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)); D-IXO@x
} 0cBk/x^s
for(int i=0;i<nEndPos.length-1;i++) X}s}E ;v9
{ #^ cmh
nEndPos = nStartPos[i+1]; &^4E)F
} "dO>P*k,
nEndPos[nEndPos.length-1] = nFileLength; Hkck=@>8H*
} UF ]g6u
} XV> )[Nd\H
P<<hg3@
NlnmeTLO5
//启动子线程 Yuo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; L)Iv]u
for(int i=0;i<nStartPos.length;i++) V!94I2%#x
{ <(U:v
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K^'NG!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #I(Ho:b
nStartPos,nEndPos,i); M)1?$'Aq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T8ftBIOi
fileSplitterFetch.start(); ^5yFb=2
} Px<*n '~}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zz1e)W/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]VU a$$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", g,N"o72)
nEndPos = " + nFileLength); BbqH02i
// fileSplitterFetch[nPos.length-1].start(); )ZA3m_w]
jg_##Oha
Kq*D_Rh2
//等待子线程结束 /?,c4K,ap
//int count = 0; hnbF}AD
//是否结束while循环 C/{tvY /o
boolean breakWhile = false; eZ^-gk?
R} #6
DWQ@]\
while(!bStop) (K(6`~
{ JWuF ?<+k
write_nPos(); !VJ5(b
Utility.sleep(500); 9<ev]XaSl
breakWhile = true; rprtp5Cg
xxN=,p
wwtk6;8@
for(int i=0;i<nStartPos.length;i++) mz~aSbb|
{ i9FHEu_
if(!fileSplitterFetch.bDownOver) 0WjPo
{ m:1f7Z>
breakWhile = false; ??!+2G#%!
break; FB-_a
} .Y"H{|]Mnh
} ,%FBELqOW
if(breakWhile) P,ox))+6
break; E9L)dMZSpj
+4,v.B@
b:,S
//count++; N<\U$\i
//if(count>4) ]ctlK'.
// siteStop(); *0 0K3
} ?1z." &
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Y GZX}-
System.err.println("文件下载结束！"); DhL]\ 4
} '01ifA^
catch(Exception e){e.printStackTrace ();} ,KMt9<
} %S<0l@=5`l
_Co*"hl>2
+s}"&IV%
//获得文件长度 Q599@5aS
public long getFileSize() u5,\Kz
{ w1je|Oil
int nFileLength = -1; Zljj
try{ *[(}rpp M
URL url = new URL(siteInfoBean.getSSiteURL()); MMpGI^x!-X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XkWO-L
httpConnection.setRequestProperty("User-Agent","NetFox"); "Yo.]PU
pL{h1^O}
J1?)z+t9~
int responseCode=httpConnection.getResponseCode(); PN!NB.
if(responseCode>=400) lJfn3
{ 8}&O7zO?
processErrorCode(responseCode); MMMuT^X
return -2; //-2 represent access is error <3wfY #;><
} i U^tv_1
<4gT8kQ$x
.."=
String sHeader; D=w5Lks
RN0@Q~oTI
@c<*l+Qc
for(int i=1;;i++) )>]~Y
{ Wb_'X |"u
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Wgt[ACioN
//Utility.log(in.readLine()); OIuEC7XM^C
sHeader=httpConnection.getHeaderFieldKey(i); O43emL3
if(sHeader!=null) #)aUKFX
{ iI27N'g
if(sHeader.equals("Content-Length")) liW0v!jBo
{ qeK_w '
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); V Q6&7@ c
break; <$^76=x,8P
} z*cC2+R}=
} p*T`fOL
else <5s51b <
break; u;fD4CA
} *Txt`z[|
} 9Ytf7NpR
catch(IOException e){e.printStackTrace ();} !^dvtv`K
catch(Exception e){e.printStackTrace ();} H5f>Q0jq
bp06xHMu
ohFUy}y
Utility.log(nFileLength); -I$qe Xy
6gLk?^.
t,mD{ENm&
return nFileLength; (RP"VEVR
} O<&8gk~
*(%]|z}]m
87Sqs1>cw
//保存下载信息（文件指针位置） cr{;gP
private void write_nPos() +ht -Bl
{ <<zYF.9L]
try{ KaJCfu yp
output = new DataOutputStream(new FileOutputStream(tmpFile)); w`kn!k8
output.writeInt(nStartPos.length); e12.suv
for(int i=0;i<nStartPos.length;i++) yG)zrRU
{ S}q6CG7 u
// output.writeLong(nPos); ^Z:oCTOP
output.writeLong(fileSplitterFetch.nStartPos); W0]W[b,:u$
output.writeLong(fileSplitterFetch.nEndPos); Gz]p2KBg
} `u%`Nj
output.close(); c~B[<.Qj
} <1HbjRw
catch(IOException e){e.printStackTrace ();} nu1s
catch(Exception e){e.printStackTrace ();} B 4pJg
} Voi`OCut
fdIO'L_
> .L\>
//读取保存的下载信息（文件指针位置） 1 m)WM,L
private void read_nPos() JG%y_ Qy?K
{ '%@fW:r~
try{ ,O[HX?>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jG"n);WF
int nCount = input.readInt(); I`?6>Z+%)
nStartPos = new long[nCount]; TA=VfA B
nEndPos = new long[nCount]; ;VY0DAp{
for(int i=0;i<nStartPos.length;i++) n%o"n?e
{ eIEr\X4\~~
nStartPos = input.readLong(); F;Q8^C0e*c
nEndPos = input.readLong(); tta\.ic
} O1+2Z\F
input.close(); -r%3"C=m
} +I$ k_
catch(IOException e){e.printStackTrace ();} xFU*,Y
catch(Exception e){e.printStackTrace ();} kY8aK8M
} /Ulv/Thl
4ZY0!'be-R
,qF;#nB-
private void processErrorCode(int nErrorCode) g5gq{KlU
{ iXp*G52
System.err.println("Error Code : " + nErrorCode); yQA6w%
} |/u&%w?W
Byx8`Cx1
Gj6(ycaS
//停止文件下载 KLpe!8tAe
public void siteStop() Xx~za{p
{ FOB9J.w4
bStop = true; D$W&6'
for(int i=0;i<nStartPos.length;i++) 26yjQ
fileSplitterFetch.splitterStop(); x>5"7MR`
/&g5f4[|p
*~~&*&+
} :x*|?zII
} ^l}Esz`-M
//负责部分文件的抓取 N=e-"8
**FileSplitterFetch.java dg9 DBn#
*/ 8lAs~c
package NetFox; gOkq>i_
jmgU'w-s
NwH`t#zd
import java.io.*; s8,{8k
import java.net.*; YGRv``(
D^+#RR'#,
86bl'FdKS
public class FileSplitterFetch extends Thread { s8,N9o[.~P
L*TPLS[lh
xz1jRI$
String sURL; //File URL ][ri A
long nStartPos; //File Snippet Start Position %UEV['=
long nEndPos; //File Snippet End Position a2l\B~n
int nThreadID; //Thread's ID g3r4>SA
boolean bDownOver = false; //Downing is over ~NYy@l
boolean bStop = false; //Stop identical bo]xah|."j
FileAccessI fileAccessI = null; //File Access interface u)]]9G _8
Z83A1`!.|
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XUf]gQu3=
{ vYT%e:8)q
this.sURL = sURL; Nqih LUv
this.nStartPos = nStart; E'|@hL-jn
this.nEndPos = nEnd; CAGaZ rx
nThreadID = id; .G"UM>.}d
fileAccessI = new FileAccessI(sName,nStartPos);//定位 GtQ$`~r
} pkd#SY
JI{|8)S
~*WSH&ip
public void run() 8Vcg30_+
{ 6$"gm$3O]
while(nStartPos < nEndPos && !bStop) o)_;cCr)q
{ ?LP&VU1
wB(A['k
uWs5+
try{ eK%~`Y
URL url = new URL(sURL); }]0f -}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]s3U+t?
httpConnection.setRequestProperty("User-Agent","NetFox"); i #5rk(^t
String sProperty = "bytes="+nStartPos+"-"; h{s- e.
httpConnection.setRequestProperty("RANGE",sProperty); y/!h.[
Utility.log(sProperty); $tGk,.#j
EAVB:gE
Tvd=EO
InputStream input = httpConnection.getInputStream(); Y9h~ hD
//logResponseHead(httpConnection); x1\a_Kt
<S*o}:iB
GEr]zMYG[A
byte[] b = new byte[1024]; 'g<0MOq{
int nRead; seT?:PCA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &"^,Ubfcn"
{ m"MTw@}SJ;
nStartPos += fileAccessI.write(b,0,nRead); d|UK=B^x
//if(nThreadID == 1) Za+26#g
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7O3\
} a78&<
[I*BEJ;W'
%<x2=#0
Utility.log("Thread " + nThreadID + " is over!"); /\=syl
bDownOver = true; Ra\>^W6z
//nPos = fileAccessI.write (b,0,nRead); tvH{[e$
} X{SD3j=G#
catch(Exception e){e.printStackTrace ();} %xE9vN;
} P{ AJH1
} 8$SA"c)
(+'*_
iV8j(HV
//打印回应的头信息 G813NoS o
public void logResponseHead(HttpURLConnection con) J%ym1A9
{ uj@rv&
for(int i=1;;i++) ,z6&k
{ MV"aO@
String header=con.getHeaderFieldKey(i); lNtZd?=>
if(header!=null) ]AlRu(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7r=BGoA2E
Utility.log(header+" : "+con.getHeaderField(header)); bAIo5lr
else +" 4E:9P?
break; GT|=Kx$;
} !oTF2Q+C
} 9p ;)s
S^}@X?v
RIXUzKLO
public void splitterStop() FsrGI (x?
{ k@qn'Zi
bStop = true; S<Zb>9pl
} w!{g^*R+!
v1h*/#
:'-FaGy
} vas
Xj:?V;
]d]tQPEU
/* u@v0I$
**FileAccess.java PxENLQ3a=
*//文件访问(定位，写) ^cO^3=
package NetFox; Q`#Y_N-h+
import java.io.*; D]nVhOg|
{}ks[%,_\
Xz`?b4i
public class FileAccessI implements Serializable{ =y" lX{}G
@}&o(q1M0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _1w?nN'
RandomAccessFile oSavedFile; 2J;h}/!H
long nPos; Q/T\Rr_d
Yc+0OBH[
#`P4s>IL1
public FileAccessI() throws IOException V9 <!pMj
{ %zg&eFRHI
this("",0); ]m0MbA
} bg$df 0
`.PZx%=
ax7]>Z=%d"
public FileAccessI(String sName,long nPos) throws IOException N~H9|CX
{ r0=Aru5n
oSavedFile = new RandomAccessFile(sName,"rw"); a}l^+
this.nPos = nPos; \]
oSavedFile.seek(nPos); 1=C>S2q
} 3| 5Af
?YR/'Vq97
;hsgi|Cy-
public synchronized int write(byte[] b,int nStart,int nLen) XjpFJ#T*$A
{ AtNu:U$
int n = -1; J[fjl6p
try{ FilHpnQCt
oSavedFile.write(b,nStart,nLen); W.h6g8|wx
n = nLen; CA[-\>J7y
} :5?g<@
catch(IOException e) +JE h7
{ <6k5nEh
e.printStackTrace (); /I~iUND"G
} @A(*&PU>j
56(S[
XBv:$F.>$
return n; M/ @1;a@\
} yP\KIm!
Ct[{>asun
^S*~<0NQ'
} aNgaV$|2a
L1#z'<IO
ws:@Pe4AF
/* |}paa
**SiteInfoBean.java A$G>D3
*/ IDbqhZp(
package NetFox; Y*iYr2?;
l v]TE"
f,Vj8@p)x
public class SiteInfoBean { Tvr2K84l
{f]K3V
R.Xh&@f`
private String sSiteURL; //Site's URL X 10(oT
private String sFilePath; //Saved File's Path dwOB)B@{H
private String sFileName; //Saved File's Name A=q)kcuy5
private int nSplitter; //Count of Splited Downloading File [@MV[$W5
yLFc?{~7
,.Ac= "f
public SiteInfoBean() [pf78
{//nSplitter的缺省值为5 HJT}v/FZ
//default value of nSplitter is 5 7r#U^d(
this("","","",5); -AcLh0pc
} ^`NU:"
:Rc>=)<7
E[bJ5o**#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k4te[6)
{ .]`LR@qf
sSiteURL= sURL; CqQ>"Y
sFilePath = sPath; &6nOCU)
sFileName = sName; 4bD^Kc4\
this.nSplitter = nSpiltter; 1wpT"5B
26|2r
?qwTOi
} cA_77#<8
mZsftby}
{Lu-!}\NP
public String getSSiteURL() >$h*1/
{ co<-gy/mCR
return sSiteURL; 47s<xQy
} wzhM/Lmo\z
:eqDEmr>
\"BoTi'2!
public void setSSiteURL(String value) Vrl)[st!;I
{ isK~=
sSiteURL = value; C=L_@{^Rgb
} =E@wi?
t_1a.Jv
](yw2c;me
public String getSFilePath() T-x1jC!B'
{ sev^
return sFilePath; Dpp3]en.
} 7r,'a{Rcn
vKYdYa\
z6e)|*cA$
public void setSFilePath(String value) "X~ayn'@w,
{ D@"g0SW4
sFilePath = value; ZGrjb22M
} ?r"][<
sr%tEKba)
=)}m4,LA
public String getSFileName() c%-s_8zvi
{ y\L$8BSL
return sFileName; Nx>WOb98
} >&V?1!N"
4/; X-
\ZiZX$
public void setSFileName(String value) `C 'WSr
{ 5&]|p'"W\
sFileName = value; Oo{+W5[
} }Th":sin},
*gRg--PY%
^znj J\
public int getNSplitter() w5,p9f}.
{ /MHqt=jP6
return nSplitter; <G0Ut6J>
} ?OPuv5!pI
H.;2o(vD
9^&B.6!6
public void setNSplitter(int nCount) azzG
{ QUm[7<"
nSplitter = nCount; 1*e7NJ/.,
} !ALq?u
} ->*~e~T
]T{v~]7:{
v cUGBGX_&
/* = c1>ja
**Utility.java +,g!xv4Q
*/ G?,"AA;
package NetFox; j]U~ZAn,K
wv`ar>qVL
VN0KK 1I
public class Utility { ^ZIs>.'
xLb=^Xjec
3<l}gB'S[
public Utility() K,6{c^qf
{ v0TbQ
>oN Wf
}]M'f:%b
} \=P(?!v
/bn$@Cy@
//线程睡眠 F2MC)&#
public static void sleep(int nSecond) 4\ |/S@.
{ z7z9lDS
try{ ,@fx[5{
Thread.sleep(nSecond); .2U3_1dX
} u9(42jj[$U
catch(Exception e) $=X>5B
{ 0>46ZzxUZ
e.printStackTrace (); `e`DSl D>
} ,hrv
} "Ec9.#U/
c[V.j+Iy#^
//日志 ]rSg,Q>E
public static void log(String sMsg) YNl".c
{ (.iwD&
System.err.println(sMsg); sIbPMu`&U
} O)DAYBv^
_;%l~q/
x}O,xquY
public static void log(int sMsg) R+t]]n6#
{ `mI5Z*]-
System.err.println(sMsg); 8GRB6-.h
} \3]O?'
} $BT[fJ'k
GIT"J}b}
HO_(it \
/* ?Q$a@)x#
**TestMethod.java o~W,VhCP
*/ GY %$7
package NetFox; @4Zkkjc4b
Pd& Npp3
R^=v&c{@
public class TestMethod { x4MTE?hT
hrO9_B|#
{LVA_7@
public TestMethod() BJ\81 R
{ ///xx/weblogic60b2_win.exe WMW=RgiW\
try{ ir>S\VT4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;;m;f^]}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); DSWmQQ
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q, "8Ty
fileFetch.start(); pr1bsrMuL
} )pe17T1|
catch(Exception e){e.printStackTrace ();} LE)$_i8gX
@Kn@j D;
yTn<5T[H
} ^16zZ*
R#.H&#
e2K9CE.O
public static void main(String[] args) &cd>.&1<2
{ p@Cas
new TestMethod(); KT*>OYI
} eE=2~ ylU
} >4-9 @i0FV
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