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)); Jn[q<e"
} LPapD@Z
for(int i=0;i<nEndPos.length-1;i++) t}XB|h
{ !q-:rW?c
nEndPos = nStartPos[i+1]; 762o~vY6$
} yxCMl.
nEndPos[nEndPos.length-1] = nFileLength; n4vXm
} 3j+=3n,
} y4/>Ol]
t?9;cS4
i_0,BVC
//启动子线程 WAwfL?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9xK4!~5V
for(int i=0;i<nStartPos.length;i++) qX p,d
{ 1akD]Z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YMj7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )&Kn(l)
nStartPos,nEndPos,i); +e0dV_T_>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); | or 8d>,
fileSplitterFetch.start(); 7~kpRa@\P
} I|F~HUzA"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Jcalf{W6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J-, H6u
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ''(fH$pY
nEndPos = " + nFileLength); v?YdLR
// fileSplitterFetch[nPos.length-1].start(); e7XsyL'|p
|D;"D
ZSF=
//等待子线程结束 hy$MV3LP
//int count = 0; z;bH<cQ
//是否结束while循环 ~'^!udF-
boolean breakWhile = false; :7$\X[
^_*jp[!`b$
SRt$4EL21
while(!bStop) ZL-uwI!`D
{ vh|Tb5W<
write_nPos(); 5W[3_P+
Utility.sleep(500); IqhICC1V-
breakWhile = true; 7>PF~=
4f4 i1i:
O1x0[sy
for(int i=0;i<nStartPos.length;i++) Ad]<e?oN=
{ -5V)q.Og
if(!fileSplitterFetch.bDownOver) T6h;Y
{ 8zQ_xE
breakWhile = false; A*7Io4e!
break; L.09\1?.n
} W{fULl
} zG-_!FIn
if(breakWhile) 8!u/
break; tC2 )j7@
Y )u_nn'[
?%\mQmjas
//count++; 9RG\UbX)^|
//if(count>4) vp\PYg;x
// siteStop(); ! Q|J']|
} JqI6k6~Q^
v!<PDw2'
hmK8jl<6
System.err.println("文件下载结束！"); j+_S$T8w
} \6`v.B&v
catch(Exception e){e.printStackTrace ();} 2 ) TG
} -"~L2f"?
j~,h)C/v
GB&Nt{
//获得文件长度 4R&*&GZ#
public long getFileSize() )u39}dpeu
{ <@u0.-]
int nFileLength = -1; 5TXg;v#Z
try{ KY4d+~2
URL url = new URL(siteInfoBean.getSSiteURL()); _MM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `4VO&lRm
httpConnection.setRequestProperty("User-Agent","NetFox"); BN+V,W
!Oeq G
N4I^.k<-A
int responseCode=httpConnection.getResponseCode(); wzD\8_;6N
if(responseCode>=400) 2}^+]5
{ JQ*D
processErrorCode(responseCode); GN\8![J
return -2; //-2 represent access is error -'80>[}q/
} 7<h.KZPc
)-0[ra]
eQ$N:]
String sHeader; :fxWz%t
mWNR(()v
90Xt_$_}s
for(int i=1;;i++) CdX`PQ
{ @4;HC=~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _FL<egK
//Utility.log(in.readLine()); "Jb3&qdU
sHeader=httpConnection.getHeaderFieldKey(i); LWD.
if(sHeader!=null) V-[2jC{
{ ^[ET&"
if(sHeader.equals("Content-Length")) q&u$0XmV
{ qovQ9O
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (l Lu?NpIi
break; ^fkCyE;=
} M6# \na
} )yHJ[
else @(Z( /P;:
break; E::L?#V
} m])Lw@#9W
} joe9.{
catch(IOException e){e.printStackTrace ();} 2*+3RrJ
catch(Exception e){e.printStackTrace ();} LFCTr/,
2bWUa~%B
-r!42`S
Utility.log(nFileLength); +Qt[1Xq
]x1p!TSU
,,S9$@R
return nFileLength; K6E}";;
} <#>Oy&E
"cwR^DoD&
rxQ<4
//保存下载信息（文件指针位置） ICk(z~D~
private void write_nPos() zEy&4Kl{+
{ _Aa[?2 O
try{ iu+3,]7Fm
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3a'q`.L
output.writeInt(nStartPos.length); QO@6VY@
for(int i=0;i<nStartPos.length;i++) for{
{ u2 7S%2P
// output.writeLong(nPos); 5Yl6?
output.writeLong(fileSplitterFetch.nStartPos); QW2?n`Fa9-
output.writeLong(fileSplitterFetch.nEndPos); |Td_S|:d
} n<E.Em1
output.close(); pL~=Z?(B
} ^b=XV&{q
catch(IOException e){e.printStackTrace ();} sD2 ^_w6j
catch(Exception e){e.printStackTrace ();} =qw&dwIQ
} S9J5(lYv~N
=:4?>2)
.vK.XFZ8R
//读取保存的下载信息（文件指针位置） qh$X^%g
private void read_nPos() c)03Ms4 D
{ _D-5}a"
try{ eO'xkm
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )`<6taKx@n
int nCount = input.readInt(); }S,-uggz
nStartPos = new long[nCount]; #'C/Gya
nEndPos = new long[nCount]; ~^x-ym5
for(int i=0;i<nStartPos.length;i++) 2\5cjdy
{ 8hZwQ[hr
nStartPos = input.readLong(); q8/ihA6:
nEndPos = input.readLong(); <^Nk.E
} R3?:\d{
input.close(); H-Pq!9[DB
} AQe!Sqg'
catch(IOException e){e.printStackTrace ();} 2% %|fU9
catch(Exception e){e.printStackTrace ();} l]$40 j
} }%+qP+O\
U%q:^S%#eG
WV2~(/hX&
private void processErrorCode(int nErrorCode) Wk}D]o0^@
{ O] H=s
System.err.println("Error Code : " + nErrorCode); E`tQe5K
} c# xO<
E3f9<hm
AVv#\JrRW
//停止文件下载 TMww
public void siteStop() { UOhVJy
{ ywEDy|Wn$~
bStop = true; QF.3c6O@
for(int i=0;i<nStartPos.length;i++) _W|R;Cz]
fileSplitterFetch.splitterStop(); o!utZmk$
6|^0_6_
%9X{{_
} /$Z m~Mp
} \6:>{0\
//负责部分文件的抓取 6b<+8w
**FileSplitterFetch.java C3)|<E
*/ "XhOsMJ
package NetFox; *> KHRR<N
5qRc4d'
r4?b0&Xq
import java.io.*; ]26mB
import java.net.*; <m0{'xw
Oqmg;\pm
U*qNix
public class FileSplitterFetch extends Thread { sMm/4AY]
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T(V8;!
String sURL; //File URL (z2Z)_6L*L
long nStartPos; //File Snippet Start Position d=y0yq{L
long nEndPos; //File Snippet End Position %[ /<+
int nThreadID; //Thread's ID f>z`i\1oO
boolean bDownOver = false; //Downing is over 5oJ Dux }
boolean bStop = false; //Stop identical ^dfx~C
FileAccessI fileAccessI = null; //File Access interface G?/c/rG
xr.XU'
YjLe(+WQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q@kOTkHv)
{ /EU; ?O
this.sURL = sURL; .=XD)>$
this.nStartPos = nStart; l{5O5%\,
this.nEndPos = nEnd; 4\6:\
nThreadID = id; LwOJ|jA(,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 > :Ze4}(
} ej52AK7
jo_ sAb
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public void run() Qn.[{rw
{ Me/\z^pF
while(nStartPos < nEndPos && !bStop) ] H&c'
{ !)c=1EX]"
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+j[`,5oS
try{ :Q-oV8t{
URL url = new URL(sURL); d0 -~|`5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @]=f?+y[ 2
httpConnection.setRequestProperty("User-Agent","NetFox"); HE;V zR
String sProperty = "bytes="+nStartPos+"-"; ZXt?[Ll
httpConnection.setRequestProperty("RANGE",sProperty); :}9j^}"c3
Utility.log(sProperty); o@/xPo|
w<t,j~ Pr#
qVBL>9O*.
InputStream input = httpConnection.getInputStream(); j[XYj6*d
//logResponseHead(httpConnection); %8w9E=
P+Z\3re
"- eZZEl(
byte[] b = new byte[1024]; *vnXlV4L
int nRead; xmr|'}Pt[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [M:S`{SbY
{ :c7CiP
nStartPos += fileAccessI.write(b,0,nRead); ?2ItB`<(
//if(nThreadID == 1) ArzDI{1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @B`Md3$7
} QU/3X 1W
O?ktWHUx
=& -[TPW
Utility.log("Thread " + nThreadID + " is over!"); Y)M8zi>b
bDownOver = true; T'1gy}
//nPos = fileAccessI.write (b,0,nRead); kH?#B%N5
} 6Cc7ejt|u
catch(Exception e){e.printStackTrace ();} DMZ`Sx
} MEq"}zrh
} <m-.aK{9
Y"!uU.=xJ
L.B~ax.|Z
//打印回应的头信息 ll<mE,
public void logResponseHead(HttpURLConnection con) |0 !I5|<k
{ <o0~H
for(int i=1;;i++) )acV-+{
{ \c7>:DH
String header=con.getHeaderFieldKey(i); tln1eN((q
if(header!=null) ."mlSW"Wm
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ai;\@$ cq
Utility.log(header+" : "+con.getHeaderField(header)); 6>DLp}d
else Qhy#r
break; jN/ j\x'
} =;{^"#r\
} r{[OJc!
n &}s-`D
qn"K9k
public void splitterStop() M{Gxjmdx
{ sLns3&n2
bStop = true; o8z)nOTO;
} q`Q}yE>9
EJm4xkYLj1
E4HU 'y~
} &q>zR6jne
Q$a
^8K/xo-
/* H+l,)Se
**FileAccess.java t;47(U
*//文件访问(定位，写) Eg8i _s~:
package NetFox; z%:&#1)
import java.io.*; uLVBM]Qj
4tJa-7
5=Lq=,K$
public class FileAccessI implements Serializable{ [ee30ELn
mX\ ;oV!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B9M>e'H%<
RandomAccessFile oSavedFile; nPA@h
long nPos; ]b}B2F'n
&erm`Ho
DDw''
public FileAccessI() throws IOException (-"`,8K 2}
{ pbn\9C/
this("",0); y=H@6$2EQ
} >n$!<
&mkpJF/
;/sHWI f+Z
public FileAccessI(String sName,long nPos) throws IOException DWf$X1M
{ O4Dr ]Xc]
oSavedFile = new RandomAccessFile(sName,"rw"); ^oeJKjJ
this.nPos = nPos; 4~|<`vqN
oSavedFile.seek(nPos); x-_vl 9P)
} cm@;*
"2hh-L7ql
u\g,.C0
public synchronized int write(byte[] b,int nStart,int nLen) m,tXE%l
{ 7NF/]y4w
int n = -1; J?Iq9f
try{ L`3n2DEBf
oSavedFile.write(b,nStart,nLen); 5 9-!6;T
n = nLen; O#_x)13
} ([LIjaoi
catch(IOException e) b{&FuvQg2
{ '3;v] L?G
e.printStackTrace (); 2 ZG@!Y|
} <Ar$v'W=F{
+)/Uu3"=
{#hVD4$b
return n; E%3TP_B3
} 7z'ha?
Ade}g'
5w<A;f
} Yc#IFmC}
UI?=]"
J@#?@0]F
/* c`kQvXx
**SiteInfoBean.java LWmB, Zf/
*/ 4v.d-^
package NetFox; 3 ^}A %-bS
fx?$9(r,
(bm;*2
public class SiteInfoBean { !j^&gRH
bFGDgwe z
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private String sSiteURL; //Site's URL >*qQ+_
private String sFilePath; //Saved File's Path m*n5zi|O
private String sFileName; //Saved File's Name @Icq1zb] y
private int nSplitter; //Count of Splited Downloading File {fz$Z!8-
`W5-.Tv
h;M3yTM-
public SiteInfoBean() oU+F3b}5p
{//nSplitter的缺省值为5 eegx'VSX4
//default value of nSplitter is 5 OO-k|\{|
this("","","",5); vsMmCd)7U
} (^: p
2@LbfoA
y4jU{,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8ws$k\>
{ 92[a;a
sSiteURL= sURL; xJhU<q~?
sFilePath = sPath; `;%ZN
sFileName = sName; 8<dOMp;}r
this.nSplitter = nSpiltter; f_\_9o"l
GP,<`l&
I1=(. *B}
} ;=~Xr"(/z
~`cwG` 'N
S!Jh2tsg`-
public String getSSiteURL() #R5U
{ ,=PKd&
return sSiteURL; -5Utlos
} 0Y?H0
T>d.#
1FERmf? ?d
public void setSSiteURL(String value) (! KG)!
{ ;ojiJ?jU
sSiteURL = value; ]<trA$ 0
} ls|LCQPx
iHBB,x
74J@F2g}?
public String getSFilePath() "/+zMLY
{ 2qU&l|>
return sFilePath; s~L</Xvo
} 7P**:b
<$i4?)f(
<bUe/m
public void setSFilePath(String value) j^SZnMQf
{ r<R4 1Fz
sFilePath = value; w{,4rk;Hr
} }31ZX
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MC!ZX)mF
public String getSFileName() UY>v"M
{ @,OT/egF4:
return sFileName; C"eXs#A
} QMp rv*i
]r/^9XaqtA
d7Ro}>lp
public void setSFileName(String value) wij,N(,H
{ GjT#%GBF
sFileName = value; FN87^.^2S
} *@S@x{{s
^vni&sJ
wEEn?
public int getNSplitter() 0^l%j8/
{ L^0v\
return nSplitter; +t!S'|C
} ?S[Y:<R{:
QU5Sy oL[
>fs2kha
public void setNSplitter(int nCount) iEHh{H(
{ ERz;H!pU8
nSplitter = nCount; (-^bj
} gS9>N/b|
} gK1g]Tc@G
!iu5OX7K|
|+f-h,
/* 4<S'
**Utility.java _elX<o4
*/ x\\7G^$<h
package NetFox; >lzA]aM$c
+RDJY(Y$
:0~QRc-u
public class Utility { \;9W.d1iU
u=NG6G
-,#+`>w
public Utility() + ,4" u
{ e@]-D FG
ff2d@P,!
%,V YiW0
} E`;;&V q-
5J.0&Dda
//线程睡眠 ~^US/"
public static void sleep(int nSecond) &"E lm
{ DSyXr~p8
try{ X_TiqV
Thread.sleep(nSecond); >FF5x#^&c
} i'HQQWd
catch(Exception e) QWO]`q`|
{ w4};q%OBj
e.printStackTrace (); 1,t)3;o$
} _M5%V>HO
} YZwaD b
J7$_VP
//日志 n! h7
public static void log(String sMsg) S-Fo
{ 4YROB912
System.err.println(sMsg); <PD?f/4 /
} {E_{JB~`
2KJ1V+g@a6
`N87h"
public static void log(int sMsg) 5 t{ja
{ 5f7zk
System.err.println(sMsg); a:Q[gF8>
} Z|m`7xeCy
} \=2m7v#E
Wch~Yb
CXaWgxlK:a
/* 9U_ks[Qa
**TestMethod.java iLX_T]1
*/ eEw.'B
package NetFox; Mt>oI SN&d
dJuD|9R
JAb6zpP
public class TestMethod { J./d!an
~}9PuYaD@
#2p#VQh
public TestMethod() lFG9=Wf
{ ///xx/weblogic60b2_win.exe Y%`SHe7M
try{ tjnPyaJEl
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4`v!Z#e/aX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); LDj<?'
SiteFileFetch fileFetch = new SiteFileFetch(bean); oOU1{[
fileFetch.start(); hlbvt-C?}"
} WrGK\Vw[
catch(Exception e){e.printStackTrace ();} jA(vTR.`
Ty4S~ClO#'
WCq /c6 D
} b~Y%gC)FR
4vZ4/#(x
N3A<:%s
public static void main(String[] args) LEWhb!U
{ `#s#it'y
new TestMethod(); /Ft:ffR|R
} OYL]j{
} E#%}ZY
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