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)); "1`c^
} r#^X]
for(int i=0;i<nEndPos.length-1;i++) [}d 3u!
{ I_Oa<J\+
nEndPos = nStartPos[i+1]; 3LX<&."z
} 2<Ub[R
nEndPos[nEndPos.length-1] = nFileLength; :^?ZVi59j
} ,R*ru*
} .qF@ }dO
xOD;pRZQ
m"@M~~bh
//启动子线程 /[_>U{~P#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $Ne#F+M9x
for(int i=0;i<nStartPos.length;i++) e 0!a &w
{ tQ] R@i
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0$* z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f,PFvT$5e
nStartPos,nEndPos,i); Lsuc*Ps
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lusINILc
fileSplitterFetch.start(); 1 !OQxY}f
} nQg6 j Zf
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %,>> <8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /1Rm^s)2z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", cdzMao
nEndPos = " + nFileLength); mVU(u_lh
// fileSplitterFetch[nPos.length-1].start(); Px'%5TKN
E%jOJA
tse(iX/D
//等待子线程结束 UHweV:(|T
//int count = 0; 8pt;''
//是否结束while循环 Y@RPQPmIQ
boolean breakWhile = false; +Bc/@.Q'
=s1"<hH}O)
$5cLhi"`
while(!bStop) }q27M
{ 0>Ecm#
write_nPos(); <;SMczR
Utility.sleep(500); Alh%Z\
breakWhile = true; WynHcxC
;c<:"ad(
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for(int i=0;i<nStartPos.length;i++) ,Ea.ts>
{ 0qZ{:}`3
if(!fileSplitterFetch.bDownOver) t'0r4&\
{ U}7$:hO"dX
breakWhile = false; z`5+BL,|ND
break; I+8m1*
} QTK\"
} >RE&>T^8
if(breakWhile) <k}>eGn
break; D OPOzh
kw|bEL9!u
1OE^pxfi>
//count++; &RpQ2*4n
//if(count>4) A CJmy2
// siteStop(); %+FM$xyJ
} =@V4V} ?
~SP.&>Q>
+JBhw4et;.
System.err.println("文件下载结束！"); 0O"GI33Mg
} qV8;;&8r
catch(Exception e){e.printStackTrace ();} eJ$?T7aUf
} z15(8Y@2]
8~\Fpz|Og
qs 52)$
//获得文件长度 rm(<?w%'?
public long getFileSize() `H^Nc\P#
{ U:gE:tf
int nFileLength = -1; hG&RGN_<6+
try{ 2%1g%
URL url = new URL(siteInfoBean.getSSiteURL()); !W]># Pm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G:A~nv9
httpConnection.setRequestProperty("User-Agent","NetFox"); dg/7?gV
(!DH'2I[
c*MjBAq
int responseCode=httpConnection.getResponseCode(); FbWkT4t|
if(responseCode>=400) _N9yC\
{ E)H8jBm6w
processErrorCode(responseCode); E=sBcb/v
return -2; //-2 represent access is error 1:q55!b
} !z58,hv
dFo9O!YX[f
VXR.2C
String sHeader; \9@*Jgpd6*
KW^s~j
#B)/d?aa'
for(int i=1;;i++) m{(D*Vuqd
{ VH,k EbJ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); DU]MMR
//Utility.log(in.readLine()); G\Toi98d*
sHeader=httpConnection.getHeaderFieldKey(i); zZki9P
if(sHeader!=null) hH )jX`Ta
{ Qf7]t-Kp
if(sHeader.equals("Content-Length")) <74q]C
{ burEo.=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); q,$UKg#i
break; L'"20=sf
} 7 fqK{^L
} wL5IAkq
else 7b:oz3?PI
break; |C7GI[P
} +lO Y IQ
} \qV5mD]"M
catch(IOException e){e.printStackTrace ();} ~=Er= 0
catch(Exception e){e.printStackTrace ();} eV1O#FLbi
.;iXe
4xe:+sA.N
Utility.log(nFileLength); I)_072^O
ZRD*^9)
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return nFileLength; ,^:Zf|V
} #x)G2T'?
V{ra,a*
V*U"OJ%
//保存下载信息（文件指针位置） ;7tOFsV
private void write_nPos() Rj+}L ~"
{ ,'={/)c<
try{ ~;wSe[
output = new DataOutputStream(new FileOutputStream(tmpFile)); B~u{LvTE
output.writeInt(nStartPos.length); ElqHZ$a?
for(int i=0;i<nStartPos.length;i++) 3f eI
{ [M@i,d-;A
// output.writeLong(nPos); >`'#4!}G5j
output.writeLong(fileSplitterFetch.nStartPos); OA4NXl'
output.writeLong(fileSplitterFetch.nEndPos); RvYew!n
} }@SZ!-t%rD
output.close(); ~k|~Q\
} 6"-LGK:
catch(IOException e){e.printStackTrace ();} hSp[BsF`,
catch(Exception e){e.printStackTrace ();} A{y3yH`#h
} 3vQ?vS|2
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UyD=x(li
//读取保存的下载信息（文件指针位置） P,CJy|[L
private void read_nPos() p Ic;9
{ (}gF{@sn
try{ <kPU*P,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `^wF]R
int nCount = input.readInt(); j05ahquI
nStartPos = new long[nCount]; qqS-0U2
nEndPos = new long[nCount]; hKt AvTg
for(int i=0;i<nStartPos.length;i++) }Jh!B|
{ *~prI1e(
nStartPos = input.readLong(); hk}M'
nEndPos = input.readLong(); <LzN/I aJ
} B/i,QBPF]
input.close(); Q(oWaG
} 7.8ukAud
catch(IOException e){e.printStackTrace ();} RTHdL
catch(Exception e){e.printStackTrace ();} [^1;8Tbk
} $M$oNOT}Y
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private void processErrorCode(int nErrorCode) \P&'4y~PL
{ EG7ki0
System.err.println("Error Code : " + nErrorCode); s/`4]B;2U
} k-b_ <Tbo|
at6f(+
}1N)3~
//停止文件下载 i*9eU*i|H
public void siteStop() o Ep\po1
{ `(W V pP?
bStop = true; pFGdm3pV
for(int i=0;i<nStartPos.length;i++) ;vQ7[Pv.j
fileSplitterFetch.splitterStop(); ) ;-AT^
5p U(A6RtS
O0WzDD
} &nZ=w#_
} &>i+2c~
//负责部分文件的抓取 {LR?#.
**FileSplitterFetch.java GB^Ch YOb
*/ goIn7ei92
package NetFox; 7I(Sa?D:
]1abz:
bveNd0hN
import java.io.*; 6.KR(V
import java.net.*; \hv*`ukF
A~h.,<+"
+ 5sTGNG
public class FileSplitterFetch extends Thread { 8l+\Qyj
jVi''#F?f
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String sURL; //File URL Zo-s_6uC
long nStartPos; //File Snippet Start Position I&Yu=v/_
long nEndPos; //File Snippet End Position 3::DURkjf
int nThreadID; //Thread's ID !_l W#feR
boolean bDownOver = false; //Downing is over ]c[80F-
boolean bStop = false; //Stop identical 'ZTE"KT
FileAccessI fileAccessI = null; //File Access interface g2:^Z==
hb_YdnG
/_26D0}UuF
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Eq~&d.j
{ Y]B2-wt-
this.sURL = sURL; l: 1Zq_?v;
this.nStartPos = nStart; WASs'Gx
this.nEndPos = nEnd; M6pGf_qt
nThreadID = id; {hZ_f3o
fileAccessI = new FileAccessI(sName,nStartPos);//定位 S-.!BQ@RMZ
} FyZw='D
j9x}D;?n
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public void run() C1r]kF
{ v(h
while(nStartPos < nEndPos && !bStop) E"pq ZP =
{ _d %H;<_
lwQI 9U[O2
nCGLuZn
try{ 4SY]Q[
URL url = new URL(sURL); ,K3)f.ArYc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G/N'8Q)
httpConnection.setRequestProperty("User-Agent","NetFox"); i7cMe8
String sProperty = "bytes="+nStartPos+"-"; RUYwDtC
httpConnection.setRequestProperty("RANGE",sProperty); RfEmkb<9Z
Utility.log(sProperty); =NH:/j^
>[O @u4
z)]_(zZ^
InputStream input = httpConnection.getInputStream(); 7=Ew[MOmM
//logResponseHead(httpConnection); Ko>pwhR}
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^3*/x%A,g
byte[] b = new byte[1024]; #f\U3p
int nRead; 5~aSkg,MD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) oPo<F5M]d%
{ x)THeH@
nStartPos += fileAccessI.write(b,0,nRead); o_bj@X
//if(nThreadID == 1) /DQoM@X
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qyp"q{k0
} w# ,:L)
>9uDY+70I3
hi`\3B
Utility.log("Thread " + nThreadID + " is over!"); FL/@e$AK
bDownOver = true; "9&6bBa
//nPos = fileAccessI.write (b,0,nRead); X<#Q~"
} HGh`O\f8
catch(Exception e){e.printStackTrace ();} |XLx6E2F
} ~y$B#.l
} O292JA
V78QV3
b H?dyS6Bx
//打印回应的头信息 #RbPNVs
public void logResponseHead(HttpURLConnection con) '7u#uL,pa1
{ [-{L@
for(int i=1;;i++) 4g$mz:vo
{ h=EJNz>U
String header=con.getHeaderFieldKey(i); )0yY|E\
if(header!=null) #gUM%$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); e~i ?E
Utility.log(header+" : "+con.getHeaderField(header)); g5; W6QX
else Ex&f}/F
break; f,)[f M4
} l{\~I
} x\*`i)su
UStZ3A'
PfF7*}P
public void splitterStop() UyEyk$6SU
{ hz>&E,<8q
bStop = true; _;G"{e.=
} b_W0tiyv%
vp[~%~1(
UqsVqi h(
} UpN:F
(`<l" @:_*
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/* Me`jh8(K\6
**FileAccess.java &t5pJ`$(Cy
*//文件访问(定位，写) O<)"kj 7
package NetFox; Z>wg o@z%
import java.io.*; ]9l=geZd%;
c03A_2%
.%M=dL>
public class FileAccessI implements Serializable{ %)i?$/
0^?3hK
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =xS(Er`r
RandomAccessFile oSavedFile; n^UrHHOL
long nPos; iKv{)5
>C*q
1WfN_JKB5
public FileAccessI() throws IOException Y6?d y\
{ <fJoHS
this("",0); 6HCP1`gg
} KNic$:i
]$EKowi
15)=>=1mR.
public FileAccessI(String sName,long nPos) throws IOException c_yf=
{ CTD{!I(
oSavedFile = new RandomAccessFile(sName,"rw"); I'`Q_5s5
this.nPos = nPos; d-#MRl$rtK
oSavedFile.seek(nPos); s4@AK48
} :\4?{,@_h
71z$a
zEl@jK,{$
public synchronized int write(byte[] b,int nStart,int nLen) (=j]fnH?
{ !BIq>pO%Ui
int n = -1; F7E#x
try{ =SRp
oSavedFile.write(b,nStart,nLen); Vv B%,_\
n = nLen; fM]zD/ g
} 3G~ T_J&
catch(IOException e) B;SYO>.W
{ PxM]3Aoa
e.printStackTrace (); Gm}ecW
} %F3M$jU
%A,4vLe~6
9mEC|(m*WK
return n; }mxy6m ,
} 17a'C
KA0Ui,q3
w[^s)1
} &y;('w
'{5|[
_SJ#k|vcq
/* u `1cXL['
**SiteInfoBean.java y"<nx3
*/ D^E1
package NetFox; /(bPc12
pUZbZ U
GO.mT/rB
public class SiteInfoBean { ]uI#4t~
W~$YKBW
V)mRG`L
private String sSiteURL; //Site's URL 0V uG(O
private String sFilePath; //Saved File's Path s_N?Y)lS+(
private String sFileName; //Saved File's Name 6wYd)MDLL
private int nSplitter; //Count of Splited Downloading File .RxH-]xk
V2W)%c'
I0h/x5
public SiteInfoBean() XkHO=
{//nSplitter的缺省值为5 oP$NTy[
//default value of nSplitter is 5 X2 c<.
this("","","",5); _8vq]|rC
} 5}x^0 LY
wN-3@
R*`A',]:9
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) i(Cd#1<
{ 02g}}{be8
sSiteURL= sURL; _Jn-#du
sFilePath = sPath; T\eOrWt/
sFileName = sName; >V2Tr$m j
this.nSplitter = nSpiltter; +/'3=!oyd
Ms;:+JI
Z 7rVM
} C:\BvPoO
~e~iCyW;S
)@Fuw*
public String getSSiteURL() 8%S5Fc#am
{ tY-{uHW&h
return sSiteURL; &> tmzlww
} 8 ;y N
/~yk
v@_b"w_TY
public void setSSiteURL(String value) p&/}0eL y
{ R#eY@N}\
sSiteURL = value; 7%) F]
} ~4S@kYe{3K
v_3r8My-
R#.FfWTZ
public String getSFilePath() >T[1=;o]
{ PE4#dx^
return sFilePath; :8cp]vdW
} i1e|UR-wl
Oz<{B]pEul
^ ry
public void setSFilePath(String value) 'te4mY}
{ AP&mr1_
sFilePath = value; 'gHa3:US
} g)c<\%
J8>y2rAi
[1K\ _
public String getSFileName() _]E H~;
{ -\O%f)R
return sFileName; H3"90^|,@
} pbM~T(Y8
1|_jV7`Mz
jHBzZ!<
public void setSFileName(String value) r8x<-u4
{ x?v/|
sFileName = value; :_E=&4&g
} =:OS"qD3l
s4uZ;
`1aEV#;
public int getNSplitter() s{\USD6
{ lArYlR}
return nSplitter; FGY4u4y
} @}k5rcQ*/
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]f#1G$
public void setNSplitter(int nCount) Loo48
{ c `C /U7j
nSplitter = nCount; j#mo Vq
} 7<;87t]]
} <RH2G
/qp)n">
<pJeiMo
/* %2>ya>/M
**Utility.java jI:5[. Y
*/ C\#E1\d
package NetFox; s|L}wtc
_P9Th#UAg
I*8i=O@0T
public class Utility { 3~v'Ev
Sxo9y0K8-
oRmz'F
public Utility() y^pzqv
{ y qDE|DIez
&!7{2E\7C
Kgh@.Ir
} zSt6q
M{M>$pt
//线程睡眠 !@j5yYf
public static void sleep(int nSecond) Tv2d?y
{ fy&vo~4i;
try{ y!JZWq%=
Thread.sleep(nSecond); Ovu!G q
} rBR,lS$4
catch(Exception e) eaSf[!24"
{ GddP)l{uCF
e.printStackTrace (); gYb}<[O!
} VE3,k'^v
} :rr;9nMR[
)"SP >2}
//日志 _4H 9rPhf
public static void log(String sMsg) 5>{
{ cZ>h[XX[
System.err.println(sMsg); DLMM1 A
} rZ}y'A
?}<4LK]
Wc]L43u
public static void log(int sMsg) \Nd8,hE
{ CF"u8yE
System.err.println(sMsg); 'Bul_D4B
} Dxj&9Ra
} ]!l]^/.
Y*oT(
6, =oTmFP
/* -U'3kaX5<
**TestMethod.java :f1Q0klwP
*/ (vL-Z[M!
package NetFox; H#yBWvj*H
,D#ssxV
II(7U3
public class TestMethod { Buazm3q8H
ca~nfo
@nIoYT='
public TestMethod() }\+7*|
{ ///xx/weblogic60b2_win.exe q0* e1QL
try{ MA9Oi(L)K
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6KT]3*B
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }@VdtH
SiteFileFetch fileFetch = new SiteFileFetch(bean); ue?e}hF
fileFetch.start(); ]r6S|;:
} +v$,/~$tI
catch(Exception e){e.printStackTrace ();} DK-V3}`q}
e}V3dC^pU
dw6U}
} NFDh!HUm
1$1s0yg
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public static void main(String[] args) ?"23XKe
{ + Xc s<+b
new TestMethod(); VG,O+I'^z
} %OS}BAh^i
} T4H/D^X|
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