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)); SX$v&L<
} p.n+m[
for(int i=0;i<nEndPos.length-1;i++) {w1sv=$+
{ j[v<xo
nEndPos = nStartPos[i+1]; Zw`Xg@;xP
} fXEF]C
nEndPos[nEndPos.length-1] = nFileLength; s-~Tf|
} -!k"*P
} vn9_tL&
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//启动子线程 N{ @B@]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; D<]z.33
for(int i=0;i<nStartPos.length;i++) =i4Ds
{ _ ^r KOd
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {YT!vD9.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &ScADmZP^d
nStartPos,nEndPos,i); oyiEOC
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MyXgp>?~T
fileSplitterFetch.start(); X~T"n<:a>
} Yw vXSA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C2<!.l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); '!I^Lfz-Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m\)z& hv<r
nEndPos = " + nFileLength); D4?5%s
// fileSplitterFetch[nPos.length-1].start(); "}Of f
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d;daYjOm
//等待子线程结束 T&
//int count = 0; t-)C0<
//是否结束while循环 l}A8
boolean breakWhile = false; K1AI:$H
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qCi6kEr
while(!bStop) %(79;#2`
{ prV:Kq;O
write_nPos(); za`
Utility.sleep(500); Es/\/vF7]D
breakWhile = true; DJ2EV^D+P
VPx"l5\
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for(int i=0;i<nStartPos.length;i++) Fc%@
{ > SU2Jw
if(!fileSplitterFetch.bDownOver) :n4?
{ C0eP/d
breakWhile = false; KWq7M8mq
break; K3Zc>QL{
} hiZE8?0+~N
} . T6fPEb
if(breakWhile) q$(@
break; 5*l~7R
(,#Rj$W
/f@VRME
//count++; nw){}g
//if(count>4) l*T>9yC
// siteStop(); </3Shq
} ]([:"j
4mq+{c0
rLw3\>y
System.err.println("文件下载结束！"); n7>CK?25
} j'Z};3y
catch(Exception e){e.printStackTrace ();} [#S}L(
} H|T!}M>
vtM!?#
@-|{qP=Dy
//获得文件长度 R}'kF63u*
public long getFileSize() 6Lk<VpAa
{ [XK Ke
int nFileLength = -1; TR/'L!EE
try{ {%.FIw k
URL url = new URL(siteInfoBean.getSSiteURL()); f0]8/)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c%9wI*l
httpConnection.setRequestProperty("User-Agent","NetFox"); o7' cC?u
!*_5 B'
v<c~ '?YzO
int responseCode=httpConnection.getResponseCode(); Bt[OGa(q
if(responseCode>=400) }>Gnpc
{ P~$FgAV
processErrorCode(responseCode); :oh(M|;/2
return -2; //-2 represent access is error u4*7n-(
} BQq,,i8H
bU9B2'%E
t2d_XQOK
String sHeader; /^v?Q9=Y
RLBjl%Q>
)xYv$6=
for(int i=1;;i++) m22M[L(q
{ WDc2Qt
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *&]x-p1m
//Utility.log(in.readLine()); bI/d(Q%#<
sHeader=httpConnection.getHeaderFieldKey(i); (,<&H;,8
if(sHeader!=null) chv0\k"'
{ Z".mEF-b
if(sHeader.equals("Content-Length")) Q|/uL`_ni
{ |y=;#A
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W!|A3V35\:
break; pcwkO
} R L&z\S
} +Gv{Apd"
else 2gLa4B-
break; &(a#I]`9M
} a'=C/ s+
} gRA}sF
catch(IOException e){e.printStackTrace ();} Blv!%es
catch(Exception e){e.printStackTrace ();} Z |wM
^c",!Lp}{
A??(}F L
Utility.log(nFileLength); ma@3BiM
#Bq.'?c'~
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return nFileLength; P[{qp8(g
} }? j>V
2(~Y ^_
)f(.{M
//保存下载信息（文件指针位置） DtkY;Yl
private void write_nPos() 3~ITvH,`s
{ JQ|qg\[
try{ %HOMX{~}#
output = new DataOutputStream(new FileOutputStream(tmpFile)); Du@?j7&l=$
output.writeInt(nStartPos.length); :l<)p;\
for(int i=0;i<nStartPos.length;i++) *opf~B_e
{ `QC
// output.writeLong(nPos); Qx{k_ye`
output.writeLong(fileSplitterFetch.nStartPos); $%~-p[)<(P
output.writeLong(fileSplitterFetch.nEndPos); 0\3mS{s
} %Ci`OhT
output.close(); Z^?1MJ:`
} 0?kaXD
catch(IOException e){e.printStackTrace ();} wcz|Zy
catch(Exception e){e.printStackTrace ();} h&Thq52R
} |tL57Wu93
=\CJsS.
H}G=%j0
//读取保存的下载信息（文件指针位置） $B6CLWB
private void read_nPos() @pq#?
{ .Y B}w
try{ HsrIw
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); O%RkU?ME
int nCount = input.readInt(); jSa9UD
nStartPos = new long[nCount]; Q|40 8EM
nEndPos = new long[nCount]; X"QIH|qx-
for(int i=0;i<nStartPos.length;i++) fh~"A`d
{ Fe8JsB-
nStartPos = input.readLong(); EX^}#|e*h
nEndPos = input.readLong(); ];BGJ5^j
} z"/Mva3|
input.close(); 4u}"ng
} #sl_ BC9
catch(IOException e){e.printStackTrace ();} 8vFt<k}G
catch(Exception e){e.printStackTrace ();} m# #( uSh
} 0ox 8_l
;{1J{-EA
,nn5LQ|l.j
private void processErrorCode(int nErrorCode) `m2e *
{ 52+;j[ ]/O
System.err.println("Error Code : " + nErrorCode); (eX9O4
} v=!Ap ; 2L
WT(inf[
&0B<iO<f
//停止文件下载 d&S4`\g?8
public void siteStop() /*g9drwaa
{ c2M-/ x-:
bStop = true; aq-`Bar
for(int i=0;i<nStartPos.length;i++) Hg8n`a;R
fileSplitterFetch.splitterStop(); FO"8B
zh5'oE&[yC
dre@V(\;hQ
} z@!zQ Vp
} m)G=4kK52-
//负责部分文件的抓取 QmQsNcF~z
**FileSplitterFetch.java f8]Qn8
*/ TBq;#+1W
package NetFox; |n9~2R
;8WgbR)ZLU
qyXx`'e
import java.io.*; 7U=|>)Q0s
import java.net.*; ^qNh)?V?]I
w k1O*_76
BR8W8nRb
public class FileSplitterFetch extends Thread { $HjKELoJ<
mHTZ:84
4%l @
String sURL; //File URL emZ^d/A
long nStartPos; //File Snippet Start Position rNzsc|a:
long nEndPos; //File Snippet End Position 1rhsmcE
int nThreadID; //Thread's ID /4 zO
boolean bDownOver = false; //Downing is over j.C)KwelBS
boolean bStop = false; //Stop identical @V$,H/v:
FileAccessI fileAccessI = null; //File Access interface e&&;"^@-
.ZSGnbJ
cG%ttfq\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException V,,/}f'
{ )9_jr(s
this.sURL = sURL; &cj/8A5-
this.nStartPos = nStart; _n9+(X3
this.nEndPos = nEnd; KX*Hev'K
nThreadID = id; $`q8-+{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 a }6Fj&hj
} KM$5ZbCF:
NwQexYm1_
z-(#Mlq:!
public void run() 1_JxDT,=>
{ wg6![Uh
while(nStartPos < nEndPos && !bStop) .0x+b-x
{ urGk_.f
Zf~[4Eeb
z`gdE0@;d3
try{ jYwv+EXg
URL url = new URL(sURL); ^{<x*/nK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4Q0@\dR9
httpConnection.setRequestProperty("User-Agent","NetFox"); X|.M9zIx
String sProperty = "bytes="+nStartPos+"-"; @g|Eb}t
httpConnection.setRequestProperty("RANGE",sProperty); qwAN=3@
Utility.log(sProperty); wn*z*
F?j;3@z[A
4m++>q
InputStream input = httpConnection.getInputStream(); r4Ygy/%
//logResponseHead(httpConnection); ZdQm&?
y^; =+Z
uA;3R\6?
byte[] b = new byte[1024]; ]+\@_1<ZI
int nRead; /BWJ)6#H
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dZ!Wj7K)
{ `!MyOI`qS
nStartPos += fileAccessI.write(b,0,nRead); mT57NP
//if(nThreadID == 1) 6T6 S9A*nT
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hjiU{@q
} !Ju?REH
2A3;#v
\Cx) ~bq<
Utility.log("Thread " + nThreadID + " is over!"); <YbOO{
bDownOver = true; $)| l#'r
//nPos = fileAccessI.write (b,0,nRead); Zl]Zy}p*+
} w>I>9O}(`
catch(Exception e){e.printStackTrace ();} 7^k`:Z
} +Ux)m4}j
} NLDmZra
=J.)xDx*
oRM EC7!A0
//打印回应的头信息 od>DSn3T
public void logResponseHead(HttpURLConnection con) y:!MWZ
{ x&3!z[m@@
for(int i=1;;i++) 4QWDuLu
{ 9H*$3
String header=con.getHeaderFieldKey(i); ~CRr)(M
if(header!=null) s~$kzEtjjU
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _>HXQ6Hw
Utility.log(header+" : "+con.getHeaderField(header)); UTQ$sg|7p
else }~lF Rf
break; OVO0Emv
} [KkLpZG
} jIMaPT
+MC>?rr_u
s-r$%9o5
public void splitterStop() e,Xvt5
{ uR"srn;^
bStop = true; puS'9Lpp
} ]I"oS?
p#.B Fy
XgKtg-,
} 9bjjo;A
@f0~a
CAY^ `K!
/* c1wM"
**FileAccess.java Kzxzz6R?
*//文件访问(定位，写) ".| 9h
package NetFox; >]"5K<-1
import java.io.*; ,[+
~az6n)
sSOI5W3A
public class FileAccessI implements Serializable{ ZZTPAmIr
_,b%t1v
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7dX1.}M<(
RandomAccessFile oSavedFile; %iIryv;
long nPos; _jef{j
A<iF37.
e =& abu
public FileAccessI() throws IOException ld94ek
{ 7"=
this("",0); ,oDZ:";
} g'Ft5fQ"o/
j._9;HifZ
ltt%X].[
public FileAccessI(String sName,long nPos) throws IOException >82Q!HaH
{ E?&dZR
oSavedFile = new RandomAccessFile(sName,"rw"); 'q1)W'
this.nPos = nPos; sCaw"{5qc
oSavedFile.seek(nPos); /exV6D r
} u7@|fND 7
%'`Dd
'jcDfv(v<
public synchronized int write(byte[] b,int nStart,int nLen) iAf, :g
{ qsFA~{o.
int n = -1; oypq3V=5
try{ XPzwT2_E
oSavedFile.write(b,nStart,nLen); =,-80WNsX
n = nLen; 6fPuTQ}fY>
} ,e>C)wq;
catch(IOException e) M#})
{ /'E+(Y&:J
e.printStackTrace (); $${ebt
} %kNkDI
*%ZfE,bu8<
Gyy:.]>&
return n; 8NeP7.U<w
} 65ijzZL;
Mim 9C]h(
e@p` -;<
} hr@KWE`
A3&8@/6,
-+|0LXo
/* B/E1nBobC
**SiteInfoBean.java D8h?s
*/ }<FBcc(n
package NetFox; Qo?"hgjlqm
=DE5Wq19
8[f]9P/i
public class SiteInfoBean { xQ1&j,R]
@)VJ,Ql$Y
O:r<es1
private String sSiteURL; //Site's URL CJjma=XH
private String sFilePath; //Saved File's Path /c/!13|
private String sFileName; //Saved File's Name H|F>BjXn5
private int nSplitter; //Count of Splited Downloading File \R&`bAdk
K]@6&H-b|
2|EHNy!
public SiteInfoBean() BAmH2"
{//nSplitter的缺省值为5 6$SsdT|8B
//default value of nSplitter is 5 D8`,PXtV
this("","","",5); zfi{SO l
} M0c"wi@S_
5/:Zj,41{
ICq;jfML
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) PKdM-R'Z
{ o [ar.+[
sSiteURL= sURL; \C}tK,79
sFilePath = sPath; :+]6SC0ql
sFileName = sName; I$qL=
this.nSplitter = nSpiltter; a<!g*UVL0M
F8b*Mt}p
`mw@"
} W@"M/<r@/
yuFuYo&[?v
?ZlwRjB\
public String getSSiteURL() P;hjr;
{ 3m7$$N|
return sSiteURL; _sZ/tU@_-K
} F1Egcx/$V
t47 f$gq
34JkB+#a
public void setSSiteURL(String value) c)@M7UK[
{ 4CX*
sSiteURL = value; S)g5Tu)
} L=Dx$#|
MrOW&7
.&r] ?O
public String getSFilePath() ]3 0 7.
{ X:8=jHkz
return sFilePath; J_rCo4}
} EF)kYz!@
c~RElL
\FVR'A1
public void setSFilePath(String value) =\X<UA}
{ oH6(Lq'q
sFilePath = value; n6Q 3X
} cY\-e?`=4
[`ttNW(_
,Hys9I
public String getSFileName() ~Gwn||g78
{ gvA&F|4
return sFileName; 8l!S<RA
} L>@0Nne7
Fdc bmQ
J|6aa
public void setSFileName(String value) 6_zL#7E'
{ `;cKN)Xk
sFileName = value; Qt>yRt
} 8VMq>-
.V/TVz!b
1f[!=p
public int getNSplitter() 8{?Oi'-|0
{ D*D83z OzN
return nSplitter; &rw|fF|]
} C:4h
Zls4@/\Q
<PV @JJ"
public void setNSplitter(int nCount) 3%<ia$
{ BvX!n"QIb
nSplitter = nCount; gN mp'Lm
} zT_{M qY
} -pqShDar|
'Iu$4xo`[
OkzfQ hC}
/* cE]tvL:g
**Utility.java #exE~@fy-
*/ ;2dhue
package NetFox; 7!MW`L/`
HCHC~FNd
00b )Bg
public class Utility { &,)9cV /
!(SaE'
7z%zXDe~T[
public Utility() `]tXQqD
{ AFMAgf{bD
,C=Fgxw(
-QZped;?*
} 4s"8e]q=
3j.f3~"
//线程睡眠 h ?p^DPo
public static void sleep(int nSecond) (#Y2H
{ R_@yj]%H=
try{ (5G^"Srw
Thread.sleep(nSecond); @9vz%1B<l
} ej!C^
catch(Exception e) 1Ete;r%5=
{ Pi+,y
e.printStackTrace (); "F%cn@l
} vRT1tOQ$
} e?Cbl'
)C|>M'g@v
//日志 evszfCH'J
public static void log(String sMsg) +(|T\%$DT
{ nHT2M{R
System.err.println(sMsg); vkBngsS
} kTC6fNj[
dAAE2}e
W"wP%
public static void log(int sMsg) X0U{9zP
{ cm7aL%D$c
System.err.println(sMsg); EzG7RjW
} #~p1\['|M
} `+* Mr
vn,L),"=
TSuHY0.cp
/* 'iL['4~.
**TestMethod.java <[a9"G7
*/ &p4q# p7,
package NetFox; z),l&7
] YQ*mvI]
:_H$*Q=1
public class TestMethod { GD*6tk;5/
fMLm_5(H
Yq;S%.
public TestMethod() },[j+wx
{ ///xx/weblogic60b2_win.exe =VY[m-q5
try{ u4.-AY {
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pV>/"K
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;o8cfD.z
SiteFileFetch fileFetch = new SiteFileFetch(bean); y f+/Kj< a
fileFetch.start(); ]Fjz+CGg
} 9"<)DS
catch(Exception e){e.printStackTrace ();} <'B`b
C{Npipd}v
tk, HvE
} 0Y"==g+>f
pK$^@~DE
teM&[U
public static void main(String[] args) cQ+V4cW Z
{ WJJ!NoP
new TestMethod(); !_V*VD
} +o_`k!
} ZC0F:=/K
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