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)); v,D_^?]@
} (Wx)YI
for(int i=0;i<nEndPos.length-1;i++) mlVv3mVyR<
{ ]UgAz
nEndPos = nStartPos[i+1]; }MIH{CMH
} VBH[aIW
nEndPos[nEndPos.length-1] = nFileLength; ~HYP:6f
} .\d0lJSr
} QIV<!SO
1)YFEU&]
rmabm\QY
//启动子线程 <`r+l5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9Np0<e3p
for(int i=0;i<nStartPos.length;i++) :?UIyN?
{ J,D{dYLDD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9~; Ju^b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), iit`'}+U
nStartPos,nEndPos,i); (Dl"s`UH~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z5vryhX_Z
fileSplitterFetch.start(); Hug{9Hr3.
} qXhrK /
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e{}o:r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); c|.:J]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (mD]}{>
nEndPos = " + nFileLength); rL s6MY
// fileSplitterFetch[nPos.length-1].start(); A;|DQR()
E, v1F!
7 %|>7
//等待子线程结束 ZF t^q/pw
//int count = 0; X<QE]RZ
//是否结束while循环 z8!u6odu %
boolean breakWhile = false; B.G!7>=
+,-rb
R:xmcUq} (
while(!bStop) QVH_B+ Q
{ 6wd]X-G++
write_nPos(); 4bBxZY
Utility.sleep(500); Y{yr-E #~M
breakWhile = true; m2! 7M%]GC
sWC"^ So
6,)y{/ENC
for(int i=0;i<nStartPos.length;i++) c[y8"M5
{ %OtW\T=u
if(!fileSplitterFetch.bDownOver) m#ie{u^
{ :kVV.a#g
breakWhile = false; A;!FtD/
break; %aKkk)s
} 5ZcnZlOOQ
} y|dXxd9
if(breakWhile) UBVb#FNF
break; _UBI,Dg]
>gZz`CH
p~.@8r(
//count++; PsgzDhRv
//if(count>4) ~ YK<T+
// siteStop(); [:QMnJ
} ?R(3O1,v^
Tpukz_F
injmP9ed
System.err.println("文件下载结束！"); )^\='(s
} #$w#"Nr9k
catch(Exception e){e.printStackTrace ();} kOCxIJ!Xp=
} wuzz%9;@B
\uk#pL
?6QJP|kE
//获得文件长度 Oi0;.<kX
public long getFileSize() IR LPUP
{ `X='g96C1
int nFileLength = -1; 0 MIMs#
try{ B@]7eVo
URL url = new URL(siteInfoBean.getSSiteURL()); m-89nOls
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &-fx=gq=
httpConnection.setRequestProperty("User-Agent","NetFox"); 9oP{Al
H/k W :k
@vYmkF`
int responseCode=httpConnection.getResponseCode(); ~TH5>``;gF
if(responseCode>=400) Qu,k
{ z#VpS=
processErrorCode(responseCode); 9|?Lz
return -2; //-2 represent access is error &=Zg0Q
} = Y-Ne6a
ZZU8B?)
5j,qAay9
String sHeader; cN7z(I0[
U"+ ry.3`
4nH91Z9=
for(int i=1;;i++) 5%+}rSn7
{ 8 tygs
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); B bw1k
//Utility.log(in.readLine()); NNwd;AC
sHeader=httpConnection.getHeaderFieldKey(i); Kk>qgi$
if(sHeader!=null) I#X2UQzP
{ )v=G}j^
if(sHeader.equals("Content-Length")) 4E-A@FR
{ $p3Wjf:bH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); fq'Xy9L
break; g]<Z]R`
} KVM@//:{
} "&#WMi
else %lJiM`a
break; D}/=\J/
} Ws*PMK.0
} Rca Os
catch(IOException e){e.printStackTrace ();} ]cqZ!4?_
catch(Exception e){e.printStackTrace ();} g1wI/
o9LD6$
U`9\P2D`/
Utility.log(nFileLength); ]jVSsSv
'?G[T28
LAY)">*49H
return nFileLength; Z!-<rajl
} )fMX!#KP
DV[ Jbl:)
q9brpbg_
//保存下载信息（文件指针位置） {,f!'i&b@
private void write_nPos() "56?/ jF
{ qi SEnRG.
try{ =3sldKL&F
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^s@*ISY
output.writeInt(nStartPos.length); j t`p<gI
for(int i=0;i<nStartPos.length;i++) UI<PNQvo9
{ # 5f|1O
// output.writeLong(nPos); Ef`5fgp? S
output.writeLong(fileSplitterFetch.nStartPos); "T a9
output.writeLong(fileSplitterFetch.nEndPos); -hVv
} ,-7/]h,l
output.close(); Jh&~/ntmm_
} ?]\W8)
catch(IOException e){e.printStackTrace ();} 9O=05CQ
catch(Exception e){e.printStackTrace ();} 4ljvoJ}xjr
} dx13vZ3[U
zK>'tFU
w{r(F`
//读取保存的下载信息（文件指针位置） =tf@4_
private void read_nPos() *K}z@a_
{ /G)KkBC
try{ #U$YZ#B
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5"}y\
int nCount = input.readInt(); Pv7f _hw
nStartPos = new long[nCount]; ?+ -/';
nEndPos = new long[nCount]; {V%%^Zhwy
for(int i=0;i<nStartPos.length;i++) 8tV=fSHd
{ t*Vao
nStartPos = input.readLong(); npO@Haw
nEndPos = input.readLong(); 1=/doo{^
} hB P$9GR
input.close(); E?Qz/*'zv
} -t%{"y
catch(IOException e){e.printStackTrace ();} k+WO &g*|
catch(Exception e){e.printStackTrace ();} &h7smZO5j
} Ok}{jwJ%W;
5U-p'c9IC
N"YK@)*Q
private void processErrorCode(int nErrorCode) ;!l*7}5X=
{ DMAf^.,S
System.err.println("Error Code : " + nErrorCode); yN9$gfJC^
} #.E\,N'
o%V @D'w
OX)#F'Sl}
//停止文件下载 R<n8M"B
public void siteStop() u[V4OU}%
{ X+dR<GN+YX
bStop = true; _=|nOj39
for(int i=0;i<nStartPos.length;i++) 6\,DnO
fileSplitterFetch.splitterStop(); 9tzoris[~
:LZ-da"QR
Bmx(qE
} -Q<z1vz
} $i,6B9
//负责部分文件的抓取 j>$=SMc
**FileSplitterFetch.java yxaT7Oqh%
*/ ]> nPqL
package NetFox; IvEMg2f}
Y%78>-2L
Zz"I.$$[M
import java.io.*; aL8p"iSG9
import java.net.*; .abyYVrN4?
snXB`UC
2wB.S_4"-<
public class FileSplitterFetch extends Thread { ZhhI@_sz
BCBEX&0hk{
Q=d.y&4%
String sURL; //File URL OZ(Dpx(Q
long nStartPos; //File Snippet Start Position SQh+5
long nEndPos; //File Snippet End Position %*$5!;
int nThreadID; //Thread's ID !OPSSP]-
boolean bDownOver = false; //Downing is over ;M}itM
boolean bStop = false; //Stop identical P7's8KOoS
FileAccessI fileAccessI = null; //File Access interface *-?Wcz
f'1(y\_fb
}czsa_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ctp?y
{ "Z;~Y=hC13
this.sURL = sURL; }TSgAwsbC
this.nStartPos = nStart; MQwIPjk8
this.nEndPos = nEnd; PXV)NC
nThreadID = id; JT4wb]kdV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qOW#Q:T
} 3Bejp+xX
X6Un;UL
$[[?;g
public void run() @'*eC}\E
{ 2$M,*Dnr
while(nStartPos < nEndPos && !bStop) `q%U{IR
{ q<n[.u1@
v9u<F6
YnSbw3U.I
try{ &B}Lo
URL url = new URL(sURL); B1E$v(P3M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @!e~G'j%VD
httpConnection.setRequestProperty("User-Agent","NetFox"); Vr 8:nP:
String sProperty = "bytes="+nStartPos+"-"; `AR"!X
httpConnection.setRequestProperty("RANGE",sProperty); yk<VlS
Utility.log(sProperty); im8 -7Xt
tmp6hB
0mTEim
InputStream input = httpConnection.getInputStream(); =ai2z2z
//logResponseHead(httpConnection); 69Nw/$
S`=n&'
6JSY56v
byte[] b = new byte[1024]; \]I
int nRead; b4CF`BG
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Tp?-*K
{ '99@=3AB:`
nStartPos += fileAccessI.write(b,0,nRead); -^Xy%
//if(nThreadID == 1) 'G8 ?'u_)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {SJsA)9:#
} #F!Kxks
T^]7R4Fg
*hF^fxLbl
Utility.log("Thread " + nThreadID + " is over!"); qEQAn/&
bDownOver = true; MWs~#ReZ
//nPos = fileAccessI.write (b,0,nRead); +< yhcSSTB
} 7Lg7ei2mN7
catch(Exception e){e.printStackTrace ();} C',6%6P
} 0 _A23.Y
} "]#'QuR
-w]/7cH
IE;\7r+h
//打印回应的头信息 J=iRul^S
public void logResponseHead(HttpURLConnection con) .*Vkua
{ rLzW`
for(int i=1;;i++) WL U}
{ tuxRVV8l
String header=con.getHeaderFieldKey(i); b9uBdo@o
if(header!=null) ]JdJe6`Mc
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6{=_718l`
Utility.log(header+" : "+con.getHeaderField(header)); jXp. qK\"
else 514Z<omrK
break; Uw)=WImz[
} ]-:6T0JuS
} ^m%52Tm h
{<K=*rrZ
Yw)Fbt^
public void splitterStop() f*m[|0qI<X
{ 3v1 7"
bStop = true; o=_c2m
} 0%<+J;'o
qTM%G-
3-|3`(
} /t5p-
S^N{wZo
OlY$v@|
/* 89HsPB1"t
**FileAccess.java {^mKvc
*//文件访问(定位，写) {C")#m-0
package NetFox; %tmp
import java.io.*; ;>>C)c4V"
#xT!E:W'
KX4],B5 +
public class FileAccessI implements Serializable{ |=K_F3aJ
b>11h
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8-Me.2K
RandomAccessFile oSavedFile; Ig \#f
long nPos; +Xy*?5E;C
&<]<a_pw
R_N:#K.M
public FileAccessI() throws IOException :O-1rD
{ )T|L,Lp
this("",0); z|N3G E(.@
} :50b8
v }\,o%t^
d@ Ja}`
public FileAccessI(String sName,long nPos) throws IOException GP a`e
{ :iUF7P1I
oSavedFile = new RandomAccessFile(sName,"rw"); #hw>tA6
this.nPos = nPos; eu#'SXSC F
oSavedFile.seek(nPos); (zcLx;N
} ae+*=,
",Cr,;]
3tAU?sV!
public synchronized int write(byte[] b,int nStart,int nLen) j/!H$0PN
{ R 94^4I
int n = -1; (u1m]WYL
try{ K8I$]M
oSavedFile.write(b,nStart,nLen); l.+yn91%>
n = nLen; vbG]mMJ
} ~AB*]Us
catch(IOException e) :iF%cy.
{ I]`-|Q E
e.printStackTrace (); * ?Jz2[B
} gm"#:< )
0<p{BL8
9jir*UI
return n; j+IrqPKC^
} 8V/L:h#7
Zu*K-ep"
Cb;WZ3HR
} F7*wQ{~
aHzHvl
+-?/e-z")
/* e^1uVN
**SiteInfoBean.java RP4Ku9hk
*/ \;X+X,M
package NetFox; V ~{fB~
Cfu=u *u
muON>^MbC
public class SiteInfoBean { Xd `vDgD
l@Z6do
k?GD/$1t
private String sSiteURL; //Site's URL *iA4:EIP
private String sFilePath; //Saved File's Path yR5XJ;Tct
private String sFileName; //Saved File's Name c3%@Wj:fo
private int nSplitter; //Count of Splited Downloading File JYb}Zw;
^Q<mV*~
(5L-G{4
public SiteInfoBean() ,5 j"ruZ
{//nSplitter的缺省值为5 @@G6p($
//default value of nSplitter is 5 &DG->$&|
this("","","",5); (rtY!<|p
} 2S[-$9
da!P0x9p
OHrY(I6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &<TzGB*
{ & WOiik
sSiteURL= sURL; `mfq 2bVc
sFilePath = sPath; DE$q+j0P
sFileName = sName; yM.IxpT#$
this.nSplitter = nSpiltter; =<@2#E)
YUU-D(
#FOqP!p.E
} D1 Z{W
B_`y|sn
N7r_77%m0
public String getSSiteURL() O)|P,?
{ f>o,N{|
return sSiteURL; O43YY2
} :,12")N
%VJ85^B3
uP3_FX: e
public void setSSiteURL(String value) ,fDEz9-,
{ b3-eR5U/
sSiteURL = value; n%^ LPD
} Di_2Plo)4
moj]j`P5a
rPNb\Ri
public String getSFilePath() +6$g!S5{
{ dCe4u<so\
return sFilePath; V"o7jsFH6n
} @oF$LMD
V3;.{0k
5Z/GK2[HL
public void setSFilePath(String value) 6Tw#^;q-
{ 1 2++RkL#
sFilePath = value; /v|"0
} @$"J|s3M
SKuIF*"!S
jCAC `
public String getSFileName() ev0oO+u
{ iI@jZVk
return sFileName; FsB^CxVg
} L9Z;:``p
#*$P'r
X{n- N5*
public void setSFileName(String value) P7ph}mB
{ R3)57OyV
sFileName = value; \;-fi.Hrf$
} 93+"D`
zl-2$}<a
R+q"_90_
public int getNSplitter() IEjP<pLe
{ ML-)I&>tT
return nSplitter; & gJV{V5Ay
} M<SdPC(+
,P'P^0qJ
F62V3 Xy
public void setNSplitter(int nCount) uPYmHA}_/
{ _LAS~x7,
nSplitter = nCount; ihh4pD27g
} 4k/VBZB
} PiV7*F4qI.
Ftw;Yz
L-pVltX
/* Q'+MFld
**Utility.java R1F5-#?'E
*/ |9"p|6G?B
package NetFox; Eh-n
9_\'LJ
8ul&x~2;X
public class Utility { ze_{=Cv&Y
,D\GGRw
O8|5KpXd@
public Utility() fgNU03jp^x
{ pA{ 5V9
^qCkt1C-M
&U+ _ -Ph
} ^8 ' sib
h/x0]@M&
//线程睡眠 th6+2&B6
public static void sleep(int nSecond) H$af/^
{ @ S<-d
try{ yNm:[bOER
Thread.sleep(nSecond); V{|}}b?w?
} :Rs^0F8)c
catch(Exception e) f84:hXo6
{ }M1sksk5
e.printStackTrace (); k{gLMl
} g}p;\o
} b 1&i#I?{
{;2vmx9
//日志 -XRn~=5
public static void log(String sMsg) +(uYwdcN
{ :'aAZegQY
System.err.println(sMsg); .(J?a"
} jCTAKaq
Z):n c% S
_"4xKh)
public static void log(int sMsg) 9Pw0m=4
{ yr#5k`&\_
System.err.println(sMsg); #,{+3Y&5-+
} mDh1>>K'~
} b$k&dT\o
/6O??6g
x{NX8lN
/* UpXz&k
**TestMethod.java lnE+Au'
*/ +n}$pM|NKU
package NetFox; 65ly2gl
zrVC8Wb
TpA\9N#$
public class TestMethod { p!Eft/A(
?Qb<-~~ j1
<8UYhGK
public TestMethod() CE15pNss
{ ///xx/weblogic60b2_win.exe IlX$YOf4
try{ uP\lCqK,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z ,^9Z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iR$<$P5
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7u\*_mrv
fileFetch.start(); -C#PQV
} `>DP,D)w(
catch(Exception e){e.printStackTrace ();} `V[!@b:
"m{,~'x
Y32O-I!9u
} ]]}tdn_
:V)lbn\
( 6(x'ByT
public static void main(String[] args) %LXM+<N8
{ 8+mH:O
new TestMethod(); +.RKi!
} QZ `tNq :/
} .kTG[)F0b
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