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)); @mOH"acGn?
} k;K)xb[w|
for(int i=0;i<nEndPos.length-1;i++) U 9_9l7&r
{ "+kL)]
nEndPos = nStartPos[i+1]; fkuLj%R
} ii[F]sR\
nEndPos[nEndPos.length-1] = nFileLength; qkt0**\
} = s>T;|
} zKw`Md
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u$DHVRrF<
//启动子线程 Wvbf"hq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; kpJ@M%46
for(int i=0;i<nStartPos.length;i++) UtPLIal
{ !}YAdZJ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %`>nS@1zp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?I6fye7
nStartPos,nEndPos,i); m? eiIrMW
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >zw.GwN|
fileSplitterFetch.start(); q*U*Fu+
} K{&mI/;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nxUJN1b!N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _-q.Q^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", pWy=W&0~qf
nEndPos = " + nFileLength); YLqGRE`W
// fileSplitterFetch[nPos.length-1].start(); $bW3_rl%X
f\]sz?KY
_,p/l&<
//等待子线程结束 $+P>~X)
//int count = 0; ?oVx2LdD|
//是否结束while循环 %-)H^i~]%
boolean breakWhile = false; /xsF90c\h
1n=lqn/
&~8oQC-eF
while(!bStop) N >FKy'.gk
{ ]JCvyz H
write_nPos(); Ja,wfRq
Utility.sleep(500); KC/=TSSXd.
breakWhile = true; -m)X]]~C
pOGeruu?
v=0(~<7B
for(int i=0;i<nStartPos.length;i++) GR&z,
{ .:@Ykdm4I
if(!fileSplitterFetch.bDownOver) fKeT,U`W
{ GGNvu)"
breakWhile = false; BzkooJ
break; 3L<wQ(
} 7op`s5i
} &+cEV6vb+
if(breakWhile) iIMd!Q.)@
break; ~D<IB#C
D&od?3}E
"Ue.@>
//count++; Mmxlp.l
//if(count>4) 5*+!+V^?X
// siteStop(); (zgW%{V@
} 0xxg|;h.,g
d6'{rje(
c9HrMgW
System.err.println("文件下载结束！"); n!NS(.o
} tXoWwQD;Y
catch(Exception e){e.printStackTrace ();} q;R],7Re
} ;|pBFKx
J#w J4!
}T; P~aG
//获得文件长度 Tu$f?
public long getFileSize() WlB
{ b<a4'M
int nFileLength = -1; (pY 7J
try{ @Fluc,Il
URL url = new URL(siteInfoBean.getSSiteURL()); + ,%&e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B|R@5mjm
httpConnection.setRequestProperty("User-Agent","NetFox"); Sx708`/Ep
]Y%Vio
JG" R\2
int responseCode=httpConnection.getResponseCode(); ey2S#%DF]
if(responseCode>=400) $CY~5A`l9
{ @aAW*D~-J
processErrorCode(responseCode); |%J{RA
return -2; //-2 represent access is error 4[.oPK=i
} 4[;X{ !
F<L EQ7T
W{5#@_pL
String sHeader; _kj wFq
ur3(HL
[NaN>BZ?
for(int i=1;;i++) !qv ea,vw
{ (MR_^t
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zfc'=ODX
//Utility.log(in.readLine()); SW*"\X;
sHeader=httpConnection.getHeaderFieldKey(i); : ]sUpO
if(sHeader!=null) $K]m{
{ Z1 Bp+a3
if(sHeader.equals("Content-Length")) MXw hxk#E
{ b6Wqr/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); byLft1
break; b:Wm8pp?
} xCg52zkH#
} ox(j^x]NC
else <}E!w_yi
break; pnjXf.g"O
} C1jHz
} /DK"QV!]s
catch(IOException e){e.printStackTrace ();} mzeY%A<0^
catch(Exception e){e.printStackTrace ();} bL'aB{s
Jll-`b 1
e4!:c^?
Utility.log(nFileLength); X'd9[).
$ {O#
Km(n7Ah"
return nFileLength; $"FQj4%d
} m;'6MHx;
PK{acen
jF0jkj1&/[
//保存下载信息（文件指针位置） {)BTR%t
private void write_nPos() gu0j.XS^
{ \9cG36
try{ 6G #}Q/
output = new DataOutputStream(new FileOutputStream(tmpFile)); :+qF8t[L
output.writeInt(nStartPos.length); pm_`>3
for(int i=0;i<nStartPos.length;i++) ;5zz<;Zy
{ x c/}#>ED
// output.writeLong(nPos); E7.2T^o;M
output.writeLong(fileSplitterFetch.nStartPos); P>s[tM
output.writeLong(fileSplitterFetch.nEndPos); !ePr5On
} XZsz/#
output.close(); mVVD!
} +3BBQ+x!
catch(IOException e){e.printStackTrace ();} 8zRP(+&W
catch(Exception e){e.printStackTrace ();} ZZHDp&lh}
} ]L9s%]o
DVSL [p?_
np8gKVD
//读取保存的下载信息（文件指针位置） |C!oxhu<
private void read_nPos() ^G4Py<s
{ .!f$ \1l
try{ Y8m1M-#w
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .#rJ+.2
int nCount = input.readInt(); `(YxI
nStartPos = new long[nCount]; umiBj)r
nEndPos = new long[nCount]; E%rk[wI
for(int i=0;i<nStartPos.length;i++) 'eLqlu|T
{ M_"L9^^>N
nStartPos = input.readLong(); q1QL@Ax
nEndPos = input.readLong(); \P.I)n`8 y
} X~lVVBO
input.close(); h|,:e;>}
} 6LalW5I
catch(IOException e){e.printStackTrace ();} BI3@|,._N
catch(Exception e){e.printStackTrace ();} Lv|q
} n?- })
{so`/EWa
[H6hyG~
private void processErrorCode(int nErrorCode) a0D%k:k5
{ D|e uX7b
System.err.println("Error Code : " + nErrorCode); l|kSsP:GO
} FFu9&8Y
,.kha8v
CIb2J)qev
//停止文件下载 U)E(`{p]
public void siteStop() >8k_n
{ GBRa.;Kk
bStop = true; /atW8 `&
for(int i=0;i<nStartPos.length;i++) R)QC)U
fileSplitterFetch.splitterStop(); /ro=?QYb
~GL]wF2#
n ~shK<!C
} -'t)=YJ
} "Y~:|?(@-
//负责部分文件的抓取 c_vqL$Dl
**FileSplitterFetch.java cc~O&?)i
*/ n=y[CKS
package NetFox; %-c*C$
P} 0%-JC
v":x4!kdX
import java.io.*; b:tob0TB
import java.net.*; Zc W:6po>
j2QmxTa!
/SrCElabP
public class FileSplitterFetch extends Thread { 1Cv-
?u" 4@
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String sURL; //File URL zi]\<?\X
long nStartPos; //File Snippet Start Position &Low/Y'.jJ
long nEndPos; //File Snippet End Position s'%R
int nThreadID; //Thread's ID 8W,Jh8N6
boolean bDownOver = false; //Downing is over FVaQEMZ^
boolean bStop = false; //Stop identical m^ tFi7c
FileAccessI fileAccessI = null; //File Access interface y:~ZLTAv
C|}iCB
-"=U?>(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `f*Q$Ulqx
{ Q9Kve3u-i
this.sURL = sURL; mi,E-
this.nStartPos = nStart; P<M?Qd1.
this.nEndPos = nEnd; $W!!wN=B
nThreadID = id; kBD>-5Sn_T
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ihIVUu-M
} \=:~ki=@B
)qo {c1X
d@XV:ae
public void run() __|+w<]
{ .QZaGw=,z
while(nStartPos < nEndPos && !bStop) _qw?@478
{ #xX5,r0
B0dQ@Hq*
a&c6.#E{y
try{ <{V(.=11
URL url = new URL(sURL); Mxyb5h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); glM$R&/
httpConnection.setRequestProperty("User-Agent","NetFox"); n%-R[vW
String sProperty = "bytes="+nStartPos+"-"; `(_s|-$
httpConnection.setRequestProperty("RANGE",sProperty); KH(%?
Utility.log(sProperty); gMWjk7
<}<zgOT[1!
=cm~vDl[
InputStream input = httpConnection.getInputStream(); lku[dQdk
//logResponseHead(httpConnection); Ye2 {f"F
_AAaC_q
!g5xq
byte[] b = new byte[1024]; VUPXO
int nRead; "alyfyBu'M
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) x4;"!Kq\
{ kEOS{C%6R
nStartPos += fileAccessI.write(b,0,nRead); JBE!j-F
//if(nThreadID == 1) x:),P-~w
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m[~V/N3
} Xejo_SV&?
>qS9PX
5-aj2>=7
Utility.log("Thread " + nThreadID + " is over!"); x[h^[oF0
bDownOver = true; bwD,YC
//nPos = fileAccessI.write (b,0,nRead); S?{#r
} zsX1QN16
catch(Exception e){e.printStackTrace ();} Z>)Bp/-
} xJ>fm%{5
} OBOtuu.
p"n$!ilbm
fGUE<l
//打印回应的头信息 >O*IQ[r-
public void logResponseHead(HttpURLConnection con) CE#gfP
{ F`gi_;c
for(int i=1;;i++) *=]&&<
{ ^(vs.U^U<
String header=con.getHeaderFieldKey(i); _ba>19csq%
if(header!=null) #gz M|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9$cWU_q{
Utility.log(header+" : "+con.getHeaderField(header)); /67 h&j
else g.BdlVB\
break; q"\Z-D0B4
} e+~\+:[?
} AgS7J(^&3
wQ^EYKD
-:|?h{q?u
public void splitterStop() `o=q%$f#k~
{ }4 )H
bStop = true; d:BG#\e]v
} Yw^m
wSa)*]%
&dM. d!
} 0AZ")<^~7
ZCmgs4W!
LAB=Vp1y3[
/* ,?>s>bHV
**FileAccess.java X:HacYqtC
*//文件访问(定位，写) T ]t'39
package NetFox; ZA0mz 65
import java.io.*; vHyC;4'
zHA!%>%'
7HIeJ
public class FileAccessI implements Serializable{ TE3lK(f
d,+Hd2o^X
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B2>H_dmQ
RandomAccessFile oSavedFile; ;LcZ`1
long nPos; 3EJj9}#x"'
G<}()+L
$"+djI?E9
public FileAccessI() throws IOException B3We|oe!
{ rDm~h~u5
this("",0); 1oR7iD^
} Zq+v6fk_Mn
>3p\m
[k.tWA,&
public FileAccessI(String sName,long nPos) throws IOException Q# ~Q=T'<
{ |2O]R s
oSavedFile = new RandomAccessFile(sName,"rw"); 4ezEW|S
this.nPos = nPos; 6 Q%jA7
oSavedFile.seek(nPos); R%{<mno/_
} SIBtmm1W
7''??X
A,JmX
public synchronized int write(byte[] b,int nStart,int nLen) ns9U/:L
{ /rK}?U
int n = -1; wxKX{Bs
try{ ?qPo=~y01
oSavedFile.write(b,nStart,nLen); SheM|I~de
n = nLen; uxXBEq;
} J%u=Ucdh
catch(IOException e) 0(eBZdRO
{ a L} %2
e.printStackTrace (); J"!vu.[
} cS5Pl
,]|#[8
j'Gt&\4
return n; PQy4{0 _
} -.1y(k^4E
'*K: lx
YmL06<Mh
} 95ZyP!
ni.cTOSx
nCUg,;_=
/* w mn+
**SiteInfoBean.java A 9( x
*/ 3x`|
package NetFox; "un]Gc
umjt]Gu[
}q_<_lQ
public class SiteInfoBean { 2M.fLQ?
Kz~ps 5
j]{_s"O
private String sSiteURL; //Site's URL N4v~;;@(
private String sFilePath; //Saved File's Path NSxoF3
private String sFileName; //Saved File's Name PRx8I .
private int nSplitter; //Count of Splited Downloading File 2<i!{;u$qL
'=39+*6?
I@T8Iv=
public SiteInfoBean() Z_$%.
{//nSplitter的缺省值为5 "H7dft/
//default value of nSplitter is 5 Xnt~]k\"
this("","","",5); #jkf1"8C
} v&9y4\j
Z?6%;n^ 54
Lb!Fcf|h
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pV9IHs}
{ &q3"g*q
sSiteURL= sURL; FEW14U'O
sFilePath = sPath; DGRXd#
sFileName = sName; )B T
this.nSplitter = nSpiltter; T/b6f;t-s
0]'7_vDs|
\.0^n3y
} VU#`oJ:{
3-[q4R
7r7YNn/?
public String getSSiteURL() 'H3^e}
{ @ju@WY45$^
return sSiteURL; rNrxaRQ
} RmI]1S_=
<lgYcdJ
eX?OYDDC0j
public void setSSiteURL(String value) Tl%`P_J)-S
{ EMh7z7}Rr
sSiteURL = value; ERUz3mjA/
} ]_Vx{oT7
hW%TM3l}
t#V!8EpBg
public String getSFilePath() (]Z_UTT
{ /sUYU(3
return sFilePath; Ghu#XJB?
} riUwBiVa?2
2V"B:X\
v:f}XK<
public void setSFilePath(String value) ]%hn`ZJ
{ s6H]J{1F
sFilePath = value; RM]\+BK
} fFMlDg[];
2L:_rR#w
q['Euy
public String getSFileName() J28M@cn
{ Tre]"2l
return sFileName; ;%B(_c
} bk[U/9Z\
Pj[PIz
Cw iKi^m
public void setSFileName(String value) 1Lc#m`Jln
{ 6o!!=}'E[
sFileName = value; O_2pIbh
} BHIRHmM<Y
Lco~,OE
~d o9;8v
public int getNSplitter() Sj-n;F|=X
{ spGb!Y`mR
return nSplitter; 9`T)@Uj2n
} HD@$t)mn
3]OE}[R
Y4OPEo5o
public void setNSplitter(int nCount) e{h<g>7
{ rDD:7*z
nSplitter = nCount; HeK/7IAqp
} [/,)
} 8{|8G-Mi
",p;Sd
0QBiC]9
/* 6|K5!2
**Utility.java d:_t-ZZo
*/ 0m7Y>0wC6T
package NetFox; S(o#K|)>
\(3y7D
!lREaSM
public class Utility { gcii9vz `
q VjdOY:z
gD0eFTN
public Utility() OtY`@\hy
{ aFc1|.Nm
.4_o>D
A|CmlAW~^
} *]. 7dec/
sWQfr$^A
//线程睡眠 Bp*K]3_
public static void sleep(int nSecond) &Q9qq~
{ KLU-DCb%
try{ jPC[_g
Thread.sleep(nSecond); Ot$-!Y;<
} >L|;|X!m9\
catch(Exception e) [=x[ w70
{ Jz?j[
e.printStackTrace (); ;5wn67'
} `Y+J-EQ
} :Gv1?M
~fBtQGdX
//日志 WKQ^NEqr3
public static void log(String sMsg) =Ee&da^MB
{ cec9l65d
System.err.println(sMsg); n?oW< &
} ]fm'ZY&
4]rnY~
tN[L@t9#cr
public static void log(int sMsg) _geWE0 E
{ #mlS}~n
System.err.println(sMsg); Hh%I0#
} Jx_cf9{
} _G_Cj{w
lackB2J9 A
?42<J%p
/* zuP B6W^
**TestMethod.java *aXF5S
*/ B6=ebM`q
package NetFox; ,c$,!.r
rjl`&POqc
32l3vv.j
public class TestMethod { a! (4Ch
v.\*./-i
-Btk 3
public TestMethod() 2;xIL]
{ ///xx/weblogic60b2_win.exe +_7*iJtD5
try{ ~)*,S^k(C.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `{4i)n%e&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .\K_@M
SiteFileFetch fileFetch = new SiteFileFetch(bean); tWo{7)Eb
fileFetch.start(); _my"%@n
} 3sc+3-TF
catch(Exception e){e.printStackTrace ();} *RT>`,t/
6~OoFm5
bf0+DvIB
} )Z[ft
9K/HO!z
m2-Sx
public static void main(String[] args) s.EI`*xylY
{ eD-#b|
new TestMethod(); R|JC1f8P5
} `id9j
} mCRt8rY;
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