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)); F>[^m Xw
} )G]J@36
for(int i=0;i<nEndPos.length-1;i++) Xf{p>-+DL
{ \ E5kpm
nEndPos = nStartPos[i+1]; "iK'O =M
} 0lYP!\J3]%
nEndPos[nEndPos.length-1] = nFileLength; PV=sqLM~
} &n83>Q
} RCK*?\m5
}y+a)2
OzRo
//启动子线程 w+!V,lU"^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :l Z\=2D
for(int i=0;i<nStartPos.length;i++) "av/a
{ e9S*^2;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^n4aoj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wu{%gtx/;^
nStartPos,nEndPos,i); xZV|QVY;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b!"qbC1
fileSplitterFetch.start(); r<P?F
} &js$qgY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |6Iw\YU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4{6,Sx
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o?.VW/"
nEndPos = " + nFileLength); XJS^{=/
// fileSplitterFetch[nPos.length-1].start(); _wW"Tn]
$mf6!p4
\sW>Y#9]
//等待子线程结束 !@ AnwV]
//int count = 0; b1=! "Y@
//是否结束while循环 w`#9Re
boolean breakWhile = false; L!ms{0rJ
s6 K~I
SST@
while(!bStop) 4m~p(r
{ (0?FZ.9%
write_nPos(); 2U+Fat@
Utility.sleep(500); +f_3JL$
breakWhile = true; V{qR/
qCm%};yt
md : Wx
for(int i=0;i<nStartPos.length;i++) DC$> 5FDv
{ j \#y
if(!fileSplitterFetch.bDownOver) w/(2fU(
{ nAj +HLO
breakWhile = false; O=!EqaExW
break; LR"7e
} "oR%0pU*
} }1sd<<\`
if(breakWhile) $O\]cQD`u
break; QNj6ETB-d
sN1I+X
AVc|(~V
//count++; /" &Jf}r
//if(count>4) [>QzT"=
// siteStop(); *;T HD>
} BBl9<ne$
Fj<a;oV
9Z3Y,`R,
System.err.println("文件下载结束！"); x:]_z.5
} H3ob 8+J
catch(Exception e){e.printStackTrace ();} bD1IY1
} @_;vE(!5
o O1Fw1Y
i^}DIx{
//获得文件长度 %IUTi6P l
public long getFileSize() 6WLq>Jo
{ 7Uh/Gl
int nFileLength = -1; \ERHnh
try{ ]XfROhgP=
URL url = new URL(siteInfoBean.getSSiteURL()); *}ZKQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6:G::"ew
httpConnection.setRequestProperty("User-Agent","NetFox"); IU]@%jA_:A
eGbjk~,f'
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int responseCode=httpConnection.getResponseCode(); (xBWxeL~
if(responseCode>=400) DpL|aRdbK
{ "j}fcrlG9
processErrorCode(responseCode); @iYr<>iDZ
return -2; //-2 represent access is error a 0qDRB
} r$!
re@OPiXa v
\e?w8R.6w^
String sHeader; G`u";w_
\!r,>P
*;<oM]W_
for(int i=1;;i++) k3e?:t 9
{ rPJbbV",+^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); nqib`U@"
//Utility.log(in.readLine()); ~_4$|WKl
sHeader=httpConnection.getHeaderFieldKey(i); {'f=*vMI
if(sHeader!=null) MrS~u
{ glNXamo
if(sHeader.equals("Content-Length")) { %af
{ ;J?zD9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); mS-{AK
break; 1jj.oa]
} R"JT+m
} (V8lmp-F
else {F*81q\
break; Q$^Kf]pD
} (#r>v h(
} 9Jf.Ls
catch(IOException e){e.printStackTrace ();} #)<WQZ)
catch(Exception e){e.printStackTrace ();} :c&F\Q=
zCpXF<_C
53?B.\
Utility.log(nFileLength); 6vZ.CUK9
/q6 ^.>b
um mkAeWb
return nFileLength; _n3"
} E&2mFg
FZJ sZeO
sfEy
//保存下载信息（文件指针位置） rp,PhS
private void write_nPos() .h>tef
{ 7?~*F7F
try{ h#I]gHQK
output = new DataOutputStream(new FileOutputStream(tmpFile)); /Os;,g
output.writeInt(nStartPos.length); f\M;m9{(
for(int i=0;i<nStartPos.length;i++) Kd^,NAg
{ G\o*j|
// output.writeLong(nPos); eTY""EWU
output.writeLong(fileSplitterFetch.nStartPos); %0^taA
output.writeLong(fileSplitterFetch.nEndPos); ch:0qgJ
} oxgh;v*
output.close(); UhF+},gU
} sT%^W
catch(IOException e){e.printStackTrace ();} oi/bp#(fa
catch(Exception e){e.printStackTrace ();} ADVHi3b
} "_36WX
Uz; pNWMk
Bis'59?U_
//读取保存的下载信息（文件指针位置） `]l*H3+hg
private void read_nPos() pe7R1{2Q_s
{ DM)%=C6<
try{ 6 2#dSd}HG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); s*.&DN
int nCount = input.readInt(); $tFmp)
nStartPos = new long[nCount]; c/ABBvd|
nEndPos = new long[nCount]; !$^LTBOH3
for(int i=0;i<nStartPos.length;i++) m}>#s3KPA
{ zD}2Zh]
nStartPos = input.readLong(); D= LLm$y
nEndPos = input.readLong(); [(4s\c
} '6W|,
input.close(); ,aQ{
} ~OQ/ |ws
catch(IOException e){e.printStackTrace ();} (cEjC`]
catch(Exception e){e.printStackTrace ();} QGQ}I
} uf&Ke k,
K trR+:
fp2.2 @[
private void processErrorCode(int nErrorCode) I2<t?c:Pn<
{ 0!!z'm3
System.err.println("Error Code : " + nErrorCode); >`!Lh`n7_
} (}NKW
mk&`dr
8 ,<F102(
//停止文件下载 kc&MO`2 W\
public void siteStop() xHY#"
{ o+T%n1$+V
bStop = true; 8<Yqpb
for(int i=0;i<nStartPos.length;i++) OKp0@A)8
fileSplitterFetch.splitterStop(); {Kkut?5
2YL)" w
v08Xe*gNU
} ;`MKi5g
} fu6Ir,
//负责部分文件的抓取 57eA(uI
**FileSplitterFetch.java b63tjqk
*/ 5t&;>-A'?'
package NetFox; 12MWO_'g8
MehMhHY
vpl> 5%
import java.io.*; 3BWYSJ|
import java.net.*; y7)$~R):-
yw9)^JU8"
z&r@c-l@
public class FileSplitterFetch extends Thread { ES&"zjr$
*D$[@-7
'qT[,iQ
String sURL; //File URL 9EqU 2~
long nStartPos; //File Snippet Start Position ?$&iVN^UA
long nEndPos; //File Snippet End Position iO_6>&(
int nThreadID; //Thread's ID kX)Xo`^Ys
boolean bDownOver = false; //Downing is over |Q)c{9sD
boolean bStop = false; //Stop identical l;C00ZBOc
FileAccessI fileAccessI = null; //File Access interface Xitsbf=Gg
M@b:~mI[sw
UX& ?^]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bzt(;>_8
{ K_X10/#b&
this.sURL = sURL; Pa-p9]gq
this.nStartPos = nStart; Lupug"p0
this.nEndPos = nEnd; 5D#Mhgun
nThreadID = id; y6*9, CF
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6+hx64 =
} gwyHDSo8:a
b^~"4fU
-'iV-]<
public void run() - P$mN6h
{ K4\#b}P!
while(nStartPos < nEndPos && !bStop) aV9QIH~
{ ^k7`:@ z0U
z|:3,$~sN
qfQg?Mr
try{ ,J3s1 ]~^
URL url = new URL(sURL); <.yL&$9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yRt>7'@X
httpConnection.setRequestProperty("User-Agent","NetFox"); @d]a#ypU
String sProperty = "bytes="+nStartPos+"-"; dq&N;kk |
httpConnection.setRequestProperty("RANGE",sProperty); ^t'mfG|DV
Utility.log(sProperty); :t36]NM
PfRe)JuB
"ApVgNB
InputStream input = httpConnection.getInputStream(); E0Y>2HOuL
//logResponseHead(httpConnection); xy$agt>j>
`Z3p( G
A*r6
byte[] b = new byte[1024]; &2EimP
int nRead; k15B5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;n)9
{ d/fg
nStartPos += fileAccessI.write(b,0,nRead); n\ yDMY
//if(nThreadID == 1) u\9t+wi}<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `(rnD
} XDWR]
fi6i{(K
1D6F WYV8
Utility.log("Thread " + nThreadID + " is over!"); 0A}'@N@G)
bDownOver = true; _4]GP3`
//nPos = fileAccessI.write (b,0,nRead); l,pI~A`w_
} LR5X=&k
catch(Exception e){e.printStackTrace ();} B?cn5
} $ MN1:ih
} ah(lH5r
CQ`$' oy?W
<oc"!c;T
//打印回应的头信息 xElHYh(\
public void logResponseHead(HttpURLConnection con) 4*K~6Vh
{ 5w# Ceg9
for(int i=1;;i++) 2tq~NA\#t
{ Kn!n}GtR
String header=con.getHeaderFieldKey(i); 0"*!0s~
if(header!=null) rLU+-_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Y30e7d* qr
Utility.log(header+" : "+con.getHeaderField(header)); E9]/sFA-]
else ZT\=:X*e
break; "5+x6/9b
} Z?7XuELKV
} yJj$iri
Vlk]
e95x,|.-_
public void splitterStop() ># {,(8\
{ &ZmHR^Flz
bStop = true; 91 ]"D;NN
} ;U02VguC
1${lHVx]
_.ny<r:g
} xzqgem`[\
U=<d;2N#
X~`<ik{q
/* *Z+8L*k97
**FileAccess.java jI-\~
*//文件访问(定位，写) PW[NW-S`c
package NetFox; `H_.<``>
import java.io.*; P2q'P&
`pHlGbrW
2Op\`Ht&
public class FileAccessI implements Serializable{ wcdD i[E>i
sC/5N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?W#>9WQi
RandomAccessFile oSavedFile; RW#&f*
long nPos; 5L'bF2SI
Y'75DE<BC
x2^Yvgc-
public FileAccessI() throws IOException Guc~] B
{ 3(Y#*f|
this("",0); *5\k1-$
} C1/<t)^
y}'c)u
%,l+?fF
public FileAccessI(String sName,long nPos) throws IOException &s +DK`
{ <rO0t9OH
oSavedFile = new RandomAccessFile(sName,"rw"); qB`-[A9HPe
this.nPos = nPos; KNkVI K
oSavedFile.seek(nPos); `YZK$ -,
} TTJFF\$?
m_ |:tU(t
(#dwIBBFt
public synchronized int write(byte[] b,int nStart,int nLen) _o 2pyV&
{ kiW|h)w_,v
int n = -1; ]/o0p
try{ MQ9Nn|4
oSavedFile.write(b,nStart,nLen); t3~ZGOn
n = nLen; bD&^-& G
} Qj?qWVapA
catch(IOException e) -FAAP&LG
{ YPjjSi:#
e.printStackTrace (); C&&*6E5
} R::0.*FF
7+,6m!4
nK@RFU6
return n; /_N*6a~
} )9^0Qk' ]
BD)5br].
rQ^X3J*`
} =Me94w>G3X
V/=NIeSE
{Z529Ns
/* :GXD-6}^|
**SiteInfoBean.java \m>mE/N
*/ QbF!V%+a's
package NetFox; h83;}>
'u\my
&0E>&1`7
public class SiteInfoBean { *u2pk>y)
[7K-L6X
X-tc Ud
private String sSiteURL; //Site's URL ,[64$=R8
private String sFilePath; //Saved File's Path MOiTzL*
private String sFileName; //Saved File's Name Ur`jmB
private int nSplitter; //Count of Splited Downloading File o3_dHbdI
O4Wn+$AN
VSK!Pc.G}
public SiteInfoBean() v<*ga7'S
{//nSplitter的缺省值为5 WBo|0(#
//default value of nSplitter is 5 .>5KwEK~
this("","","",5); 7*!h:rg
} xq?9w$
rmX'Ym9#
]BY^.!Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) H nKO
{ `^rN"\
sSiteURL= sURL; ]kJinXHW
sFilePath = sPath; sH//*y
sFileName = sName; &rTOJ1)V}
this.nSplitter = nSpiltter; C^}2::Qu
To x{Sk3L
SJYy,F],V"
} R]0p L
`N+A8
bNUb
public String getSSiteURL() mkA1Sh{hX>
{ //SH=>w2
return sSiteURL; x@-bY
} aoLYw 9
g4NxNjM;
}U)g<Kzh
public void setSSiteURL(String value) >L\>Th{o
{ =}:9y6QR.
sSiteURL = value; Y9b|lP7!
} uQ^r1 $#
*W'F6Hpu
a3&&7n
public String getSFilePath() 2"31k2H[
{ y"|QY!fK
return sFilePath; z9@Tg=#i
} $1QQidB
`MMh"# xN
@yBg)1AL
public void setSFilePath(String value) &3 QdQn,
{ QJBzv|
sFilePath = value; F9hh- "(Z
} *O>OHX
n:hHm,
~!*xi
public String getSFileName() byj}36LN62
{ JGP<'6"L$
return sFileName; NVEjUt/
} +-~:E_G
WaU+ZgDrG
#WBlEVx;Z
public void setSFileName(String value) _JlbVe[<
{ taS2b#6\+
sFileName = value; BPp`r_m8w}
} k4|9'V&1*6
vqq7IV)|
[dm&I#m=
public int getNSplitter() kB|jN~
{ 111s%
return nSplitter; #cG7h(!
} XcoV27
U@W3x@
~9&#7fU
public void setNSplitter(int nCount) `>M-J-J
{ m).S0
nSplitter = nCount; "62vwWrwO
} AlW0GK=N-p
} Eei"baw/
.ZuRH_pI
r(ej=aR
/* )E--E+j
**Utility.java )ZxDfRjL
*/ Xb0$BAP
package NetFox; 72hN%l
d|GQZAEJEt
(w31W[V'#
public class Utility { V3%"z
3;M7^DM
<eU1E}BDQ
public Utility() \Tf$i(0q
{ .\r=1HZ3
9FB[`}
yN9k-IPI
} 'H"wu /#
"m*.kB)e7
//线程睡眠 \;al@yC=T
public static void sleep(int nSecond) r)ni;aP
{ cL31g_u
try{ XCCh*qym
Thread.sleep(nSecond); m3Mo2};?
} 8(yZX4OH>
catch(Exception e) VMry$
{ g"k1O
e.printStackTrace (); 8>T#sO?+
} +D[|Mi
} |eN#9Bm
5a$Q}!6E.Y
//日志 X9W'.s.[Q
public static void log(String sMsg) UDjmXQ2,
{ ~7!=<MW
System.err.println(sMsg); \!!qzrq
} QucDIZ
|Z]KF>S]
L-B"P&
public static void log(int sMsg) xvP=i/SO
{ ]/l"
System.err.println(sMsg); "Di27Rq
} :O`7kZ]=n
} ~d0:>8zQR
OT1
~UrKyA
/* l@;UwnI
**TestMethod.java #[|~m;K(w
*/ 4@2<dw|*h
package NetFox; j7(sYo@x7
`Aa}q(}k
kF%EJuu
public class TestMethod { U_s3)/'
MQs!+Z"m>
#Tc]L<."
public TestMethod() 8fV.NCyE
{ ///xx/weblogic60b2_win.exe o1Bn^w
try{ nWfzwXP>_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); j@N z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); CSKOtqKQ)
SiteFileFetch fileFetch = new SiteFileFetch(bean); C`G+b{o
fileFetch.start(); fL0dy[Ch@
} 9((BOq
catch(Exception e){e.printStackTrace ();} ~m/nV81
Xk9mJ]31LC
lk.]!K$}
} wM$N#K@
`ChS$p"A
mf~JolucJ
public static void main(String[] args) a ~s:f5S>
{ _&(\>{pm
new TestMethod(); xwuGJ
} [ B{F(~O
} v|!u]!JM
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