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)); vfJ3idvo*w
} oDW<e'Jm
for(int i=0;i<nEndPos.length-1;i++) I(^jOgYU
{ d4p{5F7]^
nEndPos = nStartPos[i+1]; EtR@sJ<
} })zB".
nEndPos[nEndPos.length-1] = nFileLength; K=m9H=IX~T
} J-, H6u
} MdVCD^B
84p[N8
!bZhj3.
//启动子线程 piYws<Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Bbl)3$`,
for(int i=0;i<nStartPos.length;i++) O^X[9vrW
{ m~Y'$3w
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ' 1P=^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ZVdsxo<
nStartPos,nEndPos,i); .7pGx*WH^Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /$FXg;h9$
fileSplitterFetch.start(); 4-]Do?
} 5vs`uUzr
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b`h%W"|2L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $Yx6#m}[M
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FXOT+9bg
nEndPos = " + nFileLength); iot.E%G
// fileSplitterFetch[nPos.length-1].start(); RwAbIXG{0
9C557$nS^
9n>$}UI\
//等待子线程结束 ]RH=s7L
//int count = 0; y wW-p.
//是否结束while循环 >/TB_ykb
boolean breakWhile = false; %aj7-K6:t
gx!*O<|e4
f?=r3/AO
while(!bStop) ,J~,ga~
{ CB*`
write_nPos(); O+G~Qp0b>
Utility.sleep(500); vQ-ixh
breakWhile = true; 93Mdp9v+i
r{K\(UT]!
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for(int i=0;i<nStartPos.length;i++) v>#Cg\
{ WF ?/GN
if(!fileSplitterFetch.bDownOver) T!u'V'Ei2
{ zW"~YaO%C
breakWhile = false; a. h?4+^bN
break; xa87xX=a
} CrnB{Z4L
} G$;>ueM
if(breakWhile) g2g`,"T
break; X'V+^u@W
hlAR[]
{l0,T0
//count++; /]ku$.mr\
//if(count>4) {PN:bb
// siteStop(); \We"?1^
} 98ca[.ui
$.oOG"u0]
!Oeq G
System.err.println("文件下载结束！"); La`h$=#`
} wzD\8_;6N
catch(Exception e){e.printStackTrace ();} G_V.H\w
} t{_!Z(Rt5)
kRmj"9oA
N=>- Q)
//获得文件长度 Q,zC_
public long getFileSize() yB-.sGu
{ n=f`AmF;
int nFileLength = -1; >$2E1HW.
try{ $z= 0[%L
URL url = new URL(siteInfoBean.getSSiteURL()); _ymJ~MK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h6g=$8E
httpConnection.setRequestProperty("User-Agent","NetFox"); NNwc!x)*
(N,nux(0k
|WB"=PE
int responseCode=httpConnection.getResponseCode(); ]}BB/KQy^
if(responseCode>=400) CfQf7-
{ y7CWBTH0>
processErrorCode(responseCode); W;^N8ap%
return -2; //-2 represent access is error %)pP[[h
} vGXWwQ.1Tp
n4^*h4J7
{UP'tXah
String sHeader; aQ&uC )w
;5<P|:^
bX7EO 8
for(int i=1;;i++) [!^cd%l
{ ows^W8-w
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); D^|jZOJ
//Utility.log(in.readLine()); Uf# PoQ!y
sHeader=httpConnection.getHeaderFieldKey(i); 'KSa8;:=C
if(sHeader!=null) T'hml
{ smV!y8&
if(sHeader.equals("Content-Length")) dY1J<L}")
{ aIQOs
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;U |NmC+
break; (G#}*
} /4yOs@#
} ]x2Jpk99a
else 6A}eSG3
break; !&W|myN^
} (/'h4KS@
} ])C>\@c6Gm
catch(IOException e){e.printStackTrace ();} }xqXd%uz
catch(Exception e){e.printStackTrace ();} |B eA==
d^tVD`Fm
C(s\LI!r
Utility.log(nFileLength); w}d}hI
l1}R2lSEO
N*f^Z#B]
return nFileLength; Rxx>{+f4M
} *.8JP
_D-5}a"
eO'xkm
//保存下载信息（文件指针位置） )`<6taKx@n
private void write_nPos() }S,-uggz
{ 7ZQ'h3K
try{ r]0(qg
output = new DataOutputStream(new FileOutputStream(tmpFile)); `0?^[;[u[
output.writeInt(nStartPos.length); m*gj|1k
for(int i=0;i<nStartPos.length;i++) pzg&/m&F`
{ ~Yl<S(/4
// output.writeLong(nPos); P])L8zK
output.writeLong(fileSplitterFetch.nStartPos); dN<5JQql
output.writeLong(fileSplitterFetch.nEndPos); wk@yTTnb
} ;|6FdU
output.close(); 9Fk4|+OJ
} %lV@:"G
catch(IOException e){e.printStackTrace ();} $~=2{
catch(Exception e){e.printStackTrace ();} WV2~(/hX&
} v{.\iIg N
O] H=s
_#FIay\ahB
//读取保存的下载信息（文件指针位置） p'80d:
private void read_nPos() E3f9<hm
{ AVv#\JrRW
try{ Ra0=q4vdk
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~5ubh2{
int nCount = input.readInt(); ?gN9kd)
nStartPos = new long[nCount]; R4SxFp
nEndPos = new long[nCount]; kxh 5}eB
for(int i=0;i<nStartPos.length;i++) /~*Cp9F"]
{ *0~M
nStartPos = input.readLong(); \6:>{0\
nEndPos = input.readLong(); 2h<U
} y@`~9$
input.close(); b_l3+'#ofM
} wLUF v(&C
catch(IOException e){e.printStackTrace ();} U{}!y3[wK
catch(Exception e){e.printStackTrace ();} Af9+HI O
} Px#$uU
(f~gEKcB2u
uB;_vC
private void processErrorCode(int nErrorCode) &n|*uLn
{ -;>#3O-
System.err.println("Error Code : " + nErrorCode); [f/.!@sj
} um[!|g/
rrcwtLNbu
MRs,l'
//停止文件下载 sPy2/7Wqd
public void siteStop() xs%LRF#u
{ b=1%pX_
bStop = true; z,x"a
for(int i=0;i<nStartPos.length;i++) +]c}rWm
fileSplitterFetch.splitterStop(); w;+ br
AW/wI6[T
/$:U$JVb?l
} .T$D^?G!D
} 13a(FG
//负责部分文件的抓取 [4XC#OgA
**FileSplitterFetch.java vbp-`M(
*/ ;v_V+t<$
package NetFox; O:^'x*}
l E^*t`+
c#QFG1
import java.io.*; qo_]ZKL44
import java.net.*; JKy#j g:#
ue6d~8&
VNj@5s
public class FileSplitterFetch extends Thread { EZib1g&:R/
7~b!4x|Z
kaQ2A
String sURL; //File URL 9tk" :ld
long nStartPos; //File Snippet Start Position .45^=2NGmQ
long nEndPos; //File Snippet End Position G52Z)^
int nThreadID; //Thread's ID ErDL^M-`
boolean bDownOver = false; //Downing is over MCU9O
boolean bStop = false; //Stop identical Q0~j$Jc
FileAccessI fileAccessI = null; //File Access interface ^.vmF>$+I
(ua q<Cvg
rl?7W];
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s<&[\U
{ ~;unpym'
this.sURL = sURL; 62kb2C
this.nStartPos = nStart; `G?qY8
this.nEndPos = nEnd; =IHje;s
nThreadID = id; 7tgFDLA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 WeC(w+}p
} &g0g]G21*I
I60DUuF
Z^#]#f
public void run() p)3nyN=|_
{ #mLuU
while(nStartPos < nEndPos && !bStop) ?2ItB`<(
{ ntGq" o
})[($$f/
P^[/Qi}j
try{ AmcC:5
URL url = new URL(sURL); NfwYDY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wqy^8N[K]
httpConnection.setRequestProperty("User-Agent","NetFox"); mW4%2fD[
String sProperty = "bytes="+nStartPos+"-"; m<:IFx#
httpConnection.setRequestProperty("RANGE",sProperty); q4ipumy*
Utility.log(sProperty); l}}UFEA^
*eUc.MX6x
vT7g<
InputStream input = httpConnection.getInputStream(); _]|Qec)
//logResponseHead(httpConnection); <9ifPSvJ
Np2ci~"<.
)X5(#E
byte[] b = new byte[1024]; EGS%C%>l/o
int nRead; XP?*=Z]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) </s,pe79B
{ v <Hb-~
nStartPos += fileAccessI.write(b,0,nRead); z[9UQU~x?
//if(nThreadID == 1) w`gyE 6A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r,xmEj0E
} G{RTH_p
Mw^*yW
Yc`<S
Utility.log("Thread " + nThreadID + " is over!"); BU6Jyuwn
bDownOver = true; f=aIXhiYU
//nPos = fileAccessI.write (b,0,nRead); 8_xLl2
} ;%zC@a~{
catch(Exception e){e.printStackTrace ();} 3nFt1E
} n?E}b$6
} c Zvf"cIs
5~r2sCDPk
>I<PO.c!
//打印回应的头信息 G7-!`-Nk
public void logResponseHead(HttpURLConnection con) 'MQ%)hipA
{ -9o{vmB{
for(int i=1;;i++) G!Zyl^
{ v0@)t&O
String header=con.getHeaderFieldKey(i); w sY}JT
if(header!=null) &[j]Bp?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *YvRNHP
Utility.log(header+" : "+con.getHeaderField(header)); pn\V+Rg'
else [ee30ELn
break; mX\ ;oV!
} B9M>e'H%<
} nPA@h
]b}B2F'n
>eS$
public void splitterStop() }htPTOy5
{ MFwO9"<A
bStop = true; YBjdp=als
} tu}>:mk
Rs7|}Dl}
N 8t=@~]
} keCRvlZ4
/fwgqFVk
{exrwnIZj
/* *<9$D
**FileAccess.java <z)E(J\
*//文件访问(定位，写) \:&@;!a
package NetFox; A3+6#?:;
import java.io.*; $sgH'/>
cm@;*
Vb)zZ^va+
public class FileAccessI implements Serializable{ : F9|&q-W,
bQQVj?8jp
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 '6S%9ahE
RandomAccessFile oSavedFile; +>YfRqz:KB
long nPos; R$6qoqv{yG
{9'M0=
V#^yX%
public FileAccessI() throws IOException 4/*q0M{}B
{ rVzI_zYqp'
this("",0); )#[|hb=o
} t9u|iTY f!
y0IK,W'&?
$H*/;`,\[
public FileAccessI(String sName,long nPos) throws IOException -=5)NH t
{ .j?kEN?w
oSavedFile = new RandomAccessFile(sName,"rw"); #n7Yr,|Z
this.nPos = nPos; QK <\kVZ8
oSavedFile.seek(nPos); ]WL|~mG
} h-XY4gq/
NFyMY#\]
>K:u?YD[
public synchronized int write(byte[] b,int nStart,int nLen) 4#BRx#\O
{ m<@z}%v-
int n = -1; )=_ycf^MC
try{ Y&f\VNlT
oSavedFile.write(b,nStart,nLen); 6|=j+rScv
n = nLen; ];FtS>\x
} %ROwr[Dj=
catch(IOException e) [Z<Z;=t
{ |NMO__l@
e.printStackTrace (); [1(FgyE
} o`?zF+M0
OJ3UE(,I=
sb.J bE8
return n; Eipp~GD
} 7"Mk+'
>^SEWZ_[
9&
} #oV+@D`
.C!vr@@]
f j<H6|3
/* VmvQvQ/9R
**SiteInfoBean.java `;%ZN
*/ ' Q7Y-V
package NetFox; UA-7nb
pn%#w*'
aV|9H
public class SiteInfoBean { QLo(i
\N6\v5vh
5Ec/(-F
private String sSiteURL; //Site's URL 0(\+-<
private String sFilePath; //Saved File's Path ?IW_O~Js
private String sFileName; //Saved File's Name pJ^NA2
private int nSplitter; //Count of Splited Downloading File }iww:H-1
Mi0sC24b|
K-Mc6
public SiteInfoBean() aMwB>bt
{//nSplitter的缺省值为5 i[nF.I5*f
//default value of nSplitter is 5 X0$@Ik
this("","","",5); kgW @RD|
} !1Y&Y@ze
b"CAKl
<~"lie1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Poy^RpnX
{ YT-=;uK^S
sSiteURL= sURL; #&Is GyU
sFilePath = sPath; Hfc"L>
sFileName = sName; X?Pl<l&
this.nSplitter = nSpiltter; ALT^8c&K
nCnjq=
)D@~|j:
} E^V|
6|;Uq'
}nrXxfu
public String getSSiteURL() {aOkV::
{ =1hr2R(V
return sSiteURL; q mQfLz7&x
} }DjYGMrTB
0^l%j8/
L^0v\
public void setSSiteURL(String value) +t!S'|C
{ 0kDBE3i#
sSiteURL = value; R: Z_g!h
} 1~yZ T
#1/}3+=5B
gNj7@bX~
public String getSFilePath() Y`ihi,s`H
{ "v]%3i.* -
return sFilePath; D$r Uid
} l54 m22pfv
vNDu9ovs-
3Qn!y\#
public void setSFilePath(String value) mY-hN|
{ Le#spvV3J|
sFilePath = value; 1|| nR4yK
} vF={9G
"8<K'zeS8
m#5_%3T
public String getSFileName() B#l?IB~
{ = !2NU
return sFileName; K`6z&*
} :%4imgY`
Ngy=!g?Hk=
~}ovuf=%
public void setSFileName(String value) m,MSMw1p
{ dQ:cYNm
sFileName = value; h#.N3o
} fg*@<'
OI/@3"L{
W<,F28jI3v
public int getNSplitter() x_<qzlQt
{ jgu*Y{ocm
return nSplitter; -"TR\/
} pV\YG B+
LBlN2)\@
6(V /yn~
public void setNSplitter(int nCount) b]fzRdhl
{ L36Yx7gT<
nSplitter = nCount; [ !%R#+o=F
} u'5`[U -!
} 2Aq~D@,9=:
N/F$bv
h0|}TV^UJ
/* @4GA^h
**Utility.java <z)m%*lvU
*/ MZ4c{@Tg
package NetFox; `lpz-"EEV
5Jk<xWKj
p.K*UP
public class Utility { *VeW?mY,P
<=um1P3X
"MOpsb,
public Utility() eVz#7vqv
{ </~ 6f(mg
c0- ;VZ'
d IB }_L
} x~DLW1I
C"V%# K
//线程睡眠 [3>GGX[Ic
public static void sleep(int nSecond) Nh!_l
{ 6z,Dyy]tl
try{ GF<[}
Thread.sleep(nSecond); V2d,ksKwn
} m@G i6
catch(Exception e) <^R{U&Z@
{ D{7w!z
e.printStackTrace (); Qst$S}n
} ^4Uw8-/9
} |`O5Xs1{B
_F(P*[[&
//日志 Nn6S 8kc
public static void log(String sMsg) $W8Cf[a
{ YV'pVO'_+
System.err.println(sMsg); ~2*9{
} p3951-D
FiAY\4
n> w`26MMp
public static void log(int sMsg) cNK)5- U
{ nhT(P`6
System.err.println(sMsg); 9.OA, 6
} ]/2T\w.<
} @r7:NU}
l&(l$@t
3c'#6virz
/* 8;gXg
**TestMethod.java 8F5|EpB9M
*/ 'xK.UI
package NetFox; UmU:j@xvg
S]/b\B.h+
PO-"M)M
public class TestMethod { 5p"BD'^:
Zk-~ar
hlJpElYf
public TestMethod() IzLF'F
{ ///xx/weblogic60b2_win.exe -6~'cm
try{ v1G"3fy9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0JyVNuHn
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); HM[klH]s=
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]1`g^Z@ 0
fileFetch.start(); WY
} [j,txe?n
catch(Exception e){e.printStackTrace ();} #&.]" d
&p(0K4:
wVl+]zB
} GC@+V|u
=6 r:A<F!n
7N8H)X
public static void main(String[] args) J1ON,&[J
{ BzJ;%ywS
new TestMethod(); A&5:ATQ/|
} 5N7H{vT_
} @I3eK^#|P
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