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)); eO1lnO|
} !VpoZ
for(int i=0;i<nEndPos.length-1;i++) J}t%p(mb
{ -?a 26o%e
nEndPos = nStartPos[i+1]; lTsjxw o
} "@n%Z
nEndPos[nEndPos.length-1] = nFileLength; dh\P4
} =(^3}x
} l^}c!
j<$2hiI/?&
l,).p
//启动子线程 G~m<;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2<3K3uz
for(int i=0;i<nStartPos.length;i++) !R$`+wZ62
{ \)e'`29;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6LhTBV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), v:#tWEbo-
nStartPos,nEndPos,i); ~LC-[&$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KPki}'GO
fileSplitterFetch.start(); -\MG}5?!
} 7EJ+c${e.-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Qb%J8juRf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); I^]nqK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Vvo7C!$z
nEndPos = " + nFileLength); 6\t@)=C,Q
// fileSplitterFetch[nPos.length-1].start(); dN6?c'iN?2
~J]qP#C
rl.}%Ny
//等待子线程结束 7 8,n%=nG
//int count = 0; .\mj4*?/
//是否结束while循环 P<-@h1p,
boolean breakWhile = false; k:%%/
$~kA B8z
W*G<X.Hf
while(!bStop) {`_i`
{ g)B]FH1
write_nPos(); |y*c9
Utility.sleep(500); Rb;'O89Hj@
breakWhile = true; F"kAkX>3}
rM SZ"
SX#&5Ka/
for(int i=0;i<nStartPos.length;i++) ^rz_f{c]-
{ C#pjmT_
if(!fileSplitterFetch.bDownOver) :'ptuY
{ CN?gq^
breakWhile = false; jWgX_//!
break; s#MPX3itK
} +|f@^-
} YYS0`
if(breakWhile) O0:q;<>z
break; |BYRe1l6l
ykJ>*z
$Kd>:f=A
//count++; 7$#u
//if(count>4) UZ";a453r
// siteStop(); xx $cnG
} BLFdHB.$T
8,|kao:
3$/IC@+
System.err.println("文件下载结束！"); ';"VDLb3
} MOC/KNb
catch(Exception e){e.printStackTrace ();} YZ7.1`8
} A(XKyEx
j1Ezf=N6`
4z)]@:`}z
//获得文件长度 {[F A#
public long getFileSize() )gi9f1n`
{ d5-qZ{W
int nFileLength = -1; r<\u6jF
try{ }2oc#0
URL url = new URL(siteInfoBean.getSSiteURL()); X{VOAcugr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M\=2uKG#
httpConnection.setRequestProperty("User-Agent","NetFox"); |?9HU~B
Ca-j?bb!
! P4*+')M
int responseCode=httpConnection.getResponseCode(); 2zpr~cB=
if(responseCode>=400) DwF hK*
{ @|!z9Y*
processErrorCode(responseCode); :KO2| v\
return -2; //-2 represent access is error Va8&Z
} b Zt3|
n@w%Zl
9 $X-
String sHeader; -qoH,4w
8Y?;x}
q(}bfIf
for(int i=1;;i++) V8(-
{ pot~<d`:K"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9u:Q,0\
//Utility.log(in.readLine()); 2rMpgV5
sHeader=httpConnection.getHeaderFieldKey(i); ^Dx&|UwiZa
if(sHeader!=null) w =KPT''!
{ %)n=x ne
if(sHeader.equals("Content-Length")) jdBLsy@
{ Pz^544\~ou
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4P0}+
break; @ P|y{e6
} ?Ob3tUz2
} Ss`LLq0LO
else W!<U85-#S
break; Xr{v~bf
} s`UJ1eJ
} 28nFRr
catch(IOException e){e.printStackTrace ();} SAz
catch(Exception e){e.printStackTrace ();} ~K=b\xc^
Mp]rUPK
pJ{Y lS{
Utility.log(nFileLength); <vP=zk
?#fQ~ s
f!"w5qC^
return nFileLength; gFh*eCo
} @XVTU
;G!q Y
Ep}s}Stlr}
//保存下载信息（文件指针位置） uw7zWJ n
private void write_nPos() tVjsRnb{
{ ElXFeJ%[G
try{ s@C}P
output = new DataOutputStream(new FileOutputStream(tmpFile)); IK]d3owA
output.writeInt(nStartPos.length); y}H!c;
for(int i=0;i<nStartPos.length;i++) \Cj B1]I
{ wS*E(IAl
// output.writeLong(nPos); Q.[0ct
output.writeLong(fileSplitterFetch.nStartPos); P*o9a
output.writeLong(fileSplitterFetch.nEndPos); ;=N#`l
} ;\]@K6m/Ap
output.close(); *`U~?q}
} dRDnJc3
catch(IOException e){e.printStackTrace ();} He)%S]RLk
catch(Exception e){e.printStackTrace ();} v2?ZQeHr_(
} h$*!8=M
S[N5 ikg
T;uX4,|(
//读取保存的下载信息（文件指针位置） F5Va+z,jg
private void read_nPos() +qoRP2
{ b]y2+A.n
try{ h\e.e3/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Y0>y8UV
int nCount = input.readInt(); *2?@ |<(r
nStartPos = new long[nCount]; &FD>&WRV
nEndPos = new long[nCount]; iB{V^ksU
for(int i=0;i<nStartPos.length;i++) ]?*wbxU0
{ 7 3m1
nStartPos = input.readLong(); f<H2-(m
nEndPos = input.readLong(); Q;u pau
} HV.t6@\};
input.close(); O84i;S+-p
} #F#%`Rv1
catch(IOException e){e.printStackTrace ();} g'gdgfvn
catch(Exception e){e.printStackTrace ();} #S(Hd?34,
} v1[29t<I!
=fbWz
:r[`.`
private void processErrorCode(int nErrorCode) OYd !v`<
{ `]X>V,
System.err.println("Error Code : " + nErrorCode); +0~YP*I`/
} vbNBLCwug
2|L&DF:G
PdCEUh\>y
//停止文件下载 9my^Y9B
public void siteStop() q7!{?\T%
{ OH88n69
bStop = true; Z7#+pPt!
for(int i=0;i<nStartPos.length;i++) N0lC0 N?_J
fileSplitterFetch.splitterStop(); eJSxn1GW
g ?k=^C
. ^u,.
} #jk_5W
} >bxS3FCX
//负责部分文件的抓取 `g,..Ns-r
**FileSplitterFetch.java k\IbIv7?i
*/ [~ fraK,)
package NetFox; R@0R`Zs
p[-O( 3Y
Jvi#)
import java.io.*; 1,~D4lD|
import java.net.*; y^k$Us
/,dz@
8QK&_n*
public class FileSplitterFetch extends Thread { Gq6*SaTk
<UI [%yXj
Si7*& dw=
String sURL; //File URL aYeR{Y]
long nStartPos; //File Snippet Start Position <[v[ci
long nEndPos; //File Snippet End Position %RVZD#zr
int nThreadID; //Thread's ID IcEdG(
boolean bDownOver = false; //Downing is over JVJMgim)0
boolean bStop = false; //Stop identical \lY_~*J
FileAccessI fileAccessI = null; //File Access interface 4JEpl'5^Q
pJ=#zsE0
;*N5Y}?j'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :Al!1BJQ
{ ;j7#7MN2_E
this.sURL = sURL; p'k0#R$
this.nStartPos = nStart; (mOtU8e
this.nEndPos = nEnd; =vPj%oLp'a
nThreadID = id; 5\v3;;A[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 CAe!7HiR
} &L:!VL{I
GVz6-T~\>
Zc yc*{DS
public void run() *_e3 @g
{ N;R^h? '
while(nStartPos < nEndPos && !bStop) LLI.8kn7
{ 43w}qY1
>sF)BoLc
BWNi [^]
try{ lFkR=!?=
URL url = new URL(sURL); so; ]&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G5!^*jf
httpConnection.setRequestProperty("User-Agent","NetFox"); \^LFkp
String sProperty = "bytes="+nStartPos+"-"; <$YlH@;)`a
httpConnection.setRequestProperty("RANGE",sProperty); Lr+$_ t}r
Utility.log(sProperty); D=$)n_F
=%7-ZH9
Q/?$x*\>
InputStream input = httpConnection.getInputStream(); "&] -2(
//logResponseHead(httpConnection); -4K5-|>O
TrNF=x>
0"R|..l/
byte[] b = new byte[1024]; #G3<7PK
int nRead; uNyVf7u
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ni<(K 0~
{ [WJ+h~~ o
nStartPos += fileAccessI.write(b,0,nRead); Ni>[D"|
//if(nThreadID == 1) Smh,zCc>s
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vI?, 47Hj+
} [7-?7mp!B
h;Qk@F
sT.ss$HY9,
Utility.log("Thread " + nThreadID + " is over!"); TvM~y\s
bDownOver = true; 2eogY#
//nPos = fileAccessI.write (b,0,nRead); q)GdD==
} maZ)cW?
catch(Exception e){e.printStackTrace ();} K}y f>'O
} xo)P?-
} [UR-I0 s!/
6Zo}(^Ovz
/1 dT+>
//打印回应的头信息 ^ 9sjj
public void logResponseHead(HttpURLConnection con) W)/#0*7
{ 5G#n"}T
for(int i=1;;i++) ("@!>|H
{ F@t3!bj9
String header=con.getHeaderFieldKey(i); <b.D&
if(header!=null) #Z#-Ht
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x^ni1=kU
Utility.log(header+" : "+con.getHeaderField(header)); b>W%t
else R_KH"`q
break; $qiya[&G4
} ~u{uZ(~
} SM'|+ d
kM6 Qp
NbobliC=
public void splitterStop() |)&%A%m
{ GyIV Hby
bStop = true; Xvv6~
} =l6mL+C
#E?4E1bnB
%>yL1BeA4
} \+etCo
M:8R-c#![
`uFdwO'DD
/* {ax:RUQxy
**FileAccess.java wJ]d&::@h
*//文件访问(定位，写) oDR%\VY6T
package NetFox; ^~dWU>
import java.io.*; H|*m$|$,
[ 3Gf2_
RN1_S
public class FileAccessI implements Serializable{ ig!+2g
_#niyW+?~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 do%&m]#;
RandomAccessFile oSavedFile; eRYK3W
long nPos; \RiP
_-D{-Bu#
uZ5p#M_
public FileAccessI() throws IOException +0&/g&a\R
{ eDMO]5}Ht
this("",0); ]lbuy7xj63
} }6#
|=w@H]r
y `UaB3q
public FileAccessI(String sName,long nPos) throws IOException =&]L00u.
{ ^c<Ve'-
oSavedFile = new RandomAccessFile(sName,"rw"); Wri<h:1
this.nPos = nPos; /(cPfZZ
oSavedFile.seek(nPos); !Ee:o"jG{
} A<{{iBEI`
d~H`CrQE*
:]KAkhFkbb
public synchronized int write(byte[] b,int nStart,int nLen) L#J1b!D&<6
{ fl(wV.Je|
int n = -1; \Z/@C lCm
try{ s#11FfF`
oSavedFile.write(b,nStart,nLen); *T/']t
n = nLen; Wc#24:OKe3
} 6'/ #+,d'
catch(IOException e) NOva'qk
{ UVP vOtZj
e.printStackTrace (); UfGkTwoo=
} 29KiuP
XwmL.Gg:]7
[~HN<>L@C
return n; W4S,6(
} <YY14p
>Ry01G]_/h
*pq\MiD/
} ! mHO$bQ"
CrLrw T
X8|,
/* C_Dn{
**SiteInfoBean.java s_Sk0}e
*/ #mF"1QW
package NetFox; K-4PI+qQ\
z_HdISy0
/xhKd]Q
public class SiteInfoBean { Vksuu@cch
5+vaE 2v
_/|\aqF.
private String sSiteURL; //Site's URL aUp g u"
private String sFilePath; //Saved File's Path 80I#TA6C
private String sFileName; //Saved File's Name ^W^OfY
private int nSplitter; //Count of Splited Downloading File @dKTx#gZ
7I}uZ/N
Y]>t[Lo%
public SiteInfoBean() eFgA 8kY)
{//nSplitter的缺省值为5 7dWS
//default value of nSplitter is 5 ,bi^P>X
this("","","",5); P0@,fd<
} TbU#96"~.
4 KiY6)
(=0.inZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~$'awY
{ ;l+Leex
sSiteURL= sURL; # d
sFilePath = sPath; Vr}'.\$
sFileName = sName; l#o ~W`
this.nSplitter = nSpiltter; .A|udZ,
)5,v!X)
=bOW~0Z1
} {c'lhUB
]Ze1s02(
\e*]Ls#jS
public String getSSiteURL() 0kh6@y3
{ %J(:ADu]
return sSiteURL; I9Xuok!0>=
} ye&;(30Oq
nlP;nlW
~ljXzD93Z
public void setSSiteURL(String value) 0J9x9j`&j
{ lA]8&+,ZM
sSiteURL = value; ?,mmYW6TjB
} 1}x%%RD_
HJ"GnZp<
uRvP hkqm
public String getSFilePath() ,+k\p5P
{ [y(MCf19
return sFilePath; @gblW*Zhk
} 4(+PD&_J
%b$>qW\*&
)A6<c%d =x
public void setSFilePath(String value) q V=!ORuj
{ )9g2D`a4
sFilePath = value; |Cv!,]9:r
} (.:e,l{U%
ah"o~Cbj
/uc>@!F
public String getSFileName() >MZ/|`[M
{ yWK)vju"
return sFileName; A.SvA Yn
} ?,z}%p
$Sq:q0
)lkjqFQ(
public void setSFileName(String value) `Di{}/2
{ Oketwa
sFileName = value; J.a]K[ci
} x2xRBkRg=
V3Bz Mw\9r
[agMfn
public int getNSplitter() _BufO7`.
{ YK_7ip.a[
return nSplitter; )~>YH*g
} U^PgG|0N
dtDFoETz
)0`C@um
public void setNSplitter(int nCount) hN_]6,<\
{ X|dlt{Gf
nSplitter = nCount; yi[x}ffdE
} Rq-ZL{LR7
} -"x$ZnHU
]Wup/o
W/N7vAx X
/* 5xiEPh
**Utility.java ).O)p9
*/ KNl$3nX
package NetFox; inL(X;@yo
"]*tLL:`
0-gAyiKx?
public class Utility { @7}W=HB
>P(.:_^p
Uo49*Mr
public Utility() ?,/ }`3Vw
{ h[ ZN+M
kJU2C=m@e2
" bG2:
} PT ~D",k
JF]JOI6.e
//线程睡眠 sOY:e/_F
public static void sleep(int nSecond) +@UV?"d
{ 42{~Lhxt
try{ (FV >m
Thread.sleep(nSecond); (7Qo
} hH.G#-JO
catch(Exception e) BtZyn7a
{ GgU/!@
e.printStackTrace (); g(g& TO
} [g,}gyeS(
} \V:^h[ad
z?zL97H
//日志 >_} I.\X
public static void log(String sMsg) }H2R3icE
{ qs6aB0ln
System.err.println(sMsg); 3|7QUld
} %<5'=t'|-U
|Tw~@kT@
AA_%<zK
public static void log(int sMsg) 7)m9"InDI
{ 1C.VnzRnJ
System.err.println(sMsg); WIOV2+
} ICCc./l|
} M5B# TAybC
MD]>g>
[QTV9
/* ~[: 2I
**TestMethod.java *Ex|9FCt$
*/ 1YA% -~
package NetFox; ;S{(]K7i
'-6~tWC~7
%y@AA>x!
public class TestMethod { g0H[*"hj
'qi}|I
P>L +t`'
public TestMethod() <3iMRe
{ ///xx/weblogic60b2_win.exe 0(Ij%Wi,
try{ )jj0^f1!j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J,G lIv.A
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); QJNFA}*>
SiteFileFetch fileFetch = new SiteFileFetch(bean); \v{=gK
fileFetch.start(); V~bD)?M
} X]=t>
catch(Exception e){e.printStackTrace ();} ;<5q]/IHK
R]dg_Da
[lAp62i5
} wr4:Go`
NI5``BwpO
fM}#ON>Z
public static void main(String[] args) E]6 6]+;0_
{ Bx!-"e
new TestMethod(); _@g;8CA
} tkhCw/
} YqG7h,F
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