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)); ndyIsR
} ./tZ*sP:
for(int i=0;i<nEndPos.length-1;i++) _+}o/449
{ U*EBH
nEndPos = nStartPos[i+1]; 4tkb7D q
} akj#.aYk
nEndPos[nEndPos.length-1] = nFileLength; E?&YcVA
} R<3 -!p1v
} iQ;lvOja
7#HSe#0J
uv$utu>< *
//启动子线程 %f\j)qw
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $5#DU__F/
for(int i=0;i<nStartPos.length;i++) P e} T
{ ,\T`gh
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZRGe$HaU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jJ RaY3
nStartPos,nEndPos,i); X&Ospl@H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <UIE-#
fileSplitterFetch.start(); >y!R}`&0^t
} 'K23oQwDB
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k/Urz*O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); FrRUAoFO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", A(XX2f!i
nEndPos = " + nFileLength); }Oe4wEYN)
// fileSplitterFetch[nPos.length-1].start(); XB[EJGaX
B$q5/L$}
1n)YCSA
//等待子线程结束 Bi/E{k,
//int count = 0; tHvP0RxM
//是否结束while循环 )*}?EI4.
boolean breakWhile = false; @]]\r.DG
V2yX;u
G[d]t$f=
while(!bStop) T7Y+ WfYh
{ $|@-u0sv
write_nPos(); ;iN[du
Utility.sleep(500); 1yS:`
breakWhile = true; '^Q$:P{G?
;+3@S`2r
/*6[Itm_h
for(int i=0;i<nStartPos.length;i++) L8pKVr
{ ihct~y-9W
if(!fileSplitterFetch.bDownOver) ?5[$d{ Gjl
{ !6 kn>447Y
breakWhile = false; 3z k},8fu
break; K,bX<~e5
} v# fny
} _GoFwVO
if(breakWhile) T0o0_R
break; r0<zy_d'
LCSJIt
uesIkJ^Q[
//count++; j3R}]F'C*
//if(count>4) =QwT)KRB%
// siteStop(); dA#'HMh@
} Nc^:v/(P
}+:X=@Z@
7Zft]C?|@
System.err.println("文件下载结束！"); @6y)wA9Yx
} x45F-w{
catch(Exception e){e.printStackTrace ();} wF-H{C'
} H:q;IYE+a
U]M5&R=?
a3[,3
//获得文件长度 Eh *u6K)Z
public long getFileSize() \h}sA
{ #=ko4?Wr(
int nFileLength = -1; }'p*C$
try{ MMQ\V(C
URL url = new URL(siteInfoBean.getSSiteURL()); 0Y!~xyg/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I#(?xHx
httpConnection.setRequestProperty("User-Agent","NetFox"); EQy~ ^7V B
c&g*nDuDj
0.~s>xXp
int responseCode=httpConnection.getResponseCode(); E,/nK
if(responseCode>=400) QwnqysNx4
{ S`h yRw
processErrorCode(responseCode); #Fh:z4
return -2; //-2 represent access is error =s:Z-*vy!
} V|2[>\Cv
3'55!DE
d263#R
String sHeader; )SaMfP1=v
=|V#~p*
^ b{~]I
for(int i=1;;i++) >=Na,D
{ Ibv`/8xh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p3IhK>
//Utility.log(in.readLine()); )|&FBz;
sHeader=httpConnection.getHeaderFieldKey(i); Q*9Y.W.8
if(sHeader!=null) ?{1& J9H
{ $L72%T
if(sHeader.equals("Content-Length")) C5TC@w1*
{ |4Os_*tRKU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); d-I&--"ju
break; lgefTT GX)
} DNRWE1P2bg
} Go7 oj'"
else ( n!8>>+1C
break; 5QG?*Z~?7
} i&L!?6 5-f
} =pb ru=/
catch(IOException e){e.printStackTrace ();} Nfd'|#
catch(Exception e){e.printStackTrace ();} >B$B|g~
P\$%p-G
X(;WY^i!
Utility.log(nFileLength); <@>l9_=R
Bf$`Hf6
wd2z=^S~
return nFileLength; B*}:YV
} u y13SkW
U ?6.UtNf
'On%p|s)H
//保存下载信息（文件指针位置） K#x|/b'5d
private void write_nPos() WS\Ir-B
{ S3y(' PeF
try{ o}Q3mCB
output = new DataOutputStream(new FileOutputStream(tmpFile)); *dxE (dP
output.writeInt(nStartPos.length); l-8rCaq&J
for(int i=0;i<nStartPos.length;i++) pE{Ecrc3|
{ B#o6UO\
// output.writeLong(nPos); $g }aH(vf
output.writeLong(fileSplitterFetch.nStartPos); V17!~
output.writeLong(fileSplitterFetch.nEndPos); Eu[/* t+l
} T@ zV
output.close(); 8M7Bw[Q1
} $AdBX}{
catch(IOException e){e.printStackTrace ();} =A_fL{ SM
catch(Exception e){e.printStackTrace ();} +EH"A
} &[5pR60
O&@CT])8
,3Aiz|v-
//读取保存的下载信息（文件指针位置） scy_
private void read_nPos() CWSc#E
{ UYhxgPGsj
try{ 1P G"IaOb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); SL`nt
int nCount = input.readInt(); Lv<vMIr
nStartPos = new long[nCount]; ,#j'~-5
nEndPos = new long[nCount]; ^MvBW6#1
for(int i=0;i<nStartPos.length;i++) !d1a9los
{ _W>xFBy
nStartPos = input.readLong(); HnKXO
nEndPos = input.readLong(); QVkrhwp
} e. R9:
input.close(); ggy9euWV
} CsN^u H
catch(IOException e){e.printStackTrace ();} cT nC
catch(Exception e){e.printStackTrace ();} V}Ce3wgvA
} FQ u c}A
*eMMfxFl
C40o_1g
private void processErrorCode(int nErrorCode) c6VyF=2q
{ %m-U:H.Vp
System.err.println("Error Code : " + nErrorCode); 8;x0U`}Ez(
} T_fM\jdI
+.QJZo_
_[/#t|I}
//停止文件下载 !gJw?(8"
public void siteStop() <4582x,G
{ m%s:4Z%=
bStop = true; ~re~Ys
for(int i=0;i<nStartPos.length;i++) f'TEua_`
fileSplitterFetch.splitterStop(); v4F+^0?
P7$/yBI U
`7R-2 w<b?
} b8glZb*$
} gKtgW&PYm
//负责部分文件的抓取 =X7_!vSv
**FileSplitterFetch.java $ByP 9=|
*/ a`>H69(bU
package NetFox; }ldpudU
KCnm_4
I8uFMP
import java.io.*; kq@~QI?9
import java.net.*; /dHIm`. Z
} g%v<'K
BO.Db``
public class FileSplitterFetch extends Thread { \}_,g
-B?cF9
aP#/%
String sURL; //File URL Q"H/RMo-
long nStartPos; //File Snippet Start Position L2OR<3*|Av
long nEndPos; //File Snippet End Position J M`[|"R%
int nThreadID; //Thread's ID Rx?ze(
boolean bDownOver = false; //Downing is over I moxg+u
boolean bStop = false; //Stop identical my#\(E+
FileAccessI fileAccessI = null; //File Access interface R[@}Lg7+v
X!m lC51
ilAhw4A
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d0;?GQYn:
{ V)P8w#,
this.sURL = sURL; =nqHVRA
this.nStartPos = nStart; 2+ywl}9
this.nEndPos = nEnd; ?hViOh$.
nThreadID = id; lSc=c-iOv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :aH5=@[!y
} gFsqCx<q
tHK>w%|\R
KD?b|y@
public void run() bP>Kx-%q
{ tS-gaT`T
while(nStartPos < nEndPos && !bStop) 73Hm:"Eqd
{ Fu5c_"!
,e$6%R
kpxGC,I^*.
try{ '.k'*=cq0
URL url = new URL(sURL); ^b.#4i(v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6[SIDOp*^
httpConnection.setRequestProperty("User-Agent","NetFox"); b`@J"E}
String sProperty = "bytes="+nStartPos+"-"; 7VL|\^Y`q
httpConnection.setRequestProperty("RANGE",sProperty); na"!"C s3
Utility.log(sProperty); T"<)B^8f
7Gy:T47T\@
'u~0rMe4})
InputStream input = httpConnection.getInputStream(); @0d"^
//logResponseHead(httpConnection); MzDosr3:
5{bc&?"
O8SE)R~
byte[] b = new byte[1024]; _ j`tR:
int nRead; SZ}=~yoD(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) k81%$E
{ 5DVYHN9c|
nStartPos += fileAccessI.write(b,0,nRead); b` va\'&3
//if(nThreadID == 1) ~]q>}/&YLo
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e['<.Yf+
} }1W@
[c;#>UQMf
is~2{:
Utility.log("Thread " + nThreadID + " is over!"); w ?*eBLJ(G
bDownOver = true; YV!hlYOBi
//nPos = fileAccessI.write (b,0,nRead); 2;0eW&e
} N$x&k$w R
catch(Exception e){e.printStackTrace ();} kw E2V+2
} Ih>s2nL
} )Yv=:+f
|0Xf":
AI`k }sA~
//打印回应的头信息 &{UqGD#1&
public void logResponseHead(HttpURLConnection con) r$8'1s37`
{ P=_fYA3
for(int i=1;;i++) *UJ4\
{ }>d
String header=con.getHeaderFieldKey(i); ]!&$&t8.
if(header!=null) Y~e)3e
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <fM}Kk
Utility.log(header+" : "+con.getHeaderField(header)); Fm,` ]CO
else *mbzK*
break; 8QZI(Xe9r
} }YVF fi~
} S0QLM)
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8'%m!
public void splitterStop() G!;PV^6x
{ S_/S2(V"
bStop = true; Cs7ol-\)
} X-(4/T+v
JO+tY[q
_OyQ:>M6P
} 0Q`v#$?":
(:HT|gKoE
+{RTz)e?*
/* 23WrJM!2N
**FileAccess.java &JcatI
*//文件访问(定位，写) -5 D<zP/
package NetFox; %1.F;-GdsW
import java.io.*; YO$D-
{(!JYz~P
!*Eu(abD
public class FileAccessI implements Serializable{ . ump? M
?5J#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5l 3PAG
RandomAccessFile oSavedFile; 5a$EXV
long nPos; [`t ;or
C5Q!_x(
#[bL9R5NC
public FileAccessI() throws IOException }#7rg_O]>
{ yV )fJ_
this("",0); 0hV#]`9`gN
} S`U8\KTi
#Uu,yHMv:;
W>C?a=r~
public FileAccessI(String sName,long nPos) throws IOException f|FS%]fCxk
{ t4[q:[1
oSavedFile = new RandomAccessFile(sName,"rw"); HyVV,q^E
this.nPos = nPos; ws+'*7
oSavedFile.seek(nPos); ^`'\eEa
} ;Pt8\X
&hI!mo
IBo
public synchronized int write(byte[] b,int nStart,int nLen) )q-NE)
{ Syy{ ^Ae}
int n = -1; rZJJ\ , |
try{ e,/]]E/o
oSavedFile.write(b,nStart,nLen); t]@>kAA>2L
n = nLen; j<*7p:L7_>
} _&BK4?H@b
catch(IOException e) =g9n =spAn
{ WSu6chz)
e.printStackTrace (); kpIn_Ea
} c 'wRGMP
jez0 A
H.ksI;,
return n; uBx\xeI
} $jg[6`L$
#Az#_0=
L)J1yw
} f7~dn#<@
B_Q{B|eEt&
)|xu5.F
/* Q_0+N3
**SiteInfoBean.java FL^ _)`
*/ -&>V.hi7
package NetFox; tfGs|x
j'z#V_S
W_`]7RO8
public class SiteInfoBean { /)sP, 2/
.EL3}6"A
.iRKuBM/
private String sSiteURL; //Site's URL +ig%_QED[\
private String sFilePath; //Saved File's Path Lc{arhN
private String sFileName; //Saved File's Name @"MYq#2c$
private int nSplitter; //Count of Splited Downloading File S>~f.
wWb>V&3
a+cMXMf
public SiteInfoBean() .cHgYHa
{//nSplitter的缺省值为5 k i<X^^
//default value of nSplitter is 5 S@HC$
this("","","",5); uI7n{4W*x
} w~b:9_reY
$:F+Nf 8
OX]$Xdb2:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5p[}<I{
{ QPDh!A3T
sSiteURL= sURL; FpRYffT 9u
sFilePath = sPath; n?EgC8b9
sFileName = sName; ~~OFymQ%?q
this.nSplitter = nSpiltter; **hQb$
uGMzU&+
+M0pmK!
} ca_mift
"CJ~BJI%
kWXLncE
public String getSSiteURL() Kd5'2"DI
{ wc;n= %
return sSiteURL; qg oB}n%
} z3+@[I$
7EE{*}?0E
fZo#:"{/K
public void setSSiteURL(String value) T?pS2I~
{ 8Agg%*Qs}
sSiteURL = value; smf"F\Ws
} (?r,pAc:
SV>tw`2
=9jK\ T^
public String getSFilePath() 4`5yrCd
{ )RJEOl1
return sFilePath; q*&R&K;q
} ~(^P(
2IJK0w@
H{*Dc_
public void setSFilePath(String value) :25LQf^nz
{ 7Bp7d/R-
sFilePath = value; y!#-[K:
} rL{R=0
N y'\Q"Y]
.T'@P7Hdx
public String getSFileName() ]c/E7|0Q
{ T$%|=gq
return sFileName; p\w<~pN[
} 4nsJZo#S/
H$h#n~W~
j<p.#jkT
public void setSFileName(String value) I%3[aBz4
{ U N9hZ>9
sFileName = value; 7)lEZJK&T
} m-Eh0Zl>Z
dz_S6o ]
Jl/wP
public int getNSplitter() WoEK #,I;
{ nq M7Is
return nSplitter; p~$cwbQ!
} O(T5
$H)^o!
4@PA+(kvS
public void setNSplitter(int nCount) Xqf,_I=V
{ |THpkfW
nSplitter = nCount; :o'x?]
} 3Z b]@n
} dvB=Zk]m
/|0-O''
BX >L7n
/* sey,J5?
**Utility.java ]q]xU,
*/ n=.P46|
package NetFox; G!q[NRu
+hyOc|5
|bY@HpMp
public class Utility { 1$>+rW{a
|[*Bn3E:
f>N DtG.6
public Utility() <`}P
{ Pxlc RF
%O"8|ZG9{
IzP,)!EE
} :7v'[b
BQ-x#[%s
//线程睡眠 &`r/+B_W
public static void sleep(int nSecond) uz8LF47@:-
{ n#(pT3&
try{ V(7,N(
Thread.sleep(nSecond); z#*.9/y\^R
} .xRdKt!p
catch(Exception e) y\?ey'o
{ f"ezmZI
e.printStackTrace (); n|i:4D
} Rf:.'/<^
} U$OZkHA[
`b?uQ\#-M
//日志 2Rk}ovtD[
public static void log(String sMsg) .GrOdDK$ns
{ `/8@Fj
System.err.println(sMsg); u^Q`xd1
} '75T2Ud
i>m%hbAk
%* "+kwZ
public static void log(int sMsg) idI w7hi4
{ a1Fx|#! mq
System.err.println(sMsg); &hOz(825r
} -%asHDQ{
} p* >z:=
}3(!kW
V1aP_G-:
/* hOj{y2sc
**TestMethod.java @62T:Vl
*/ '}.Yf_
package NetFox; /R#zu_i
">H*InF
{9x_E {
public class TestMethod { <Ky-3:pxeM
At Wv9
@*6fEG{,q
public TestMethod() \x<8
{ ///xx/weblogic60b2_win.exe g)X3:=['
try{ /fI}QY1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); S=UuEmU5N
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cAWn*%
SiteFileFetch fileFetch = new SiteFileFetch(bean); Uj!3MF
fileFetch.start(); o@:"3s
} dOhSqx56
catch(Exception e){e.printStackTrace ();} :#rP$LSYC
-&Rv=q>
'/d51
} yJA~4
SDnl^a
2b"*~O;
public static void main(String[] args) vm [lMx
{ `^M]|7
new TestMethod(); IskL$Y ^
} \]X.f&u
} l]*RiK2AC
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