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)); g S;p::
} Uq/(xh,t5
for(int i=0;i<nEndPos.length-1;i++) [?BmW{*u.
{ x#e(&OjN7
nEndPos = nStartPos[i+1]; Nh41o0
} {=7W;uL
nEndPos[nEndPos.length-1] = nFileLength; HLAYmXX"w
} #kX=$Bzk
} joifIp_
=MG
xZS
//启动子线程 :H<u@%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sp[nKo^
for(int i=0;i<nStartPos.length;i++) {"e/3
{ bK%go
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9il!w g?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3Fh<%<=
nStartPos,nEndPos,i); 5.xvOi|.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DRi!WWivn
fileSplitterFetch.start(); ?M7nbfy[A@
} V0L^pDLOV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "8Pxf=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); j2#Vdw|j
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", H(]lqvO
nEndPos = " + nFileLength); bE^Z;q19
// fileSplitterFetch[nPos.length-1].start(); ']f]:X;6w
T~%5^+[h
Tp<=dH%$%"
//等待子线程结束 ]k{cPK
//int count = 0; ZzI^*Nyg
//是否结束while循环 ")HTUlcAe}
boolean breakWhile = false; sEdWBT 8
Z8kO*LYv
QA.B.U7!
while(!bStop) bqf=;Nvog
{ X8bo?0
write_nPos(); Lq LciD
Utility.sleep(500); wH!]B-hn
breakWhile = true; N{P (ym2yR
_Ux>BJmP
AUoi$DF(@
for(int i=0;i<nStartPos.length;i++) QE!cf@~n"
{ |82V`CV
if(!fileSplitterFetch.bDownOver) 8pDJz_F!{
{ .Rc&EO
breakWhile = false; ^F`FB..:y
break; 4ej$)AdW3
} )sB`!:~HjP
} "C=HBJdYB5
if(breakWhile) u[s+YGS
break; LjXtOF
*kL1r w6
?Dm!;Z+7
//count++; H:9( XW
//if(count>4) DfV_08
// siteStop(); wGISb\rr
} Z#>k:v
AGCqJ8`|T
?ArQ{9c
System.err.println("文件下载结束！"); |=38t8Ge&
} H7#RL1qM&
catch(Exception e){e.printStackTrace ();} v1 oSf
} jKI+-s
Rl3KE)<
V%ykHo
//获得文件长度 e@0wF59
public long getFileSize() [Bpgb57En
{ +#Ov9b
int nFileLength = -1; )_.@M '?
try{ _V:D7\Gs
URL url = new URL(siteInfoBean.getSSiteURL()); S~/iHXm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1Q?hskL
httpConnection.setRequestProperty("User-Agent","NetFox"); %F&j B
g:;v]
,{8~TVO
int responseCode=httpConnection.getResponseCode(); 9KXp0Q?-$
if(responseCode>=400) .Ji r<"*<
{ P$]Vb'Fz
processErrorCode(responseCode); g-}Vu1w0{6
return -2; //-2 represent access is error ,fET.s^|U
} Uk;SY[mU
4ItXZo
T X6Ydd
String sHeader; `2S{.s
@[ :sP
VWfrcSZg6M
for(int i=1;;i++) mW8CqW\Q5
{ RNX}Wlo-s
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [.<vISRir
//Utility.log(in.readLine()); zy$hDy0
sHeader=httpConnection.getHeaderFieldKey(i); )\VUAD%~e7
if(sHeader!=null) ,~G _3Oz
{ A|Y\Y}
if(sHeader.equals("Content-Length")) y62;&{?m
{ ItOVx!"@9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5QSd$J
break; `i{o8l
} >r]# 77d
} Mh_jlgE'd#
else yuI5# VUS
break; E/s3@-/
} &nz1[,
} f+I*aBQ
catch(IOException e){e.printStackTrace ();} X:62)^~'
catch(Exception e){e.printStackTrace ();} 31b-r[B{%
1Tiq2+hmf
pd7FU~-
Utility.log(nFileLength); :hJhEQH(9
]E=JUYf0
?LNwr[C0
return nFileLength; oY.JK
} 4F:RLj9P!
L</"m[
gXw\_ue<
//保存下载信息（文件指针位置） AQ0L9?
private void write_nPos() &S|laqH
{ JHO9d:{-
try{ *Z/B\nb
output = new DataOutputStream(new FileOutputStream(tmpFile)); " *Ni/p$I
output.writeInt(nStartPos.length); 9m6w.:S
for(int i=0;i<nStartPos.length;i++) 7B&nV92S
{ Xq)'p8C?
// output.writeLong(nPos); xc*ys-Nv
output.writeLong(fileSplitterFetch.nStartPos); s#qq% @
output.writeLong(fileSplitterFetch.nEndPos); :'!?dszS
} cL1cBWd
output.close(); 7<1Y%|x`
} 4]dPhsey
catch(IOException e){e.printStackTrace ();} m CdkYN#
catch(Exception e){e.printStackTrace ();} E&K8hY%5
} fp>o ^+VB
{H>iL
B2Orw8F
//读取保存的下载信息（文件指针位置） {'r*Jb0
private void read_nPos() ?$s2]}v
{ sPZa|AKHb
try{ ^OQ_iPPI
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /?J_7Lg
int nCount = input.readInt(); U`8)rtYw
nStartPos = new long[nCount]; ,5L&$Q6
nEndPos = new long[nCount]; oFIs,[Go
for(int i=0;i<nStartPos.length;i++) |x kixf4zz
{ !8A5Y[(XD
nStartPos = input.readLong(); H"&N<"hw
nEndPos = input.readLong(); [yVU p+
} <B``/EX^
input.close(); u?'X%'K*
} Bo~wD|E2
catch(IOException e){e.printStackTrace ();} 4< H-ol
catch(Exception e){e.printStackTrace ();} [R Ch7FE23
} , 1`eH[
I}8F3_b,#
$@#nn5^IX
private void processErrorCode(int nErrorCode) gXfAz,
{ ~I^]O \?
System.err.println("Error Code : " + nErrorCode); 6"=e+V@
} % vP{C
g@EKJFjl
z&t6,0q`5
//停止文件下载 `86b
public void siteStop() TLV)mCZ
{ <]!IC]+
bStop = true; 8vP d~te
for(int i=0;i<nStartPos.length;i++) Aw|3W ]
fileSplitterFetch.splitterStop(); '$U"RP^(
<Jvrmm[
O42An$}
} $L`7J$'^
} vu#:D1/BB
//负责部分文件的抓取 ^#Z(&/5f0
**FileSplitterFetch.java IM@Qe|5
*/ ! TRiFD
package NetFox; %-SP
~&qe"0
I7Eg$J&
import java.io.*; ca`=dwe>
import java.net.*; --/ .
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O;zW'*c+
public class FileSplitterFetch extends Thread { T-x`ut7c
x*)Wl!
lW2qVR
String sURL; //File URL odhgIl&u
long nStartPos; //File Snippet Start Position sy#Gb#=#
long nEndPos; //File Snippet End Position ucn aj|
int nThreadID; //Thread's ID G ;z2}Ei
boolean bDownOver = false; //Downing is over 6Ym[^U
boolean bStop = false; //Stop identical JvUKfsnu{
FileAccessI fileAccessI = null; //File Access interface &x;nP6mV
,Bta)
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException o+nU{
{ s9Xeh"
this.sURL = sURL; -0kwS4Hx2
this.nStartPos = nStart; e"bF"L
this.nEndPos = nEnd; -1{N#c/U
nThreadID = id; 5|Y4GQVz
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b+C>p2%
} =DtM.oQ>
xJ3#k;
[$./'-I]
public void run() @wg*~"d
{ Y,8M[UIK
while(nStartPos < nEndPos && !bStop) $HH(8NoL
{ *s!8BwiE
_ x7Vyy5
:4WwCpgz,
try{ WOwIJrP
URL url = new URL(sURL); lfGiw^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3!d|K%J
httpConnection.setRequestProperty("User-Agent","NetFox"); uM\~*@
String sProperty = "bytes="+nStartPos+"-"; x=H*"L=
httpConnection.setRequestProperty("RANGE",sProperty); c)lK{DC
Utility.log(sProperty); p#?1l/f"
Zj},VB*T
X{ Nif G
InputStream input = httpConnection.getInputStream(); A$ S9 `
//logResponseHead(httpConnection); L*5&hPU
Og,,s{\
U,]z)1#X|
byte[] b = new byte[1024]; +Q'/c0o
int nRead; ,og@}gOMB
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |S4yol
{ 3v{GP>
nStartPos += fileAccessI.write(b,0,nRead); O,bj_CWx
//if(nThreadID == 1) 5!5P\o
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :hevBBP
} k}BNFv8
0h; -Yg
zX5p'8-
Utility.log("Thread " + nThreadID + " is over!"); d8x$NW-s
bDownOver = true; O" z=+79q
//nPos = fileAccessI.write (b,0,nRead); ;bZ)q
} J|I|3h<T
catch(Exception e){e.printStackTrace ();} S'A~9+
} MVTU$ 65
} p%G\5.GcJL
Xu'u"amt
u?aq' "t
//打印回应的头信息 B0YY7od
public void logResponseHead(HttpURLConnection con) Fc nR}TE
{ JL*-L*|Zcl
for(int i=1;;i++) oACE:h9U
{ 3)T5}_
String header=con.getHeaderFieldKey(i); `yVJ `}hm
if(header!=null) S>'wb{jj!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qV(Plt%
Utility.log(header+" : "+con.getHeaderField(header)); 3rWqt
else -m__I U
break; }XAoMp
} ^i\zMMR
} pZWp2hj{X
.AV--oA~
Tn-H8;Hg
public void splitterStop() 3FS:]|oC
{ ha(hG3C
bStop = true; HFf| >&c&
} ]])i"oew
HDC`g
)kdPAw
} b|xz`wUH0$
HL_MuyE
L ~
/* G&;W
**FileAccess.java eR3!P8t
*//文件访问(定位，写) 0">#h
package NetFox; TM"i9a? ;
import java.io.*; MLp5Y\8*
CE?R/uNo{
1W-!f%
public class FileAccessI implements Serializable{ 5:AAqMa
aoCyYnZD
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t=U[ ;?
RandomAccessFile oSavedFile; KRz\ct|
long nPos; i1scoxX3\
O,DA{> *m
6bU/IVP
public FileAccessI() throws IOException )"q2DjfX*
{ x-q er-
this("",0); v|`)~"~
} cOS|B1xG
!Dun<\
j7i[z>:Y
public FileAccessI(String sName,long nPos) throws IOException &18} u~M
{ PAqziq.
oSavedFile = new RandomAccessFile(sName,"rw"); B]kz3FF
this.nPos = nPos; m(&ZNZK
oSavedFile.seek(nPos); rb9x||
} txliZ|.O
TpnkJygIm
T$k) ^'
public synchronized int write(byte[] b,int nStart,int nLen) =JEnK_@?K\
{ 0$P40 7
int n = -1; 0w\gxd~'
try{ [.0R"|$sy+
oSavedFile.write(b,nStart,nLen); 8rw;Yo<k
n = nLen; (3_2h4O
} E]+W^VG
catch(IOException e) Ot(EDa9}IJ
{ o{:D
e.printStackTrace (); !iZ*ZPu
} *%g*Np_P
'1bdBx\<.
X3q'x}{
return n; R*QL6t
} 9}5Q5OZ
vL-%"*>v
jd~r~.y
} _hXadLt
\24neD4cM@
*S;v406
/* & 8e~<
**SiteInfoBean.java "ua/65cq9
*/ D?9=q
package NetFox; %1e`R*I
K34y3i_
bu\,2t}B
public class SiteInfoBean { l%;)0gT
ydBoZ3}
%M ~X:A;4
private String sSiteURL; //Site's URL Inr ~9hz
private String sFilePath; //Saved File's Path v6iV#yz3(
private String sFileName; //Saved File's Name }!B<MGBd
private int nSplitter; //Count of Splited Downloading File C[wnor!
iT IW;Cv
V_0e/7}Ya
public SiteInfoBean() II),m8G
{//nSplitter的缺省值为5 Ma_! 1Y
//default value of nSplitter is 5 ^@jOS{f l
this("","","",5); Oq|pd7fcgm
} cITQ,ah
CK.Z-_M
AEEy49e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |f`!{=?
{ I_N"mnn@Nr
sSiteURL= sURL; lOYwYMi
sFilePath = sPath; dpTap<Noby
sFileName = sName; vsLn@k3
this.nSplitter = nSpiltter; /I: d<A
~!Onz wmO
^${-^w@,%V
} c~dX8+
ptrLnJ|%
<y~`J`-
public String getSSiteURL() Lt=#tu&d
{ AvhmN5O=
return sSiteURL; u},<On
} UPLr[>Q#
wgI$'tI
2D&tDX<
public void setSSiteURL(String value) KWU#Swa`
{ 6\'v_A O
sSiteURL = value; >b<br
} Z+Z`J; ,
>WG$!o+R
!*EHr09N7
public String getSFilePath() #|2w^Kn
{ +-HaYB|p
return sFilePath; q!}&<w~|
} 5Ss=z
.wYx_
AY|8wf,LS
public void setSFilePath(String value) IOt!A
{ jr'O4bo%
sFilePath = value; ^d-`?zb
} >.~^(
dH?;!sJ
R (4 :_ xc
public String getSFileName() Fy^!*M-
{ G8eAj%88
return sFileName; #jK{)%}mA
} yQ6{-:`)
9/q4]%`
]Jm9D=
public void setSFileName(String value) =suj3.
{ _ ?=bW
sFileName = value; q'{E $V)E
} tUL(1:-C
pSay^9ZI
p4|:u[:&
public int getNSplitter() [WC-EDO2lb
{ v5 $"v?PT
return nSplitter; Uu8Z2M
} bV`Zo(z
#%B1,.A
JFl@{6c
public void setNSplitter(int nCount) h dPKeqg7
{ O*!+D-
nSplitter = nCount; Q]7r?nEEhW
} 4ILCvM
} M9 _h0
u6cWLVt
Cz m`5
/* o^7}H{AE
**Utility.java X~%Wg*Hm
*/ 0 UjT<t^F
package NetFox; 1%EIP-z
vpTS>!i
ogDyrY}]
public class Utility { &+JV\
xOPSw|!w
A0o6-M]'0
public Utility() y}nM'$p
{ Xpjk2[,
0.bmVN<
B1J+`R3OX
} ,7k)cNstW
;]+kC
//线程睡眠 =i\~][-
public static void sleep(int nSecond) X62z>mM
{ + ECV|mkk
try{ .K;*uq:0
Thread.sleep(nSecond); \d%&_rp
} ` _[\j]
catch(Exception e) $Ob]JAf}
{ 23&;28)8
e.printStackTrace (); {Km|SG[-q
} XR]]g+Z
} J4xt!RW!
${0Xq k
//日志 "kVN|Do
public static void log(String sMsg) 7H++ pOF
{ Q->'e-\E<"
System.err.println(sMsg); ~\Fde^1
} &I<R|a
}a-ikFQ]
<`~]P$
public static void log(int sMsg) "EQ}xj
{ h$4V5V
System.err.println(sMsg); x(}@se
} E+UOuf*(
} k;l^wM
&3S;5{7_e
NS mo(c>5
/* ~iydp
**TestMethod.java N@Bqe{r6j
*/ YtxBkKiJ2V
package NetFox; Z;SRW92@
UFC.!t-Z
$1#|<|
public class TestMethod { M\>y&'J-
W;OxH"eC
J+w"{ O
public TestMethod() {b7P1}>-*
{ ///xx/weblogic60b2_win.exe =KMd! $J\
try{ /Y|9!{.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :G$NQ*(z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l{_>?]S5
SiteFileFetch fileFetch = new SiteFileFetch(bean); Pg|q{fc
fileFetch.start(); m-7^$
} ~ m,z|
catch(Exception e){e.printStackTrace ();} x!]ZVl]
hRtnO|Z6
L'z;*N3D
} /,$6`V
,K8PumM_
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public static void main(String[] args) C `k^So)
{ =+A8s$Pb
new TestMethod(); xBR2tDi%
} HaJD2wvr
} (*^_wq-;
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