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)); )I$_wB!UV
} #eR*|W7o
for(int i=0;i<nEndPos.length-1;i++) htkn#s~=
{ ~^KemwogPN
nEndPos = nStartPos[i+1]; b"/P
} wNcf7/ky
nEndPos[nEndPos.length-1] = nFileLength; 6 @'v6 1'
} .' 3;Z'%"g
} \ Lrg:
i[T!{<
OI::0KOv
//启动子线程 0waQw7 E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^Me__Y
for(int i=0;i<nStartPos.length;i++) n)^B0DnIk
{ W29@`93
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bUU_NqUf*3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <eQS16
nStartPos,nEndPos,i); KZsSTB6J
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3' mQ=tKa
fileSplitterFetch.start(); ]* ':
} `:R8~>p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), svHs&v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @0-<|,^]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", J XbG|L
nEndPos = " + nFileLength); qIuY2b`6
// fileSplitterFetch[nPos.length-1].start(); s{'r'`z.
sMs 0*B-[
bt-y6,> +E
//等待子线程结束 <vhlT#p
//int count = 0; 'HH[[9Q
//是否结束while循环 zxT&K|
boolean breakWhile = false; u\Tq5PYXt
D)K/zh)
'\[GquK;P
while(!bStop) `G@]\)-!
{ WVir[Kv%
write_nPos(); o~*% g.
Utility.sleep(500); mj{TqF
breakWhile = true; Vj2]-]Cm
(wo.OH
j1_CA5V
for(int i=0;i<nStartPos.length;i++) >#)^4-e
{ !QSL8v@c
if(!fileSplitterFetch.bDownOver) Jx.Jx~
{ "tn]s>iAd=
breakWhile = false; ZZX|MA!
break; 1<Qb"FN!2
} l]uF!']f
} 5)AMl)
if(breakWhile) &Plc
break; [yW0U:m
xbvZ7g^
?FA} ;?v
//count++; #JWW ;M6F
//if(count>4) Nw/4z$].J
// siteStop(); ~]O~a}]g(
} Cevl#c5p>
g-bHf]'
F$^RM3
System.err.println("文件下载结束！"); es6!p 7p?
} }[ld=9p(
catch(Exception e){e.printStackTrace ();} {M)Y6\v
} sV%<U-X
7:)=
to|O]h2*U2
//获得文件长度 z)#I"$!d
public long getFileSize() Vof[yL `
{ [h {zT)[
int nFileLength = -1; V<*PaS..
try{ |~Z.l
URL url = new URL(siteInfoBean.getSSiteURL()); RplLU7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .!/DM-C
httpConnection.setRequestProperty("User-Agent","NetFox"); X6)-1.T&
;%0$3a
x&@. [FJhO
int responseCode=httpConnection.getResponseCode(); zgI!S6q
if(responseCode>=400) 6k|o<`~,
{ *%=BcV+,
processErrorCode(responseCode); |a*VoMZ
return -2; //-2 represent access is error bqWo*>l
} LPc)-t|p"
@!"w.@Y
{P&{+`sov
String sHeader; "3(""0Q
iVu
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for(int i=1;;i++) nD@/,kw"
{ 3"NO"+Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ZX'q-JUv f
//Utility.log(in.readLine()); |-a5|3
sHeader=httpConnection.getHeaderFieldKey(i); k Pi%RvuQ
if(sHeader!=null) U0 nSI
{ ;wK;
if(sHeader.equals("Content-Length")) >E;kM B
{ Tvqq#;I
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); WYSqnmi
break; opU=49b
} |r>+\" X
} 7 XE&[o
else NvW`x
break; 6<u=hhL
} [uU"=H|
} kVz9}Xp"
catch(IOException e){e.printStackTrace ();} Yd'Fhvo8
catch(Exception e){e.printStackTrace ();} j)xRzImu
lqe|1vN
Y3=5J\d!a
Utility.log(nFileLength); n("Xa#mY[
lR5[UKr
X6)%2TwO
return nFileLength; U6cpj
} 1j"G~TM
P{fT5K|
~"|MwR!0
//保存下载信息（文件指针位置） `?E|frz[
private void write_nPos() M(8dKj1+
{ n_QSuh/Wn
try{ )O\w'|$G
output = new DataOutputStream(new FileOutputStream(tmpFile)); 10R#}~D
output.writeInt(nStartPos.length); .);~H#
for(int i=0;i<nStartPos.length;i++) SQ'\Kd=
{ ~tx|C3A`d
// output.writeLong(nPos); E)sC:oO
output.writeLong(fileSplitterFetch.nStartPos); D+m#_'ocL
output.writeLong(fileSplitterFetch.nEndPos); <` [o|>A Z
} i<@"+~n~GK
output.close(); X .,Lmh
} W>TG!R 5
catch(IOException e){e.printStackTrace ();} JYbsta
catch(Exception e){e.printStackTrace ();} ,Ei!\U^)
} +q n[F70}
Cm@rXA/
}?G([s56
//读取保存的下载信息（文件指针位置） nVB.sab
private void read_nPos() :j^IXZW
{ 2qd5iOhX+
try{ [x{z}rYH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,+2!&"zD
int nCount = input.readInt(); PWciD '!
nStartPos = new long[nCount]; 6`Hd)T5{w
nEndPos = new long[nCount]; gxnIur)
for(int i=0;i<nStartPos.length;i++) }aO6%
{ 8u8-:c%{
nStartPos = input.readLong(); k_;g-r,
nEndPos = input.readLong(); q)j b9e
} m.F}9HI%hN
input.close(); GdN9bA&,
} E? lK(C
catch(IOException e){e.printStackTrace ();} {g9*t}l4
catch(Exception e){e.printStackTrace ();} {E=BFs
} $, hHR:
zUuOX5-6x
gGZ-B<
private void processErrorCode(int nErrorCode) ;k?Z,M:
{ 'Em3;`/C*+
System.err.println("Error Code : " + nErrorCode); 7N:3
} TOT#l6yqdd
M( w'TE@
O06 2c)vIY
//停止文件下载 /U$5'BoS
public void siteStop() ,3XlX(P
{ 6v"WI@b4
bStop = true; =/5^/vwgY
for(int i=0;i<nStartPos.length;i++) hY5GNYDh
fileSplitterFetch.splitterStop(); 5Ve`j,`=<
hGU m7
*kYJwO^
} TWSqn'<E
} cMs8D
//负责部分文件的抓取 ygK@\JHn
**FileSplitterFetch.java 3vXa#f>P<
*/ kB` @M>[
package NetFox; e"#QUc(
niA>afo
($nQmr;t
import java.io.*; `T\_Wje(
import java.net.*; bv^wE,+?o
f9K+o-P.h
7D(Eo{ue
public class FileSplitterFetch extends Thread { CdZ. T/x
m!5MGq~
gV}c4>v(
String sURL; //File URL !78P+i
long nStartPos; //File Snippet Start Position o75l&`
long nEndPos; //File Snippet End Position _V`F_C\\#
int nThreadID; //Thread's ID E"%dO
boolean bDownOver = false; //Downing is over Ec9%RAxl
boolean bStop = false; //Stop identical t:x"]K
FileAccessI fileAccessI = null; //File Access interface C/?x`2'
FuC#w 9_
mzf~qV^T
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mE\)j*Nnv
{ mzRH:HgN?
this.sURL = sURL; 63E)RR_Lh
this.nStartPos = nStart; #V{!|Y'
this.nEndPos = nEnd; M!YGv
nThreadID = id; bMq)[8,N
fileAccessI = new FileAccessI(sName,nStartPos);//定位 E-jJ!>&K
} jl>jy6T
0fGt7 "Q
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public void run() d>gQgQ;g
{ r>#4Sr
while(nStartPos < nEndPos && !bStop) frokl5L@
{ 2BKiA[ ;;
kyi"U A82
+iqzj-e&e[
try{ 1B#iJZ}
URL url = new URL(sURL); `@xnpA]l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f AY(ro9Q(
httpConnection.setRequestProperty("User-Agent","NetFox"); 7@R^B=pb
String sProperty = "bytes="+nStartPos+"-"; LC7%Bfn!
httpConnection.setRequestProperty("RANGE",sProperty); o2D;EUsNX
Utility.log(sProperty); ,|g&v/WlC%
aX,6y1
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InputStream input = httpConnection.getInputStream(); w5 #;Lm
//logResponseHead(httpConnection); NR,R.N^[
:d6]rOpX
j.!5&^;u4
byte[] b = new byte[1024]; SoWMP2/
int nRead; n-9a0_{k
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) uZTbJ3$$
{ 2KlVj]!7
nStartPos += fileAccessI.write(b,0,nRead); &^`[$LtYd
//if(nThreadID == 1) shD4";8*@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :q>)c]
} Quwq_.DU
J`4V\D}n
?bH`
Utility.log("Thread " + nThreadID + " is over!"); Mp QsM-iW
bDownOver = true; Dz,|sHCmk
//nPos = fileAccessI.write (b,0,nRead); j0^1BVcj
} #kk5{*`
catch(Exception e){e.printStackTrace ();} ]u^ybW"
} 7z_ZD0PxPc
} YSzC's[
rB-R(2 CCN
N1}r%!jk/
//打印回应的头信息 )(OGo`4Qz
public void logResponseHead(HttpURLConnection con) T/0cPn0>
{ L&KL]n
for(int i=1;;i++) ]UkqPtG;
{ ^M1jv(
String header=con.getHeaderFieldKey(i); D9 Mst6
if(header!=null) O2":)zU.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z6Fl$FFP
Utility.log(header+" : "+con.getHeaderField(header)); ZA&bp{}D
else mBEMwJ}O`
break; ~|[i64V<^
} U'^ G-@
} l,9rd[
R|k:8v{V=
<isU D6TC
public void splitterStop() ._]*Y`5)d
{ xU2i&il^!
bStop = true; Jz4;7/
} D9H%jDv
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fRxn,HyV
} 7|"l/s9,
Y3#8]Z_"}O
W9{i~.zo
/* qu.AJ*
**FileAccess.java M+M ;@3
*//文件访问(定位，写) uGn BlR$}
package NetFox; aTfc>A;
import java.io.*; .:XXc
~1XC5.*-
#F6<N]i
public class FileAccessI implements Serializable{ mE;^B%v
!u:Fn)j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7yJE+o'
RandomAccessFile oSavedFile; l*(L"]
long nPos; RD0*]4>]
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0}YadNb7
public FileAccessI() throws IOException +U<.MVOo.
{ ([|^3tM
this("",0); ~;-2eKw
} 0eKLp8;Lh
@NiLKcL#
\Unawv~
public FileAccessI(String sName,long nPos) throws IOException Xgl %2'
{ mhM;`dl
oSavedFile = new RandomAccessFile(sName,"rw"); Y O|hwhe_
this.nPos = nPos; M?Fv'YE
oSavedFile.seek(nPos); Lp3pJE
} A k~|r#@
t\]kVo)
'SXLnoeTa
public synchronized int write(byte[] b,int nStart,int nLen) ;1s;"
{ I FvigDj?
int n = -1; T*S)U ;
try{ .76Z
oSavedFile.write(b,nStart,nLen); lfG',hlI;
n = nLen; O$x +>^
} xnJ#}-.7
catch(IOException e) z:N?T0b(
{ K47.zu
e.printStackTrace (); ,<C~DSAyZ
} [vz2< genn
?)[=>Kp
l: kW|
return n; B qINU
} w11L@t[5W8
CKSs(-hkJ
<IBUl}|\
} *y(UI/c
dQFUQ
Pf;RJeD
/* `Ba?4_>k
**SiteInfoBean.java )iVuac]E++
*/ TwF.UL@G%
package NetFox; [,;O$j}
|MN2v[y
qG2P?DR
public class SiteInfoBean { e|>@ >F]K
QxuU3#l
\F\xZ.r
private String sSiteURL; //Site's URL AFeFH.G6Jr
private String sFilePath; //Saved File's Path o.Bbb=*rZ
private String sFileName; //Saved File's Name D(&Zq7]n
private int nSplitter; //Count of Splited Downloading File T!pA$eE
:o87<) _F
+;*4.}
public SiteInfoBean() ^jcVJpyT@R
{//nSplitter的缺省值为5 oA:`=f%\
//default value of nSplitter is 5 . Y$xNLoP[
this("","","",5); a[,p1}!_
} L^PBcfg
#)i+'L8
' QjJ^3A
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #s#BYbF
{ *5\'$;Rg
sSiteURL= sURL; HX,i{aWWy
sFilePath = sPath; ~0o>B$xJ
sFileName = sName; Q \SSv;3_
this.nSplitter = nSpiltter; +VJyGbOcC
W<TfDEEa
fN21[Jv3
} c>! ^\
G)f!AuN=
bYX.4(R
public String getSSiteURL() <u1`o`|-
{ ]3Ibl^J
return sSiteURL; t0?tXe.B
} E70o nR!i
b_u; `^
bA'N2~.,
public void setSSiteURL(String value) >5TXLOYZ
{ )4hA Fy6l
sSiteURL = value; .81 ~ K[
} ~]9EhC'l
cXr_,>k
I"QU{]|J
public String getSFilePath() ``@e7~F{
{ &m]jYvRc
return sFilePath; Q4Qf/q;U
} k'sPA_|
_EP~PW#J
T.B7QAI. H
public void setSFilePath(String value) wbk$(P'gN
{ obv_?i1
sFilePath = value; (yeWArQ
} ]US!3R^
AM#s2.@
*o!#5c
public String getSFileName() p;D {?H/
{ OB^j b8
return sFileName; MUCes3YJH
} (\wV)c9
[M:<!QXw
ytV[x
public void setSFileName(String value) Bt1v7M
{ 79k+R9m
sFileName = value; P?jI:'u!R.
} {Q`Q2'@
QF22_D<.}J
0HQTe>!
public int getNSplitter() b&d4(dk
{ *iyc,f^w
return nSplitter; jR+kx:+
} NSR][h_
#BgiDLh
Adfnd
public void setNSplitter(int nCount) r;>.*60AT
{ 10GU2a$0"$
nSplitter = nCount; =.):tGDp
} }^b
} RXu`DWN
9C!b f \
<^942y-=
/* 9T1-{s R
**Utility.java 3;!!`R>e
*/ MOi1+`kwh
package NetFox; :2XX~|
sv#b5,>9
T&:~=
public class Utility { Um*&S.y
S0LaQ<9.
-3m!970
public Utility() t8.3
{ |eJR3o
I SdB5Va
Im]6-#(9\|
} @~&^1%37)
&]A0=h2{P*
//线程睡眠 MlW*Tugg
public static void sleep(int nSecond) g;7u-nP
{ tDMNpl
try{ )M"xCO3a
Thread.sleep(nSecond); >LPIvmT4D?
} ~8-xj6^
catch(Exception e) $'::51
{ 4AF.KX7
e.printStackTrace (); P{: 5i%qC
} k%aJ%(
} UA*Kuad
<,U$Y>
//日志 mHH>qW{`
public static void log(String sMsg) .*J /F$
{ l|;]"&|_]c
System.err.println(sMsg); %J9+`uSl
} .S* sGauM
C9,Uwz<!]
M~+DxnJ=
public static void log(int sMsg) ][YC.J
{ CW.T`F
System.err.println(sMsg); !;${2Q
} ocZ^rqo2w
} ;Sp/N4+
}'n]C|gZ
2R;#XmKS
/* x,fL656t
**TestMethod.java WSGho(\
*/ k<NxI\s8]
package NetFox; QiJ
lnF{5zc
LyL(~Jc|
public class TestMethod { ktp<o.f[
8PWEQ<ev7>
HK%W7i/k@
public TestMethod() j[dgY1yE:
{ ///xx/weblogic60b2_win.exe >&^jKfY
try{ @3S:W2k
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); e_cK#9+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); BKgCuz:y
SiteFileFetch fileFetch = new SiteFileFetch(bean); *9EW&Ek
fileFetch.start(); "98j-L=F+
} dyohs_
catch(Exception e){e.printStackTrace ();} %8d]JQ
r@ !
H?V b
} Q\btl/?
Wr'1Y7z
y! QYdf?
public static void main(String[] args) ,R-aO= %
{ Wv~&Qh}
new TestMethod(); x@[6u
} 7<Y aw,G
} =F %lx[9Ye
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