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)); &._!)al
} n5.>;N.*
for(int i=0;i<nEndPos.length-1;i++) ~7pjk
{ |a{]P=<q
nEndPos = nStartPos[i+1]; :OCuxSc%5
} d|]O<]CG_
nEndPos[nEndPos.length-1] = nFileLength; 4_+Pv6
} [+g@@\X4
} ,:4DN&<
jJZsBOW[8
m>ycN
//启动子线程 V=&,^qZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7E`(8i
for(int i=0;i<nStartPos.length;i++) T-C#xmY(
{ ulf/C%t,R
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xGfDz*t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zpqGh
nStartPos,nEndPos,i); z,FTsR$x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @b\ S.
fileSplitterFetch.start(); *Ca)RgM
} c%@~%IGF
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _i[)$EgFm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cEc,eq|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lVdT^"~3
nEndPos = " + nFileLength); ,6;xr'[o*
// fileSplitterFetch[nPos.length-1].start(); Xexe{h4t_>
vo ;F;
&3Z. #*
//等待子线程结束 +'/}[1q1/T
//int count = 0; *fi;ZUPW3
//是否结束while循环 @GQ8q]N:<
boolean breakWhile = false; ]A72)1
oL Vtu5
/;&+< }
while(!bStop) BwJ^_:(p~
{ c~UAr k S
write_nPos(); u:$x6/t
Utility.sleep(500); ;,=h59`
breakWhile = true; ]}[Yf
wB>S\~i
b"M`@';+
for(int i=0;i<nStartPos.length;i++) K- I\P6R`
{ :X1cA3c!
if(!fileSplitterFetch.bDownOver) g&+Y{*Gp
{ T5Sg2a1&
breakWhile = false; tB7K&ssi
break; &.Latx
} /Y[o=Uyl
} 3`k[!!
if(breakWhile) FU\/JF.j
break; ?orhJS
0^9:KZ.!
b>QM~mq3^I
//count++; cc41b*ci$
//if(count>4) "65||[=8
// siteStop(); /&$"}Z6z
} Ty3CBR{6
5'X74`
(@ fa~?v>@
System.err.println("文件下载结束！"); y98JiNq
} i)7n c
catch(Exception e){e.printStackTrace ();} DhLr^Z!h3;
} EK?@Z.q+
mN\%fJ7
goDV2alC^
//获得文件长度 Yz=h"Zr
public long getFileSize() M!Z*QY."P
{ }UKgF.
int nFileLength = -1; jVad)2D
try{ cX%:
URL url = new URL(siteInfoBean.getSSiteURL()); |Bx||=z`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F1gt3 ae
httpConnection.setRequestProperty("User-Agent","NetFox"); V(;55ycr
-(\1r2 Y
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int responseCode=httpConnection.getResponseCode(); 3s`V)aXP
if(responseCode>=400) 48tcgFg[
{ /a[V!<"R
processErrorCode(responseCode); [)#u<lZ<~
return -2; //-2 represent access is error t_dcV%=
} qDnCn H
+ a-wv
5vD3K!\u
String sHeader; xwPI
"jL1.9%"
I&L.;~
for(int i=1;;i++) (n=9c%w
{ "^;#f+0
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); j4;Du>obQ
//Utility.log(in.readLine()); \U/v;Ijf
sHeader=httpConnection.getHeaderFieldKey(i); _*s~`jn{H
if(sHeader!=null) QVIcb;&:}
{ h&lyxYZ+T$
if(sHeader.equals("Content-Length")) /~40rXH2C
{ {7vgHutp
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :?HSZocf
break; \V]t!mZ-}l
} ,-@xq.D
} C<_Urnmn
else h`=r)D
break; A9 U5,mOz
} jcE Msc
} p-.Ri^p
catch(IOException e){e.printStackTrace ();} '%R<"
catch(Exception e){e.printStackTrace ();} 8tU>DJ}0
swttp`
C(G(^_6
Utility.log(nFileLength); jDR')ascn
H4t)+(:D'
d$w(-tV42
return nFileLength; ^f9>l;Lb
} z. 'Fv7
>-b&v$
wb b*nL|P
//保存下载信息（文件指针位置） H"eS<eT
private void write_nPos() nE_Cuc>K\
{ >?z:2@Q)B
try{ FC{})|yh }
output = new DataOutputStream(new FileOutputStream(tmpFile)); $!f!,fw+
output.writeInt(nStartPos.length); 42&v% ;R
for(int i=0;i<nStartPos.length;i++) *ot>WVB
{ `?l3Ct*
// output.writeLong(nPos); "# !D|[h0
output.writeLong(fileSplitterFetch.nStartPos); 2`EVdl7B]
output.writeLong(fileSplitterFetch.nEndPos); ;`DD}j`
} tAERbiH
output.close(); K4: $=
} 3A_G=WaED
catch(IOException e){e.printStackTrace ();} vB.l0!c\e_
catch(Exception e){e.printStackTrace ();} @OzMiN
} Or7 mD
[ 7g><
uAUp5XP|Z
//读取保存的下载信息（文件指针位置） #.H}r6jqs
private void read_nPos() $E\^v^LW
{ h$>wv`
try{ 'S*k_vuN
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eNbpwne
int nCount = input.readInt(); 1fH<VgF`
nStartPos = new long[nCount]; 6kN:*
nEndPos = new long[nCount]; L_Q S0_1
for(int i=0;i<nStartPos.length;i++) -\4zwIH
{ 7b,(\Fm
nStartPos = input.readLong(); Q,gLi\siI
nEndPos = input.readLong(); {]^O:i"
} 7CGyC[[T~
input.close(); s9@Sd
} r{_>ldjq
catch(IOException e){e.printStackTrace ();} H>XFz(LWh
catch(Exception e){e.printStackTrace ();} zU&L.+
} KnGTcoXg_
.t=
'1Y\[T*
private void processErrorCode(int nErrorCode) eVJ^\z:4
{ }gv8au<
System.err.println("Error Code : " + nErrorCode); Z.1> kZ
} q9]IIv
6~xBi(m`
d|lpec
//停止文件下载 Rko M~`CT
public void siteStop() A%XX5*
{ UE.4qY_7
bStop = true; wNYg$d0M
for(int i=0;i<nStartPos.length;i++) T^:fn-S}=
fileSplitterFetch.splitterStop(); ac8P\2{"
!q' 4D!I
bm#(?
} ++jAz<46
} tU:EN;H
//负责部分文件的抓取 =r9r~SR#
**FileSplitterFetch.java b~w=v_[(I
*/ ;+/o?:AH
package NetFox; }t%W1UJ
*F`A S>
m@Rtlb
import java.io.*; 'xE _Cj
import java.net.*; mJ}opy!{;
Vzl^Ka'
S/tIwG ~e3
public class FileSplitterFetch extends Thread { gckI.[!b
/.z;\=;[n!
Ul+Mo&y-
String sURL; //File URL )]htm&q5
long nStartPos; //File Snippet Start Position aZ|=(]
long nEndPos; //File Snippet End Position )"+2Z^1-
int nThreadID; //Thread's ID >e,mg8u6$
boolean bDownOver = false; //Downing is over om h{0jA0
boolean bStop = false; //Stop identical )#iq4@)|g
FileAccessI fileAccessI = null; //File Access interface ,yd=e}lQx
9DQa PA6
cV{o?3<:B
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException kwpK1R4zs
{ x1&W^~
this.sURL = sURL; Pr ]Ka
this.nStartPos = nStart; Av'GB
this.nEndPos = nEnd; Yz$3;
nThreadID = id; y|wlq3o
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `;l.MZL!
} }a AH
d;mx<i=/
&0zT I?c
public void run() )Gw~XtB2
{ zOgTQs"ZH
while(nStartPos < nEndPos && !bStop) -#!x|ne
{ jh2t9SI~
N- H^lqD
Z[__"^}
try{ A+J*e
URL url = new URL(sURL); K"j_>63)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); } :=Tm]S
httpConnection.setRequestProperty("User-Agent","NetFox"); 'R`tLN
String sProperty = "bytes="+nStartPos+"-"; r%:+$aIt
httpConnection.setRequestProperty("RANGE",sProperty); $Iv2j">3)
Utility.log(sProperty); Tm_B^W}
]0hrRA`
r}[7x]sP
InputStream input = httpConnection.getInputStream(); <S?ddp2
//logResponseHead(httpConnection); AdRX`[ik
Q'_z<V
AKMm&(fh%
byte[] b = new byte[1024]; b4^`DHRu6
int nRead; !*6CWV0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >D201&*G%
{ {ZY+L;eg1
nStartPos += fileAccessI.write(b,0,nRead); b&1`NO
//if(nThreadID == 1) J{^RkGF
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b#7{{@H
} (=~&+z
$!&*xrrNM
]?*I9
Utility.log("Thread " + nThreadID + " is over!"); "Ph^BUAb
bDownOver = true; q.,JVGMS
//nPos = fileAccessI.write (b,0,nRead); |2{wG4
} 5^^XQ?"
catch(Exception e){e.printStackTrace ();} OS8q( 2z?s
} Y>'|oygHA
} !%$`Eq)M^7
" Hd|7F'u=
Qxj JN^Q
//打印回应的头信息 {%_L=2n6
public void logResponseHead(HttpURLConnection con) As>_J=8} 3
{ W.kM7z>G
for(int i=1;;i++) XQw>EZdj_N
{ Ja9e^`i;
String header=con.getHeaderFieldKey(i); _%QhOY5tv"
if(header!=null) =:~R=/ZXk
//responseHeaders.put(header,httpConnection.getHeaderField(header)); K4kMM*D
Utility.log(header+" : "+con.getHeaderField(header)); hdrm!aBd
else *QH28%^
break; |P%Jw,}]9
} =Q\r?(Iy
} Dc,I7F|%
jYKor7KTqT
%$b:X5$Z
public void splitterStop() >p"c>V& 8
{ ?!+MM&c-n
bStop = true; R6(oZph
} >D4#y
&G-!qxe
/HaHH.e
} i*Z"Me
"yS _s
s=;uc]9g
/* @<elq'2
**FileAccess.java R#I0|;q4|p
*//文件访问(定位，写) r[*Vqcz
package NetFox; k=jk`c{<[
import java.io.*; X"fb;sGT
h%uZYsK
ye,>A.
public class FileAccessI implements Serializable{ oaIi2=Tf
++^l]8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 MB~=f[cUnd
RandomAccessFile oSavedFile; 0E3[N:s
long nPos; 7Mg=b%IYs
;;#qmGoE
:qd`zG3
public FileAccessI() throws IOException 'ZDp5pCC;
{ 24z< gO
this("",0); f,kZ\Ia'r
} PoxK{Y
\nPEyw,U
X\bOz[\
public FileAccessI(String sName,long nPos) throws IOException J4fi'
{ Utnr5^].2O
oSavedFile = new RandomAccessFile(sName,"rw"); ,F,X ,
this.nPos = nPos; *%%g{ 3$
oSavedFile.seek(nPos); R#%(5-Zu#R
} iO|se:LY<
@$[?z9ck"
W04@!_) <
public synchronized int write(byte[] b,int nStart,int nLen) tMf}
{ MkfBuW;)
int n = -1; jIC_[
try{ old(i:2
oSavedFile.write(b,nStart,nLen); l`#4KCL(
n = nLen; S[PE$tYT#t
} wn/_}]T
catch(IOException e) 8%A#`)fb
{ u{['<r;I
e.printStackTrace (); u)}$~E>
} A kC1z73<
Lr$go6s
J}v}~Cv
return n; C~2F9Pg
} QdF5Cwf4
6-$jkto
p<2L.\6"
} E8$20Ue
D$ dfNiCH
6e9,PS
/* }B\a<0L/
**SiteInfoBean.java Ve}(s?hU5
*/ f$e[u Er
package NetFox; [ 9 {*94M
oHd FMD@
Mo?~_|}
public class SiteInfoBean { ]zE;Tw.S
_aGOb;h
%b&".mN
private String sSiteURL; //Site's URL {o_X`rgrL
private String sFilePath; //Saved File's Path $WyD^|~SF
private String sFileName; //Saved File's Name vQosPS_2L
private int nSplitter; //Count of Splited Downloading File G&D7a/G\
H?<N.Dq
n0r+A^]
public SiteInfoBean() C7lH]`W|/
{//nSplitter的缺省值为5 IUE~_7
//default value of nSplitter is 5 @$S+Ne[<
this("","","",5); zMbN;tu
} F,W~,y
'&x#rjo#
ZZ2vvtlyG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )97SnCkal
{ sGyeb5c
sSiteURL= sURL; :o0JY= 5
sFilePath = sPath; UK595n;P
sFileName = sName; fkuLj%R
this.nSplitter = nSpiltter; B~]k#Ot)
QLXN*c
e-:yb^
} #pP[xE"Y
jN{Xfjmfv
QS%%^+E2
public String getSSiteURL() K-bD<X
{ F"&~*m^+
return sSiteURL; G,?hp>lj
} 'Y*E<6:
xf<at->
pWy=W&0~qf
public void setSSiteURL(String value) !nqUBa
{ $@z5kwx:P
sSiteURL = value; (!ZM{Js%
} ^8 zR
OVm\
*@Lp`thq
public String getSFilePath() ;nep5!s;<
{ VPO N-{=`
return sFilePath; 2/vMoVT,
} AP68V
-m)X]]~C
>"|B9Woc
public void setSFilePath(String value) GR&z,
{ \]</w5 Pi,
sFilePath = value; 6g 5#TpCh
} 8K.R=
J2::'Hw*s
iIMd!Q.)@
public String getSFileName() D&od?3}E
{ !Fca~31R'
return sFileName; Gr7=:+0n|P
} uD}2<$PP
_Tf4WFu2
*AG#316
public void setSFileName(String value) 5*j?E
{ ;|pBFKx
sFileName = value; <vUbv
} wfNk=)^$
y+X2Pl
]"t@-PFX<
public int getNSplitter() + ,%&e
{ Q9~*<I> h;
return nSplitter; 1$D_6U:H0
} oI=fx Sjd
0O9Ni='Tn
|%J{RA
public void setNSplitter(int nCount) >hPQRd
{ ,VCyG:dw
nSplitter = nCount; v9:9E|,U+
} ur3(HL
} kddZZA3`
q#T/
QIB\AAclO
/* +@94;me
**Utility.java Yn@lr6s
*/ 6%t1bM a
package NetFox; byLft1
ePr&!Tz#
/LvRP yj@
public class Utility { $*AYcy7
eZSNNgD<:
5MN8D COF
public Utility() ;LG#.~f
{ e4!:c^?
<g1hxfKx5
t/cY=Wp
} ht2\y&si
t; 4]cg:_
//线程睡眠 Bk*F_>X"
public static void sleep(int nSecond) _JHd9)[
{ eM$sv9?
try{ d Vj_8>
Thread.sleep(nSecond); *A"~m!=
} =T(6#"
catch(Exception e) "t(p&;d
{ # WAZ9,t
e.printStackTrace (); qv]}$WU
} 4x
} E~]R2!9
)/pU.Z/
//日志 zG ^$"f2
public static void log(String sMsg) 43mP]*=A
{ MRb-H1+Xf
System.err.println(sMsg); Y8m1M-#w
} J%x\=Sv
SZ,YS 4M
<kGU,@6PF
public static void log(int sMsg) L1cI`9
{ =p*]Az
System.err.println(sMsg); | N[<x@
} BI3@|,._N
} lu<xv
Nv(9N-9r
7]blrN]
/* | #47O
**TestMethod.java H."EUcE{
*/ 9~p[
package NetFox; ti I.W
)}"wesNo".
^Wt*
public class TestMethod { ^pQCNKLBY
#vti+A~n,4
aqj@Cjk4Z
public TestMethod() Uk^B"y_
{ ///xx/weblogic60b2_win.exe (oEC6F
try{ uTKD 4yig
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X*{2[+<o
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); orWbU UC
SiteFileFetch fileFetch = new SiteFileFetch(bean); B56L1^7
fileFetch.start(); ]sE?ezu
} ?u" 4@
catch(Exception e){e.printStackTrace ();} AlAYiUw{
*Zt#U#
D/vOs[X o,
} ^eo|P~w g
u~WVGjoQ
" @v <Bk
public static void main(String[] args) '}B+r@YCN
{ Rb%8)t x
new TestMethod(); P<M?Qd1.
} +yk24 `>
} ZWc]$H?
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