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)); l$_q#Kd
} f wE b
for(int i=0;i<nEndPos.length-1;i++) c?(;6$A
{ ''D\E6c\
nEndPos = nStartPos[i+1]; k|uW~I)
} ~V34j:
nEndPos[nEndPos.length-1] = nFileLength; vNWCv
} IhR;YM[K
} KYw~(+gHv2
WzinEo{f
Cj/J&PDQ
//启动子线程 l7T@<V
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; x)}.@\&%
for(int i=0;i<nStartPos.length;i++) mM#[XKOC<
{ <b.O^_zQF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;D8175px;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ccR#<Pb6q
nStartPos,nEndPos,i); |-)2 D=P
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L/Tsq=
fileSplitterFetch.start(); 2.p?gRO
} 6Dl]d%.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wn1` 9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); bT>1S2s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Nh^ lC
nEndPos = " + nFileLength); rd_!'pG
// fileSplitterFetch[nPos.length-1].start(); =# /BCL7
;6)Onwx
C}'Tmi
//等待子线程结束 xcHuH-}
//int count = 0; D`9a"o
//是否结束while循环 HpKF7oJ'N
boolean breakWhile = false; #r,LV}*qg
faIHmU
a>H8,a
while(!bStop) F[@M?
{ %|izt/B
write_nPos(); ^{}$o#iof
Utility.sleep(500); e)M)q!nG
breakWhile = true; e+~Q58oD
q?##S'
dje}CbZ
for(int i=0;i<nStartPos.length;i++) ']&rPvkL
{ fbrCl!%P
if(!fileSplitterFetch.bDownOver) q)f-z\
{ 7Zw.mM!i
breakWhile = false; |& Pa`=sp
break; 3:g~@PB
} ~PZIYG"D
} i-FsA
if(breakWhile) w D}g\{P
break; B:]%Iu|
WKvG|YRDq
$8{v_2C){
//count++; `^mY*Cb e
//if(count>4) 9Hm>@dBhM
// siteStop(); $6DA<v^=z
} U6xs'0
"CTK%be{q/
*=b36M
System.err.println("文件下载结束！"); V`& O`
} I&JjyR
catch(Exception e){e.printStackTrace ();} <|>7?#s2=
} ,!>1A;~wT
7^FJ+gN8b
_O;2.M%@
//获得文件长度 w!--K9
public long getFileSize() ;7*R;/
{ /v-:ca)7mI
int nFileLength = -1; I3hN7
try{ sNHxUI
URL url = new URL(siteInfoBean.getSSiteURL()); | k?r1dj%O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~cH3RFV
httpConnection.setRequestProperty("User-Agent","NetFox"); `|`Qrv4}
8<:.DFq
L/KiE+Y
int responseCode=httpConnection.getResponseCode(); i(mQbWpN
if(responseCode>=400) s ;2ih)[
{ chakp!S=
processErrorCode(responseCode); s9[547?`
return -2; //-2 represent access is error sLze/D_M*
} zPc kM)
QzilivJf
k1E(SXcW9
String sHeader; C3:CuoE X
PHR:BiMZ
DkJ "#8Yl=
for(int i=1;;i++) RAU"
{ $!v:@vNMs
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); uW0Dm#
//Utility.log(in.readLine()); b <z)4
sHeader=httpConnection.getHeaderFieldKey(i); W,fXHYst
if(sHeader!=null) /C
{ *?3c2Jg=E
if(sHeader.equals("Content-Length")) ?rxq//S2
{ .K`EflN
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9p4=iXfR
break; b Od<x >@
} .D{He9
} 5>\~jf
else u"gtv
break; 4A)@,t9+
} h>"j!|#!s
} bPA >xAH
catch(IOException e){e.printStackTrace ();} :r4o:@N'
catch(Exception e){e.printStackTrace ();} mX5%6{],
2(AuhZ>
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Utility.log(nFileLength); W9!K~g_
b'%)?{E
K_ Odu^
return nFileLength; ZxB7H{
} <j}A=SDZ)
KBa ]s q_
@!Rklhb
//保存下载信息（文件指针位置） YkSHJ{>
private void write_nPos() ):lH
{ ;6M [d
try{ B}+li1k
output = new DataOutputStream(new FileOutputStream(tmpFile)); {I8C&GS
output.writeInt(nStartPos.length); v>/_U
for(int i=0;i<nStartPos.length;i++) X]}:WGFM
{ gC+?5_=<
// output.writeLong(nPos); ]$i@^3`[w
output.writeLong(fileSplitterFetch.nStartPos); fS$;~@p
output.writeLong(fileSplitterFetch.nEndPos); d_7hh
} =Q*x=}NH
output.close(); PiN^/#D
} l[<U UEjZJ
catch(IOException e){e.printStackTrace ();} 89x;~D1
catch(Exception e){e.printStackTrace ();} FfNUFx2N
} x c]#8K
yA#nnu1
-B& Nou
//读取保存的下载信息（文件指针位置） e'MW"uCP}
private void read_nPos() ]0XlI;ah
{ Lp)P7Yt-
try{ _:]g:F[ #
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); AsI\#wL)
int nCount = input.readInt(); "hk {"0E
nStartPos = new long[nCount]; Ab6R?mUM
nEndPos = new long[nCount]; erhez
for(int i=0;i<nStartPos.length;i++) [1nUq!uTm
{ ,KCxNdg^#-
nStartPos = input.readLong(); ey6ujV7!
nEndPos = input.readLong(); h[mJ=LIrg
} k [LV^oEg
input.close(); {1gT{2/~@
} &["e1ki
catch(IOException e){e.printStackTrace ();} ]iMqIh"
catch(Exception e){e.printStackTrace ();} oL~?^`cGZ
} L{rd',
R.cR:fA
hr!'
private void processErrorCode(int nErrorCode) ]T6pH7~
{ O7p=N8V
System.err.println("Error Code : " + nErrorCode); y,/i3^y#_
} Q'Tg0,,S
4fL`.n1^
I1Otu~%d
//停止文件下载 IdM~' Q>\
public void siteStop() SsPZva
{ lQd7p+21
bStop = true; s94*uZ(C/
for(int i=0;i<nStartPos.length;i++) hI9q);g
fileSplitterFetch.splitterStop(); |Sm/s;&c6
o{hX?,4i
A'.=SA2.Y
} }'*6 A
} l))Q/8H
//负责部分文件的抓取 2$ &B@\WY
**FileSplitterFetch.java x[0O*ty-*<
*/ ITg<u?z_
package NetFox; ~Hu!iZ2]
a{@}vZx>3
6']HmM
import java.io.*; yRIXUCy
import java.net.*; @mmnr?_w
Bhv$
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public class FileSplitterFetch extends Thread { ]jYFrOMy4S
gq"d$Xh$x7
h[&"KA
String sURL; //File URL *\(z"B
long nStartPos; //File Snippet Start Position EY:IwDA.}
long nEndPos; //File Snippet End Position AL.psw-Il
int nThreadID; //Thread's ID '_^T]fr}
boolean bDownOver = false; //Downing is over +<j7^AEG
boolean bStop = false; //Stop identical Zazff@O *
FileAccessI fileAccessI = null; //File Access interface ,uAp;"YJeV
:W5W @8Y
JXM]tV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cPD_=.&
{ OZ+v ~'oD
this.sURL = sURL; ?C#E_
this.nStartPos = nStart; a&V;^ /
this.nEndPos = nEnd; N+h05`
nThreadID = id; ^lAM /
fileAccessI = new FileAccessI(sName,nStartPos);//定位 '3Lu_]I-
} FY ms]bv
pF4Z4?W
M `^[Y2 c
public void run() h%krA<G9
{ IHYLM;@L
while(nStartPos < nEndPos && !bStop) '*`#xNu[
{ Z*q9vX
xbm%+
5&V=$]t
try{ PO`p.("h
URL url = new URL(sURL); Aeb(b+=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pK@=]K~l0
httpConnection.setRequestProperty("User-Agent","NetFox"); IQRuqp KL
String sProperty = "bytes="+nStartPos+"-"; ?%h$deJ
httpConnection.setRequestProperty("RANGE",sProperty); V`1,s~"q
Utility.log(sProperty); C/IF~<B
)](ls@*
Ic9L@2m
InputStream input = httpConnection.getInputStream(); 3o%vV*
//logResponseHead(httpConnection); d=PX}o^
}=5>h' <
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byte[] b = new byte[1024]; I I+y
int nRead; D&"D[|@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) yGdX>h
{ +cfEyiub
nStartPos += fileAccessI.write(b,0,nRead); Gv_~@MN
//if(nThreadID == 1) W<r<K=`5P
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q$c6l[(g
} k*\Bl4g
=~GP;=6
x,!Dd
Utility.log("Thread " + nThreadID + " is over!"); <w{?b'/q
bDownOver = true; UX@%1W!8
//nPos = fileAccessI.write (b,0,nRead); dRX~eIw
} wqb4w7%
catch(Exception e){e.printStackTrace ();} 5To@d|{
} m2c'r3UEu
} C#kE{Qw10r
d:@+dS
H<(F$7Q!\
//打印回应的头信息 X zJ#)}f
public void logResponseHead(HttpURLConnection con) ~U0%}Bbh
{ 566!T_
for(int i=1;;i++) K(EJ`2]:r
{ >}+{;d
String header=con.getHeaderFieldKey(i); N1a]y/
if(header!=null) gQy%T]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m,k0 h%
Utility.log(header+" : "+con.getHeaderField(header)); 3~~X,ZL
else D&G6^ME
break; S6<o?X9,I
} P`biHs8O
} x>yqEdR=o
g8<ODU0[g
~#r>@C
public void splitterStop() A2|Bbqd
{ 79T_9}M
bStop = true; >jW**F
} &C9IR,&
n-Iz!;q
.xT?%xSi/
} q+?&w'8
<=4$.2ym
_3`GZeGV
/* M|(VM=~
**FileAccess.java h`&TDB2
*//文件访问(定位，写) h4hAzFQ.s
package NetFox; SZWNN#w60?
import java.io.*; LT%~Cuf
:3D8rqi:
|]&3*%b@
public class FileAccessI implements Serializable{ Z",0 $Gxu
xWxHi6U(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %J*1F
RandomAccessFile oSavedFile; S5).\1m h[
long nPos; n!4}Hwz!
]Jswxw
#Pd9i5~N
public FileAccessI() throws IOException Zux L2W
{ mI&3y9; (
this("",0); EXSH{P O+
} y" =?l
4e#g{,
H:G``Vq;0m
public FileAccessI(String sName,long nPos) throws IOException #un'?]tZF
{ nAP*w6m0j
oSavedFile = new RandomAccessFile(sName,"rw"); -RP{viGWK
this.nPos = nPos; (Yy#:r;U
oSavedFile.seek(nPos); #VhdYDbW
} s)\PY
!!.@F;]W
\#[DZOI~
public synchronized int write(byte[] b,int nStart,int nLen) Mc?_2<u-
{ ! Vl)aL
int n = -1; #?Ix6 {R
try{ -c>3|bo
oSavedFile.write(b,nStart,nLen); L 0Ckw},,
n = nLen; mU[\//
} R*6TS"aL
catch(IOException e) O]IAIM
{ IR"C?
e.printStackTrace (); ^C K!=oO
} U%Fa.bL~
X}GX6qAdt
_#~D{91 j:
return n; 24od74\
} OsOfo({I_
);HhV,$n
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} U>n[R/~]
:"y2u
I!!cA?W
/* +184|nJ<2
**SiteInfoBean.java &tUX(
*/ ]HWeVhG
package NetFox; [#!Y7Ede
%S%UMA.
1#L%Q(G
public class SiteInfoBean { 26}3
[m! P(o
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private String sSiteURL; //Site's URL #+<YFm\i
private String sFilePath; //Saved File's Path ,OrrGwp&
private String sFileName; //Saved File's Name w.rcYywI
private int nSplitter; //Count of Splited Downloading File Eg&5tAyM
QUkP&sz
OeGLMDw
public SiteInfoBean() }S*]#jr&
{//nSplitter的缺省值为5 BW)@.!C
//default value of nSplitter is 5 :/gHqEC24
this("","","",5); (-J'x%2)
} +b_[JP2
mCn:{G8+
jc3Q3Th/zn
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) M]%dFQ
{ O:'qwJ#~
sSiteURL= sURL; x;SY80D
sFilePath = sPath; [zl4"|_`
sFileName = sName; 3{qB<*!p"G
this.nSplitter = nSpiltter; s3sD7 @
r?~_^
;I@\}!%H
} "1\GU1x
3 [#Rm>,Vu
rosD)]I7
public String getSSiteURL() ZJ+ad,?,
{ xVYa-I[Z
return sSiteURL; "3++S
} $KT)Kz8tF
$v_&jE
tZx}/&m-
public void setSSiteURL(String value) ePq(.o
{ &E6V'*<93
sSiteURL = value; LB({,0mcX
} _PGd\>Ve
E 6MeM'sx
d"E3ypPK
public String getSFilePath() sZ7,7E|_
{ ' -9=>
return sFilePath; }(DH_0
} y8C8~-&OK
]a.^F
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public void setSFilePath(String value) db_}][;.c
{ [+l6x1Am
sFilePath = value; $!$If( 7
} 0;)Q
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-{C Gn5]_#
public String getSFileName() f.%3G+
{ o~CEja&(
return sFileName; jAcKSx$}y"
} ~z]VDEJ{q
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a[z$ae7
public void setSFileName(String value) IG\Cj7{K^
{ NX8hFwR
sFileName = value; oC} u
} V?0IMc
O&y`:#
tux0}|[^'
public int getNSplitter() f8WI@]1F
{ 79}jK"Gc
return nSplitter; mN.[bz
} D@.qdRc3
<]DUJuF-M
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public void setNSplitter(int nCount) ^A=tk!C
{ ~b X~_\
nSplitter = nCount; &Ruq8n<
} SsZSR.tD
} '3sySsD&O
%K=_
#639N9a~
/* X6(s][Wn
**Utility.java 8HZ+r/j
*/ h~CLJoK<
package NetFox; Z^'\()3t
.oLV\'HAR
u3,O)[qV
public class Utility { %yjD<2J;
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q{B?j%.o
public Utility() T*=*$%
{ IFS_DW
mW{>
f^"pZS
} pWv1XTs@t:
N#-pl:J(
//线程睡眠 k 9z9{
public static void sleep(int nSecond) ]b sabS?
{ d}ycC.h4k
try{ 5E~^-wX
Thread.sleep(nSecond); ZE_
} o59$vX,
catch(Exception e) b.\xPb
{ <Up?w/9
e.printStackTrace (); R)\^*tkz7
} 6'@{ * u
} Za3}:7`Gu
'x"(OdM:[
//日志 Sx e6&
public static void log(String sMsg) udLIAV*
{ pPo xx"y
System.err.println(sMsg); {N/%%O.b
} 66" 6>
S >CKm:7
:|niFK4
public static void log(int sMsg) fHH
{ i 61k
System.err.println(sMsg); S 593wfc
} #eJ<fU6Da
} 324XoMO
;`:YZ+2 Z
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/* 5Lej_uqF
**TestMethod.java 9jEH"`qqk
*/ A( vdlj
package NetFox; }b&S3?ONt
>,]8iMh
}$L63;/H
public class TestMethod { {A:uy
!%('8-x%
xLOQu.
public TestMethod() V8TdtGB.|h
{ ///xx/weblogic60b2_win.exe bSX/)')jU
try{ x4H#8ZK!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gC/ e]7FNr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T+$H[&j
SiteFileFetch fileFetch = new SiteFileFetch(bean); /kkUEo+
fileFetch.start(); @CL#B98jl
} FC,=g`Q!
catch(Exception e){e.printStackTrace ();} Kmx^\vDs
V<H9KA
D5?8`U m=
} "W(Ae="60
@&O4a2+
g)#{<#*2
public static void main(String[] args) wLXJ?iy3
{ yivu|q
new TestMethod(); X4!7/&
} e:9EP,
} ^Q$OzsEk
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