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)); .{sKEVK
} *z[G+JX
for(int i=0;i<nEndPos.length-1;i++) XndGe=O
{ >2h|$6iWP
nEndPos = nStartPos[i+1]; X8~dFjhX
} +v4P9V|s
nEndPos[nEndPos.length-1] = nFileLength; L#sw@UCK
} \{r-e
} t`NZ_w /
!wiW#PR
?CO\jW_ *n
//启动子线程 $jT&]p
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +Go(yS
for(int i=0;i<nStartPos.length;i++) :$k':0 n
{ =B4,H=7Spf
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HUqG)t*c1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Oop5bg
nStartPos,nEndPos,i); F*V<L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <!b~7sZkTc
fileSplitterFetch.start(); }$M 2XF
} '=MaO@ @
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fxfzi{}uj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5`qt82Qm
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,XT#V\qne
nEndPos = " + nFileLength); nk.Y#+1)
// fileSplitterFetch[nPos.length-1].start(); [Du@go1C
Z$qFjWp
3t<XbHF9
//等待子线程结束 U'^AJ2L8
//int count = 0; i0F.c\
//是否结束while循环 [h>|6%sW
boolean breakWhile = false; [A$5~/Q{U1
&v!=\Fig4
pR_cI]{=SA
while(!bStop) l`lo5:w
{ KrOoxrDcp
write_nPos(); s( @w1tS.
Utility.sleep(500); &8'.Gwm}
breakWhile = true; %Q]u_0P*
<p@c%e,_
XL[/)lX{
for(int i=0;i<nStartPos.length;i++) (vte8uQe
{ l;i,V;@t
if(!fileSplitterFetch.bDownOver) !0ly1T 9
{ q6A!xQs<
breakWhile = false; 9pPb]v,6
break; p- 5)J&
} _;mN1Te
} O%)@> 5#S
if(breakWhile) &gJKJ=7
break; }~P%S(zB
n8(B%KF
p7(Pymkd
//count++; '\%c"?
//if(count>4) OJd!g/V
// siteStop(); 6BIP;, M=
} Xx{ho4qq
mv@cGdxu
KTn,}7vZ
System.err.println("文件下载结束！"); xe^*\6Y
} x_9<&Aj6
catch(Exception e){e.printStackTrace ();} *8}Y0V\s
} \)'nxFKqV
`|K,E
Z09FW>"u
//获得文件长度 K/RQ-xd4
public long getFileSize() jvx9b([<sG
{ J6x\_]1:*
int nFileLength = -1; 216+ tX5Z
try{ 8r[ZGUV
URL url = new URL(siteInfoBean.getSSiteURL()); 4 -)'a} O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vQrce&
httpConnection.setRequestProperty("User-Agent","NetFox"); Ta#vD_QP
rQiX7
EubR]ckB
int responseCode=httpConnection.getResponseCode(); htc& !m
if(responseCode>=400) $q*kD#;mh
{ -1Y9-nn[m
processErrorCode(responseCode); MLg<YL
return -2; //-2 represent access is error pT]M]/y/:
} &pwSd
iO=xx|d
fr'M)ox1
String sHeader; s vn[c*
)#-27Y
4GJ1P2
for(int i=1;;i++) 7L)1mB.
{ tB.;T0n
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mhTpR0
//Utility.log(in.readLine()); ZK5(_qW&i
sHeader=httpConnection.getHeaderFieldKey(i); 0 eZfHW&
if(sHeader!=null) H"(:6 `
{ MhC74G
if(sHeader.equals("Content-Length")) 1?)iCe
{ xw: v|(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >yvP[$]!6
break; !mFo:nQ)}
} $,08y
} \V@SCA'
else *Yv"lB8
break; 2&91C[da0
} $;un$ko6%
} <B 5^
catch(IOException e){e.printStackTrace ();} 8>x.zO_.c>
catch(Exception e){e.printStackTrace ();} &_FNDJ>MCk
`;fh<kv
PK1j$&F
Utility.log(nFileLength); hT6:7_UD
*ggTTHy
>(z{1'f{
return nFileLength; .fcU&t
} |Y3!Lix
hZnT`!iFE^
2'g< H-[
//保存下载信息（文件指针位置） =fMSmn1S
private void write_nPos() O{8"f\*
{ b3b 4'l
try{ hTI8hh
output = new DataOutputStream(new FileOutputStream(tmpFile)); .;WJ(kB\U
output.writeInt(nStartPos.length); (ohkM`83k
for(int i=0;i<nStartPos.length;i++) THHrGvb
{ 3(P^PP8
// output.writeLong(nPos); 475yX-A
output.writeLong(fileSplitterFetch.nStartPos); N>`+{
output.writeLong(fileSplitterFetch.nEndPos); "M6a_rZ2W
} FW7+!A&F
output.close(); Ff>Y<7CQ v
} pH#&B_S6z=
catch(IOException e){e.printStackTrace ();} b qB[vPsI
catch(Exception e){e.printStackTrace ();} R7*Jb-;$!
} Wq)'0U;{$
A{h hnrr8
, >Y.!
//读取保存的下载信息（文件指针位置） _yjM_ALjo
private void read_nPos() L*tXy>&b.
{ kN9S;o@)
try{ FcIH<_r
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $}oQ=+c5
int nCount = input.readInt(); e<5+&Cj
nStartPos = new long[nCount]; N&NOh|YS
nEndPos = new long[nCount]; V2es.I
for(int i=0;i<nStartPos.length;i++) :{4G=UbAI
{ G_5sF|(mq
nStartPos = input.readLong(); OxElvbM#
nEndPos = input.readLong(); +C;ZO6%w
} )|LX_kyW
input.close(); /og}e~q
} wlqV1.K
catch(IOException e){e.printStackTrace ();} u#p1W|\4
catch(Exception e){e.printStackTrace ();} M)Rp+uQ
} hM\QqZFyp
Te'^O,C)y$
qq-&z6;$
private void processErrorCode(int nErrorCode) g|<)J-`Q
{ =khjD[muC
System.err.println("Error Code : " + nErrorCode); 3FUZTX]Q1
} $Br^c< y
~p;<H
{EJVZG:&
//停止文件下载 *B}vYX
public void siteStop() :'y
{ >|0yH9af
bStop = true; N)Qj^bD!
for(int i=0;i<nStartPos.length;i++) ,b>cy&ut
fileSplitterFetch.splitterStop(); e"r'z n
UQ|0Aqwq
PL~k `L
} >&^w\"'
} QZ{&7mc>
//负责部分文件的抓取 NJqALm!(
**FileSplitterFetch.java (m;P,*
*/ !qrF=a
package NetFox; 4NR,"l)
miS+MK"
{J})f>x<xM
import java.io.*; %>I!mD"X\
import java.net.*; !P@u4FCs
QX%m4K/a
<eN>X:_N
public class FileSplitterFetch extends Thread { uNd;;X
@<vDR">
0IDHoNaT<
String sURL; //File URL 0O-p(L=
long nStartPos; //File Snippet Start Position 9Z*`{
long nEndPos; //File Snippet End Position R5]R pW=G
int nThreadID; //Thread's ID %h|z)
boolean bDownOver = false; //Downing is over #PXl*~PrQ/
boolean bStop = false; //Stop identical |D]jdd@!a2
FileAccessI fileAccessI = null; //File Access interface 6FEtq,;0w
/oiAAB27
JS(KCY9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YD@V2gK
{ tB(Q-c
this.sURL = sURL; !c6lP'U
this.nStartPos = nStart; 1<\cMY6
this.nEndPos = nEnd; p00\C
nThreadID = id; Rp`}"x9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l^$:R~gS
} AX'(xb,
}i[i{lKj
twgU ru
public void run() 0?p_|X'_
{ EzNmsbtZ(
while(nStartPos < nEndPos && !bStop) hNx`=D9[7
{ g-^CuXic
}$qy_Esl
0@AK
try{ $Z{ fKr
URL url = new URL(sURL); yv3myaS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |lJXI:GG
httpConnection.setRequestProperty("User-Agent","NetFox"); /2l4'Q=
String sProperty = "bytes="+nStartPos+"-"; r}hj,Sq'
httpConnection.setRequestProperty("RANGE",sProperty); \XRViG,|5
Utility.log(sProperty); ?-@hNrx
^[zF_df
s ^)W?3t]
InputStream input = httpConnection.getInputStream(); FNc[2sI
//logResponseHead(httpConnection); ZLL0 6p
Nq*\{rb
qk_ s"}sS
byte[] b = new byte[1024]; bO2$0!=I
int nRead; &7@6Y{!/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6bb=;
{ VKN^gz
nStartPos += fileAccessI.write(b,0,nRead); K03a@:
//if(nThreadID == 1) k(^zhET
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |qI_9#M\(
} m7M*)N8
=,T~F3pK
_&F6As !{
Utility.log("Thread " + nThreadID + " is over!"); Mm6 (Q
bDownOver = true; 7FMHz.ZRE
//nPos = fileAccessI.write (b,0,nRead); 4uNcp0
} k ,<L#?,a
catch(Exception e){e.printStackTrace ();} 0.@/I}R[
} #h r!7Kc;N
} U Ciq'^,
-CL7^
'|FM|0~-J
//打印回应的头信息 c7iu[vE'+
public void logResponseHead(HttpURLConnection con) .7)A8R7Wt
{ r,b
for(int i=1;;i++) ;OdUH
{ 'kh%^_FH7
String header=con.getHeaderFieldKey(i); 8|d[45*q
if(header!=null) 4yBe(&N-d
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #e9B|Y?b
Utility.log(header+" : "+con.getHeaderField(header)); ,%KB\;1mn'
else (j-(fS
break; >Mvt;'c
} ^2mXXAQf7^
} gcv,]v8
N}dJ)<(2~
pg>P]a{
public void splitterStop() -9aht}Z
{ RisrU
bStop = true; *K+*0_
} G %#us3x
F5MWxAS,>
$iP#8La:Y
} ZnJnjW PQ
x(t}H8q
'6xn!dK
/* ^MddfBwk
**FileAccess.java =} vG|
*//文件访问(定位，写) 8L|C&Ymj
package NetFox; ,$}Q#q
import java.io.*; G+%ZN
M.IV{gj
Cog:6Gnw
public class FileAccessI implements Serializable{ c3 wu&*p{
tXp)o>"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W:) M}}&H
RandomAccessFile oSavedFile; [{zekF~)@
long nPos; +6;OB@
@C!q S7k)
-_314j=`/
public FileAccessI() throws IOException >Y\4v}-
{ S((8DSt*
this("",0); He]F~GXP
} ntF(K/~Y
GB !3Z
EAq >v t83
public FileAccessI(String sName,long nPos) throws IOException 1gt[_P2u
{ d@w I: 7
oSavedFile = new RandomAccessFile(sName,"rw"); Yb6\+}th
this.nPos = nPos; 6C3y+@9
oSavedFile.seek(nPos); #|e<l1F
} F;_;lRAb
5o72X k
>)5vsqGZaK
public synchronized int write(byte[] b,int nStart,int nLen) ;J5oO$H+68
{ j2\G1@05
int n = -1; K^>qn,]H'
try{ ,%jJ ,G,
oSavedFile.write(b,nStart,nLen); IcIMa
n = nLen; ZtvU~'Q
} @eMyq1ZU
catch(IOException e) *Zc-&Dk:Ir
{ h5Z\9`f[
e.printStackTrace (); ZU@V]+ww
} !PQRlgcG
un/eS-IIh
brVT
return n; :heJ5*!,
} A%2!Hr
l%U9g
zeua`jQ
} y7w>/7q
^{Vm,nAQqs
cbteNA!>
/* o j^U
**SiteInfoBean.java /J6CSk
*/ -5qO}^i$a
package NetFox; {otvJ|'N
~Ep&:c4:D
asJYGqdF
public class SiteInfoBean { }.hBmhnZmI
@%TQ/L^|
Qz<-xe`o8]
private String sSiteURL; //Site's URL Hc+<(g
private String sFilePath; //Saved File's Path +|0m6)J]
private String sFileName; //Saved File's Name 49#-\=<gt
private int nSplitter; //Count of Splited Downloading File iKK=A.g
3a5H<3w_
givK{Yt<B
public SiteInfoBean() 'Oc8[8
{//nSplitter的缺省值为5 @2u<Bh}}
//default value of nSplitter is 5 980+Y
this("","","",5); 3LTO+>, |"
} '|cuVxcE55
B8nXWi
cshUxabB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) td m{ V st
{ 1dq.UW\
sSiteURL= sURL; 2KG j !w
sFilePath = sPath; p<+]+,|\~:
sFileName = sName; f*I5m=
this.nSplitter = nSpiltter; F;ZLoG*U
yjpjJ
G]SE A
} V4"AFArI
.dygp"*
4a 5n*6G!
public String getSSiteURL() :vr,@1c
{ CJC|%i3
return sSiteURL; f&`*x t/
} \?g%>D:O;
(r|T&'yK
7q?YdAUz
public void setSSiteURL(String value) < d]|5
{ kal8k-$#
sSiteURL = value; s=$7lYX
} l:ED_env:
_5)#{o<
M{S7ia"s
public String getSFilePath() 0{,zE
{ s%:fB(
return sFilePath; y>OZ<!`
} MPB6
%,^7J;
<|8l;
public void setSFilePath(String value) Y}Dp{
{ )_=&)a1U
sFilePath = value; I45A$nV#Q
} {)[i\=,`{
BOWTH{KR<<
bXW)n<y
public String getSFileName() J.&q[
{ ELPJ}moWZ
return sFileName; e%P;Jj476
} {, |"Rpd
`~}7k)F(
X=hgLK^3<,
public void setSFileName(String value) lVFX@I=pI
{ *"5a5.`%,
sFileName = value; `%Ghtm*
} y"hM6JI
MT5A%|He
I%&9`ceWY
public int getNSplitter() EH:1Z*|Z{\
{ q^cFD
return nSplitter; C0W~Tk\C2
} v Y\O=TZT
|x4yPYBL
P=@lkF!\#
public void setNSplitter(int nCount) w(U/(C7R
{ D6]$P%t9
nSplitter = nCount; D7.P
} K4yYNlY
} hK"=~\,
+,[3a%c)H
=, 0a3D6b
/* vz:0"y
**Utility.java g?VME]:
*/ qIT{`hX
package NetFox; 85fDuJ9$Z"
AN>`M?EQ
B#MW`7c
public class Utility { =tNiIU
Tc(R-Wi
{XXNl)%
public Utility() S=g-&lK
{ OgS8.wX
$iPN5@F
*\WI!%
} `Y;gMrp
@e,Zmx
//线程睡眠 O}-7 V5
public static void sleep(int nSecond) {|h"/
{ Mh|`XO.5I
try{ w3N%J>4_E
Thread.sleep(nSecond); DRoxw24
} iq:[+
catch(Exception e) 48Lmy<}*
{ ,m?D\Pru
e.printStackTrace (); b1u'ukDP\
} % 4"~O _S
} DG\YZV4
N]}+F w\5
//日志 5ecz'eA%
public static void log(String sMsg) }tZAU\z
{ N)*e^Nfb
System.err.println(sMsg); +-\9'Q
} P` F'Nf2U
;QQ7vo
5#)<rK
public static void log(int sMsg) HdUW(FZ
{ KL mB
System.err.println(sMsg); -C}59G8
} ~k0)+D}
} *F*fH>?C#
0|!<|N<
B9DxV>mr\r
/* ;cn.s,
**TestMethod.java GKhwn&qCKb
*/ \,gZNe&Vv
package NetFox; -!>ZATL<B
bMZn7c
g<4M!gi
public class TestMethod { 9sjW
8@KFln )[
SWsv,
public TestMethod() Mgs|*u-5
{ ///xx/weblogic60b2_win.exe V8$bPVps
try{ u2BW]T]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,M&0<k\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &[Zap6]
SiteFileFetch fileFetch = new SiteFileFetch(bean); #(+HSZm
fileFetch.start(); i;zGw.;Q
} 9*+0j2uhQ
catch(Exception e){e.printStackTrace ();} %Dls36F
.0E4c8R\X
by]|O
} <1+6O[>{
~:<@`
!b->u_
public static void main(String[] args) fKz"z{\,0
{ {kl{mJ*
new TestMethod(); w1#jVcUQ
} kr`BUW3
} ';\gR/L
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