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)); aRdk^|}
} #,Fk
for(int i=0;i<nEndPos.length-1;i++) f}Eoc>n
{ i|*(vH&D.
nEndPos = nStartPos[i+1]; XWo:~\
} %L:e~*
nEndPos[nEndPos.length-1] = nFileLength; LtJ$ZE^GB
} `]_#_
} VT?JTW
tmDI2Z%7
NjMbQM4
//启动子线程 }=?kf3k
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; epJVs0W
for(int i=0;i<nStartPos.length;i++) K;,n?Q w
{ +IK~a9t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7]@vPr;:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), y'*^ '
nStartPos,nEndPos,i); b4Zkj2L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HY~\e|o
fileSplitterFetch.start(); dMCV !$
} 5Z]`n
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d2'9C6t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~#h@.yW^JN
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8h=H\v^f
nEndPos = " + nFileLength); CA7tI >y_
// fileSplitterFetch[nPos.length-1].start(); MM3X! tq
={~`0,
E[/<AY^@!z
//等待子线程结束 UaiDo"i
//int count = 0; qtnLQl"M
//是否结束while循环 QK&<im-
boolean breakWhile = false; 7C9qkQ Jqn
Yl% Ra1
O`g44LW2n
while(!bStop) i{I'+%~R
{ *Tl"~)'t~
write_nPos(); -d[9mS
Utility.sleep(500); 6{8qATLR
breakWhile = true; K%[Rv#>;q|
vE;`y46&r
H|tbwU)J
for(int i=0;i<nStartPos.length;i++) z `T<g!Y
{ dz5a! e [
if(!fileSplitterFetch.bDownOver) "S(m1L?
{ &"BmCDOq
breakWhile = false; ?=dyU(
break; v:PNt#Ta
} ELk$lm&@
} {oy(08`6
if(breakWhile) yyPkjUy[
break; MlkTrKdGi
AA;\7;k{
1 9$ufod
//count++; puG$\D-[
//if(count>4) ^6Q(he
// siteStop(); /FJAI
} KXL]Qw FN
#*BcO-N
OthQ)&pqX
System.err.println("文件下载结束！"); 30-XFl
} #.$p7]
catch(Exception e){e.printStackTrace ();} rtS(iD@B"
} DM/J,q
UO5^4
,}2M'DSWa
//获得文件长度 x|<rt966A
public long getFileSize() /(8Usu?g.
{ ;eI,1 [_
int nFileLength = -1; 5u'"m<4
try{ ^Jcs0c @\
URL url = new URL(siteInfoBean.getSSiteURL()); y&-wb'==p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WEFYV=I\
httpConnection.setRequestProperty("User-Agent","NetFox"); k|F<?:C
BB-E"<
7G.IGXK$
int responseCode=httpConnection.getResponseCode(); %a&Yt
if(responseCode>=400) .e!dEF)D
{ X3tpW`alo
processErrorCode(responseCode); x$QOOE]
return -2; //-2 represent access is error ,'v]U@WK
} (Gf1#,/3~
cF_ Y}C
(5]<t&M
String sHeader; F8$.K*tT
M&Sjo' ( .
h`-aO u
for(int i=1;;i++) C|5eV=f)P
{ lsU|xOB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); MLtfi{;LH
//Utility.log(in.readLine()); jY-{hW+r
sHeader=httpConnection.getHeaderFieldKey(i); s+YQ :>F
if(sHeader!=null) /zMiy?
{ mk~&>\
if(sHeader.equals("Content-Length")) G4{ zt3{
{ PCF!Y(l
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); B4bC6$Lg
break; *>h"}e41
} p 2It/O
} wqx@/--E(
else "X4OUk
break; c}kZx1
} A1Ia9@=Mf
} lO3$V JI
catch(IOException e){e.printStackTrace ();} ~cbq5||
catch(Exception e){e.printStackTrace ();} FUkO$jnO
OE]zC
C=2
Utility.log(nFileLength); Iz*'
f9W@!]LHJ
?M.n 9|}y
return nFileLength; fNPHc_?Ybj
} kngkG|du
}26?bd@e`
lCLz!k2di
//保存下载信息（文件指针位置） v!27q*;8H
private void write_nPos() 7tP?([o%F
{ 9G_bM(q'^2
try{ 8VQJUwf;
output = new DataOutputStream(new FileOutputStream(tmpFile)); Gu}|CFL\
output.writeInt(nStartPos.length); /.9j$iK#
for(int i=0;i<nStartPos.length;i++) Vz6p^kMB
{ ZgQ4~s
// output.writeLong(nPos); +kP)T(6
output.writeLong(fileSplitterFetch.nStartPos); #|k;nFJ
output.writeLong(fileSplitterFetch.nEndPos); qL.1N~$2
} VC5LxA0{
output.close(); _p<W
} NNLZ38BV7
catch(IOException e){e.printStackTrace ();} 6d&dB
catch(Exception e){e.printStackTrace ();} 3`uv/O2~i
} secD `]
_TfG-Ae
|=L~>G
//读取保存的下载信息（文件指针位置） ^2%_AP0=
private void read_nPos() :IlRn`9X`
{ B{$4s8XU
try{ j&,,~AZm
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A;7p
int nCount = input.readInt(); 7nM]E_
nStartPos = new long[nCount]; :@x24wN/
nEndPos = new long[nCount]; +EjH9;gx
for(int i=0;i<nStartPos.length;i++) =cI -<0QSn
{ 0h/gqlTK1
nStartPos = input.readLong(); T;K@3]FbX
nEndPos = input.readLong(); E/2kX3}
} 1DVu`<OXcH
input.close(); xS?[v&"2
} ^ZV1Ev8T6
catch(IOException e){e.printStackTrace ();} (7^5jo[D
catch(Exception e){e.printStackTrace ();} 1"?3l`i
} rOQ@(aUAZ
&6<>hqR^
1)yEx1
private void processErrorCode(int nErrorCode) 4XpW#>
{ BOClMeA4
System.err.println("Error Code : " + nErrorCode); dZcRLLR
} \H|tc#::{
d/5i4g[q
/.B7y(
//停止文件下载 0t[|3A~Q
public void siteStop() 2z+Vt_%
{ p vone,y2
bStop = true; kx&Xk0F_g
for(int i=0;i<nStartPos.length;i++) t`=TonLb8
fileSplitterFetch.splitterStop(); PDQC^2Z
T n.Cj5
C^9G \s'
} c-3-,pyM_T
} Ks'msSMC
//负责部分文件的抓取 reseu*5
**FileSplitterFetch.java dz@L}b*
*/ ZGO%lkZ.
package NetFox; 0?OTa<c
$I*ye+a*{q
:cU6W2EV
import java.io.*; I/4:SNha
import java.net.*; NwPGH=V
j#L"fW^GM
s|B
public class FileSplitterFetch extends Thread { eGcc'LBr;
F]o&m::/K
K8`Jl=}z%&
String sURL; //File URL [ u7p:?WDW
long nStartPos; //File Snippet Start Position F/,K8<|r>
long nEndPos; //File Snippet End Position 4)MKYhm
int nThreadID; //Thread's ID =)_9GO
boolean bDownOver = false; //Downing is over A+Uil\%
boolean bStop = false; //Stop identical -OV:y],-
FileAccessI fileAccessI = null; //File Access interface 6[3oOO:uo
\yt-_W=[
(Z(O7X(/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U8TH}9Q
{ U9^o"vT
this.sURL = sURL; z}?*1c
this.nStartPos = nStart; L&h@`NPO a
this.nEndPos = nEnd; PNy)TqdRS
nThreadID = id; <ua`WRQr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @CGci lS=
} yQ$Q{,S9
|NuX9!S
ueI1O/Mi
public void run() Su"9`
{ T%0vifoQ_$
while(nStartPos < nEndPos && !bStop) ;MRK*sfw{
{ =AEl:SY+
.quui\I3
U`YPzZp_
try{ 99W-sV
URL url = new URL(sURL); 7G6XK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )@lZ~01~d
httpConnection.setRequestProperty("User-Agent","NetFox"); 2?vjj:P+h
String sProperty = "bytes="+nStartPos+"-"; BG ]w2=
httpConnection.setRequestProperty("RANGE",sProperty); 2"0q9Jg
Utility.log(sProperty); }E[u" @}
;QYUiR
0_nY70B
InputStream input = httpConnection.getInputStream(); Pn?Ujjv
//logResponseHead(httpConnection); *B<Ig^c
7oUecyoj
kpF")0qr
byte[] b = new byte[1024]; %LI[+#QE
int nRead; z}Y23W&sX
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3B*b d
{ 5Bwr\]%$P
nStartPos += fileAccessI.write(b,0,nRead); /~sNx
//if(nThreadID == 1) !~sgFR8W
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k55s-%Ayr
} OYnxEdo7
VN3"$@-POK
cD^`dn%$
Utility.log("Thread " + nThreadID + " is over!"); O5rHN;\_
bDownOver = true; VycCuq&M
//nPos = fileAccessI.write (b,0,nRead); )w.+( v(
} 4Js2/s
catch(Exception e){e.printStackTrace ();} ;/-v4
} {tS^Q*F
} "&$ [@c
2pr#qh8
u.\FNa
//打印回应的头信息 1P8XVI'
public void logResponseHead(HttpURLConnection con) ^a>3U l{
{ eXs^YPi
for(int i=1;;i++) _:N+mEF
{ ub/Z'!
String header=con.getHeaderFieldKey(i); `.oWmBey\
if(header!=null) L@mNfLK
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kmNa),`{s
Utility.log(header+" : "+con.getHeaderField(header)); ^Om0~)"q
else \xCI8 *W
break; =w&bS,a"y
} @=i-*U
} ;)nkY6-
X667*L^
Q:L^DZkGV
public void splitterStop() 9F~e^v]zp
{ 0iKSUwps
bStop = true; "+0Yhr?
} 2OA0rH"v
cWp5' e]A
W;Pdbf"
} %|"0p3
EO.Se9ux
f`;y "ba
/* i}tBB~]
**FileAccess.java TTYM!+T
*//文件访问(定位，写) Xmmb^2I
package NetFox; ,(&p"O":
import java.io.*; >Bw<THx
x]6-r`O7r
v|K,
public class FileAccessI implements Serializable{ pA%}CmrMq
Ru&>8Ln0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a-\M)}T
RandomAccessFile oSavedFile; "=0(a)01p:
long nPos; xM+_rU M|h
{/)q=
,H)v+lI
public FileAccessI() throws IOException k^H&IS!
{ k4C3SI*`4
this("",0); 9mmkFaBQ
} KD<smwXjG
X[SdDYMY
>P<8E2}*
public FileAccessI(String sName,long nPos) throws IOException cD%_+@GaU
{ S|jE1v"L
oSavedFile = new RandomAccessFile(sName,"rw"); L2sUh+'|
this.nPos = nPos; o^efeI
oSavedFile.seek(nPos); gTM*td(~^
} [ pe{,lp
7^oO N+=d
@%^JB
public synchronized int write(byte[] b,int nStart,int nLen) #NyfE|MKBC
{ DXa!"ZU
int n = -1; i-jrF6&
try{ ,<CFjtelO
oSavedFile.write(b,nStart,nLen); 6*aU^#Hz6
n = nLen; =,Zkg(M
} UR|Au'iu
catch(IOException e) {}n]\zO %
{ 3>'TYXs-
e.printStackTrace (); W?:e4:Q
} /&i6vWMhP
De-hHY{>
gX%"Ki7.
return n; 6(1S_b=a
} ?Tlt(%f
u\AL`'v
7WMF8(j5
} nb~592u
U[R[VY7
f=EWr8mno
/* Ql1J?9W
**SiteInfoBean.java kf:Nub+h t
*/ si,)!%b
package NetFox; ?onEqH>
5$?)f&M
rJM/.;Ag
public class SiteInfoBean { b|DiU}
v,L@nlD]
(&KBYiwr
private String sSiteURL; //Site's URL @kPe/j/[1
private String sFilePath; //Saved File's Path fq[1|Q
private String sFileName; //Saved File's Name 1xD?cA\vu
private int nSplitter; //Count of Splited Downloading File K%g_e*"$
| 9 <+!t\
OQJ#>*?
public SiteInfoBean() 6QYHPz
{//nSplitter的缺省值为5 ujf]@L?
//default value of nSplitter is 5 8Q(A1U
this("","","",5); :\]qB&
} u_=^Bd
_u9bZ'
rU |%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3^,p$D<T:,
{ 0aqq*e'c
sSiteURL= sURL; YD,<]q%
sFilePath = sPath; +Ym#!"
sFileName = sName; E*vh<C
this.nSplitter = nSpiltter; |%g)H,6c
]p@q.P
)B9/P>c
} +7mUX
4g)$(5jI}
$YiG0GK<"
public String getSSiteURL() m2\[L/W]
{ Vz]yJ:
return sSiteURL; r`Bm"xI
} (-Qr.t_B`
Rr0]~2R
O& 1z-
public void setSSiteURL(String value) w&>*4=^a
{ 8xt8kf*k
sSiteURL = value; 4jw q$G
} _/NPXDL
c{3P|O&.
U.Fs9F4M#
public String getSFilePath() F*JbTEOn
{ jGUegeq
return sFilePath; b=kY9!GN,v
} L>n^Q:M
G2dPm}sZG
;qs^+
public void setSFilePath(String value) >-j([%
{ XG!^[ZDs
sFilePath = value; .umN>/o[
} XzB3Xs?W2
]zz%gZz
)Vo%}g?6!
public String getSFileName() ul{D)zm\D
{ Ie}7#>S
return sFileName; sitgz)Ki^
} rrSFmhQUk
^[VEr"X
t9r R>Y9
public void setSFileName(String value) r2\}_pIj
{ Z~K} @
sFileName = value; g:YUuZ
} W/.n R[!
I2gSgv%
J4Ca0Ag
public int getNSplitter() m A('MS2
{ wlDo(]mj=O
return nSplitter; 3uL$+F
} 5&_R+g
"iJAM`Hi
5O~;^0iC
public void setNSplitter(int nCount) k)zBw(wr
{ TVVu_ib
nSplitter = nCount; j:$Z-s
} USJ4Z
} 8l<~zIoO
;?Q0mXr
f\z9?Z(~
/* F(`Q62o@
**Utility.java 65GC7 >[
*/ G+tzp&G@
package NetFox; "?6R"Vk?:
3}B-n!|*
OI:T#uk5
public class Utility { On}b|ev
93/`e}P"o
o\qeX|.70
public Utility() 0R;`)V\^
{ rS0#]Gg
Hp@cBj_@P2
*fSX3Dk
} `(]mUW
fVYv 2
//线程睡眠 O O-Obg^
public static void sleep(int nSecond) ppu<k N
{ [OFT!=.y &
try{ t&-c?&FO\;
Thread.sleep(nSecond); fO837
} z=4E#y`?U
catch(Exception e) \}Kad\)
{ W$` WkR
e.printStackTrace (); ^y~oXS(
} a?)g>e HN
} _k5$.f:Yj<
iig&O(,
//日志 dBHki*.u
public static void log(String sMsg) Is97>aid
{ UJ`%uLR~
System.err.println(sMsg); sA }X)aP
} Cyud)BZvm
G }M!
Lve$H(GHT
public static void log(int sMsg) BbI),iP
{ }dSFv
System.err.println(sMsg); Y5TBWcGU%
} (CE2]Nv9")
} .yb8<qs
s%?<:9
V{{UsEVO
/* WX+@<y}%
**TestMethod.java t5QGXj
*/ FYK}AR<=
package NetFox; &<hk&B
HPK}Z|Vl
XlGB`P>?KD
public class TestMethod { mHc2v==X\-
7VJf~\%1j
obw:@i#
public TestMethod() U27ja|W^
{ ///xx/weblogic60b2_win.exe L~_zR>
try{ ~5Rh7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qt%/0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); n4zns,:)/
SiteFileFetch fileFetch = new SiteFileFetch(bean); os(}X(
fileFetch.start(); FFH{#|_1
} hflDVGBW
catch(Exception e){e.printStackTrace ();} +7K]5p;!~
l_x>.'a
h#8{fr)6
} s'@@q
]j(Ld\:L
dRTpGz
public static void main(String[] args) <pUc( tPoz
{ j MA%`*r
new TestMethod(); _[ `"E'
} 98WJ"f_ #
} !v3wl0
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