http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); Q< :RLKVT
} v.jxG{~.
for(int i=0;i<nEndPos.length-1;i++) e(?w h
{ K@O^\
nEndPos = nStartPos[i+1]; 'f-r 6'_ZX
} FzJ7 OE|
nEndPos[nEndPos.length-1] = nFileLength; $0 olqt:
} W}CM;~*L
} uX6yhaOp|
x)~i`$
{p84fR1P
//启动子线程 @vt.Db
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9RJF
for(int i=0;i<nStartPos.length;i++) h)HEexyRg
{ g|>LT_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sCFxn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H&)}Z6C"
nStartPos,nEndPos,i); +P2oQ_Fk`9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !5o j~H
fileSplitterFetch.start(); \_ 3>v5k|
} IW0S*mO$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n:%4SZn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9D3{[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", by/H:5}7
nEndPos = " + nFileLength); zsg\|=P
// fileSplitterFetch[nPos.length-1].start(); @KQ.tF*
gJ \6cZD
SMX]JZmH
//等待子线程结束 N,Eap KG
//int count = 0; mn/)_1',
//是否结束while循环 +i&<`ov
boolean breakWhile = false; Q7_5
3f[Yk#"
.S/5kLul
while(!bStop) o.{W_k/n
{ D:1@1Jr
write_nPos(); =&bI-
Utility.sleep(500); & o5x
breakWhile = true; 5#K*75>
M^o_='\bE
x}+zhRJ
for(int i=0;i<nStartPos.length;i++) fST.p|b7
{ p0Jr{hM
if(!fileSplitterFetch.bDownOver) .<"XE7
{ =nhY;pY3u
breakWhile = false; [7Lr"
break; dHc\M|HCC
} +OE!Uqnt
} 94"+l@K
if(breakWhile) hmu>s'
break; 7Y5r3a}%
[.gk{> #
vd%g'fTy9
//count++; 4)S99|1
//if(count>4) vI{aF- #
// siteStop(); (pxH<k=Ah
} .XJ'2yKof
7n7Xyb
XX8HSw!w
System.err.println("文件下载结束！"); vMTf^V
} Q(bOar5
catch(Exception e){e.printStackTrace ();} tbFAVGcAM
} iW5cEI%tb
sQJ\{'g
]r Uj<[O
//获得文件长度 YOl$sgg}
public long getFileSize() _U s"
{ F]\ Sk'}&
int nFileLength = -1; t'n@yX_
try{ 3UZd_?JI[^
URL url = new URL(siteInfoBean.getSSiteURL()); x-BU$bx5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @^{`!>Vt
httpConnection.setRequestProperty("User-Agent","NetFox"); Xs0)4U
mUBy*.
vO}r(kNJ
int responseCode=httpConnection.getResponseCode(); PG&t~4QM`
if(responseCode>=400) _~<sb,W
{ e"E8BU
processErrorCode(responseCode); uvId],dQ5
return -2; //-2 represent access is error A)f-r
} , >LJpv
dli(ckr
(` *BZ_
String sHeader; yw^Pok5.
n1sYD6u<&
Q{[@n
for(int i=1;;i++) wQhNQ(H~\
{ `i.BB jx`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,mHME~
//Utility.log(in.readLine()); =zkN63S
sHeader=httpConnection.getHeaderFieldKey(i); -DI >O/
if(sHeader!=null) GX>8B:]o|
{ 1m*)MZ)
if(sHeader.equals("Content-Length")) EA"hie7
{ lLD#|T3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \V? .^/
break; Q:-T'xk@
} TnF~'RZYb
} V]7/hN-Y}
else B7%K}|Qg
break; .shi?aWm
} :zY4phR
} D=e*rrL7a
catch(IOException e){e.printStackTrace ();} 4V@%Y,:ee
catch(Exception e){e.printStackTrace ();} Rb6BY-/J
Pb5yz-?
l6 G6H$
Utility.log(nFileLength); LA3m,
L'+bVP{L
] ZV[}7I.
return nFileLength; [`n_> p!
} `Fd \dn
gRLt0&Q~
qM\ 2f<)
//保存下载信息（文件指针位置） ^^a6 (b
private void write_nPos() hA7=:LG
{ ;_<~9;
try{ ~KK} $iM
output = new DataOutputStream(new FileOutputStream(tmpFile)); x[0T$
output.writeInt(nStartPos.length); nWd!ovd
for(int i=0;i<nStartPos.length;i++) wvv+~K9jq
{ Z"`w>c.
// output.writeLong(nPos); )lG}B U.
output.writeLong(fileSplitterFetch.nStartPos); >h7(kj:
output.writeLong(fileSplitterFetch.nEndPos); yE:y[k0E
} |E8sw a
output.close(); y=Y k$:-y
} Zxebv#4
catch(IOException e){e.printStackTrace ();} :?M_U;;z2+
catch(Exception e){e.printStackTrace ();} DQG%`-J
} \c_g9Iqa
qc8Ge\3s
OSBR2Z;=
//读取保存的下载信息（文件指针位置） M':-f3aT%
private void read_nPos() F9%_@n
{ `B%%2p&
try{ v;,W ^#`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wm5&5F4:
int nCount = input.readInt(); I}`pY3
nStartPos = new long[nCount]; R@c])\^]
nEndPos = new long[nCount]; )OI}IWDl
for(int i=0;i<nStartPos.length;i++) kckRHbeU
{ DyC*nE;
nStartPos = input.readLong(); 1Lb)S@Q`*R
nEndPos = input.readLong(); vk7IqlEQ
} K[T0);hZR
input.close(); VVJ0?G (?
} "~4V(
catch(IOException e){e.printStackTrace ();} 5rsz2;#p
catch(Exception e){e.printStackTrace ();} &^`Wtd~g
} %\JGDM*m
cv'8_3
SU0SsgFB
private void processErrorCode(int nErrorCode) 4C;;V m4~
{ Fb,*;M1'
System.err.println("Error Code : " + nErrorCode); <cTX;&0=
} 9D3W_eIc
wd`p>
lR?y tIY
//停止文件下载 !tq]kKJ3:
public void siteStop() ,Fn;*
{ [2@:jLth=
bStop = true; tA(oD4H9
for(int i=0;i<nStartPos.length;i++) 8"h;+;
fileSplitterFetch.splitterStop(); k4{!h?h
Ej(BE@6>s
ZqclmCi
} ~XR('}5D
} |lNp0b
//负责部分文件的抓取 |4+'YgO
**FileSplitterFetch.java }a"=K%b<\
*/ Xu-~j!
package NetFox; aO{@.
7$*E0
Tvv>9gS
import java.io.*; r_+Vb*|Y
import java.net.*; SdnnXEB7
)Jt. Z^J<
, z\Qd07u
public class FileSplitterFetch extends Thread { ]L3U2H`7
3zsp6kV
JD*HG]
String sURL; //File URL OY1bFIE
long nStartPos; //File Snippet Start Position Kbu>U{'
long nEndPos; //File Snippet End Position <X*oW".
int nThreadID; //Thread's ID & AK\Pw)
boolean bDownOver = false; //Downing is over ,!Wo6{'
boolean bStop = false; //Stop identical %{ BV+&
FileAccessI fileAccessI = null; //File Access interface ?dJd7+A
%bw+>:Tr
[{Wo:c9Qq1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6FDj:~
{ "](Q2
this.sURL = sURL; )>~jjR
this.nStartPos = nStart; 3EYEd39E
this.nEndPos = nEnd; ^\PRzY
nThreadID = id; f0P,j~]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 JSUD$|RiJ
} 2TGND-(j
-;cF)C--12
S(.J
public void run() vjX,7NY?
{ 7rD 8
while(nStartPos < nEndPos && !bStop) #M!u';bZ
{ z}-CU GS
6%V:Z
xoVd[c!
try{ \PS]c9@,rc
URL url = new URL(sURL); `R0~mx&6G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k<*v6 sNs;
httpConnection.setRequestProperty("User-Agent","NetFox"); JWHsTnB
String sProperty = "bytes="+nStartPos+"-"; #`y[75<n
httpConnection.setRequestProperty("RANGE",sProperty); dOv\]
Utility.log(sProperty); DOyO`TJi
M4Cb(QAVP
I'xc$f_+
InputStream input = httpConnection.getInputStream(); J* !_O#
//logResponseHead(httpConnection); GP+=b:C{E
b'pwRKpx
_#\Nw0{
byte[] b = new byte[1024]; lL zR5445)
int nRead; |mMsU,*gB
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R+.4|1p
{ k2Cq9kQq
nStartPos += fileAccessI.write(b,0,nRead); XoD:gf
//if(nThreadID == 1) ^?{&v19m
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B-g-T>8
} 4- QlIIf
{aA6b
<,$*(dX)(
Utility.log("Thread " + nThreadID + " is over!"); OcUj_Zd
bDownOver = true; T^!Q(`*
//nPos = fileAccessI.write (b,0,nRead); .4]XR/I$
} A$p&<#
catch(Exception e){e.printStackTrace ();} z#G\D5yX[*
} ~AD>@;8fG
} aNry>2:
-`8@
}Rz,}^B
//打印回应的头信息 ~6=6YP
public void logResponseHead(HttpURLConnection con) !{*yWpZ:
{ 8^EWD3N`
for(int i=1;;i++) i'<hT q4
{ qJF'KHyU{l
String header=con.getHeaderFieldKey(i); wdj?T`4
if(header!=null) X.{xHD&_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2XL^A[?
Utility.log(header+" : "+con.getHeaderField(header)); z:S:[X0
else 6<@mBZ
break; ,7:GLkj
} ;|K }
} 1D[V{)#
'bRf>=
G1it 3^*$
public void splitterStop() iJdJP)!tz6
{ 1PxRj
bStop = true; kKRu]0J~[
} . AA# G
< e3] pM
L[PqEN\i
} ]2L11"erP
BHp>(7,
] K&ca
/* 6Z1O:Bou
**FileAccess.java `yq) y>_
*//文件访问(定位，写) pS-o*!\C.
package NetFox; r;b`@ .
import java.io.*; Y->sJm
)0I-N)
M &-p
public class FileAccessI implements Serializable{ K?M~x&Q
ThP~k9-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8Y%
RandomAccessFile oSavedFile; 2FdwX,O.
long nPos; lq-F*r\/~+
o[wiQ9Tl
\RDqW+,
public FileAccessI() throws IOException el<Gd.p.d
{ /T qbl^[
this("",0); }^H(EHE
} 5Bq;Vb
d$o m\@
!!A(A^s
public FileAccessI(String sName,long nPos) throws IOException iLQO .'{U
{ dH0>lV
oSavedFile = new RandomAccessFile(sName,"rw"); )/f#~$ws
this.nPos = nPos; W|{!0w
oSavedFile.seek(nPos); &OFVqm^
} ?0u"No52m
5O~xj:
I;AS.y
public synchronized int write(byte[] b,int nStart,int nLen) ^x*J4jl
{ ~BTm6*'h
int n = -1; sAO/yG
try{ )(YJ6l
oSavedFile.write(b,nStart,nLen); Z OAg7
n = nLen; #2\M(5d
} Y&M{7
catch(IOException e) x$Wtkb0<
{ StR)O))I
e.printStackTrace (); T__@hfT
} {|%^'lS
P{s1NorKDh
PRYm1Y
return n; Gyy4)dP
} ^4JK4+!Zfq
`6Q+N=k~Z
aA*h*
} XmO]^ `
,F!-17_vt
)jwovS?V
/* f7 ew<c\
**SiteInfoBean.java F*z>B >{)
*/ $0{h Uex
package NetFox; p? +!*BZ
ZQR)k:k7
A$~H`W<yxB
public class SiteInfoBean { i+Ne.h
q}'<[Wg
@w%kOX
private String sSiteURL; //Site's URL \Rt>U|%
private String sFilePath; //Saved File's Path f[`&3+
private String sFileName; //Saved File's Name ~6u|@pnI
private int nSplitter; //Count of Splited Downloading File cWQ &zc
O d6'bO;G
taVK&ohWx
public SiteInfoBean() U/HF6=Wot
{//nSplitter的缺省值为5 vGH]7jht
//default value of nSplitter is 5 ELG{xN=o
this("","","",5); MjBI1|*
} m-[xrVV
6P9#6mZ
[$>@f{:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }f{5-iwD}
{ *c.w:DkfB
sSiteURL= sURL; /gaC
sFilePath = sPath; /a$Zzs&xs
sFileName = sName; 1)xj 'n
this.nSplitter = nSpiltter; /ml+b8@
K)Ya%%6[U#
55y}t%5
} $Zi{1w
>Ir?)h
4;jAdWj3
public String getSSiteURL() +U1fa9NSn
{ t=fAG,k5
return sSiteURL; n68qxD-X
} O#^qd0e'P!
8SiWAOQAL
5M>SrZH
public void setSSiteURL(String value) oY\;KPz
{ -G1R><8[
sSiteURL = value; Uu`}| &@i
} !}eq~3
)DW".c
NP.qh1{NP
public String getSFilePath() |c$*Fa"A
{ DM,;W`|6%
return sFilePath; ~2NTXp
} tnXW7ej^
tuo'Uk)
:K \IS`
public void setSFilePath(String value) \u/=?b
{ N>j*{]OY+{
sFilePath = value; I$TD[W
} s,laJf
Q."rE"}<
FGo)]U
public String getSFileName() >^f]Lgp
{ /PBK:B
return sFileName; a5]]AkvA
} !$-QWKD4
poZ&S
pL.~z
public void setSFileName(String value) v`jFWq8I,
{ "LZv\c~v,%
sFileName = value; 3\B~`=*q/
} LKud'
JS >"j d#
~W gO{@Mw
public int getNSplitter() r_V^sX
{ Ys5Iqj=mp
return nSplitter; gFM~M(
} ;UQ&yj%x
' b,zE[Q
~c=*Y=)LG
public void setNSplitter(int nCount) HM\}C.u
{ \7(OFT\u:
nSplitter = nCount; rqM_#[Y?
} ${UH!n{
} /jU4mPb;\D
- :x6X$=
Pv$O=N6-
/* #/K71Y
**Utility.java xAf?E%_pi
*/ Nu; 9
package NetFox; Z3 na.>Z
erV&N,cI
aXD|XE%
public class Utility { fqm6Pd{:(
`7 J4h9K
I"jub kI=Z
public Utility() WODgG@w
{ VBu6,6
aFy'6c}
]@msjz'
} ZN`I4Ak
04E#d.o'
//线程睡眠 {<Vw55)#0Q
public static void sleep(int nSecond) h`:gMhn
{ }4*~*NoQ
try{ e({-.ra
Thread.sleep(nSecond); =NL(L
} 3{- 8n/4 k
catch(Exception e) 9\R+g5
{ v$|cF'yyF=
e.printStackTrace (); F)tcQO"G
} O/f+B}W
} Ar$Am
y-:d`>b>\
//日志 (Mt-2+"+
public static void log(String sMsg) f@xjNm*'Z
{ K~\Ocl
System.err.println(sMsg); i"y @Aj!7
} :AC( \
j{NcDepLn
%y\
public static void log(int sMsg) {X&H
{ ,-Yl%R.W=
System.err.println(sMsg); O ;B[ZMV
} }xy[&-dh
} 6.QzT(
M[ ,:NE4H
09HqiROw
/* !JwR[X\f
**TestMethod.java ~jOk?^6
*/ HS 1zA
package NetFox; 1:q5h*
~0gHh
e:WKb9nT
public class TestMethod { Ne2eBmY}(
n]WVT@
vF$sVu|B
public TestMethod() E$E#c8I:
{ ///xx/weblogic60b2_win.exe ~fF;GtP
try{ iXuSFman
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); H}}C>p"!,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Fpy-?U
SiteFileFetch fileFetch = new SiteFileFetch(bean); *Ag,/Cm]
fileFetch.start(); |`ZW(}~
} l>jNBxB|/A
catch(Exception e){e.printStackTrace ();} 4Y}{?]>pu
Z[zRZ2'i5
>iI-Cs7TD
} .d%CD`8!
@7,k0H9Moa
rW0-XLbL5H
public static void main(String[] args) |jTRIMj%,_
{ : ]~G9]R`
new TestMethod(); ~~3 BV,
} xEqr3(
} R"qxT.P(
点击下载更多相关资料