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)); aYPD4yX"/
} N13wVx
for(int i=0;i<nEndPos.length-1;i++) j= Ebk;6p
{ A@k`$xevVj
nEndPos = nStartPos[i+1]; N\WEp?%~
} CLX!qw]@ +
nEndPos[nEndPos.length-1] = nFileLength; >ay% !X@3"
} K\vyfYi
} d(8X?k.S
Y1h)0_0
p$OkWSi~
//启动子线程 f<aJiVP
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I~P]_DmM
for(int i=0;i<nStartPos.length;i++) BjyGk+A
{ j@+QwZL|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;Jq7E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xHY#"
nStartPos,nEndPos,i); 1 n<7YO7}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8<Yqpb
fileSplitterFetch.start(); HOrD20
} {Kkut?5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2YL)" w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v08Xe*gNU
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;`MKi5g
nEndPos = " + nFileLength); fu6Ir,
// fileSplitterFetch[nPos.length-1].start(); tHV81F1J
ag\xwS#i5H
NU?05sF
//等待子线程结束 idh5neyL
//int count = 0; b )mU9
//是否结束while循环 E[N3`"
boolean breakWhile = false; Y$ To)qo
XrD@q
c O[Hr
while(!bStop) .gK>O2hI
{ 1'{A,!
write_nPos(); }Kc03Ue`%e
Utility.sleep(500); i[d@qp!H=
breakWhile = true; @mB*fl?-
BLskUrPF
0qUBt9rA
for(int i=0;i<nStartPos.length;i++) 2En^su$
{ 8KU5x#
if(!fileSplitterFetch.bDownOver) .G|9:b
{ =u#xPI0:
breakWhile = false; ic_q<Y}
break; LmQS;/:
} Y^~Dr|5%
} bzt(;>_8
if(breakWhile) K_X10/#b&
break; Pa-p9]gq
s;eOX\0
OcWzo#q4[
//count++; W<AxctId
//if(count>4) _:0
// siteStop(); `swf~
} =6N%;2`84
i`}nv,
c0%.GcF0{
System.err.println("文件下载结束！"); W%bzA11l
} ClvqI"Rd
catch(Exception e){e.printStackTrace ();} )LP=IT
} $ 3/G)/A
Vo2{aK;
|6d0,muN
//获得文件长度 R;68C6 4
public long getFileSize() aX'R&R
{ w`")^KXi
int nFileLength = -1; 4.}{B_)LK
try{ AQH\ ;L
URL url = new URL(siteInfoBean.getSSiteURL()); .0b$mSV[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dq&N;kk |
httpConnection.setRequestProperty("User-Agent","NetFox"); d?uN6JH9
2MapB*
<:rbK9MIl
int responseCode=httpConnection.getResponseCode(); !b0ANIp
if(responseCode>=400) ^+m6lsuA
{ '4""Gz
processErrorCode(responseCode); 0$~zeG"
return -2; //-2 represent access is error -N3fhW#)
} GYq.!d@O
=I}8-AS~V
Pq@%MF]5
String sHeader; Av#_cL
Xj^Hy"HC^~
vCB0x:/
for(int i=1;;i++) Y%B:IeF}
{ n7r )wy
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); V#Hg+\{d
//Utility.log(in.readLine()); cR0OJ'w
sHeader=httpConnection.getHeaderFieldKey(i); ph;ds+b
if(sHeader!=null) O~1vX9
{ ).BZPyV<
if(sHeader.equals("Content-Length")) )S;pYVVAl
{ hrRkam!y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ob"48{w$
break; t69C48}15
} G{ 9p.Q
} |H LU5=Y
else l^B PTg)X@
break; {|;5P.,l
} ,W!v0*uxp&
} <ETR6r
catch(IOException e){e.printStackTrace ();} f`dQ $Kh
catch(Exception e){e.printStackTrace ();} ;c!}'2>vM
,1}c% C*,Q
NR*s7>
Utility.log(nFileLength); ZT\=:X*e
{b<;?Dus^
Z?7XuELKV
return nFileLength; 0KQDw
} 9HjtWQn
Z+qTMm
7NY9UQ
//保存下载信息（文件指针位置） QR+{Yp
private void write_nPos() t=IpVl!
{ {g%F 3-
try{ {Gd<+tQg
output = new DataOutputStream(new FileOutputStream(tmpFile)); _qZ?|;o^
output.writeInt(nStartPos.length); :slVja$e
for(int i=0;i<nStartPos.length;i++) -/k;VT|
{ H1alf_(_ \
// output.writeLong(nPos); )9.i'{{ 0
output.writeLong(fileSplitterFetch.nStartPos); -jv%BJJlX
output.writeLong(fileSplitterFetch.nEndPos); Z uh!{_x;
} / p_mFA]@
output.close(); U',9t
} |)7dh B
catch(IOException e){e.printStackTrace ();} ? ^EB"{
catch(Exception e){e.printStackTrace ();} zj?^,\{A
} =sR]/XSK
QL<uQ`>(
}3"FQ/6C
//读取保存的下载信息（文件指针位置） >8pmClVvmR
private void read_nPos() $<y10DfO
{ A1mxM5N
try{ )@X `B d
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Vz"Ja
int nCount = input.readInt(); @213KmB.
nStartPos = new long[nCount]; ww_gG5Fc$
nEndPos = new long[nCount]; <0Mc\wy
for(int i=0;i<nStartPos.length;i++) V8aLPJ0_
{ ((2 g
nStartPos = input.readLong(); h;^H*Y&`
nEndPos = input.readLong(); 2W}f|\8MX
} M7\; Y
input.close(); 1nt VM+
} cVg!"
catch(IOException e){e.printStackTrace ();} _*xjG \!
catch(Exception e){e.printStackTrace ();} tKnvNOhn
} ,}("es\b
(#dwIBBFt
_o 2pyV&
private void processErrorCode(int nErrorCode) $6(,/}==0
{ v-V#?+#
System.err.println("Error Code : " + nErrorCode); E!~Ok
} Slk__eC
i|@lUXBp
)CYm/dk
//停止文件下载 )4[Yplo
public void siteStop() Z/|oCwR
{ M!{;:m28X!
bStop = true; [r,ZM
for(int i=0;i<nStartPos.length;i++) wTpjM@F?J|
fileSplitterFetch.splitterStop(); * 5H
/``4!jU
[>B`"nyNQ
} nK@RFU6
} ux[h\Tp
//负责部分文件的抓取 qhKW6v
**FileSplitterFetch.java B{#*PAK=
*/ Q: H`TSR]
package NetFox; !N`$`qAK
986y\9Zu
"Y9PS_u(~
import java.io.*; 3$.R=MQ7
import java.net.*; D[m+=-
[r_YQ*+ej
%Fh*$gzh*5
public class FileSplitterFetch extends Thread { Y7|R vLWoP
q`l&G%
$_j\b4]%
String sURL; //File URL k/"^W.B aj
long nStartPos; //File Snippet Start Position kIm)Um
long nEndPos; //File Snippet End Position sXD.*D
int nThreadID; //Thread's ID -QUr|:SK:
boolean bDownOver = false; //Downing is over ?r~|B/]
boolean bStop = false; //Stop identical B,@<60u
FileAccessI fileAccessI = null; //File Access interface (8[etm
;*3OkNxa3
?0v(_ v
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ez3>}E,
{ L(p{>Ykcc
this.sURL = sURL; hdi/k!9[\
this.nStartPos = nStart; ;1S~'B&1Q
this.nEndPos = nEnd; 52*9q!
nThreadID = id; EJdl%j
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `^rN"\
} =~)J:x\F
5hVp2w-
GI&XL'K&
public void run() \S[7-:Lu^
{ &rTOJ1)V}
while(nStartPos < nEndPos && !bStop) C^}2::Qu
{ To x{Sk3L
#].n0[
_QD##`<
try{ :YL`GSl
URL url = new URL(sURL); kRCuc}:SB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !`u
httpConnection.setRequestProperty("User-Agent","NetFox"); a/9R~DwN
String sProperty = "bytes="+nStartPos+"-"; *rY@(|
httpConnection.setRequestProperty("RANGE",sProperty); E]^wsS>=
Utility.log(sProperty); cULASS`,
q,#j *
[D]9M"L,vQ
InputStream input = httpConnection.getInputStream(); xQ4'$rL1d
//logResponseHead(httpConnection); PT9,R^2T!
:8}iZ.
=%p%+F@RlW
byte[] b = new byte[1024]; 9#:b+Amzz
int nRead; !xU1[,9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;TaR1e0
{ 24ojjxz+
nStartPos += fileAccessI.write(b,0,nRead); yfBVy8Sm
//if(nThreadID == 1) sh $mOy
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {Vc%ga|E
} dQ4VpR9|;
uF xrv
0P(U^rkR~
Utility.log("Thread " + nThreadID + " is over!"); F9hh- "(Z
bDownOver = true; E0;KTcZi
//nPos = fileAccessI.write (b,0,nRead); n:hHm,
} a?LrSk`
catch(Exception e){e.printStackTrace ();} h$#QRH
} K`=O!;
} 5dH}cXs
0KW@j>=jK
zJp}JO
//打印回应的头信息 1_D|;/aI
public void logResponseHead(HttpURLConnection con) QZcdfJck=+
{ ]9xuLJ)
for(int i=1;;i++) '@Zau\xC
{ B8+J0jdg6%
String header=con.getHeaderFieldKey(i); /Iwnl
if(header!=null) ()< E?D=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RC_w 1:h
Utility.log(header+" : "+con.getHeaderField(header)); 5r=xhOe`
else !.\EU*)1
break; s "KPTV
} ^CIO,I
} m5O;aj* i
v/n4Lp$W^
-E6#G[JJ
public void splitterStop() ]7qn&(]
{ R3nCk-Dq
bStop = true; ^/|agQ7D2
} W6. )7Y,
OH`| c
%9,:
} ff.(X!
)E--E+j
R,mOV8y"W[
/* Xb0$BAP
**FileAccess.java 72hN%l
*//文件访问(定位，写) hE|Z~5\Y,>
package NetFox; =x9SvIm/tH
import java.io.*; {H]xA3[]
p2]@yE7w
8@Zg@>,
public class FileAccessI implements Serializable{ +mM=`[Z`??
=T73660
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?F{sym@i
RandomAccessFile oSavedFile; ^Eu]i
long nPos; 4uQ\JD(*Eu
en"]u,!
6#Ag^A
public FileAccessI() throws IOException !N\<QRb\q
{ _zAHN0d
this("",0); wul$lJ?tE
} K?;_T$^K
BCDmce`=l
$XBn:0U
public FileAccessI(String sName,long nPos) throws IOException [E9V#J89
{ v'R{lXE
oSavedFile = new RandomAccessFile(sName,"rw"); m5!~PG:_
this.nPos = nPos; P}So>P~2
oSavedFile.seek(nPos); ^*CvKCS
} (0L7Ivg<
3NI3b-7
]Gk;n/! B
public synchronized int write(byte[] b,int nStart,int nLen) NSQ}:m
{ QucDIZ
int n = -1; |Z]KF>S]
try{ L-B"P&
oSavedFile.write(b,nStart,nLen); xvP=i/SO
n = nLen; l(c2 B
} Q5[x2 s_d
catch(IOException e) lSMv9:N
{ bve_*7CEM
e.printStackTrace (); {WBe(dc_%
} +iS'$2)@
;E Z5/"T
9YpgzCx Z
return n; N$\'X<{
} eWKFs)C]
p~Tp=d)/
glMYEGz6p
} rF9|xgFK
[}xVz"8V
6`KR
/* ,2t|(V*"&
**SiteInfoBean.java Ban@$uf
*/ yyp0GV.x
package NetFox; [v@3|@
SM57bN
-^1}J
public class SiteInfoBean { 8Zj=:;
r7Vt,{4/
t>hoXn^-
private String sSiteURL; //Site's URL tcDWx:Q
private String sFilePath; //Saved File's Path t0*kL.
private String sFileName; //Saved File's Name vY 0EffZ
private int nSplitter; //Count of Splited Downloading File 0P{^aSxTP
-L4fp
Nk.m$
public SiteInfoBean() 7a$K@iWU
{//nSplitter的缺省值为5 vbt0G-%Z
//default value of nSplitter is 5 "_LDs(&
this("","","",5); Rz sgPk
} v|!u]!JM
;rggO0Y
/{)}y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0bG[pp$[
{ UB5CvM28
sSiteURL= sURL; NCrNlHIF
sFilePath = sPath; pUcN-WA
sFileName = sName; BiFU3FlTf
this.nSplitter = nSpiltter; s ;3k#-w
?*oBevUnCY
M~rN17S
} XmZs4~\K$G
s3(mkdXv
U0ZT9/4
public String getSSiteURL() *5|;eN
{ oI\Lepl*
return sSiteURL; ,9A1p06
} fL^$G;_?3
|IcA8[
0oNNEC
public void setSSiteURL(String value) L3/SIoqd
{ 6TR` O
sSiteURL = value; v3p0
} _4#Mdnh}[
AvmI<U
(DLk+N4UHA
public String getSFilePath() ?-Qq\D^+
{ I cJy$+
return sFilePath; f|v5itO2
} <?2g\+{s9
CXQ+h
_p^?_
public void setSFilePath(String value) c-`'`L^J
{ e/7rr~"|
sFilePath = value; ;\'d9C
} Ub,5~I+`
q1a*6*YB
T`zUgZ]
public String getSFileName() QZh#&Qf;
{ e2"<3
return sFileName; z|M+ FHl$
} q`Rc \aWB%
La2f]+sV
qjm6\ii:)
public void setSFileName(String value) /f*QxNZ,p
{ htuYctu`
sFileName = value; :5'8MU
} |F}6Zv
o?{-K-'B$
[g/ &%n0^
public int getNSplitter() 1zcaI^e#
{ B>;`$-
return nSplitter; +s j2C
} .),Fdrg
(v,g=BS,
;hgRMkmz4<
public void setNSplitter(int nCount) c]/X >8;
{ p!o?2Lbiw
nSplitter = nCount; F(;=^w
} Leu93f2
} Nx;Oz
L^FQ|?*
uFUVcWt
/* a5k![sw\
**Utility.java 6M#}&Gv
*/ l!*!)qCB(S
package NetFox; : GdLr
9Ro7xSeD
8C=8Wjm
public class Utility { gq7l>vT.
HhZ>/5'(
g=na3^PL6
public Utility() (|2:^T+
{ t"$#KP<
ysH'X95
Z#t}yC%^d
} o.g)[$M8cF
@hF$qevX
//线程睡眠 6n?0MMtR
public static void sleep(int nSecond) ]<BT+6L
{ 8x`EUJ
try{ $xqX[ocor
Thread.sleep(nSecond); Aa`R40yl
} gQYs,
catch(Exception e) /tG[pg{[
{ +C36OcmT~
e.printStackTrace (); ROr|n]aJj
} nIqNhJ+
} ts/Ha*h
6hO]eS
//日志 WB.w3w[f
public static void log(String sMsg) ce<88dL
{ 7PbwCRg
System.err.println(sMsg); TtWWq5X|
} >sGiDK @
fyF8RTm{
xyrlR;Sk
public static void log(int sMsg) SUb:0GUa
{ MMy\u) 4
System.err.println(sMsg); -KL5sK
} IMSLHwZ
} T0X+\&W
0TqIRUz "C
em9nuXG
/* cB6LJ}R
**TestMethod.java $EnBigb!
*/ pS~=T}o
package NetFox; 2AXf'IOqE
IP!`;?T=
W.(Q u-AE(
public class TestMethod { %$&_!
WS.lDMYE7
cS%;JV>C
public TestMethod() a] P0PH~
{ ///xx/weblogic60b2_win.exe J(5#fo{Q.g
try{ T2}X~A
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =<X4LO)C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); XC!Y {lp
SiteFileFetch fileFetch = new SiteFileFetch(bean); }E^k*S
fileFetch.start(); !PfdY&.)
} N (0%C?
catch(Exception e){e.printStackTrace ();} Y?V.O
}BWT21'-Y
F):1@.S
} ODxCD%L
h,ipQ>
8'Iei78Ov
public static void main(String[] args) &&7&/
{ 07G'"=
new TestMethod(); ?h:xO\h8
} |~B`[p]5H
} hz+c]K
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