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)); l1eF&wNC
} zaG1
for(int i=0;i<nEndPos.length-1;i++) Q8^g WBc
{ MhZ\]CAs9
nEndPos = nStartPos[i+1]; d#-'DO{k
} %IK[d#HO
nEndPos[nEndPos.length-1] = nFileLength; Yqb3g(0
} cCO2w2A[*
} ;Miag'7
##BfI`FJ
Ih^ziDcW
//启动子线程 Q<T+t0G\O-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9;R'Xo=y
for(int i=0;i<nStartPos.length;i++) tWaM+W
{ H,0Io
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Xsd+5="{N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1s6L]&B
nStartPos,nEndPos,i); XxLauJP K
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uO5y{O2W
fileSplitterFetch.start(); ;-6
} f8S!FGiNc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1`)e}p&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +{au$v}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", VRD:PVz
nEndPos = " + nFileLength); ]La~Bh6;m
// fileSplitterFetch[nPos.length-1].start(); |:,i
fzjAP7 y
4^_'LiX3[
//等待子线程结束 9qI#vHA
//int count = 0; %JPBD]&M
//是否结束while循环 XB;C~:
boolean breakWhile = false; =H;F{J"
!pxOhO.V
{3eg4j.Z
while(!bStop) fzZ`O{$8
{ !z2KQ 4C
write_nPos(); X{ f#kB]w
Utility.sleep(500); xP-\)d-.aN
breakWhile = true; 1fqJtP6
%![3?|8~
T,/:5L9
for(int i=0;i<nStartPos.length;i++) =:_DXGW2H
{ 9y?)Ga
if(!fileSplitterFetch.bDownOver) odhcU5
{ lw=!v%L
breakWhile = false; q#\4/Dt
break; >!WH%J
} Dy|)u1?
} 'f-8P
if(breakWhile) uYCWsw/
break; :N64FR#
og`K!d~
hj,yl&
//count++; Y+!z]S/x
//if(count>4) ";;Nc>-Y
// siteStop(); v@QfxV2
} W9:(P
GD0Q`gWNe
p mUG`8SY
System.err.println("文件下载结束！"); vbEO pYCS
} %/w%A:y#&
catch(Exception e){e.printStackTrace ();} Ni>!b6Z`[
} =fK6P6'B
s y>}2orj~
`Ha<t.v(
//获得文件长度 Iad&Z8E
public long getFileSize() 'a G`qPB
{ ]XEUD1N;I
int nFileLength = -1; {ep.So6
try{ X.eocy
URL url = new URL(siteInfoBean.getSSiteURL()); S`pBEM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C_;A~iI7
httpConnection.setRequestProperty("User-Agent","NetFox"); szGGw
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E7 P'}
int responseCode=httpConnection.getResponseCode(); P(aN6)D
if(responseCode>=400) ;k (M4?
{ @ RP?)*8}&
processErrorCode(responseCode); -+y3~^EYm,
return -2; //-2 represent access is error 22@w:
} AmB*4p5b
7gE/g`"#
c7A]\1 ~
String sHeader; 3jjV bm
y'C
.4[M7)
for(int i=1;;i++) D[dI_|59a
{ [F+*e=wjN>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ie(M9QMp
//Utility.log(in.readLine()); cC]lO
sHeader=httpConnection.getHeaderFieldKey(i); Q!{,^Qb
if(sHeader!=null) ?*&5`Xh
{ Yc^,Cj{OM
if(sHeader.equals("Content-Length")) ,c|Ai(U
{ 1*?L>@Wdy
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); LAY~hF"
break; )yUSuK(Vu
} 95sK;`rE+
} 3|BB#;
else +NTC!/
break; 6 -BC/
} ^#]eCXv
} MH/bJtNq
catch(IOException e){e.printStackTrace ();} ~uu{ v')
catch(Exception e){e.printStackTrace ();} pkc*toW
v;(k7
Bhk@0\a
Utility.log(nFileLength); <OTx79m
yH0vESgv
S]?I7_
return nFileLength; gwDVWhq
} jD?*sd
dH)\zCt
eC`G0.op
//保存下载信息（文件指针位置） k,61Va
private void write_nPos() 6*:U1{Gl)
{ Pr3>}4M
try{ OlM3G^1e1
output = new DataOutputStream(new FileOutputStream(tmpFile)); p8MN>pLP%
output.writeInt(nStartPos.length); WmuYHEU
for(int i=0;i<nStartPos.length;i++) 4VhKV JX
{ kOQ!]-;
// output.writeLong(nPos); nw0Tg= P
output.writeLong(fileSplitterFetch.nStartPos); V W(+sSQ
output.writeLong(fileSplitterFetch.nEndPos); U% OlYP$g
} 4wPP/`
output.close(); {J-Ojw|Y b
} H^+Znmo
catch(IOException e){e.printStackTrace ();} e17]{6y
catch(Exception e){e.printStackTrace ();} NmTo/5s
} ''}2JJU{
vG~JK[
s#FX2r3=Fg
//读取保存的下载信息（文件指针位置） ;N!opg))d<
private void read_nPos() o,'Fz?[T%
{ CP Ju=
try{ Va^(cnwa
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); yC7lR#N8j0
int nCount = input.readInt(); lT_dzO
nStartPos = new long[nCount]; .9q`Tf
nEndPos = new long[nCount]; RO| }WD)
for(int i=0;i<nStartPos.length;i++) VBz G`&NG
{ Z GrDa
nStartPos = input.readLong(); 6S^JmYq
nEndPos = input.readLong(); :XB^IyO-A
} }$#PIyz
input.close(); H__'K/nH+
} i4mP*RwC
catch(IOException e){e.printStackTrace ();} JtxitF2
catch(Exception e){e.printStackTrace ();} ucFfxar"
} ?@7Reh\
DJ`xCs!R
n@J>,K_B
private void processErrorCode(int nErrorCode) 's$/-AV
{ .gY=<bG/fA
System.err.println("Error Code : " + nErrorCode); 2:&L|;
} xXCsJ9]
d'[q2y?6N
z\>ZgRi~n
//停止文件下载 Gm=e;X;r
public void siteStop() \lK `
{ 0P;\ :-&p
bStop = true; )B"E+Q'h{7
for(int i=0;i<nStartPos.length;i++) 3g5D[>J'
fileSplitterFetch.splitterStop(); h]&o)%{4
_7 ^:1i~:.
<(l`zLf4p
} YwZ]J
} [= Xb*~
//负责部分文件的抓取 IGo+O*dMw
**FileSplitterFetch.java Jt3*(+J>/
*/ uCc5)
package NetFox; &.JJhX
vJe c+a
gUme({h&|
import java.io.*; oiQ:&$y
import java.net.*; ^(KDtc
t?Q
XoGOY|2`6
public class FileSplitterFetch extends Thread { = VMELk!z
zN/nKj: Q
p ^Y2A
String sURL; //File URL b1yS1i D
long nStartPos; //File Snippet Start Position bd[iD?epD]
long nEndPos; //File Snippet End Position x[mh^V5ld
int nThreadID; //Thread's ID -m$2"_
boolean bDownOver = false; //Downing is over .dj}y jd]f
boolean bStop = false; //Stop identical m`n#Q#6
FileAccessI fileAccessI = null; //File Access interface oWq]\yT<`
UTqKL*p523
1z_1Hl
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?=b#H6vs
{ )NO,G
this.sURL = sURL; W Haf}.V
this.nStartPos = nStart; ysFp$!9Ux
this.nEndPos = nEnd; zpg512\y
nThreadID = id; {FR+a**
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9Dd`x7$a
} TWdhl9Ot
Tn?D~?a*O
u/%Z0`X
public void run() a\KM^jrCD
{ "g5MltH
while(nStartPos < nEndPos && !bStop) NT{'BJ
{ zKThM#.Wa
#)4p,H
y0'WB`hNQ
try{ dRUmC H
URL url = new URL(sURL); HahA} Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ={50>WXE
httpConnection.setRequestProperty("User-Agent","NetFox"); P>Ru
String sProperty = "bytes="+nStartPos+"-"; [d=BN ,?
httpConnection.setRequestProperty("RANGE",sProperty); |}@teN^J*U
Utility.log(sProperty); qNUd "%S
VH] <o0
3?TUt{3g
InputStream input = httpConnection.getInputStream(); JY%l1:}G3
//logResponseHead(httpConnection); t-Ble
t-SZBNb
B/B`=%~5_^
byte[] b = new byte[1024]; &_' evZ8
int nRead; V!s#xXD}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) fC/P W`4Ae
{ F(w<YU%6
nStartPos += fileAccessI.write(b,0,nRead); %&eBkN!T
//if(nThreadID == 1) +NoVe#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Gz2\&rmN
} QV -ZP'e^
_5o5/@
TJ|do`fw>
Utility.log("Thread " + nThreadID + " is over!"); **c"}S6:mC
bDownOver = true; dJ~Occ1~r
//nPos = fileAccessI.write (b,0,nRead); xPJ@!ks9
} WfQZ7e
catch(Exception e){e.printStackTrace ();} U-D00l7C
} K14v6d
} +9M";'\c
\b#`Ahf`
jVna;o)
//打印回应的头信息 7?8+h
public void logResponseHead(HttpURLConnection con) Ym2Ac>I4
{ )Jh:~9L%='
for(int i=1;;i++) tO3#kV\,
{ IV%Rph>d
String header=con.getHeaderFieldKey(i); z}Vg4\x&
if(header!=null) C1OiMb(:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c=re(
Utility.log(header+" : "+con.getHeaderField(header)); 3pyE'9"f6
else 4W=fQx]
break; fIn^a3TV
} NKiWt Z"
} -X-sykDm
3S @)Ans
o'? WWJK6w
public void splitterStop() )ib$*dmUP
{ QFFFxaeJg
bStop = true; [4+I1UR`
} #Vy:6O
b`;Cm)@X!)
GyfKSj;
} O"wo&5b_
!PgwFJ
Us_1 #$p,
/* 5+t$4N+P
**FileAccess.java %0'7J@W
*//文件访问(定位，写) {D8yqO A}
package NetFox; sYB2{w
import java.io.*; "oh;?gQ.
)!FheoR
9}+X#ma.Nc
public class FileAccessI implements Serializable{ Nl^uA
o* e'D7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 DH)E9HL
RandomAccessFile oSavedFile; (4/W)L$
long nPos; s%G%s,d
&d]@$4u$;
wJu9.
public FileAccessI() throws IOException z}Um$'. =
{ (IIZvCek
this("",0); &g]s@S|%
} HE0m#
I/u>Gt
83VFBY2q
public FileAccessI(String sName,long nPos) throws IOException csV3mzP
{ %zO>]f&
oSavedFile = new RandomAccessFile(sName,"rw"); [rz5tfMp
this.nPos = nPos; H;#C NB<e
oSavedFile.seek(nPos); AB<%GzW0(
} w"L]?#
#X0Xc2}{f
_/YM@%d
public synchronized int write(byte[] b,int nStart,int nLen) |O;vWn'U2
{ ~.z82m
int n = -1; )"_&CYnd
try{ fr}.#~{5Y
oSavedFile.write(b,nStart,nLen); o ^ 08<
n = nLen; 2s}G6'xE]P
} MjbgAH-
catch(IOException e) h)s&Nqg1B
{ M^G9t*I
e.printStackTrace (); 9U3.=J
} <@c@`K
g!Ui|]BI9
# hw;aQ
return n; (Dn1Eov
} h<qi[d4X
kV4L4yE
+}eK8>2
} c=aZ[
)|W6Z
uH#X:Vne
/* V{X/yN.u
**SiteInfoBean.java =Z..&H5i
*/ x@D>JG
package NetFox; "BIhd*K[~
]`|;ZQiD
a6?t?:~|
public class SiteInfoBean { { T<[-"h
{U4{v=,!I
@~FJlG(n
private String sSiteURL; //Site's URL R_"6E8N
private String sFilePath; //Saved File's Path #}Bv/`t
private String sFileName; //Saved File's Name ;@O8y\@
private int nSplitter; //Count of Splited Downloading File Ml/K~H tN
r4 qs!(
Z_>:p^id
public SiteInfoBean() =F_j})O5
{//nSplitter的缺省值为5 Nw%^Gs<~
//default value of nSplitter is 5 'C@yJf
this("","","",5); %BQ?DTtb7'
} ZA}!Rzo
i8%Z(@_`
<[=[|DS l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8C*xrg#g:
{ sXYXBX[
sSiteURL= sURL; 5C9 .h:c4y
sFilePath = sPath; z?GtC{L9
sFileName = sName; 99n;%W>
this.nSplitter = nSpiltter; 4b}'W}
c?6(mU\x
+~7[T/v+n
} [8vqw(2Tm(
"B9zQ,[Q
]deO\mB
public String getSSiteURL() OaY]}4tI$
{ 3h6,x0AG
return sSiteURL; Equ%6x
} 6=x]20
hMgk+4*
Fxn=+Xgg
public void setSSiteURL(String value) gx2v(1?S
{ D'Uc?2X,&
sSiteURL = value; SCjVzvG$yg
} 2o7o~r
!:~C/B{
QaXdO=3
public String getSFilePath() [=:4^S|M
{ )i:"cyoE
return sFilePath; y,c\'}*H
} ZIc-^&`r=
g^U-^f
a, `B.I
public void setSFilePath(String value) RK_z!%(P
{ -$kbj*b##
sFilePath = value; 9h<iw\$'
} ~8'HX*B]z
|1Nz8Vr.
^5+7D1>W%
public String getSFileName() iphdJZ/f
{ #nKGU"$+
return sFileName; 5U*${
} C*Qx
s}DNu<"g
NkQain9
public void setSFileName(String value) la_
{ L>N)[;|
sFileName = value; $GVf;M2*
} @;[.#hK
\P*%u
1Sv$!xX`n
public int getNSplitter() 1M[|9nWUC
{ YP{mzGdE&
return nSplitter; "T}HH
} |+=ctpx9&
SQk5SP
7K!n'dAi6
public void setNSplitter(int nCount) HBw0N?
{ }~#qDrK
nSplitter = nCount; s3~6[T?8
} V_9\Ax'X
} Y1BxRd?D
=g=Vv"B_
1+-F3ROP
/* l%`~aVGJ
**Utility.java |~=4ZrcCP
*/ UQtG<W]<
package NetFox; myB!\WY
:m("oC@}
{[+Q\<
public class Utility { sB01QVx47
QFhQfn
eXmYw^n
public Utility() ^{g+HFTA@
{ |G)bnmi7
/ZSdY_%s
uJ,I6P~9
} WW~QK2o-@
b~K-mjJI
//线程睡眠 u_$Spbc]/
public static void sleep(int nSecond) >k u7{1)
{ IZ]L.0,
try{ $U%N$_k?
Thread.sleep(nSecond); .r@'9W^8
} fXkemB^)_
catch(Exception e) puGy`9eKv1
{ =}W)%Hldr.
e.printStackTrace (); ralU9MN.
} hPUYq7B
} y(Q.uYz*
[_p&,$z8[
//日志 DzY`O@D[
public static void log(String sMsg) s06R~P4
{ yMf["AvG
System.err.println(sMsg); iHyA;'!Os
} qV@Hu/;
3. g-V
j<i:rk|
public static void log(int sMsg) om,=.,|Ld
{ R=HcSRTkA
System.err.println(sMsg); vu)V:y
} DFqVZ
} 3a,7lTUuB
hfQ^C6yR
wW^3/
/* ;p)fW/<
**TestMethod.java [kZe6gYP&
*/ }-M%$~`
package NetFox; 1Q9eS&
79MB_Is]s
D5 ^WiQ<
public class TestMethod { |Oe$)(`|h
L|w}#|-
MbC&u:@ "v
public TestMethod() {7o|*M
{ ///xx/weblogic60b2_win.exe [2ZZPY9?Q
try{ HLDg_ On8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $RV'DQO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); oJEjg>%n
SiteFileFetch fileFetch = new SiteFileFetch(bean); t8b,@J`R
fileFetch.start(); cBnB(t%
} L+"5g@
catch(Exception e){e.printStackTrace ();} i52:<< 8a
*AN2&>Y
jo=,j/,l
} !8>tT
xBMhk9b^0
?QCHkhU
public static void main(String[] args) GvT'v0&+
{ w.H\j9E l
new TestMethod(); >=Un=Q%
} g\ p;
} eVbaxL!Q^
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