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)); rj H`
} )%JD8;[Jq
for(int i=0;i<nEndPos.length-1;i++) fUcLfnr
{ Ttv9"z
nEndPos = nStartPos[i+1]; LAZVW</
} w}<^l
nEndPos[nEndPos.length-1] = nFileLength; MC=G"m:_
} G?V"SU.
} >#N[GrJAE
:%tuNJjj
yBn_Kd
//启动子线程 [!?wyv3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vD=%`G[m
for(int i=0;i<nStartPos.length;i++) m)f|:MM
{ g#W_S?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yr4ou
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (@]tG?I=
nStartPos,nEndPos,i); ?q%b*Ek
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); am:.NG+
fileSplitterFetch.start(); ~b8a^6:R"
} ^Rmoz1d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v*P[W_.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !A[S6-18%-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v.`+I-\.z)
nEndPos = " + nFileLength); %ejeyc
// fileSplitterFetch[nPos.length-1].start(); #%cR%Z
exphe+b
K}2Npo FS
//等待子线程结束 sb'p-Mj
//int count = 0; -2lRia
//是否结束while循环 (2%>jg0M
boolean breakWhile = false; K/Jk[29"\
z~.9@[LG]
k!13=Gh
while(!bStop) l10-XU02
{ $Q4=37H+
write_nPos(); [.U^Wrd
Utility.sleep(500); d;g-3Pf
breakWhile = true; :r39wFi
0P9Wy!f7
U_*3>Q
for(int i=0;i<nStartPos.length;i++) KW>VOW<.
{ KnFQ)sX^
if(!fileSplitterFetch.bDownOver) 3M$X:$b
{ S.]MOB dt
breakWhile = false; k5s?lWH
break; bs:QG1*.
} +:y&{K
} .Qk{5=l6P
if(breakWhile) ^^ j/
break; h60\ Y 8
\-G5l+!
M8Juykw
//count++; TMY{OI8a
//if(count>4) 8GW ut=D
// siteStop(); 54wM8'+
} 6puVw-X
r\bq[9dX>
lrn+d$!@
System.err.println("文件下载结束！"); i^/DiWdyf
} (n}%a6M
catch(Exception e){e.printStackTrace ();} IrUi Eq
} c&A]pLn+x
Pzptr%{
7p !zp9|
//获得文件长度 'XEK&Yi1
public long getFileSize() `~|DoSi^d
{ X,&xhSzg?
int nFileLength = -1; Q~h6J*
try{ N[]U%9[=2F
URL url = new URL(siteInfoBean.getSSiteURL()); `:R-[>5P8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,0FwBK
httpConnection.setRequestProperty("User-Agent","NetFox"); oX#9RW/ >I
Z3Gm
*<?XTs<
int responseCode=httpConnection.getResponseCode(); n)Hk8)^8
if(responseCode>=400) sD.6"w7}
{ Q{8qm<0g
processErrorCode(responseCode); QWKs[yfdo
return -2; //-2 represent access is error 0|GpZuGO9
} i@Vs4E[b
]|;7R^o3|
O<bDU0s{M
String sHeader; xdCs5ko
GPMrs)J*!
\N4d_fPj
for(int i=1;;i++) N:A3kp
{ }]tFz}E\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6/VNuQ_#
//Utility.log(in.readLine()); Ko]QCLL
sHeader=httpConnection.getHeaderFieldKey(i); H'D#s;SlR
if(sHeader!=null) 2(hvv-
{ ~NA1SZ{Y+
if(sHeader.equals("Content-Length")) #`r(zI[
{ R9bhC9NP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); w<v1N
break; 9=H}yiJz
} O{Dm;@J-aM
} lGl[^ 0
else omNpE_
break; T4Xtuu1
} jC#`PA3m=
} yi sF5`+
catch(IOException e){e.printStackTrace ();} o?;F.W_
catch(Exception e){e.printStackTrace ();} b{zAJ`|#[n
/A0 [_
Gg'<Q.H
Utility.log(nFileLength); D!c1;IHZ
mJSK; @w<O
n9N#&Q"7m
return nFileLength; bcUC4g\9N
} >0kmRVd
H&~5sEGa
bl$+8!~
//保存下载信息（文件指针位置） 71JM [2
private void write_nPos() lb-S0plw
{ ,Le&I9*%
try{ ~8XX3+]z:X
output = new DataOutputStream(new FileOutputStream(tmpFile)); .WBI%ci
output.writeInt(nStartPos.length); m(8jSGV
for(int i=0;i<nStartPos.length;i++) av'd%LZP
{ s"pR+)jf1D
// output.writeLong(nPos); 6F@zCv"w
output.writeLong(fileSplitterFetch.nStartPos); SPfD2%jjC
output.writeLong(fileSplitterFetch.nEndPos); Pz5ebhgq
} Y1#-^,qg
output.close(); Pd)K^;em
} MZ;"J82p
catch(IOException e){e.printStackTrace ();} b*btkaVue
catch(Exception e){e.printStackTrace ();} N$N;Sw
} %bCcsdK
sN6 0o 7.
*i=?0M4S
//读取保存的下载信息（文件指针位置） Qw3a"k-
private void read_nPos() Z}sG3p
{ [ c ~LY4:
try{ 8O"x;3I9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "[%;B0J
int nCount = input.readInt(); >k$[hk*~
nStartPos = new long[nCount]; ^U-vD[O8
nEndPos = new long[nCount]; Rel(bA-[N
for(int i=0;i<nStartPos.length;i++) }9L 40)8
{ l-DGy#h+z
nStartPos = input.readLong(); UgF)J
nEndPos = input.readLong(); !L&=?CX
} O\|C,Epm
input.close(); O!#L#u53
} 1?/5A|?V4+
catch(IOException e){e.printStackTrace ();} ,Hik(22
catch(Exception e){e.printStackTrace ();} ()+jrrK
} NYSj^k;^(z
JxX jDYrU
#Pb7EL#c
private void processErrorCode(int nErrorCode) LV}UBao5n
{ 4FfwpO3,Ku
System.err.println("Error Code : " + nErrorCode); ir?Uw:/f
} [JX}1%NA
N:UDbLjw~
?=/}Ft
//停止文件下载 qB+:#Yrx/
public void siteStop() ,xAM[h&
{ +t7c&td\
bStop = true; ~|aeKtCs(.
for(int i=0;i<nStartPos.length;i++) eZ8Y"i\!y
fileSplitterFetch.splitterStop(); /tId#/Y
FT|/WZR
>.!5M L\
} vWnHC
} ~aauW?
//负责部分文件的抓取 +WV_`Rx#
**FileSplitterFetch.java dVj'
*/ [#STR=_f
package NetFox; :=iM$_tp'
V'HlAQr
;y?D1o^r8W
import java.io.*; -7Aw s)
import java.net.*; (!XYH@Mz<w
rvwl
'y+bx?3Z
public class FileSplitterFetch extends Thread { 6g~o3
[T.(MbP
K=!ZI/+ju
String sURL; //File URL a.Rp#}f
long nStartPos; //File Snippet Start Position s0`|G|.}
long nEndPos; //File Snippet End Position aowPji$H
int nThreadID; //Thread's ID 3IJI5K_
boolean bDownOver = false; //Downing is over V(''p{
boolean bStop = false; //Stop identical '1kj:Np
FileAccessI fileAccessI = null; //File Access interface LAK-!!0X
$8X tI
U'h[{ek
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T ,O<LFv
{ 7=QC+XSO
this.sURL = sURL; Vav+$l|j@
this.nStartPos = nStart; t_zY0{|P
this.nEndPos = nEnd; ~ ];6hxv
nThreadID = id; L?D~~Jb
fileAccessI = new FileAccessI(sName,nStartPos);//定位 02J6Pn3
} njwR~aL`|
aoakTi!}
'^-4{Y^2E
public void run() giSG 6'WA
{ qV,$bw
while(nStartPos < nEndPos && !bStop) ik1L
{ T^(n+lv
p^zEfLTU
Z@.ol Y
try{ LO$#DHPt
URL url = new URL(sURL); ,# jOf{L*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z:B Y*#B
httpConnection.setRequestProperty("User-Agent","NetFox"); Cs1%g
String sProperty = "bytes="+nStartPos+"-"; Kz3h]/A.
httpConnection.setRequestProperty("RANGE",sProperty); UTK.tg
Utility.log(sProperty); ;FgEE%
E/L?D
N5w]2xz!
InputStream input = httpConnection.getInputStream(); *p#YK|
//logResponseHead(httpConnection); C!/8e (!N
iz GaV[
HDW\S#
byte[] b = new byte[1024]; k+Ma_H`
int nRead; A]SB c2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) H'= i
{ RSWB!-
nStartPos += fileAccessI.write(b,0,nRead); O'& \-j 1
//if(nThreadID == 1) _"w!KNX>(~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e2hk
} bU4+PA@$
4qSS<SqY
Aya;ycsgE
Utility.log("Thread " + nThreadID + " is over!"); IrwF B
bDownOver = true; 3d)+44G_)
//nPos = fileAccessI.write (b,0,nRead); LWb}) #E
} ]kplb0`
catch(Exception e){e.printStackTrace ();} wmcp`8w.
} 7quwc'!
} l& ^B
n,Mw# r?y
8s5ru)
//打印回应的头信息 M"$RtS|h
public void logResponseHead(HttpURLConnection con) q!oZ; $
{ E~g}DKs_5
for(int i=1;;i++) R?9Plzt5
{ 8H`l"
String header=con.getHeaderFieldKey(i); ~z1KD)^
if(header!=null) (b2^d
//responseHeaders.put(header,httpConnection.getHeaderField(header)); VU'l~%ql
Utility.log(header+" : "+con.getHeaderField(header)); 0!'M#'m
else B3+WOf5W
break; +U/"F|M
} ?oDfI
} S| -{wC%
{e
+VW]%6+
public void splitterStop() [Z Gj7
{ vls> 6h
bStop = true; 98}vbl31j
} =$zr t
I/-w65J]
<@j
} rMFZ#38d
7<Js'\Z
(X7yNIPfA
/* d\Z4?@T<5
**FileAccess.java [3NV #
*//文件访问(定位，写) @dKf]&h%%
package NetFox; 0|Ft0y`+
import java.io.*; ziGL4c0p
w>UV\`x
vHe.+XY
public class FileAccessI implements Serializable{ 4_:e+ ql
W2(=m!:U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 r$eL-jQmn
RandomAccessFile oSavedFile; zw9ULQ$#
long nPos; h?tV>x/Fu
F%$Ws>l
daJ-H
public FileAccessI() throws IOException AezXou&
{ F7Yuky
this("",0); &'2l_b
} um;U;%?Q
Z$K%@q,10+
4IE#dwZW
public FileAccessI(String sName,long nPos) throws IOException =|zLr"
{ DYk->)
oSavedFile = new RandomAccessFile(sName,"rw"); d}CMX$1
this.nPos = nPos; Ec/+9H6g
oSavedFile.seek(nPos); Ds5&5&af
} -xEg"dY/
}slEkpk?]
ATewdq[C
public synchronized int write(byte[] b,int nStart,int nLen) 1fp&"K:yR
{ X KeK;+
int n = -1; j*\MUR=
try{ 1:V/['|*g)
oSavedFile.write(b,nStart,nLen); Y{{,62D
n = nLen; `b$I)UUm
} Jq@LZ2^
catch(IOException e) r2`?Ta
{ \05C'z3]
e.printStackTrace (); Gwk@X/q
} ]qQB+]WN
>CA1Ub&ls
z$,hdZ]
return n; .^W0;ISX
} duTSU9
]z@]Fi33Y
O$\N]#
} c9K\K~bk
FpYoCyD}
u(qpdG||7
/* s@9#hjv2
**SiteInfoBean.java ";%1sK
*/ 7] H4E.(l
package NetFox; <CdO& xUY
BW1O1zIh\
z#ET-[I
public class SiteInfoBean { svII =JB
WocFID:b
X13bi}O6#
private String sSiteURL; //Site's URL FL}8h/
private String sFilePath; //Saved File's Path 83|/sWrvh
private String sFileName; //Saved File's Name GR9F^Y)K{
private int nSplitter; //Count of Splited Downloading File =!2
QX/`s3N
O5"80z38[
public SiteInfoBean() 'McVaPav
{//nSplitter的缺省值为5 qz):YHxT]n
//default value of nSplitter is 5 C8-q<t#SF
this("","","",5); dzap]RpB
} vOU-bF%u
TlJF{ <E
Sx7xb]3XI"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) q9>w3 <
{ A1@a:P=
sSiteURL= sURL; [\y>Gv%
sFilePath = sPath; ?2agU
sFileName = sName; IbC)F> Dq
this.nSplitter = nSpiltter; auU{Iy
+-i@R%
o@-cT`HP
} sP#5l @
5,3h'\ "!
2TO1i0
public String getSSiteURL() N[%IrN3
{ %\u>%s<9
return sSiteURL; -b<+Ra
} ]H*=Z:riu
3FfS+q*3S
K!j2AP3
public void setSSiteURL(String value) -vQ`}e1
{ n%}0hVu
sSiteURL = value; NoT oLt\
} 6/)A6Tt
x :s-\>RcA
idQr^{
public String getSFilePath() }#1g;
{ YZd4% zF
return sFilePath; : s35{K
} fQ@["b
tBt\&{=|D
)DW;Gc
public void setSFilePath(String value) bZ=d!)%P-{
{ e): &pqA
sFilePath = value; asb")NfIm
} QCMF_;aNI
U3>G9g>^B
:v+39
public String getSFileName() &e{&<ZVR
{ 6mZFsB
return sFileName; K(hf)1q
} cVU[>gkg_
MZ.Jkf(
8Vp"}(Q
public void setSFileName(String value) }6\p7n
{ (_D#gr{S=
sFileName = value; FRr<K^M
} nX~sVG{Q
D0~mu{;c$
s;L7 _.hH@
public int getNSplitter() *ZRQ4i[+
{ 9tJiIr8i
return nSplitter; !,]_tw>R
} k&^fIz
y37@4p^@9
r'j*f"uAm
public void setNSplitter(int nCount) 9d v+u6)
{ n/?_]
nSplitter = nCount; L(iWFy1& T
} ^z_~e@U
} ]P-;]*&=
%@LVoP!@!
<~]s+"oVc
/* qT(j%F
**Utility.java .Sm7na K
*/ SJL?(S*
package NetFox; V7.EDE2A3
P66>w})@
jZ)1]Q2
public class Utility { `6'fX[j5
|]V0sgpoZ
hW]:CIqk
public Utility() ~R3@GaL1
{ |#"<{RS+w
i0hF9M
XB2[{XH,
} [W` _`
P@)zNik[
//线程睡眠 b:oB $E
public static void sleep(int nSecond) PKk_9Xd
{ XfharJ_b
try{ y<MXd,eE
Thread.sleep(nSecond); nF]lSg&]X
} =98@MX%P
catch(Exception e) @#;2P'KL
{ D >$9(
e.printStackTrace (); G7b>r
} R0vWj9nPh
} }<m9w\pA
ar }F^8Ku
//日志 pxjb^GZ0
public static void log(String sMsg) r1f##
{ !{jDZ?z{h
System.err.println(sMsg); g,*LP
} N2WQrTA:S+
[WW3'= e^
Qt`}$]
public static void log(int sMsg) cyL"?vR*<
{ p@0Va
System.err.println(sMsg); ]hRCB=G
} ,ir(~g+{g
} +/E`u|%|\]
4-1=1)c*
u[k0z!p_ c
/* 8Th{(J_
**TestMethod.java %|Sh|\6A!
*/ 2NB/&60<
package NetFox; Gf*|f"O
2[zFKK
UDl[
public class TestMethod { CEzwI _
xvU@,bzz
|L wn<y
public TestMethod() u)J&3Ah%
{ ///xx/weblogic60b2_win.exe cHP~J%&L
try{ 6_}& WjU'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xO3-I@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?o$ hlX
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,%Sf,h?"^
fileFetch.start(); K FMx(fD
} <l>o6K
catch(Exception e){e.printStackTrace ();} !'#Y-"=ypk
,0k3Qi%
<9Sg,ix't
} jxeZ,w o
cug=k
ol#| .a2O
public static void main(String[] args) uPh/u!
{ ebv"`0K$
new TestMethod(); 2":{3=oW~
} wB%N}bi!
} ny++U;qi
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