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)); HYwtGj~5
} 4;|@eN
for(int i=0;i<nEndPos.length-1;i++) d(_;@%p1X
{ j9d^8)O,
nEndPos = nStartPos[i+1]; 03?7kAI
} J?$`Tnx^
nEndPos[nEndPos.length-1] = nFileLength; x,fX mgE
} #trb4c{{5
} ;uhpo
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[sXnB$
//启动子线程 UfNcI[xr
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Njmb{L]Cps
for(int i=0;i<nStartPos.length;i++) :5-t$^R
{ ;39~G T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +UX~TT:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Htm;N2$d
nStartPos,nEndPos,i); qCI0[U@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #ULzh&yO
fileSplitterFetch.start(); b(Nxk2uv
} peZ'sZ6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *G"}m/j-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); NcyE_T
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", i$g6C
nEndPos = " + nFileLength); \!Wph5wA
// fileSplitterFetch[nPos.length-1].start(); zLSha\X
~j36(`t
Srom@c
//等待子线程结束 \B Uno6
//int count = 0; !F08F>@D
//是否结束while循环 l,k.Jo5
boolean breakWhile = false; aE2Yl
FwpTQix!
):st-I!o
while(!bStop) WxJV zHtR
{ El^V[s'3
write_nPos(); +ZJ1> n
Utility.sleep(500); >*1YL)DBT\
breakWhile = true; QD;:!$Du
k0IztFyj:R
``,q[|
for(int i=0;i<nStartPos.length;i++) e% #?B *
{ ?2<V./2F
if(!fileSplitterFetch.bDownOver) D}/nE>*
{ A(1WQUu j
breakWhile = false; M=sGPPj
break; (2dkmn
} |H'wDw8
} H03R?S9AQ
if(breakWhile) , D}
break; *EF`s~
:+v4,=fHy
d:g0XP
//count++; 2rrC y C
//if(count>4) X_(n
// siteStop(); jMP;$w
} IQyw>_~]
m/"}Y]n!
LrhQG
System.err.println("文件下载结束！"); DoFF<LXBt
} W0LJXp-v
catch(Exception e){e.printStackTrace ();} |5(un/-C
} bmw"-W^U[
xsRu~'f
uC5W1LyI
//获得文件长度 p&lT! 5P!A
public long getFileSize() PcEE@W9
{ ,F?O} ijk
int nFileLength = -1; ;tWi4iT+.
try{ _53NuEM1
URL url = new URL(siteInfoBean.getSSiteURL()); K[[ 5H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wF)g@cw
httpConnection.setRequestProperty("User-Agent","NetFox"); t/c)[l hV
xP5Z -eL
n7,LfO#
int responseCode=httpConnection.getResponseCode(); '&F PkT:5
if(responseCode>=400) -f=4\3y3p
{ d$PQb9Q+f
processErrorCode(responseCode); Df}3^J~JX
return -2; //-2 represent access is error "[2D&\$
} znNv;-q
t}2M8ue(&
r~;TId} #
String sHeader; DC,]FmWs!+
uE&2M>2
F>"B7:P1:Q
for(int i=1;;i++) PHg(O:3WG
{ o(Q='kK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); */ok]kX'
//Utility.log(in.readLine()); 43/!pW
sHeader=httpConnection.getHeaderFieldKey(i); BF(Kaf;<t.
if(sHeader!=null) SAUG+{Uq
{ dk@iAL*v
if(sHeader.equals("Content-Length")) Rqun}v}
{ [OwrIL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); f4+}k GJN
break; zF_aJ+i:~
} 86ml.VOR
} )"&\S6*!
else .!Q?TSQ+{!
break; "/zDcZbL;
} Kc{~Q
} 4 moVS1
catch(IOException e){e.printStackTrace ();} Wf9K+my
catch(Exception e){e.printStackTrace ();} kg()C%#u
|&\cr\T\r
l1D"*J 2`
Utility.log(nFileLength); DTM xfQdk
J85Kgd1 \a
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return nFileLength; !K/zFYl
} z1~FE
Y[`%j\=
m^Rf6O^
//保存下载信息（文件指针位置） k4BiH5\hA
private void write_nPos() Kv#TJn
{ $6yr:2Xvt
try{ <dX7{="&
output = new DataOutputStream(new FileOutputStream(tmpFile)); ZO!)G
output.writeInt(nStartPos.length); zXT[}J VV
for(int i=0;i<nStartPos.length;i++) _|KeB(W
{ )!C|DSw
// output.writeLong(nPos); (#VF>;;L
output.writeLong(fileSplitterFetch.nStartPos); Bt1&C?_$T
output.writeLong(fileSplitterFetch.nEndPos); "(^1Dm$(
} Iw;J7[hJ&$
output.close(); Avo"jN*<d
} M{M?#Q
catch(IOException e){e.printStackTrace ();} =RQ\i6Y
catch(Exception e){e.printStackTrace ();} uJ>_ 2
} =ms o1
Czt>?8x`
~0ZLaiJ
//读取保存的下载信息（文件指针位置） 6)Dp2
private void read_nPos() '/K-i.8F
{ Tz2<# pLR
try{ JnBg;D|)@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y3)R:h4AH
int nCount = input.readInt(); e!|T Tap
nStartPos = new long[nCount]; 6>;dJV
nEndPos = new long[nCount]; x2 m A
for(int i=0;i<nStartPos.length;i++) Odj4)
{ o_DZ
nStartPos = input.readLong(); "T'?Ah6
nEndPos = input.readLong(); 'X1fb:8m8
} `B71`
input.close(); cb9q0sdf
} Q.`O;D}x
catch(IOException e){e.printStackTrace ();} 09C[B+>h
catch(Exception e){e.printStackTrace ();} 8A3!XA
} eWwI@ASaA
Q]2v]PJ6"
bx8|_K*^
private void processErrorCode(int nErrorCode) !mtX*;b(e
{ *Wmn!{\g
System.err.println("Error Code : " + nErrorCode); tx01*2]pX
} RB `<Zw
Y]!{ nW
C`>|D [
//停止文件下载 VLfE3i4Vwl
public void siteStop() )4/227b/(
{ @Zd/>'
bStop = true; ZsikI@?
for(int i=0;i<nStartPos.length;i++) CkA ~'&C
fileSplitterFetch.splitterStop(); 4Js9"<w
[MVG\6Up(
#.z`clK#
} YQk<1./}I
} -jOCzp
//负责部分文件的抓取 >"q~9b A
**FileSplitterFetch.java .}zpvr8YP
*/ M,nLPHgK
package NetFox; e.:SBXZ
<xWBS/K
@fwk
import java.io.*; 9x0Ao*D<t
import java.net.*; 60u}iiC@
msiftP.
k4ijWo{:0
public class FileSplitterFetch extends Thread { *K1GX
h%T$m_
yxU??#v|g
String sURL; //File URL ]jL`*tI\S
long nStartPos; //File Snippet Start Position 3d0Yq
long nEndPos; //File Snippet End Position a;$'A[hq
int nThreadID; //Thread's ID dJ0qg_ U&
boolean bDownOver = false; //Downing is over M&5;Qeoiv
boolean bStop = false; //Stop identical y8.(filNB
FileAccessI fileAccessI = null; //File Access interface ,awp)@VG7
7iJ=~po:o
<M4Qc12jP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException KoPhPH
{ `]xot8
this.sURL = sURL; v<qiu>sbz}
this.nStartPos = nStart; 0^PI&7A?y
this.nEndPos = nEnd; EL[N%M3
nThreadID = id; 9O/l{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 M;i4ss,}!
} z a^s%^:yK
8O5@FU 3
_4VS.~}/R
public void run() + ^9;<>P
{ i+z;tF`
while(nStartPos < nEndPos && !bStop) 0$9I.%4jAJ
{ CdN,R"V0$@
FOU^Wcop%
mjd9]HgN
try{ K(M@#t1_&
URL url = new URL(sURL); &sRjs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V\V:uo(C
httpConnection.setRequestProperty("User-Agent","NetFox"); ]EzX$T
String sProperty = "bytes="+nStartPos+"-"; 'r5[tK}
httpConnection.setRequestProperty("RANGE",sProperty); m8|&z{
Utility.log(sProperty); )@]Y1r4U
<2Qh5umQ
;uC +5g`
InputStream input = httpConnection.getInputStream(); +'NiuN
//logResponseHead(httpConnection); @fH?y Z=>
kM`!'0kt
h*qoe(+ZD
byte[] b = new byte[1024]; 'e(`2
int nRead; ?*~Pgh >uL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .7HnWKUV
{ x>@+lV'O
nStartPos += fileAccessI.write(b,0,nRead); 2_4m}T3
//if(nThreadID == 1) &@dWd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &x(^=sTHI
} J6H3X;vxQw
sH>Z{xjr
W1UG\d`2
Utility.log("Thread " + nThreadID + " is over!"); 7Lr}Y/1=
bDownOver = true; $^2 j#]uX
//nPos = fileAccessI.write (b,0,nRead); T&2aNkuG
} 2_x~y|<9
catch(Exception e){e.printStackTrace ();} MO{6B#(<F
} Ij_VO{]G'l
} VS#i>nlT
%DQ.f*%
# Z*nc0C
//打印回应的头信息 4K@`>Y5g*
public void logResponseHead(HttpURLConnection con) Z81{v<c;
{ ]byj[Gd
for(int i=1;;i++) q >9F21W
{ aeESS;JxJj
String header=con.getHeaderFieldKey(i); A|BvRZd
if(header!=null) K%: :
//responseHeaders.put(header,httpConnection.getHeaderField(header)); LW;UL}av
Utility.log(header+" : "+con.getHeaderField(header)); E6-alBi%
else ZU&I`q|Y6
break; ?^F#}>C
} 1f 0"z1
} G}tq'#]E{z
]Qp0|45=
G;+hc%3y
public void splitterStop() -L/5Nbup
{ Sdc;jK 9d!
bStop = true; $+Hv5]/hb
} 5Dy800.B2
_"ysJ&
>sE5zj|V
} 2w=0&wG4K
x@I@7Pvo3
m6bI<C3^5
/* `A\ !Gn?
**FileAccess.java y?-wjJS>
*//文件访问(定位，写) T|p$Ddt`+
package NetFox; 'iN8JO>
import java.io.*; 877>=Tp|
<R:KR(bT
*xs8/?
public class FileAccessI implements Serializable{ Ed|7E_v
'M\ou}P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xA nAW
RandomAccessFile oSavedFile; g]C+uj^
long nPos; GA6)O-^G
yZaQ{]"
x3L3K/qMg
public FileAccessI() throws IOException $-VW)~Sl
{ SvH=P!`+
this("",0); E'LkoyI
} l}X3uyS
j0sR]i
voaRh@DZ%/
public FileAccessI(String sName,long nPos) throws IOException F!VC19<1O8
{ 17G7r\iNYq
oSavedFile = new RandomAccessFile(sName,"rw"); $Q|66/S^
this.nPos = nPos; Nuk\8C
oSavedFile.seek(nPos); FuaGr0]
} |pr~Ohz
0[0</"K%1m
^HKxaW9W
public synchronized int write(byte[] b,int nStart,int nLen) `3r*Ae
{ p&bQ_XOH
int n = -1; 4qjY,QJ
try{ G%anot
oSavedFile.write(b,nStart,nLen); 9VIsLk54^
n = nLen; ;W#G<M&n'
} x>5#@SX J
catch(IOException e) Hux#v>e
{ 8T 6jM+ h
e.printStackTrace (); 3}$L4U
} ltHC+8aZ
udg;jR-^
:$[m[y7i
return n; ?S!lX[#v
} F1?@tcr'
<4*7HY[
$$\| 3rj!
} b/]C,P
FFH-Kw,
CQsVGn{x
/* dvsOJj/b
**SiteInfoBean.java 1S\q\kz->D
*/ yA(H=L-=!1
package NetFox; f&^K>Jt1@#
:4Sj2
U,Z.MPQ
public class SiteInfoBean { RXgi>Hz
Q=~e|
Oa7`Y`6
private String sSiteURL; //Site's URL L4SFu.J'
private String sFilePath; //Saved File's Path z-(dT
private String sFileName; //Saved File's Name blaxUP:
private int nSplitter; //Count of Splited Downloading File ` M"Zq
L<QqQ"`
t ba%L
public SiteInfoBean() X>F/0/
{//nSplitter的缺省值为5 sBF}j.b
//default value of nSplitter is 5 ImklM7A
this("","","",5); yXrFH@3
} H@__%KBw
+t/VF(!
~mK9S^[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KWy4}7a@,s
{ MsX`TOyO!
sSiteURL= sURL; tTF/$`Q#*
sFilePath = sPath; )1J&tV*U
sFileName = sName; !=cW+=1
this.nSplitter = nSpiltter; jbC7U9t7
CbS9fc&
|,t#Au}61
} fVo)# Bj
Y.F:1<FAtf
sxnj`z
public String getSSiteURL() Tp[ub(/;7
{ Y4!v1
return sSiteURL; QS_"fsyN:
} X,x{!
$}W=O:L+D
;% !'K~
public void setSSiteURL(String value) %S.R@C[3
{ /$WEO[o
sSiteURL = value; XkuNLs4
} im%'S6_X4
B4[onYU
kP6g0,\|a|
public String getSFilePath() z9&$Xao
{ %dO'kU/-
return sFilePath; -`iZBC50
} 5ah]E
k=w%oqpN
uQ9P6w=Nt
public void setSFilePath(String value) |CY.Y,
{ h3>/..l
sFilePath = value; fX#Em'Ab[
} `EBo(^n}O
`dn|nI2
U`IDZ{g
public String getSFileName() z930Wi{@
{ @\z2FJ79w
return sFileName; !4]wb!F
} yYp!s
=4m?RPb~b
/u*((AJ?Qv
public void setSFileName(String value) ggJn oL
{ O|?>rK
sFileName = value; jUI'F4.5x-
} wb.47S8
!m'lOz
t_x\&+W
public int getNSplitter() )g9Zw_3
{ [$;6LFs}
return nSplitter; Kt;h'?
} _CciU.1k&,
3iR;(l}
w2YfFtgD,
public void setNSplitter(int nCount) M{3He)&
{ *Jmy:C<>
nSplitter = nCount; P< O[S
} o.keM4OQ
} +/-#yfn!TR
LylB3BM
2"c$#N
/* a~9U{)@F
**Utility.java hcWkAR
*/ 37T<LU
package NetFox; @i$9c)D
=UM30 P/
2}/Z.)^Q
public class Utility { 1ePZs$
l~!\<, !
liA)|.H
public Utility() SQ1.jcWW[
{ k/u6Cw0/
o;D87E6Z
;Bat!K7W
} C*,-lk0b@
[C,<Q
//线程睡眠 K;sH0*
public static void sleep(int nSecond) cuB~A8H#}
{ w\:-lXw
try{ $[by)
Thread.sleep(nSecond); B=jJ+R
} %kxq"=3
catch(Exception e) }f+If{
{ l|/h4BJ'
e.printStackTrace (); B-@6m
} Tu?+pz`h
} SWNi@
Nh^T,nv*l
//日志 {W)Kz_
public static void log(String sMsg) 4h@jJm
{ (Ub=sC
System.err.println(sMsg); N&]v\MjI62
} [}9sq+##
\ExM.T
-}/u?3^-
public static void log(int sMsg) E5~HH($b
{ C\ZL*,%}
System.err.println(sMsg); m.iCGX
} aEo!yea
} r`qMif'
nL%;^`*8
-icOg6%
/* @{iws@.
**TestMethod.java 1XSA3;ZEc
*/ $3[IlQ?
package NetFox; #v0"hFOH,
*p`0dvXG2
x1:+M]Da
public class TestMethod { (v6tE[4
=Mzg={)v
cv=nGFx6
public TestMethod() l"5$6h
{ ///xx/weblogic60b2_win.exe s:'M[xI
try{ ZR.1SA0x?O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +FfT)8@W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w17\ \[
SiteFileFetch fileFetch = new SiteFileFetch(bean); %<lfe<;^t
fileFetch.start(); jV]'/X<
} 4EQ7OGU
catch(Exception e){e.printStackTrace ();} MqGF~h|+
|5_bFB+&
bZHuEh2w
} x|d Xa0=N_
!C *%,Ak
es]\xw
public static void main(String[] args) +0rMv
{ T]Gxf"mK
new TestMethod(); C)~YWx@v
} x%23oPM
} `zGK$,[%
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