws IOException /$rS0@p
{ nWZrB s _
this("",0); YKh%`Y1<
} O)5-6lm
%!rsu-W:Y
Yb =8\<;
public FileAccessI(String sName,long nPos) throws IOException Pr<?E[
{ $zCUQthL@
oSavedFile = new RandomAccessFile(sName,"rw"); $)@zlnU
this.nPos = nPos; HIhoYSwB
oSavedFile.seek(nPos); >[xQUf,p
} I{cn ,,8
ecf7g)+C
rI]:| k
public synchronized int write(byte[] b,int nStart,int nLen) )KRO=~Y
{ q#\eL~k
int n = -1; 3F}d,aB A
try{ F{T|lTl
oSavedFile.write(b,nStart,nLen); 9/s-|jD
n = nLen; /gFyow1W
} 6}ax~wYct
catch(IOException e) uR"]w7=
{ +[2lS54"W4
e.printStackTrace (); 00pHnNoxW
} &U 'Ds!
g1J]z<&
f\(Kou$
return n; jv0e&rt
} >8NQ8i=]V1
5. l&nt'
q>omCk%h
} |J}~a8o
3\@6i'
[1vrv(u>
/* NM]6 o
**SiteInfoBean.java I3s}t$`y(
*/ 8'cDK[L
package NetFox; 3YT _GW{
'ZDa*9nkF
eB]ZnJ2^=
public class SiteInfoBean { E0oJ|My
^$#Q_Y|
ac&tpvij
private String sSiteURL; //Site's URL fCVSVn"o
private String sFilePath; //Saved File's Path 2dI:],7
private String sFileName; //Saved File's Name rz.`$b
private int nSplitter; //Count of Splited Downloading File \R#XSW,
q5RLIstQ\
4*dT|NU
public SiteInfoBean() 03#_ (
{//nSplitter的缺省值为5 pI^n("|
//default value of nSplitter is 5 WD)[Ac[
this("","","",5); Ql V:8:H$
} ]CL70+[^9
oD}I{&=wa
L|H{;r'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) z`_N|iEd
{ da<1,hF
sSiteURL= sURL; FP\[7?ZLn
sFilePath = sPath; g{a0,B/j
sFileName = sName; &`%C'KZ
this.nSplitter = nSpiltter; 1IsR}uLh
)i>KYg w
eX$Biv1N
} "{:*fI;!
_6[NYv$"
L`p[Dq.
public String getSSiteURL() 5s|gKM
{ Cv=0&S.
return sSiteURL; lubS{3<
} @rdC/=Y[
fAm2ls7c
lk'RWy"pw
public void setSSiteURL(String value) =Vv{td
{ ~>EVI=?
sSiteURL = value; SVHtv0Nx
} b13>>'BMB
#*`|}_6L
8_LDS
public String getSFilePath() r#j*vO '
{ ?:2Xh/8-
return sFilePath; uJ$"2<O
} SW=p5@Hy{
z(=:J_N
=wQ=`
public void setSFilePath(String value) %SE g(<
{ 04"hQt{[
sFilePath = value; GQQ!3LwP\O
} npF[J x[
f0uiNy(r$
^m7PXY
public String getSFileName() ,s)H%
{ ~E\CAZ
return sFileName; ^q6~xC,/
} +1y#=iM{
ZAP+jX;
~Mx fud
public void setSFileName(String value) p)ONw"sb
{ 8?$2;uGL
sFileName = value; nGt8u4gcP
} Zry>s0
7MfT~v
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public int getNSplitter() (!b: gG
{ c'6H@m#=
return nSplitter; 8+u8piG
} gM*s/,;O"
Vh<`MS0X
7~16letQ
public void setNSplitter(int nCount) a !IH-XJ2
{ ZUu^==a
nSplitter = nCount; W< n`[
} |);>wV"
} xEBjfn
Q^k#?j#
(gZ!o_
/* !2Orklzd1
**Utility.java /F_ :@#H
*/ JVkawkeX
package NetFox; sa`Yan
S|[UEU3FpB
GXfVjC31z
public class Utility { g{%';
UyQn onS
o;[oy#aWl_
public Utility() &0g,Xkr
{ g|P hNo
1@WGbORc*
82X.
} Y8PT`7gd`
R+K[/AA
//线程睡眠 #RF=a7&F
public static void sleep(int nSecond) Trrh`@R
{ gy{a+Wbc*
try{ @I&"P:E0F;
Thread.sleep(nSecond); =Wf@'~K0k"
} `T70FsSJ
catch(Exception e) QP#Wfk(C
{ #-;BU{3*
e.printStackTrace (); G DV-wPX
} L9T u>4
} {9Y'v
$<v_Vm?6d
//日志 z m'jk D|
public static void log(String sMsg) ! Cl/=0$[L
{ +2SX4Kxu
System.err.println(sMsg); Iqsk\2W]a3
} qC)VT3
L?0l1P
f[IchCwX
public static void log(int sMsg) +]-KzDsr"V
{ lIz_0rE
System.err.println(sMsg); 2An`{')
} Bt,Xe~$z-
} R~~rqvLm
=@2V#X]M*
#E9['JnZ
/* 'l|_$3
**TestMethod.java yr>bL"!CA
*/ ;X(n3F
package NetFox; ?_aR-[XRg
spJ(1F{|V
4*x!B![]y
public class TestMethod { Ct)MvZ
sh ;uKzQ
3ZlI$r(
public TestMethod() >K :"[?
{ ///xx/weblogic60b2_win.exe iI*7WO[W
try{ 8(>.^667
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QCR-lxO1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +,Az\aT/%
SiteFileFetch fileFetch = new SiteFileFetch(bean); |xVCl<{F%
fileFetch.start(); 86#mmm)
} 2JP?6N
catch(Exception e){e.printStackTrace ();} KeB4Pae|V
_m],(J=,z
)\-";?sYky
} (L$~zw5gr
|8 bO5l:
Wq(l :W'
public static void main(String[] args) C8EC?fSQ
{ /\rq$W_
new TestMethod(); <(4#4=ivP
} ,SF.@^o@a
} Eap/7U1Q
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