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)); )lk&z8;.=
} 0&_UH}10
for(int i=0;i<nEndPos.length-1;i++) Vv1|51B
{ ?L&|Uw+
nEndPos = nStartPos[i+1]; M-V&X&?j
} z7GTaX$d
nEndPos[nEndPos.length-1] = nFileLength; 9d[5{"2j
} D,qu-k[jMI
} v[e:qi&fG
RPd}Wf
Z[__"^}
//启动子线程 uVyGk~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2owEw*5jl/
for(int i=0;i<nStartPos.length;i++) o]:3H8
{ Ig]iT
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kVK/9dy-F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), OCZaQ33
nStartPos,nEndPos,i); s,k
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LJk%#yV|_
fileSplitterFetch.start(); &F STpBu
} ;2'q_Btk4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Urr#N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); X3'H `/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l7#yZ*<v
nEndPos = " + nFileLength); 6`vC1PK^
// fileSplitterFetch[nPos.length-1].start(); M" ^PW,k
EnOU?D
ib{-A&
//等待子线程结束 N_:qRpp6i
//int count = 0; _=CZR7:O
//是否结束while循环 EBz}|GY;
boolean breakWhile = false; [(1c<b2r
9z)5Mdf1j
w?kJ+lmOQy
while(!bStop) U!U$x74D5
{ sBrI}[oyx
write_nPos(); {ZY+L;eg1
Utility.sleep(500); P) 3mX.(}
breakWhile = true; U- )i+}Ng
J{^RkGF
E4m`
for(int i=0;i<nStartPos.length;i++) ,|&9M^
{ A\8}|r(>9E
if(!fileSplitterFetch.bDownOver) K2%w0ohC
{ ,^#yo6-
breakWhile = false; KM^ufF2[
break; #9K-7je;j
} ME'|saP
} _6ay-u
if(breakWhile) RV@*c4KvO+
break; 6G=j6gK%P
M1KqY:9E
-D6exTxh"
//count++; vWGwVH/K
//if(count>4) 4:gRr
// siteStop(); }.s~T#v
} M|:UwqV>
Yw#2uh
tHzZ@72B7
System.err.println("文件下载结束！"); Qxj JN^Q
} M(/r%-D
catch(Exception e){e.printStackTrace ();} g<~Cpd
} bV,}Pp+/"!
9k{PBAP
/ X1 x
//获得文件长度 _a1x\,R|DB
public long getFileSize() )"pF R4
{ uu`G 2[t
int nFileLength = -1; S~|T4q(
try{ 72'5%*1
URL url = new URL(siteInfoBean.getSSiteURL()); pR~U`r5z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8<Hf"M
httpConnection.setRequestProperty("User-Agent","NetFox"); 5LOo8xN
,cNLkoN
KZ/=IP=
int responseCode=httpConnection.getResponseCode(); e=.]F*:J
if(responseCode>=400) ght$9>'n
{ T?X_c"{8M
processErrorCode(responseCode); <>Hj ;q5p
return -2; //-2 represent access is error (DI>5.x"
} 6'FdGS
qT+%;(
X7rMeu
String sHeader; uCcYPvm
SJHr_bawd
L*:jXmUM_~
for(int i=1;;i++) aTt12Sc
{ '*3h!lW1.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); kBffF@{
//Utility.log(in.readLine()); j:VbrR
sHeader=httpConnection.getHeaderFieldKey(i); b9l;a+]d
if(sHeader!=null) OLE[UXD-E
{ fZoHf\B]{
if(sHeader.equals("Content-Length")) jbAx;Xt'=M
{ OynXkH]0T+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <[-nF"Q
break; pS:4CNI{
} o,)?!{k}
} ;5)P6S.D
else ]?(-[
break; B8}Nvz /
} ajEjZ6
} @<elq'2
catch(IOException e){e.printStackTrace ();} Fx2bwut.K
catch(Exception e){e.printStackTrace ();} yPal<c
3qf Ym}d
r[*Vqcz
Utility.log(nFileLength); va0{>Dc+
jEZMUqGY!
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return nFileLength; Eqj_m|@
} rogT~G}q
Rx}$0c0
o6uJyCO
//保存下载信息（文件指针位置） ~GZY5HF
private void write_nPos() ):[7E(F=
{ >7QvK3S4%
try{ =Lf,?"S
output = new DataOutputStream(new FileOutputStream(tmpFile)); XzEc2)0'v
output.writeInt(nStartPos.length); s*-n^o-
for(int i=0;i<nStartPos.length;i++) TIQkW,
{ I+tb[*X+
// output.writeLong(nPos); NeE t
output.writeLong(fileSplitterFetch.nStartPos); q-}Fvel u
output.writeLong(fileSplitterFetch.nEndPos); lIW }EM
} bAx-"Lu
output.close(); SMpH._VFeE
} zo4qG+>o
catch(IOException e){e.printStackTrace ();} &tg&5_
catch(Exception e){e.printStackTrace ();} FG.em
} F9,DrB,B{
,Y/ g2 4R
!:q/Ye3.
//读取保存的下载信息（文件指针位置） t%E!o0+8Z
private void read_nPos() sTn<#l6
{ hHV";bk
try{ ,[P{HrHx
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); hpO`]
int nCount = input.readInt(); [PNT\ElT
nStartPos = new long[nCount]; ?#}N1k\S
nEndPos = new long[nCount]; =A83W/4
for(int i=0;i<nStartPos.length;i++) pHLB= r
{ BRgXr
nStartPos = input.readLong(); JvVWG'Z"
nEndPos = input.readLong(); cj$[E]B3V*
} UG+d-&~Ll
input.close(); 5kCUaPu
} 1;Ou7T9w
catch(IOException e){e.printStackTrace ();} wea-zN
catch(Exception e){e.printStackTrace ();} b4[bL2J$h1
} H9YW
Nn!+,;ut
W*Zkc:{eB
private void processErrorCode(int nErrorCode) DH\0z[
{ : y%d
System.err.println("Error Code : " + nErrorCode); g/CSGIIT
} 1_PoqD!q
&,{fw@#)_
M l Jo`d
//停止文件下载 _`&m\Qe>
public void siteStop() `d5%.N
{ 1Q<^8N)pf
bStop = true; )u[emv$
for(int i=0;i<nStartPos.length;i++) A kC1z73<
fileSplitterFetch.splitterStop(); $4h5rC g0
ywGd>@
J}v}~Cv
} }dgfqq
} 4T|b Cs?e
//负责部分文件的抓取 kmP]SO?tx
**FileSplitterFetch.java >=:&D)m"
*/ "s0)rqf<
package NetFox; VVac:
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v%+:/m1
import java.io.*; Br1&8L-|%
import java.net.*; %5M/s'O?i
kMi/>gpQ
e2s]{obf
public class FileSplitterFetch extends Thread { HK,cJahq
}wr{W:j
g{OwuAC_
String sURL; //File URL RJ 8+h
long nStartPos; //File Snippet Start Position dCi?SIN
long nEndPos; //File Snippet End Position $'BSH4~|.
int nThreadID; //Thread's ID Pg,b-W?n*
boolean bDownOver = false; //Downing is over + jc!5i .
boolean bStop = false; //Stop identical Q=;U@k@>
FileAccessI fileAccessI = null; //File Access interface &"f";
n}F&1Z
JTO~9>$ B
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException de.&`lPRf
{ Dz>^IMsY
this.sURL = sURL; )h"<\%LU
this.nStartPos = nStart; 8!O5quEc
this.nEndPos = nEnd; Ta ?_5
nThreadID = id; }vxw*8d?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~zCEpU|@N
} -JMdE_h
{XR6>]
*H"B _3<n
public void run() -]/I73!b
{ #lmB AL~3
while(nStartPos < nEndPos && !bStop) t<#mP@Mz=N
{ UQ)W%Y;[0
Aw$x;3y
zi|+HM
try{ F U_jGwD
URL url = new URL(sURL); `q}I"iS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zMbN;tu
httpConnection.setRequestProperty("User-Agent","NetFox"); @L<*9sLWh
String sProperty = "bytes="+nStartPos+"-"; 7Ri46Tkt
httpConnection.setRequestProperty("RANGE",sProperty); Xe6w|
Utility.log(sProperty); ~ {E'@MU
wvO|UP H\
R;s?$;I
InputStream input = httpConnection.getInputStream(); l~c@^!
//logResponseHead(httpConnection); sGyeb5c
bLlKe50
G_;)a]v8)
byte[] b = new byte[1024]; 2`7==?
int nRead; GPkmf%FJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2D75:@JL}|
{ xHL( !PF
nStartPos += fileAccessI.write(b,0,nRead); 7!@-*/|!S9
//if(nThreadID == 1) EYtL_hNp}I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cii_U=
} -~s!73pDY
Isvx7$Vu+
6h|q'.Y
Utility.log("Thread " + nThreadID + " is over!"); z.7cy@N6
bDownOver = true; f[<m<I
//nPos = fileAccessI.write (b,0,nRead); B:5Rr}eY+
} K-bD<X
catch(Exception e){e.printStackTrace ();} *W.C7=
} <;vbsksZeH
} f,h J~
h].<t&
"$#xK|t
//打印回应的头信息 ;YA(|h<
public void logResponseHead(HttpURLConnection con) |SoCRjuCPM
{ }YB*]<]
for(int i=1;;i++) :o|\"3
{ \w/yF4,3<w
String header=con.getHeaderFieldKey(i); `IP/d
if(header!=null) +ln9c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^V?<K.F
Utility.log(header+" : "+con.getHeaderField(header)); S|SV$_ (
else [$qyF|/K`n
break; v25R_""~
} 4" Cb/y3
} "S8uoSF`>
vMA]j>>
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public void splitterStop() 2/vMoVT,
{ -=%@L&y1
bStop = true; QqFR\6
} (\\eo
r[2ILe
}Ga\wV
} gRCdY8GH
6g|*`x{
d ^^bke$~
/* GGNvu)"
**FileAccess.java BzkooJ
*//文件访问(定位，写) 3L<wQ(
package NetFox; 7op`s5i
import java.io.*; &+cEV6vb+
iIMd!Q.)@
2;zb\d
public class FileAccessI implements Serializable{ _2hS";K
SG6kud\b
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 H<VTa? n
RandomAccessFile oSavedFile; _y),J'W^3u
long nPos; tz5e"+Tz
W=j[V Oq
Cbg!:Cws
public FileAccessI() throws IOException FKIw!m ~
{ f-bVKHt
this("",0); h}*/Ge]aM
} kO,zZF&
V}J)\VZ2#
w1hPc!I
public FileAccessI(String sName,long nPos) throws IOException kw#;w=\>R{
{ D>HOn^
oSavedFile = new RandomAccessFile(sName,"rw"); y+X2Pl
this.nPos = nPos; M.x=<:upp
oSavedFile.seek(nPos); gnFr}L&j
} C9~52+S
",^Mxm{
kqM045W7
public synchronized int write(byte[] b,int nStart,int nLen) I%r{]-Obr-
{ JG" R\2
int n = -1; ey2S#%DF]
try{ $CY~5A`l9
oSavedFile.write(b,nStart,nLen); @aAW*D~-J
n = nLen; 8VeQ-#7M/
} isQ[ Gc!8
catch(IOException e) !B\R''J5
{ Rtb7|
e.printStackTrace (); ?\vh9
} %6t2ohO"
\Pj
!zkZQ2{Wn
return n; zfc'=ODX
} SW*"\X;
: ]sUpO
$K]m{
} Z1 Bp+a3
6A>dhU
!D@ZYK;
/* |_] Q$q[[%
**SiteInfoBean.java 8kU!8^mH
*/ C"!gZ8*\!9
package NetFox; o9JMH.G
v*;-yG&
ex::m&
public class SiteInfoBean { ]b\yg2
+_; l|uhT;
8.XoVW#
private String sSiteURL; //Site's URL X.Rb-@
private String sFilePath; //Saved File's Path /JHc!D
private String sFileName; //Saved File's Name J&M o%"[)
private int nSplitter; //Count of Splited Downloading File 7[> 6i
b\3Oyp>
?98("T|y;
public SiteInfoBean() :[O 8
{//nSplitter的缺省值为5 ()5[x.xK@
//default value of nSplitter is 5 X;i~<Tq
this("","","",5); EH256f(&
} gu0j.XS^
iH/6M
d{SG Cr 9d
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Jth[DUH8H
{ %/|9@er
sSiteURL= sURL; ;5zz<;Zy
sFilePath = sPath; x c/}#>ED
sFileName = sName; E7.2T^o;M
this.nSplitter = nSpiltter; P>s[tM
t"= E^r
2nSSFx r
} >33=<~#n
|$vX<. S
{[+mpKq
public String getSSiteURL() vhpNpgz
{ Kla'lCZ
return sSiteURL; $6mX
} cki81bOT
\HKxh:F'
YL]Z<%aKt
public void setSSiteURL(String value) |G?htZF
{ Y8m1M-#w
sSiteURL = value; .#rJ+.2
} `(YxI
umiBj)r
E%rk[wI
public String getSFilePath() CDP U\ZG
{ {OXFN;2
return sFilePath; ,q}MLTSi
} H@q?v+2
U*22h` S
ujlY!-GM
public void setSFilePath(String value) g/P+ZXJ
{ -(
sFilePath = value; bYEy<7)x
} iV&6nh(
x4E7X_
ldiD2 Q
public String getSFileName() Fs9I7~L3
{ "uaMk}[ <!
return sFileName; lfqiyYFm
} t m7^yn:
f"%{%M$K
W3MU1gl6k{
public void setSFileName(String value) wE?'Cl
{ KwPOO{4]g
sFileName = value; B"!l2
} a-=8xs'
^pQCNKLBY
y#U+c*LB
public int getNSplitter() G LIi6
{ aqj@Cjk4Z
return nSplitter; gk"$,\DI
} c_vqL$Dl
cc~O&?)i
n=y[CKS
public void setNSplitter(int nCount) %-c*C$
{ hw= Ft4L
nSplitter = nCount; "|qqUKJZ
} orWbU UC
} ;[M}MFc/`
9f&C
>pp5;h8!
/* "nw;NIp!
**Utility.java b[o"7^H
*/ 6YGubH7%_
package NetFox; 6]W=nAD
BYVY)<v/
KG|n
public class Utility { LR".pH13
nV-mPyfL8
^,/RO5
public Utility() .k%[4:Fe
{ ?~hHGf\^b6
Qo;zHZ'
VJickXA
} {<R2UI5m5
8,?h~prc
//线程睡眠 {q`jDDM
public static void sleep(int nSecond) B9NWW6S
{ 19E8'@
try{ tt0f-:#
Thread.sleep(nSecond); @zU6t|mhz
} .J)I | '
catch(Exception e) 6W]9$n\"?
{ ABD)}n=%c
e.printStackTrace (); e?JW
} 1~Oe=`{&
} SL#0kc0x
hc>HQrd
//日志 <{V(.=11
public static void log(String sMsg) Mxyb5h
{ glM$R&/
System.err.println(sMsg); '>cKH$nVC}
} ]:Nsf|C0
NQ(1
@mw5~+
public static void log(int sMsg) k <=//r
{ 4dO~C
System.err.println(sMsg); eYN5;bx)W
} |wiqGzAr{
} $$Oey)*
aMWmLpv4'
"alyfyBu'M
/* x4;"!Kq\
**TestMethod.java ?[g=F <r
*/ "Zl5<
package NetFox; 5ni~Q 9b
T 6)bD&
b{L/4bu
public class TestMethod { r:f[mk"-"A
S- pV_Ff
nbm&wa[
public TestMethod() 1FlX'[vh
{ ///xx/weblogic60b2_win.exe U+:m4a
try{ _+K_5IO4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }1Gv)l7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Cd,jDPrw
SiteFileFetch fileFetch = new SiteFileFetch(bean); eJxw)zd7
fileFetch.start(); qf!p 9@4F[
} YH vLGc%
catch(Exception e){e.printStackTrace ();} w<Wf?aG
YG3J$_?y0
'gC_)rK*
} /fZeWU0W
jcuB
/{+y2.{j
public static void main(String[] args) mRL"nC
{ "D63I|O)
new TestMethod(); +jS|2d
} Sdt`i
} X-6de>=
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