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)); eN@V?G26K
} @cNX\$J
for(int i=0;i<nEndPos.length-1;i++) 8Letpygm
{ 89:Ys=
nEndPos = nStartPos[i+1]; XM$r,}B k
} +2=N#LM
nEndPos[nEndPos.length-1] = nFileLength; U]lXw+&
} <4,>`#NEo
} _8b)Xx@5
WC,&p
0t<]Uf
//启动子线程 7vRJQe)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bNR}Mk]?
for(int i=0;i<nStartPos.length;i++) 4A:@+n%3m
{ s{#ZRmc2B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *Z=K9y,IC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =CEQYk-y1
nStartPos,nEndPos,i); s.]7c CY
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }wrZP}zM>
fileSplitterFetch.start(); bS_!KU
} LUv>0G#L[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G<,@|6"w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,p/iN9+Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /w{DyHT
nEndPos = " + nFileLength); pb_+_(/c
// fileSplitterFetch[nPos.length-1].start(); {~ ZSqd
P]-d(N}/H
Me[T=Tt`@w
//等待子线程结束 -J4?Km
//int count = 0; a9qB8/Gg[
//是否结束while循环 O.e^?ysp/
boolean breakWhile = false; 8'?V5.6?|~
iy Zs:4jkc
Asicf{HaX
while(!bStop) _H(m4~M
{ A@#9X'C$^
write_nPos(); d paZ6g
Utility.sleep(500); K~OfC
breakWhile = true; )Ac+5bs
Z3Os9X9p
8SK}#44Xz
for(int i=0;i<nStartPos.length;i++) O/$pT%D1x
{ hN$6Kx>{
if(!fileSplitterFetch.bDownOver) w}^z1n
{ .Y[sQO~%
breakWhile = false; #>dfP"}&,
break; 9'C kV[
} 72@raA#y
} 6W."hPP
if(breakWhile) q[1:h
break; QN:gSS{30
aPaGnP:^
2628 c`
//count++; fQc2K|V
//if(count>4) VYI%U'9Q
// siteStop(); @$z/=gsy
} ]0.? 1se
{;]:}nA
pzmm cjEC
System.err.println("文件下载结束！"); &Al9%W
} _@jBz"aq\
catch(Exception e){e.printStackTrace ();} Dp!3uR']p
} 6b4Kcl<i
t=J\zyX!
My0h9'K
//获得文件长度 !fr /WxJ
public long getFileSize() 1BUdl=o>S
{ z|[#6X6tT
int nFileLength = -1; ,$@nbS{Q]
try{ !xyO
URL url = new URL(siteInfoBean.getSSiteURL()); j7=I!<w V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5*~Mv<#
httpConnection.setRequestProperty("User-Agent","NetFox"); G^]T
=cE:,z;g
t QkEJ pj
int responseCode=httpConnection.getResponseCode(); WJCEiH
if(responseCode>=400) ^:W.R7|
{ ]YYjXg}%
processErrorCode(responseCode); Xm&L@2V
return -2; //-2 represent access is error _S5\5[^
} [,)yc/{*
) \Mwv&k1
IE!fNuR4
String sHeader; 3 G/#OJ
cMOvM0f
2GQq(_
for(int i=1;;i++) #<|5<U
{ FLdO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ",&#9
//Utility.log(in.readLine()); h"/FqO
sHeader=httpConnection.getHeaderFieldKey(i); P]gksts9f.
if(sHeader!=null) ~Fv&z'R
{ sL|lfc'bB
if(sHeader.equals("Content-Length")) "f\2/4EIl
{ =\.Oc+p4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Cr|v3Y#h'
break; t]LCe\#
} ;mH1J'.(a
} 50% |9D0?Y
else T">-%-t
break; uP/PVoKQ
} ?F'gh4
} CZyOAoc<
catch(IOException e){e.printStackTrace ();} ;V]EF
catch(Exception e){e.printStackTrace ();} D7cOEL<
o8\@R
J&UFP{)
Utility.log(nFileLength); =t1.j=oC
LcCb[r
.kh%66:
return nFileLength; L'=2Uk#.D
} T5_z^7d
%\PnsnJ9Q
(x,w/1
//保存下载信息（文件指针位置） $+P9@Q$
private void write_nPos() %J4]T35^2
{ yo*c& >
try{ P lJl#-BO
output = new DataOutputStream(new FileOutputStream(tmpFile)); |VMc,_D
output.writeInt(nStartPos.length); ^ a%U *>P
for(int i=0;i<nStartPos.length;i++) opTDW)
{ FSv')`}
// output.writeLong(nPos); :Z(?Ct&8
output.writeLong(fileSplitterFetch.nStartPos); 9],;i7c
output.writeLong(fileSplitterFetch.nEndPos); =$601r
} h+F@apUS
output.close(); ;;'b;,/
} :/fG %e
catch(IOException e){e.printStackTrace ();} -e7|DXj
catch(Exception e){e.printStackTrace ();} Vt{C80n&N
} Xm`s=5%
+4^XFPq~
`EVTlq@<
//读取保存的下载信息（文件指针位置） eIc~J!?<&V
private void read_nPos() F4X/ )$Dk
{ _.0c~\VA
try{ 6W$ #`N>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bep}|8,#u
int nCount = input.readInt(); v<bq1QG
nStartPos = new long[nCount]; *0M#{HQ
nEndPos = new long[nCount]; jQ.]m
for(int i=0;i<nStartPos.length;i++) ie+&@u
{ EB jiSQw
nStartPos = input.readLong(); Z'dY,<@
nEndPos = input.readLong(); vco/h
} Y'"2s~_ Z
input.close(); K[)N/Q
} K0 .f4o
catch(IOException e){e.printStackTrace ();} cAC2Xq
catch(Exception e){e.printStackTrace ();} o+{}O_r
} Zy@35;r
L^rtypkJ
, M$*c
private void processErrorCode(int nErrorCode) ^qqP):0y1V
{ ;>[).fX>/
System.err.println("Error Code : " + nErrorCode); j~c7nWfX
} jzV*V<
{"8\~r&b
m3XL;1y:a
//停止文件下载 I$0`U;Xd
public void siteStop() {OP-9P=p
{ t+Mr1e
bStop = true; yAtM|:qq
for(int i=0;i<nStartPos.length;i++) C3-l(N1O{
fileSplitterFetch.splitterStop(); At%g^
I=&5mg=m
A@*P4E`xp
} 8h9t8?
} xtf]U:c
//负责部分文件的抓取 evsH>hE^
**FileSplitterFetch.java d+~c$(M)
*/ uoFH{.)
package NetFox; 'GQ1;9A57
>`= '~y8
<'op
import java.io.*; AC,$(E
import java.net.*; Vi`+2%4
vrn IEur
7>xxur&
public class FileSplitterFetch extends Thread { '[JrP<~^o
=%Gecj
C.@R#a'
String sURL; //File URL ]g3&gw
long nStartPos; //File Snippet Start Position I%%\;Dy
long nEndPos; //File Snippet End Position W-=~Afy
int nThreadID; //Thread's ID liFNJd`|o+
boolean bDownOver = false; //Downing is over l3n* b6
boolean bStop = false; //Stop identical qfE/,L(B
FileAccessI fileAccessI = null; //File Access interface f[ GH
AM##:4
^mFuZ~g;?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException hU5[k/ q
{ Z<En3^j`
this.sURL = sURL; 1Y@6oT
this.nStartPos = nStart; ih2H~c>O
this.nEndPos = nEnd; U/,`xA;v>
nThreadID = id; +OK.[ji?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h0Acpd2
} >!A&@1[M
/7|u2!#Ui
td q;D
public void run() ?nrd$,
{ X55Eemg/
while(nStartPos < nEndPos && !bStop) aMuc]Wy#
{ N<Rb<p%
x '3<F
Kr=DoQ."d8
try{ 9g>]m6
URL url = new URL(sURL); 3nd02:GF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;M8N%
httpConnection.setRequestProperty("User-Agent","NetFox"); QV+('
String sProperty = "bytes="+nStartPos+"-"; HoymGU`w
httpConnection.setRequestProperty("RANGE",sProperty); Nol',^)
Utility.log(sProperty); FOB9CsMe
1 dz&J\|E#
C5i]n? )S
InputStream input = httpConnection.getInputStream(); "vH@b_>9|
//logResponseHead(httpConnection); go6Hb>
Gw!jYnU
k<"ZNQm$.
byte[] b = new byte[1024]; EU ThH.
int nRead; cG?RisSZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) en!cu_]t
{ ,V)yOLApVj
nStartPos += fileAccessI.write(b,0,nRead); RK/SeS
//if(nThreadID == 1) ^qiTO`lg
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -}2q-
} x_v pds
gO<>L0,j
`*9W{|~Gwx
Utility.log("Thread " + nThreadID + " is over!"); BI;in;Ln
bDownOver = true; j!&g:{ e
//nPos = fileAccessI.write (b,0,nRead); q{@>2AlK
} hc>hNC:a
catch(Exception e){e.printStackTrace ();} V5K`TC^
} ?.|qRzWL
} W=mh*G3y
fcr\XCG7U
fbNVmjb$)
//打印回应的头信息 ,":ADO-
public void logResponseHead(HttpURLConnection con) !s\-i6S>
{ vwZ2kk!|i
for(int i=1;;i++) \M="R-&b
{ jFw?Ky2
String header=con.getHeaderFieldKey(i); 0u QqPF t
if(header!=null) p:k>!8.Qho
//responseHeaders.put(header,httpConnection.getHeaderField(header)); h:"<x$F
Utility.log(header+" : "+con.getHeaderField(header)); .2!'6;K
else ff?:_q+.N
break; s4;SA
} ?5'UrqYSW
} cQu1WgQ G
Th`IpxV
U|uvSJ)X
public void splitterStop() h?bm1e5kE
{ F_zs"ex/
bStop = true; GasIOPzK
} @4T+0&OI10
0#G&8*FMN
8D)*~C'85E
} KxGK`'E'r
_&.CI6
j?g{*M
/* '2/48j X5
**FileAccess.java @wYuc{%S
*//文件访问(定位，写) Z99%uI3
package NetFox; p/cVQ
import java.io.*; {#zJx(2yG
OY51~#BF
N#6&t8;kTC
public class FileAccessI implements Serializable{ 3vHEPm]
+<Uc42i7n
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .AWRe1?
RandomAccessFile oSavedFile; hR[Qdu6r
long nPos; 9-Qub+0o
wP+wA}SN
/"~CWNa
public FileAccessI() throws IOException z4&|~-m,
{ o\g",O4-
this("",0); }PK8[N
} 3E+u)f lmB
"So+
z./u;/:
public FileAccessI(String sName,long nPos) throws IOException G3OqRH
{ `V$i*{c:#
oSavedFile = new RandomAccessFile(sName,"rw"); D5]T.8kX(7
this.nPos = nPos; +K; X$kB
oSavedFile.seek(nPos); ]gQgNn?
} rts@1JY[
AHIk7[w
@L=xY[&{
public synchronized int write(byte[] b,int nStart,int nLen) QApil
{ e#0R9+"Ba
int n = -1; 4@4$kro
try{ Qg%B<3 <
oSavedFile.write(b,nStart,nLen); 3EI$tP@4
n = nLen; Z'/:
} MJt?^G (w?
catch(IOException e) b=wc-nA
{ mKvk6OC
e.printStackTrace (); #:v|/2
} &+xNR2";
{Ymn_
KaauX m
return n; 8)\ ?6C
} 1Vp['&
4@.qM6 \\q
H CZ#7Z
} xeIt7b?#
O< v0{z09*
{<v?Z_!68
/* GASDkVoij
**SiteInfoBean.java gH,^XZe
*/ f2`[skNj
package NetFox; O8wR#(/
G yvEc3|@
}Cvf[H1+
public class SiteInfoBean { %|I~8>m
YiTiJ9jf
^|5vmI'E
private String sSiteURL; //Site's URL LS}u6\(
private String sFilePath; //Saved File's Path k^w!|%a[
private String sFileName; //Saved File's Name 9G[!"eZ}
private int nSplitter; //Count of Splited Downloading File {dH87 nt
P6!c-\
9f\Lon4lX
public SiteInfoBean() *Ew`Fm H
{//nSplitter的缺省值为5 t3}>5cAxy
//default value of nSplitter is 5 CCNrjaA
this("","","",5); Q_$aiE
} g=0`^APql
~Y7>P$G)
6U Q~Fv`]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )[C]1N=tK
{ 1Mn=m w
sSiteURL= sURL; zVKbM3(^
sFilePath = sPath; l~b# Y&
sFileName = sName; p[2`H$A
this.nSplitter = nSpiltter; S1p4.qJ
93Kd7x-3
tg_xk+x
} T`mG+"O
E#[_"^n
oCg|* c|+
public String getSSiteURL() CBN,~wzP*
{ ]$oo1ssZ1
return sSiteURL; o,>9|EMQZ
} wj!YYBH
RZoSP(6
J~Uq'1?
public void setSSiteURL(String value) <tXk\cOg
{ -N $4\yp
sSiteURL = value; OyH>N/
} eS-akx^@
MKPxF@N(
[1nfSW
public String getSFilePath() <|8N\FU{
{ Q=9Ce@[
return sFilePath; :%7y6V*
} \e+h">`WgX
"A\h+q-
0`UI^Y~Q
public void setSFilePath(String value) QiC}hj$
{ B6ee\23
sFilePath = value; 2T 3tKX
} =hFIH\x
o|(Ivt7jk
!xcLJ5^W
public String getSFileName() O/Cwm;&t
{ =\~<##sRJ
return sFileName; o-i9 :AHs
} `&ufdn\j
NH9"89]E
o|`[X'
public void setSFileName(String value) NW_i<#
{ >vQ8~*xd
sFileName = value; PtsQV!
} OD[q u
D[/h7Ha
+a3H1 tt~
public int getNSplitter() 8k +^jj
{ !aQb Kp
return nSplitter; wtM1gYl^
} Xna58KF/
_cvA1Q"
":@\kw
public void setNSplitter(int nCount) 59Lc-JJ
{ Ui?iMtDr
nSplitter = nCount; HOt,G _{
} 4j|IG/m
} sg`
%\"<lyD
Ls<^z@I
/* {ooztC
**Utility.java (vP<}
*/ ?_ 476A
package NetFox; ^?J3nf{
f8e :J#jbS
CiWz>HWH
public class Utility { Oh# z zo
wxJu=#!M
S5o,\wT
public Utility() uM)#T*(
{ I'`90{I
9Js+*,t
HK NT. a
} U7#C.Z
_mWVZ1P
//线程睡眠 Ie4\d2tQ;
public static void sleep(int nSecond) <*Nd%Ca
{ Gsn$r(m{K
try{ NC%96gfD
Thread.sleep(nSecond); j)ME%17
} GJ5R <f9I
catch(Exception e) ui RO,B}z
{ s<>d&W 0=
e.printStackTrace (); kx?f,^-
} BItH0r7
} z~"Q_gme
_?>x{![
//日志 :6MV@{;PJ
public static void log(String sMsg) iC{(vL0P+
{ WD55(
System.err.println(sMsg); YdDP;, DA
} mW2D"-s
n:|a;/{I]9
577#A,O
public static void log(int sMsg) .Hnhd/ c
{ qv^P
System.err.println(sMsg); gky+.EP.
} )SZzA'
} /!?b&N/d)
EXMW,
kXV;J$1
/* /WGD7\G'8
**TestMethod.java :.9Y
*/ :wq][0)
package NetFox; AJ+\Qs(0
yg.o?eML
:i4AkBNK
public class TestMethod { fMIRr5
5dGfO:Dy_
NH;e|8
public TestMethod() Qs '_\|/-
{ ///xx/weblogic60b2_win.exe B(WmJ6e
try{ }uNj#Uf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); denxcDFu/~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iX o(
SiteFileFetch fileFetch = new SiteFileFetch(bean); _dELVs7OL
fileFetch.start(); Zs(BViTb|
} ^k*%`iQ
catch(Exception e){e.printStackTrace ();} ~s-bA#0S
^&D5J\][
wz1nV}
} ?wu@+
-:95ypi
I{Ip
public static void main(String[] args) \=D+7'3
{ -RJ~Sky[
new TestMethod(); t{g@z3
} L(bDk'zi
} {+zG.1o^
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