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)); CNRSc4Le
} bVcJ/+Yx|
for(int i=0;i<nEndPos.length-1;i++) RZxh"lIo
{ bg|$1ue
nEndPos = nStartPos[i+1]; Kii@Z5R_?
} QP(d77n
nEndPos[nEndPos.length-1] = nFileLength; |r+ x/,2-
} c7+6[y DVE
} J0Yb_(w
! #Pn_e
al#(<4sJ
//启动子线程 ;C-ds
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; F(1E@xs
for(int i=0;i<nStartPos.length;i++) CY?J$sN
{ % (h6m${j
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7B0`.E^~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), F+Kju2
nStartPos,nEndPos,i); kVLZdXn,q2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q7u|^Gu,5
fileSplitterFetch.start(); npeL1zO-$
} [`tOhL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;ZB=@@l(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kt Z~r. +
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", P_b5`e0O
nEndPos = " + nFileLength); $-DW+|p.?^
// fileSplitterFetch[nPos.length-1].start(); yPfx!9B
=9,mt K~
pej-W/R&
//等待子线程结束 mqeW,89
//int count = 0; H.?`90IQ
//是否结束while循环 trwo(p
boolean breakWhile = false; YQ+8lANC
&=t~_ Dc
At>e4t2@
while(!bStop) G>^= Bm_$
{ oG22;
write_nPos(); @}jg5}
Utility.sleep(500); `Zp*?
breakWhile = true; $ ^)g,
=WN8><K!
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for(int i=0;i<nStartPos.length;i++) tM@%EO
{ Up-^km
if(!fileSplitterFetch.bDownOver) VB^1wm
{ Q~^v=ye
breakWhile = false; Z3zD4-p$_
break; zKk=R6w
} W SvhC
} O|m-[]
if(breakWhile) -= c&K&
break; Z>`frL
y2g)*T!m
b7'A5]X
//count++; e}gGl<((g
//if(count>4) "kt7m
// siteStop(); j~rW 2(
} xE_~.EoB
MR,>]| ^
t`6~ud>
System.err.println("文件下载结束！"); ).Z U0fV
} iMYJVB=
catch(Exception e){e.printStackTrace ();} 5[6{o$I
} N#OO{`":Z`
&mJm'Ks
yqb$,$
//获得文件长度 9nd,8Nji
public long getFileSize() $*fEgU% c
{ AGlFbc(L
int nFileLength = -1; |Ntretz`\
try{ 'cN3Vvk
URL url = new URL(siteInfoBean.getSSiteURL()); )x,-O#"A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,=u!hg
httpConnection.setRequestProperty("User-Agent","NetFox"); 74A&#ecb{
Y,KSr|vG
uq!d8{IMu
int responseCode=httpConnection.getResponseCode(); ^x >R #.R
if(responseCode>=400) {f6~Vwf
{ sVS),9\}
processErrorCode(responseCode); 7?Twhs.O
return -2; //-2 represent access is error P#KTlH
} n7#}i2:
-C*UB
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String sHeader; Gd2t^tc
?D@WXE0a
p?<T _9e
for(int i=1;;i++) Vg`32nRN
{ 7@!ne&8Z?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]EvK.ORy
//Utility.log(in.readLine()); DvBRK}'
sHeader=httpConnection.getHeaderFieldKey(i); =eeZtj.
if(sHeader!=null) Kb#Z(C9
{ kSqMI'89
if(sHeader.equals("Content-Length")) ,h9N,bIQg
{ fXx !_Z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8Dc'"3+6
break; J+nUxF;EE
} d+6-ten
} )WF*fcx{
else 1NU@k6UHl
break; X_J(P?
} BWG#W C
} }woNI
catch(IOException e){e.printStackTrace ();} 5l /EZ\q
catch(Exception e){e.printStackTrace ();} j !rQa^
MryY<s
iriF'(1
Utility.log(nFileLength); wb (quu
gO]jeO
lZhd^69y
return nFileLength; v^Pjvv=
} {wVJv1*l
^yVKW5x
47^R
//保存下载信息（文件指针位置） 5>"X?U}He
private void write_nPos() \~@a/J
{ <lHVch"(^$
try{ nG !6[^D
output = new DataOutputStream(new FileOutputStream(tmpFile)); S,2{^X
output.writeInt(nStartPos.length); i.6+CA
for(int i=0;i<nStartPos.length;i++) )Vnqz lI5
{ ?LA`v_
// output.writeLong(nPos); `@Tl7I\
output.writeLong(fileSplitterFetch.nStartPos); VF] ~J=>i
output.writeLong(fileSplitterFetch.nEndPos); {Z{!tR?+
} u|D|pRM-LT
output.close(); $Z{Xt*
} 0l>4Umxr{J
catch(IOException e){e.printStackTrace ();} B@v"giJgr
catch(Exception e){e.printStackTrace ();} 4n,>EA85
} DE_<LN
*B1%-
zY&/^^y
//读取保存的下载信息（文件指针位置） tg'2v/
private void read_nPos() U%E364;F
{ ! 4{T<s;q
try{ cfA)Ui
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); G [$u`mxV^
int nCount = input.readInt(); 68-2EWq
nStartPos = new long[nCount]; 86<[!ZM
nEndPos = new long[nCount]; ),]XN#jp(u
for(int i=0;i<nStartPos.length;i++) {m7>9{`
{ pu?D^h9/
nStartPos = input.readLong(); '\I!RAZ
nEndPos = input.readLong(); kcN#g-0
} @<,YUp,%S
input.close(); q7ubRak
} ~Ddlr9Ej
catch(IOException e){e.printStackTrace ();} C)xM>M_CB
catch(Exception e){e.printStackTrace ();} 1&Ruz[F5
} ~gJJ@j 0n
Qvl3=[S
CFyu9Al
private void processErrorCode(int nErrorCode) 95%QF;h
{ P!K;`4Ika
System.err.println("Error Code : " + nErrorCode); z)&ZoSXWc
} T5b*Ia
1DT}_0{0Q
* j]"I=D
//停止文件下载 s%l`XW;v
public void siteStop() [OK(
{ +(l(|lQy$
bStop = true; rI.CCPY~s
for(int i=0;i<nStartPos.length;i++) g:]X '%Ub
fileSplitterFetch.splitterStop(); C6ry]R@
.\:{6_
b]cnTR2E
} FvVR \a
} W_%@nm\y
//负责部分文件的抓取 `@)>5gW&p
**FileSplitterFetch.java E/IoYuB
*/ rIJv(&l
package NetFox; FQW{c3%qZ
}{S f*
:7Jpt3
import java.io.*; m(o^9R_=^9
import java.net.*; lz>>{
F*rsi7#!pG
`<x((@#
public class FileSplitterFetch extends Thread { $9}jU#Z|hd
Bt[Wh@
rS&"UH?c7
String sURL; //File URL #[$zbZ(I>:
long nStartPos; //File Snippet Start Position {Ne5*HFV
long nEndPos; //File Snippet End Position <2,NWn.
int nThreadID; //Thread's ID $3c9iVK~_
boolean bDownOver = false; //Downing is over PqVz^(Wz
boolean bStop = false; //Stop identical {#C)S&o)6
FileAccessI fileAccessI = null; //File Access interface 0LD$"0v/C3
J_eu(d[9
7*I:cga
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException TkyP_*
{ w8iXuRv
this.sURL = sURL; S\"#E:A
this.nStartPos = nStart; ,6AnuA
this.nEndPos = nEnd; "HwSW4a]
nThreadID = id; U6x$R O!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 tQ7:4._
} *-\qO.4\
,d`6 {ll
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public void run() $/#F9>eZ
{ tQWjNP~
while(nStartPos < nEndPos && !bStop) b9RJ>K
{ Da-U@e!
{v>8Kp7_R
J5"d|i
try{ ,`,1s9\&t
URL url = new URL(sURL); HnsPXF'8g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1G<S'd+N
httpConnection.setRequestProperty("User-Agent","NetFox"); Zgw4[GpL
String sProperty = "bytes="+nStartPos+"-"; LTWiCI
httpConnection.setRequestProperty("RANGE",sProperty); ^Gwpx+
Utility.log(sProperty); &qyXi[vw
?"-1QG
;FnU[Q`M#L
InputStream input = httpConnection.getInputStream(); C/#?S=w`4
//logResponseHead(httpConnection); ;6}> Shs
1uco{JX<S
*)D$w_06S
byte[] b = new byte[1024]; JA2oy09G
int nRead; :`B70D8ku
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 51gSbkVX
{ 9}A\BhtiM
nStartPos += fileAccessI.write(b,0,nRead); WJTc/
//if(nThreadID == 1) ~A03J:Yc7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;Z.sK-NJ4
} noZ!j>f{@l
k7kPeq
sv)4e)1
Utility.log("Thread " + nThreadID + " is over!"); M4)Y%EPc
bDownOver = true; LbUH`0:%t
//nPos = fileAccessI.write (b,0,nRead); S{jm4LZ
} ~FnuO!C
catch(Exception e){e.printStackTrace ();} 'OI(MuSn
} e(H{C
} 5;@2SY7,
3FG'A[x3O
1Vx>\A
//打印回应的头信息 d]vom@iI
public void logResponseHead(HttpURLConnection con) 3?Fe(!@
{ 6 \}.l
for(int i=1;;i++) "EBCf.3-
{ KM9H<;A
String header=con.getHeaderFieldKey(i); *nB-] w/
if(header!=null) U;#G$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %?Q<
Utility.log(header+" : "+con.getHeaderField(header)); #xh M&X
else wufQyT`
break; 49=L9:
} YBL.R;^v
} gjzU%{T?
NAX`y2z
S2 MJb
public void splitterStop() vG:S(/\>
{ -`D<OSt7
bStop = true; Q%W>m0%
} Mtc-
`SQobH
[IgqK5@
} :}CcWfbT
z.;!Pj
Z|xgZG{
/* ;Kh?iqn^
**FileAccess.java 5|Oj\L{
*//文件访问(定位，写) '4}8WYKQ
package NetFox; "sT)<Wc
import java.io.*; "A0y&^4B@
OVGB7CB]S
G +AP."M?
public class FileAccessI implements Serializable{ 6!H,(Z]j
+&G]\WX<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T^q^JOC4
RandomAccessFile oSavedFile; _k#GjAPM
long nPos; 3R%yKa#
UG3}|\.u
^%0^DN
public FileAccessI() throws IOException yq[. WPve
{ iNilk!d6Q3
this("",0); |l@z7R+4*
} <o/lK\>
"\u<\CL
53>(2 _/[r
public FileAccessI(String sName,long nPos) throws IOException g_rk_4]
{ pG22Nx
oSavedFile = new RandomAccessFile(sName,"rw"); KwgFh#e
this.nPos = nPos; m'M5O@?
oSavedFile.seek(nPos); s>%.bAxc
} >M0^R}v
KGc!#C
;@ G^eQ
public synchronized int write(byte[] b,int nStart,int nLen) gLg.mV1<
{ }z,9!{~`
int n = -1; ].sD#~L_
try{ >vf-,B
oSavedFile.write(b,nStart,nLen); ^]Q.V
n = nLen; n5)ml)m
} Nw(hN+_u
catch(IOException e) e,d}4 jy
{ 3i\Np =
e.printStackTrace (); S9^SW3
} ~NLthZ(O
KzQFG)q,
+3sbpl2}
return n; ?9>wG7cps7
} @pH6FXVGzt
6:AEg
fs-LaV 0
} R0mkEM
w#ZzmO
]{|lGtK %
/* ; 6PRi/@
**SiteInfoBean.java hwA&SS
*/ r^H,H'BohJ
package NetFox; q*tGlM@R?
HXC\``E
TY5R=jh=
public class SiteInfoBean { W*DKpJy
jatlv/,
\S1W,H|
private String sSiteURL; //Site's URL 8@LUL)"
private String sFilePath; //Saved File's Path >P:U9 b
private String sFileName; //Saved File's Name f=VlOd
private int nSplitter; //Count of Splited Downloading File =F}qT|K
G e5Yz.Qv
byMy-v;
public SiteInfoBean() fD3'Ye<R
{//nSplitter的缺省值为5 d R=0K
//default value of nSplitter is 5 uA;#*eiA/
this("","","",5); VW*?(,#j{
} Dsn=fht
}0Uh<v@
O[{/P:a
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7l[@c|e
{ $ZZ?*I
sSiteURL= sURL; *po o.Zz
sFilePath = sPath; >)G[ww[
sFileName = sName; f6Lc"b3s1
this.nSplitter = nSpiltter; GAZRQ
(5,x5l]-N
fR~0Fy Gp
} '/t9#I@G\
c q[nqjC=
/#SfgcDt
public String getSSiteURL() 6({)O1Z
{ ,4`Vl<6
return sSiteURL; pL} F{G.
} 6R^32VeK($
WVhQ?2@}
9<toDg_
public void setSSiteURL(String value) <8Tp]1z
{ CTKw2`5u
sSiteURL = value; kX`m( N$
} /;/:>c
0#Pa;(
,c$tKj5ulQ
public String getSFilePath() TBQ68o
{ _-TW-{7bh
return sFilePath; !bCL/[
} n7G`b'
K(lSR
b_6cK#
public void setSFilePath(String value) A+foc5B
{ LyNmn.nN
sFilePath = value; @1&"S7@}u
} K(PSGlI f
On~KTt3Mp
V|B4lGS&
public String getSFileName() NqD Hrx
{ ,7:-V<'Yv
return sFileName; i2(v7Gef
} 9W]OtSG
_?cum~A@
L@=$0p41;
public void setSFileName(String value) IHi[3xf<
{ ?PTXgIC
sFileName = value; S ~h*U2
} 4e eh+T
w xte
dI%ho<zm]
public int getNSplitter() 1n&%L8]
{ P(2OTfGGx
return nSplitter; :aaX Y:<
} $oM>?h_=
4ytdcb
\xl$z*zI
public void setNSplitter(int nCount) |39,n~"o&
{ EK[J!~
nSplitter = nCount; GH-Fqz
} "+7E9m6I
} Jq(;BJ90R
7=u Gf$/
na~ FT[3C
/* y9R%%i
**Utility.java UjoA$A!Od;
*/ @~|;/OY>"
package NetFox; Nb !i_@m%s
v6=%KXSF
oOvQAW8`
public class Utility { u*I'c2m
/Mw;oP{&b
r"{jrBK$
public Utility() ys`oHSf
{ Nj2l>[L;
.AO-S)wHR
n~\; +U
} uHZ4 @w:
CR9wp]-Vd
//线程睡眠 WrDFbcH
public static void sleep(int nSecond) f"j9C%'*
{ NNqvjM-
try{ }}]Lf3;
Thread.sleep(nSecond); yn]Sc<uK
} pKq[F*Lut
catch(Exception e) lGR0-Gh2
{ B?-w<":!
e.printStackTrace (); '5$@I{z
} 5j]!r
} &}P#<"Fo8Q
5rck]L'
//日志 tl!dRV92
public static void log(String sMsg) x X3I`
{ y6d!?M(0U
System.err.println(sMsg); ZpOME@9,
} >]ux3F3\
w8Z#]kRv
H{5, -x
public static void log(int sMsg) Hqs-q4G$
{ |3B<;/v5
System.err.println(sMsg); }`QZV_
} W&9qgbO]
} j[dZ*Jr_
FqbGT(QB0
*Us}E7/"'
/* ~<K,P
**TestMethod.java e/+.^ '{
*/ #>:S&R?2t
package NetFox; (Ytr&gh;0
K O\HH
:^{KY(3
public class TestMethod { Nk\ni>Du3
52o^]
r`Fs"n#^-4
public TestMethod() ,GVX1B?
{ ///xx/weblogic60b2_win.exe '9.@r\g
try{ VV$#<D<)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qvy*; <w
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); RZ{O6~VH
SiteFileFetch fileFetch = new SiteFileFetch(bean); L#a!fd
fileFetch.start(); 4l*cX1!
} H"w;~;h
catch(Exception e){e.printStackTrace ();} 7w9'xY
`.~S/$a.&
'#=n>
} N3#^Ifn[
1QmOUw}yj
}[!=O+gO
public static void main(String[] args) A*+gWn,4Y_
{ }8}`A\dgV
new TestMethod(); N\tFK*U^I
} 5 Slz^@n
} 5({_2meJ:
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