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)); 1Nw&Z0MI
} ?UQVmE&
for(int i=0;i<nEndPos.length-1;i++) y|q4d(P.
{ d9|dHJf
nEndPos = nStartPos[i+1]; #/@U|g
} ([UuO}m-
nEndPos[nEndPos.length-1] = nFileLength; AL! ^1hCF
} c&)H
} Jl&bWp^3
j11\t
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//启动子线程 [6BLC{2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /7*jH2
for(int i=0;i<nStartPos.length;i++) zB\g'F/
{ 8-cG[/|0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sl|s#+Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _3tHzDSG#
nStartPos,nEndPos,i); m3 ;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wq_c^Ioy
fileSplitterFetch.start(); &T]+g8''
} UT [7 J
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m\7-/e2a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #h ;j2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", WM: ~P$%cx
nEndPos = " + nFileLength); 28SlFu?
// fileSplitterFetch[nPos.length-1].start(); rui}a=rs
hSaS2RLF
9:A>a3KOH
//等待子线程结束 '*!R gbj;
//int count = 0; *jGB/ y
//是否结束while循环 [6 wI22
boolean breakWhile = false; [V{JuG;s
x+|Fw d
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while(!bStop) "%urT/Fv&
{ %H>vMR-,~
write_nPos(); |`s}PcV
Utility.sleep(500); 66D<Up'K
breakWhile = true; wc)[r~On(5
*x`z5_yfO
[ar:zlV8
for(int i=0;i<nStartPos.length;i++) 4DEsB)%X
{ cGkl=-oQ'
if(!fileSplitterFetch.bDownOver) R%aH{UhE`
{ b@^M|h.Va
breakWhile = false; lZ0+:DaP2
break; T;GBZR%
} V-A^9AAPm
} qh0)~JL4
if(breakWhile) &o^wgmS
break; /`\-.S9
vPmP<c)cb
h@Ea$1'e,
//count++; 7EY~5U/4
//if(count>4) \bQ|O7s
// siteStop(); 7;;W{W%
} ro@Zbm;P
#i ?@S$
N$pwTyk
System.err.println("文件下载结束！"); H24g+<Tv
} POH>!lHu
catch(Exception e){e.printStackTrace ();} qS&PMQ"$
} rZu_"bcJ
WeuV+}\b
`m3@mJ!>\
//获得文件长度 90sMS]a
public long getFileSize() V==' 7n
{ FtM7+>Do.
int nFileLength = -1; z"}k\B-5
try{ jm RYL("
URL url = new URL(siteInfoBean.getSSiteURL()); X]cB`?vR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }Bc'(2A;,
httpConnection.setRequestProperty("User-Agent","NetFox"); ol!o8M%Q
KblOP{I
kjaz{&P
int responseCode=httpConnection.getResponseCode(); n#z^uq|v
if(responseCode>=400) |GK [I
{ ^eM=h
processErrorCode(responseCode); rctn0*MP
return -2; //-2 represent access is error qqw6p j
} T~"tex]
oCy52Bm.!
HZ8 j[kO
String sHeader; :N8D1e-a
<kLY1EILM
8S]Mf*~S'
for(int i=1;;i++) &M>S$+I n
{ e7,iO#@:m
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Redp'rXT<h
//Utility.log(in.readLine()); a:zx&DwM
sHeader=httpConnection.getHeaderFieldKey(i); FAM`+QtNw
if(sHeader!=null) pal))e!B
{ FVY,CeA.
if(sHeader.equals("Content-Length")) WU<#_by g
{ H7Y}qP5X
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C| Mh<,~E
break; +V2a|uvEc
} rA`zuYo
} LvWU %?
else >=U$s@
break; U&u7d$ANP
} )[p8
} #> CN,eiZ
catch(IOException e){e.printStackTrace ();} 6\5U%~78
catch(Exception e){e.printStackTrace ();} >7;JZuVo
w-B\AK?}
d[~c-G6
Utility.log(nFileLength); |o!<@/iH=
X[@>1tl
*uEU9fX
return nFileLength; S BFhC
} `b\4h/~
^iV@NVP
z7<^aS
//保存下载信息（文件指针位置） N->;q^
private void write_nPos() 2CmeO&(Qf*
{ <ht>>
try{ Phb<##OB
output = new DataOutputStream(new FileOutputStream(tmpFile)); T&R`s+7
output.writeInt(nStartPos.length); n|,Es!8:o
for(int i=0;i<nStartPos.length;i++) 2~ 'Q#(
{ #m$H'O[WG\
// output.writeLong(nPos); xje{kx#
output.writeLong(fileSplitterFetch.nStartPos); yLDHJ}R
output.writeLong(fileSplitterFetch.nEndPos); ,7j`5iq[m
} fx;5j;
output.close(); r#Pd@SV
} 8U;!1!+ 7)
catch(IOException e){e.printStackTrace ();} z? {#/
catch(Exception e){e.printStackTrace ();} Ev^Xs6 }"
} dHp6G^Y
L1F){8[
vo::y"
//读取保存的下载信息（文件指针位置） {#[a4@B0
private void read_nPos() "Q/3]hc.
{ ?0?'
try{ PN.6BJvu
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kBONP^xI
int nCount = input.readInt(); A%GJ|h,i
nStartPos = new long[nCount]; IcQ?^9%{
nEndPos = new long[nCount]; Z(<ul<?r
for(int i=0;i<nStartPos.length;i++) piId5Gx7
{ D>|:f-Z6Z
nStartPos = input.readLong(); AGv;8'`
nEndPos = input.readLong(); .s!:p pwl
} v,M2|x\r}
input.close(); t[Q^Xp
} +$UfP(XmH
catch(IOException e){e.printStackTrace ();} 'P~*cr ?A
catch(Exception e){e.printStackTrace ();} {'b8;x8h
} O Z#?
`3+U6>U [
^M80 F7
private void processErrorCode(int nErrorCode) t%TZu>(1O
{ ^#=L?e
System.err.println("Error Code : " + nErrorCode); H!Od.$ZIX
} }!d}febk_
xO.7cSqgw
$(NfHIX
//停止文件下载 ~Fx[YPO,
public void siteStop() <pE G8_{}
{ o?b%L
bStop = true; 5sE^MS1
for(int i=0;i<nStartPos.length;i++) {c J6Lq&
fileSplitterFetch.splitterStop(); h)<R#xw
)ld7^G
%/^d]#
} #>,cc?H-
} 1z`,*eD7
//负责部分文件的抓取 !;xE7w
**FileSplitterFetch.java }Sh-4:-D
*/ O[`Ob6Q{F
package NetFox; l~=iUZW<
:rj78_e9
7'8O*EoB'
import java.io.*; -m@s 9k
import java.net.*; 1]<!Xuk^f
9F-k:hD |
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public class FileSplitterFetch extends Thread { ;+jp,( 7
{jVFlKP>
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String sURL; //File URL OM.^>=
long nStartPos; //File Snippet Start Position M ?3N
long nEndPos; //File Snippet End Position kzmt'/L8
int nThreadID; //Thread's ID [yyV`&
boolean bDownOver = false; //Downing is over o2|(0uN'
boolean bStop = false; //Stop identical VsmL#@E
FileAccessI fileAccessI = null; //File Access interface +sI.GWQ_:
a(7ryl~c=
xC{NIOYn'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~3%3{aa
{ U\ L"\N7
this.sURL = sURL; Z\L@5.*ydE
this.nStartPos = nStart; _qg6( X
this.nEndPos = nEnd; %b?Pasf.
nThreadID = id; &-*nr/xT
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z`*cI
} $"i690
vqs~a7E-P
G<z)Ydh_
public void run() @Dy.HQ~
{ ;FmSL#]I
while(nStartPos < nEndPos && !bStop) wY95|QS
{ c`+ITNV
"tR.'F[n4P
zb" hy"hKw
try{ Qx6/QaS?
URL url = new URL(sURL); K$.zO4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); moR]{2Cd{
httpConnection.setRequestProperty("User-Agent","NetFox"); vhHMxOZ;
String sProperty = "bytes="+nStartPos+"-"; n1t(ns|
httpConnection.setRequestProperty("RANGE",sProperty); Q*8-d9C
Utility.log(sProperty); hG@ys5
`[KhG)Y7t
TH|hrL;:8
InputStream input = httpConnection.getInputStream(); e!yw"Cf*
//logResponseHead(httpConnection); [1*/lt|+p
-1:Z^&e/
$imx-H`|
byte[] b = new byte[1024]; c{Kl?0#[
int nRead; (2li:1j
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nADd,|xD3
{ /ZDc=>)~
nStartPos += fileAccessI.write(b,0,nRead); {X$Mwqhpp;
//if(nThreadID == 1) SoX V
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mig3.is
} X W)A~wPBs
=5`@:!t7
~Hs{(7
Utility.log("Thread " + nThreadID + " is over!"); dO[4}FZ$
bDownOver = true; gp)ds^
//nPos = fileAccessI.write (b,0,nRead); `VsGa
} Lm|X5RVq
catch(Exception e){e.printStackTrace ();} X2[cR;;'
} j 7URg>i0
} nrIL_
!cb#fl
uE j6A
//打印回应的头信息 J7GsNFL
public void logResponseHead(HttpURLConnection con) fYy.>m+P1
{ ^0Q*o1W
for(int i=1;;i++) ^WD$ gd
{ @>5<m'}2
String header=con.getHeaderFieldKey(i); }^[@m#
if(header!=null) zRu`[b3u<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); dLf8w>i`T
Utility.log(header+" : "+con.getHeaderField(header)); tTH%YtG
else jyhzLu
break; / yi:Q0
} a1SOC=.M;
} BUinzW z{a
mj=|oIMwT
BA-nxR
public void splitterStop() 14!J\`rI
{ =on!&M
bStop = true; GiXde}bm
} fZ}Y(TG/
%>2t=)T
?MM3LA! <
} df*#?Ok
.4>s2
t5X lR]` w
/* ]?(F'&
**FileAccess.java n-3j$x1Ne
*//文件访问(定位，写) C-u/{CP
package NetFox; Ok&>[qu
import java.io.*; HY;?z`=
%uVJLz
_|3TC1N$n
public class FileAccessI implements Serializable{ X'7S|J6s
jHH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 MuV0;K\
RandomAccessFile oSavedFile; SRN9(LN
long nPos; ]t)M}^w
*g4Cy8$
]A$^ l,
public FileAccessI() throws IOException Treh{s
{ e[mhbFf-
this("",0); ,'CWt]OS'
} 7&V^BW
|.O!zRm
h5rP]dbhXU
public FileAccessI(String sName,long nPos) throws IOException R.IUBw5;/
{ J xm9@,
oSavedFile = new RandomAccessFile(sName,"rw"); 07Q[L'}y@
this.nPos = nPos; "P5bYq%0v
oSavedFile.seek(nPos); $H-D9+8 7
} 1{x~iZa
ZT"|o\G^Q
7. 9s.*
public synchronized int write(byte[] b,int nStart,int nLen) ynZ[c8.
{ ;K\N
int n = -1; C6UMc} 9h
try{ ?w37vsN
oSavedFile.write(b,nStart,nLen); '$h@
n = nLen; D4Y!,7WEVt
} CKt|c!3 7
catch(IOException e) ESxC{ "
{ /~l/_Jct@G
e.printStackTrace (); }&T<wm!
} Of7) A
)^f9[5ee
ix7 e])m(
return n; ]9&q'7*L
} "Dl9<EZ
?ey&Un"
6!%d-Z7)
} b^,Mw8KsO
_SIs19"lR
+GYMJK`S+
/* 0uIV6LI
**SiteInfoBean.java 2r}uE\GN
*/ \W`}L
package NetFox; J'ZFIT_>
FW)^O%2s
I0w@S7
public class SiteInfoBean { '!^E92
N _~KZQ11^
Uty(sDtu
private String sSiteURL; //Site's URL q"+ q
private String sFilePath; //Saved File's Path K>R;~ o
private String sFileName; //Saved File's Name Md>f
private int nSplitter; //Count of Splited Downloading File `}9 1S
a|P~LMPM
YKe0:cWc
public SiteInfoBean() 85|95P.<
{//nSplitter的缺省值为5 +# RlX3P
//default value of nSplitter is 5 }.MoDR3\
this("","","",5); oBj>9I;
} c7g.|R
X4}`>
=EcIXDzC>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p_5>?[TW:
{ 1x\VdT
sSiteURL= sURL; \_gp50(3
sFilePath = sPath; o7Cnyy#:
sFileName = sName; lv00sa2z
this.nSplitter = nSpiltter; ~w1{zxs
fsrg2:kQ
N{^>MRK=5
} l|vWeBs
n=G>y7b
BK(pJNBh
public String getSSiteURL() sm2p$3v
{ xS~yH[k
return sSiteURL; 7"n)/;la
} 6)#- 5m
kj{rk^x
| or 8d>,
public void setSSiteURL(String value) V#zhGAMy.
{ 3{Ek-{9
sSiteURL = value; nb0 Py>4
} vn0cKz@
cXb @H#
A]Q1&qM%
public String getSFilePath() mEB2RLCM
{ |5O >>a()
return sFilePath; Et}C`vZ+Ve
} ~mXZfG/D
l:zU_J6
.#=j <&
public void setSFilePath(String value) ;.nP%jD
{ FVsu8z u
sFilePath = value; X(r)Z\
} *Z]5!$UpC
j8[`~pb
'R4>CZ%jV
public String getSFileName() 1Lm].tq
{ I~p8#<4#b
return sFileName; _.d}lK3$2
} \3H<z@;
(30<oE{
t$]&,ucW#
public void setSFileName(String value) i{tTUA
{ qJ{r!NJJ 8
sFileName = value; ;[TljcbS
} 943I:, B
L4YVH2`0)
JCw{ ?^F"
public int getNSplitter() (orrX Ez
{ |5oKq'(b
return nSplitter; {yvb$ND|j{
} Y!++CMzU
QL)>/%yU
1DEO3p
public void setNSplitter(int nCount) <a8#0ojm
{ O`wYMng)
nSplitter = nCount; qDby!^ryc
} a. h?4+^bN
} CS~=Z>6EjA
./"mn3U
*Rz{44LP&
/* ,U6*kvHS6
**Utility.java +(;8@"u
*/ jd ["eI
package NetFox; o"'iXUJ
%B#hb<7}
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public class Utility { R&6n?g6@/V
N4I^.k<-A
<A#5v\{.;~
public Utility() G_V.H\w
{ =ud`6{R
M*d-z
wXc,FD$
} ~?FK ; (
n_<mPU
//线程睡眠 o;ik Z*+*
public static void sleep(int nSecond) :fxWz%t
{ mWNR(()v
try{ S3R|8?|
Thread.sleep(nSecond); CdX`PQ
} >j&1?M2C
catch(Exception e) R<Z^L~)
{ $Llta,ULE
e.printStackTrace (); .D+RLO z
} F|ETug n
} 3H1Pp*PH
.|T2\M
//日志 ?ouV
public static void log(String sMsg) HDyQzCG,
{ fucUwf\_
System.err.println(sMsg); {UP'tXah
} aQ&uC )w
`koOp
|}Q( F+cL
public static void log(int sMsg) Af`z/:0<
{ W&<g} N+
System.err.println(sMsg); fCLcU@3W?
} Gu2_dT
} Y;8 >=0ye
V?=TVI*k
8|w-XR
/* F#6cF=};@
**TestMethod.java /E)9v$!
*/ L*P_vCC
package NetFox; [d}qG#N
,aI,2U91
d;{y`4p)s
public class TestMethod { (/'h4KS@
KZ]r8
.%_)*NUZ
public TestMethod() $)Wb#B
{ ///xx/weblogic60b2_win.exe @\ }sb]
try{ TfL4_IAG.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X&s7%]n+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :ztyxJv1
SiteFileFetch fileFetch = new SiteFileFetch(bean); CQ<8P86gt
fileFetch.start(); ai4PM b$p
} 7UnzIe
catch(Exception e){e.printStackTrace ();} /M:H9Z8!
V7P6zAJy
t')h{2&&!2
} `Z:3`7c
;J'OakeVO
c)03Ms4 D
public static void main(String[] args) z4g+2f7h-X
{ eO'xkm
new TestMethod(); )`<6taKx@n
} @YCv
} zHV|-R
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