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)); NLyXBV[hV
} jAC78n,Fi@
for(int i=0;i<nEndPos.length-1;i++) d]SYP
{ (?>cn_m
nEndPos = nStartPos[i+1]; KxIyc7.
} M&KyA
nEndPos[nEndPos.length-1] = nFileLength; +Rwx%=
} -:<lkq&/
} [|RjHGf
| kXm}K
};b1ahaG
//启动子线程 iidT~l
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /7/0x ./{
for(int i=0;i<nStartPos.length;i++) FJ54S
{ 1$pb (OK
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XN;&qR^j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gl8Ib<{
nStartPos,nEndPos,i); Q`ME@vz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S_b/DO
fileSplitterFetch.start(); Xj@+{uvQB
} ^A9M;q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p=Y>i 'CG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;b0NGa(k
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;a r><w
nEndPos = " + nFileLength); Elb aFbr
// fileSplitterFetch[nPos.length-1].start(); ,DQjDMjrf
O=}g4c
XRtD< jlA"
//等待子线程结束 nlGHT
//int count = 0; ^U@~+dw
//是否结束while循环 iPj~I
boolean breakWhile = false; ^YlI>_3s
wRvb8F0
3@<zg1.9-
while(!bStop) 0N;%2=2_E
{ Ak@Dyi?p
write_nPos(); 86 .`T l;
Utility.sleep(500); UzG[:ic%
breakWhile = true; mJ5H=&Z
n V&cC
Bp?
for(int i=0;i<nStartPos.length;i++) ru9zTZZD
{ vScjq5"p
if(!fileSplitterFetch.bDownOver) .0p^W9
{ N|usFqCNk^
breakWhile = false; N( Oyi
break; M4yI`dr6
} vFv3'b$;G
} ]a'99^?\
if(breakWhile) zjl!9M!
break; W7sn+g\
[?0d~Q(R#
i|WQ0fD
//count++; 4hs)b
//if(count>4) Fhf<T`
// siteStop(); EGVM)ur
} eWs&J24
P8Qyhc
K.~q+IYP[
System.err.println("文件下载结束！"); 3Q^fVn$tk
} Na{Y}0=^y
catch(Exception e){e.printStackTrace ();} L2UsqVU
} >ut" OL9J
}baR5v
ac{?+]8}
//获得文件长度 L%"LlSg
public long getFileSize() C[sh,
{ 6gL-OJNo
int nFileLength = -1; iUi>y.}"P
try{ |{>ER,<-
URL url = new URL(siteInfoBean.getSSiteURL()); Z4b||
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }<a^</s
httpConnection.setRequestProperty("User-Agent","NetFox"); SmwQET<H
!69&Ld
zi@]83SS#
int responseCode=httpConnection.getResponseCode(); cVnJ^*Z
if(responseCode>=400) qet>1<
{ 8^/I>0EZ
processErrorCode(responseCode); X}ma]
return -2; //-2 represent access is error WJH\~<{mP
} )!:sFa 1
c2nKPEX&5
]`g@UtD9`
String sHeader; &ANP`=
n2B){~vE
')Y'c
for(int i=1;;i++) tBbOY}.VD
{ yw-8#y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >Gml4vGK
//Utility.log(in.readLine()); (V`Md\NL`
sHeader=httpConnection.getHeaderFieldKey(i); i%m"@7.kk
if(sHeader!=null) W,5Hx1z R
{ =@&cHY
if(sHeader.equals("Content-Length")) s$ENFp7P
{ AlE8Xu9UB
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \_V-A f{6
break; <EO$]>;0
} dO> VwP
} q[q?hQ/b
else B%CTOi
break; }je,")#W
} S-Y=-"
} ~}EMk3
catch(IOException e){e.printStackTrace ();} \wcam`f
catch(Exception e){e.printStackTrace ();} {%lXYMyu
'rp }G&m
^&@w$
Utility.log(nFileLength); >@xrs
EP'h@zdz
@hQlrq5c
return nFileLength; l/TjQ*
} Z;Ez"t&U
W&*f#E
!G^L/?z3
//保存下载信息（文件指针位置） c#-U%qZ
private void write_nPos() M>9-=$7
{ tz4 ]qOH8
try{ gI^oU4mq
output = new DataOutputStream(new FileOutputStream(tmpFile)); BS Iy+
output.writeInt(nStartPos.length); N'r3`8tS
for(int i=0;i<nStartPos.length;i++) F:@70(<w%
{ y&}E~5O
// output.writeLong(nPos); *4+3ObA
output.writeLong(fileSplitterFetch.nStartPos); x3jb%`o#!
output.writeLong(fileSplitterFetch.nEndPos); %VYAd)gC
} [[PEa-992
output.close(); poGc a1
} IG)s^bP
catch(IOException e){e.printStackTrace ();} ;c~cet4
catch(Exception e){e.printStackTrace ();} zJP6F.Ov!
} k.("3R6v:
.+7;)K
B`*ZsS=R-
//读取保存的下载信息（文件指针位置） 5;0g!&-t#
private void read_nPos() fVb-$
{ eSWLrryY
try{ /|#&px)G
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w0w G-R ?
int nCount = input.readInt(); G'3qzBJ#
nStartPos = new long[nCount]; FZ!`B]]le,
nEndPos = new long[nCount]; H 0+dV3
for(int i=0;i<nStartPos.length;i++) \fA{1
{ bM8If"
nStartPos = input.readLong(); mPI8_5V8]
nEndPos = input.readLong(); =mA: ctu~v
} }ci#>
input.close(); IDnC<MO>
} 'smWLz}
catch(IOException e){e.printStackTrace ();} /}Jj
catch(Exception e){e.printStackTrace ();} ono4U.C9
} 3a.kBzus
:Y9NLbv
'F>'(XWWQ
private void processErrorCode(int nErrorCode) =t6z \WB
{ ml\4xp,
System.err.println("Error Code : " + nErrorCode); G}&Sle]
} X[f=h=|
\j&^aAp r
UnI48Y
//停止文件下载 -S3MH1TZ
public void siteStop() M\yT).>z
{ Neg,qOt
bStop = true; oc8:r
for(int i=0;i<nStartPos.length;i++) =Umw$+fJr
fileSplitterFetch.splitterStop(); $<:E'^SAS
`PY>Hgb
%f($*l.
} jqPkc28
} V(Ub!n:j
//负责部分文件的抓取 K|dso]b/
**FileSplitterFetch.java .e_cgad :
*/ +$oF]OO
package NetFox; ]\7]%(
XC.%za8
@|Rrf*J?%
import java.io.*; \Y"Wu
import java.net.*; 2WU@*%sk"
=Zi2jL?On
m1Y>Nj[f
public class FileSplitterFetch extends Thread { a4irokJv#
R {-5Etv
{&"N%;`Q
String sURL; //File URL ! u:Weoz
long nStartPos; //File Snippet Start Position qUly\b 47
long nEndPos; //File Snippet End Position ^tXJj:wtS
int nThreadID; //Thread's ID ]c! ;L5
boolean bDownOver = false; //Downing is over 6R=W}q4
boolean bStop = false; //Stop identical Q+YRf3$
FileAccessI fileAccessI = null; //File Access interface J~#;<e{\"
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w8n|B?Sr
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Fd0%lnui
{ P*cNh43U
this.sURL = sURL; CiB%B`,N
this.nStartPos = nStart; ,?L2wl[
this.nEndPos = nEnd; lbpq_=
nThreadID = id; V0)fZS@tf
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8']9$#
} s8}@=]aA
\hB5@e4i2
uDEvzk42
public void run() V7/I>^X
{ aG^4BpIP
while(nStartPos < nEndPos && !bStop) iezO9`
{ k{'0[,mx#
Yb E-6|cz
9/nn)soC3
try{ 0:+WO%z
URL url = new URL(sURL); {?yr'*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Hla0 5N' 4
httpConnection.setRequestProperty("User-Agent","NetFox"); s0PrbL%_`
String sProperty = "bytes="+nStartPos+"-"; ^Vpq$'!
httpConnection.setRequestProperty("RANGE",sProperty); i9/aAH0
Utility.log(sProperty); nw-I|PVTNa
]C) 4
J>\B`E
InputStream input = httpConnection.getInputStream(); 92EWIHEWZ
//logResponseHead(httpConnection); t^w"w`v\u
p\bDY
xXM{pd
byte[] b = new byte[1024]; utIX %0
int nRead; /kfgx{jZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) C+TI]{t
{ P'`r
nStartPos += fileAccessI.write(b,0,nRead); )a-Du$kd
//if(nThreadID == 1) bFW=ylF9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @7B$Yy#
} yxH ( c
?Orxmxc 2
t2lS ~l)
Utility.log("Thread " + nThreadID + " is over!"); QDu2?EYZq
bDownOver = true; o#skR4lwe
//nPos = fileAccessI.write (b,0,nRead); U-|NY
} uXKERzg
catch(Exception e){e.printStackTrace ();} >k'c'7/
} jrS[f
} l g-X:Z.
{DR`;ea])1
ndkti5L,
//打印回应的头信息 9T1ZL5
public void logResponseHead(HttpURLConnection con) v61[.oS
{ ia MUsa{
for(int i=1;;i++) <"_d]?,
{ IyPwP*A
String header=con.getHeaderFieldKey(i); :AE&Ny4
if(header!=null) |cR;{Z8?_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ` eXaT8
Utility.log(header+" : "+con.getHeaderField(header)); 'nwx9]q
else ~x|F)~:0=
break; uH(f$A
} /C6k+0ApMT
} N|6MP e
8@tPm$
](s'L8(x
public void splitterStop() ?nmn1`UT
{ PBp^|t]E>
bStop = true; q,+yqrt
} 0}CGuws
M#8uv-L
;S>])5<
} (Kv#m 3~
m8o(J\]
7eiV{tYF
/* %;rHrDP(>
**FileAccess.java *#C+iAF|)'
*//文件访问(定位，写) lk( }-
package NetFox; WUh$^5W
import java.io.*; h"/<?3{
Zd')57{
wf:OK[r9
public class FileAccessI implements Serializable{ ^Gqt+K%
N9v1[~ bv_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c\Q7"!e
RandomAccessFile oSavedFile; nuw70*ell
long nPos; W#hj 1
=,UWX3`f
Ac<Phy-J
public FileAccessI() throws IOException LL3#5AA"k|
{ "*Tb" 'O
this("",0); vuoQz\
} hBBUw0"
6,0_)O}\b
5Er2}KZJv,
public FileAccessI(String sName,long nPos) throws IOException *^:N.&]
{ \Z+z?K O
oSavedFile = new RandomAccessFile(sName,"rw"); 9T*v9d
this.nPos = nPos; FSA1gAW6g
oSavedFile.seek(nPos); '7iSp=
} )3>hhuaa
(EI;"N (x
c1E'$- K@
public synchronized int write(byte[] b,int nStart,int nLen) 6x%h6<#xh*
{ id1s3b;
int n = -1; ,&R/4:I
try{ -}KC=,]vh
oSavedFile.write(b,nStart,nLen); SN1}xR$
n = nLen; Z7=`VNHc
} `.i!NBA'6
catch(IOException e) .p e(lP
{ `|ASx8_!
e.printStackTrace (); 1*@'-mj
} Jz2N
pP*a
uA#P'?
return n; z{o' G3
} lc~%=
:gep:4&u
-(~!Jo_*'
} Yi$vg
a_'2V;
//s:5S<Z
/* !X;1}
**SiteInfoBean.java N _86t
*/ H*$jc\ dC
package NetFox; f)^_|8
5 4L\Jx
]zWon~
public class SiteInfoBean { K|:@Z
):b$xNn
TX&Jt%
private String sSiteURL; //Site's URL x7eQ2h6O
private String sFilePath; //Saved File's Path c'S,hCe*
private String sFileName; //Saved File's Name M!REygyx
private int nSplitter; //Count of Splited Downloading File F!]lU`z)=
7~5ym15*
K>DRJz
public SiteInfoBean() $h*L=t(
{//nSplitter的缺省值为5 8n*.).33
//default value of nSplitter is 5 <w)r`D6
this("","","",5); O8j_0
} )'6DNa[y
$Z\.-QE\
FXi{87F2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Jc|6&
{ e-"nB]n^/
sSiteURL= sURL; H?)w!QX
sFilePath = sPath; Na?!;1]_
sFileName = sName; RM!<8fXYD
this.nSplitter = nSpiltter; |4uWh
;;:-l99
l@\#Ywz
} hKT
$D|e>U
T<55a6NoK
public String getSSiteURL() 4DL)rkO
{ Cc%LztP>
return sSiteURL; rU2%dkTa
} j ~1B|,H
Zf65`K3
;3B1_vo9
public void setSSiteURL(String value) NqDHCI
{ 9.a3&*tV[
sSiteURL = value; q@nP}Pv&5
} ~e+\k>^eN
>U]C/P[+
\ytJ=0r
public String getSFilePath() c0;t4( &8
{ /Q2mMSK1h
return sFilePath; Q=/</|
} :$m}UA-9
(}EB2V9Hh
L.jh
public void setSFilePath(String value) |ayVjqJ*
{ }l],.J\BGX
sFilePath = value; &iA?+kV
} +KvU$9Ad>
q gLaa
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public String getSFileName() s0k`p<q
{ d\ 1Og\U|A
return sFileName; qT`k*i?
} %Ntcvp)
;I}kQ!q
q(.:9A*0
public void setSFileName(String value) b;cdIl!3
{ !,Va(E|=
sFileName = value; X@LRsg
} -/g B|J
GJtZ&H
&'}RrW-s
public int getNSplitter() 17G'jiYH
{ znaUBv_
return nSplitter; 8\5 T3AF
} [ji#U s:h
b{]z wpf
Dm-zMCf}Q
public void setNSplitter(int nCount) Zy(W^~NT
{ fv9V7
nSplitter = nCount; Te}8!_ohyC
} fDvl/|62{
} EodQ*{l
'{V0M<O
?Vf o+a,
/* nAjO6g6E
**Utility.java [`rba'
*/ glF; eT
package NetFox; 8F&=a,ps[
{O`w,dMOI
Y[K*57fs
public class Utility { ( 8c9 /7h
+L9Eqll
jg\Z;_!W
public Utility() ZfgJ.<<
{ N,;5{y1;J
S7L=#+Z
I$0)Px%z
} ,Qnd3[2[
oze&
//线程睡眠 H s"HID
public static void sleep(int nSecond) )>`G
{ 6DuEL=C
try{ bj"J'
Thread.sleep(nSecond); :kf`?u
} `R=HKtr?
catch(Exception e) GP:77)b5
{ R5 9S@MsuD
e.printStackTrace (); 30.@g[~
} s8#X3Rp
} *UmI]E{g3(
ktdW`R\+
//日志 @p NNq
public static void log(String sMsg) WUsKnf
{ kT!9`S\
System.err.println(sMsg); pFHz"]
} 9uBM<
~(IB0=A{v
ZObhF#Y9
public static void log(int sMsg) t{WzKy
{ O2BDL1o
System.err.println(sMsg); iIq)~e/ Z
} vc+ARgvH+
} 8qEVOZjV&
Ts ^"xlK
P}TI q#
/* mHBnC&-/
**TestMethod.java :E@3Vl#U
*/ cvfr)K[0
package NetFox; E7Y`|nT
uJ5Eka
|Clut~G
public class TestMethod { f'aVV!
D*F4it.
j.L-{6_s>~
public TestMethod() Ffv`kn@
{ ///xx/weblogic60b2_win.exe PUBWZ^63
try{ -!N&OZ+R
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0Emr<n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q"<acqK
SiteFileFetch fileFetch = new SiteFileFetch(bean); (Xq)py9
fileFetch.start(); )Ib<F7v
} *i- _6s
catch(Exception e){e.printStackTrace ();} cgm~>
L.1_(3NG
]b%Hy
} ?$6Y2
q&/Yg,p\
u*tN)f3
public static void main(String[] args) :SGF45>B@
{ 9lW;Nk*j:
new TestMethod(); Yl#Rib
} ae0> W
} RQ'H$r.7g
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