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)); dm40qj
} A$n.'*gK
for(int i=0;i<nEndPos.length-1;i++) !q$>6P
{ fe"w--v
nEndPos = nStartPos[i+1]; >Z<ZT
} 7GG`9!l]D
nEndPos[nEndPos.length-1] = nFileLength; UH;bg}=8
} a`]ZyG*P
} -[pfLo
^eefR5^_w
G#@#j]8
//启动子线程 kmo#jITa`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ' V*}d
for(int i=0;i<nStartPos.length;i++) w7Mh8'P54
{ u,}>I%21
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DMs8B&Y=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9C{Xpu
nStartPos,nEndPos,i); l@u "iGw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6W3."};
fileSplitterFetch.start(); +lZ-xU1
} Eza^Tbq%j?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AE`UnlUSF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); n "^rS}Y]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1vCp<D9<
nEndPos = " + nFileLength); 0(9gTxdB
// fileSplitterFetch[nPos.length-1].start(); Xc^(e?L4
m^0 I3;
C8YStT
//等待子线程结束 + 65<|0
//int count = 0; TiZ MY:^
//是否结束while循环 k`]76C7
boolean breakWhile = false; Zy{hYHQ
_ouZd.
| z_av
while(!bStop) Ol<LL#<j4
{ 9&<c)sS&B
write_nPos(); B<h4ZK%
Utility.sleep(500); (!0_s48f
breakWhile = true; B}*\ pdJ
_ Qek|>
,I+O;B:0
for(int i=0;i<nStartPos.length;i++) kK 5~hpv
{ \IzZJGi
if(!fileSplitterFetch.bDownOver) 9$VdYw7D
{ 7lJ8<EP9 u
breakWhile = false; V~5vR`}
break; CDW|cr{
} 7~ZG"^k
} SrOv* D3
if(breakWhile) kkj@!1q(wO
break; >yqEXx5{
#)#'^MZX
2t
//count++; ;A*sub
//if(count>4) RU=g|TL
// siteStop(); ^YfAsBs&
} 3/& |Z<f
Z/v )^VR
B>z^W+Unyn
System.err.println("文件下载结束！"); C:bA:O
} <S;YNHLC
catch(Exception e){e.printStackTrace ();} XRyeEwA;pp
} kI5LG6
3W.D^^)eCV
Z3ODZfu>
//获得文件长度 W=|'&UU Ul
public long getFileSize() ]^{5`
{ 0tMzVxS
int nFileLength = -1; V/R@=[
try{ L;b-=mF
URL url = new URL(siteInfoBean.getSSiteURL()); (5[#?_~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I/v#!`L
httpConnection.setRequestProperty("User-Agent","NetFox"); -(}N-yu
W&Xi&[Ux
5"q{b1
int responseCode=httpConnection.getResponseCode(); KpS=oFX{}
if(responseCode>=400) YxA nh
{ R_Bf JD.
processErrorCode(responseCode); M$f_I +
return -2; //-2 represent access is error rfZg
} ^BI&-bR@
9+5F(pd(
c]z^(:_>
String sHeader; 0&r}'f?
OT)`)PZ"
=U:]x'g(
for(int i=1;;i++) CaoQPb*
{ 40-/t*2Ly
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]Rp<64I o
//Utility.log(in.readLine()); v{\~>1J{
sHeader=httpConnection.getHeaderFieldKey(i); |ZCv>8?n
if(sHeader!=null) P5"B7>L:
{ #}Ays#wA>?
if(sHeader.equals("Content-Length")) : B1 "=ly
{ I4c%>R
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6Hd^qouid
break; D6e<1W
} *1>Tc,mb
} _F8-4
else U[#q"'P|l
break; $.B}zY{
} ~ r$I&8
} Ox'KC
catch(IOException e){e.printStackTrace ();} % %2~%FVb
catch(Exception e){e.printStackTrace ();} !yV)EJ:$
15DlD`QV
U2JxzHXZ
Utility.log(nFileLength); y>RqA*J
X<1ymb3
[FWB
return nFileLength; L;KLmxy#
} g|!=@9[dv
icK U)
-r0oO~KT
//保存下载信息（文件指针位置） 1;>RK
private void write_nPos() BTE&7/i21
{ SC2g5i`
try{ a<V Mh79*
output = new DataOutputStream(new FileOutputStream(tmpFile)); 52.hJNq#L
output.writeInt(nStartPos.length); VrFI5_M/
for(int i=0;i<nStartPos.length;i++) )9!ZkZbv_m
{ a$6pA@7}
// output.writeLong(nPos); Io_7
output.writeLong(fileSplitterFetch.nStartPos); Z \-
output.writeLong(fileSplitterFetch.nEndPos); _g"su#
} Q?9eu%G6I
output.close(); OQT i$2
} fAvB!e
catch(IOException e){e.printStackTrace ();} HlX7A1i/
catch(Exception e){e.printStackTrace ();} ACgWT
} &0-Pl.M
_'s5FlZq
\z2d=E
//读取保存的下载信息（文件指针位置） u)ZZ/|
private void read_nPos() ['0^gN$:e
{ vF@.BM>
try{ 9x9E+DG#(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +Pn`AV1
int nCount = input.readInt(); Gs}lw'pK
nStartPos = new long[nCount]; jg3['hTJT
nEndPos = new long[nCount]; %,)Xi
for(int i=0;i<nStartPos.length;i++) q0\$wI
{ Q@UY4gA'
nStartPos = input.readLong(); q{)Q ?E
nEndPos = input.readLong(); %E2C4UbY
} 2Xfy?U
input.close(); <^8OYnp
} 'wTJX>
catch(IOException e){e.printStackTrace ();} WF<*rl
catch(Exception e){e.printStackTrace ();} +Nka,C^O"
} sM%.=~AN
cACnBgLl
zU};|Zw
private void processErrorCode(int nErrorCode) V0:db
{ u\UI6/
System.err.println("Error Code : " + nErrorCode); jTY{MY Jh
} 6[>Zy)P
]PXpzruy
(8j@+J
//停止文件下载 8L(KdDY
public void siteStop() \G1(r=fU
{ /M_kJe,%
bStop = true; oga0h'
for(int i=0;i<nStartPos.length;i++) 5wMEp" YHE
fileSplitterFetch.splitterStop(); faI4`.i
Qp>Q-+e0
PFeK;`[
} O,KlZf_B
} dtq]_HvTJ
//负责部分文件的抓取 yAVt[+0
**FileSplitterFetch.java ~9+\
*/ k+cHx799
package NetFox; aeF^&F0
7kidPAhY
W-ECmw(
import java.io.*; Bk~M^AK@~
import java.net.*; .'N#qs_
2E3x=
G{oM2`c'#8
public class FileSplitterFetch extends Thread { ZbcpE~<a
cY*lsBo
C/pu]%n@4
String sURL; //File URL ^kpu9H
long nStartPos; //File Snippet Start Position Z7R+'OC
long nEndPos; //File Snippet End Position Aaix? |XN
int nThreadID; //Thread's ID ZsYT&P2
boolean bDownOver = false; //Downing is over x68s$H
boolean bStop = false; //Stop identical ~# |p=Y
FileAccessI fileAccessI = null; //File Access interface /d-7n|#E
ZpY"P6
rk(0w|zR+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException FKB)o7
{ >pA9'KWs]
this.sURL = sURL; ]qc2jut"
this.nStartPos = nStart; ^zaN?0%S33
this.nEndPos = nEnd; @;z}Hk0A
nThreadID = id; 'GcZxF0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 aG\B?pn-
} 6e;.}i
\<A@Nf"
|4a#O8d
public void run() zHCz[jlrMq
{ U=bZy,FT$
while(nStartPos < nEndPos && !bStop) 7e&%R4{b
{ v<Ux+-
[t`QV2um
_/!IjB:(70
try{ 3^zOG2
URL url = new URL(sURL); %@FTg$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VIxcyp0X
httpConnection.setRequestProperty("User-Agent","NetFox"); #65Uei|F`+
String sProperty = "bytes="+nStartPos+"-"; oMi"X"C:q
httpConnection.setRequestProperty("RANGE",sProperty); ,!4(B1@
Utility.log(sProperty); ?wx|n_3<:
1cdM^k
C,D~2G
InputStream input = httpConnection.getInputStream(); Z5o6RTi
//logResponseHead(httpConnection); #yVY!+A
izi=`;=D^
zKk2>.
byte[] b = new byte[1024]; ABp/uJI)
int nRead; 5<ycF_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u|D_"q~+6
{ A3N<;OOk
nStartPos += fileAccessI.write(b,0,nRead); AHhck?M^
//if(nThreadID == 1) 9_GR\\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cv["Ps#;`W
} aNCIh@m~
Ol24A^
lH^[b[
Utility.log("Thread " + nThreadID + " is over!"); R@r"a&{/
bDownOver = true; r#pC0Yj!3
//nPos = fileAccessI.write (b,0,nRead); _`zj^*%
} 6F3#Rxh
catch(Exception e){e.printStackTrace ();} #\$R^u]!
} 5!G}*u.
} I%whM~M1+
3say&|kJ
LdAfY0
//打印回应的头信息 "tbKKh66
public void logResponseHead(HttpURLConnection con) /%U+kW
{ a ^b_&}y
for(int i=1;;i++) Bn/{J
{ GV([gs
String header=con.getHeaderFieldKey(i); igsJa1F
if(header!=null) X&6p_Lo
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i1?H*:]
Utility.log(header+" : "+con.getHeaderField(header)); iVt6rX
else x,z+l-y
break; NQ!jkojD
} q8.K-"f(Q
} MDS;qZx=
0>m-J
,r{\aW@
public void splitterStop() /AP@Bhm
{ F"3PP ~
bStop = true; oToUpkAI
} @%K@oDL
(&FSoe/!['
Cv|ya$}a
} r"a0!]n
gYx|Na,+
YzSUJ=0/
/* 8|w_PP1oE
**FileAccess.java Z*QsDS
*//文件访问(定位，写) nJ4i[j8
package NetFox; Qsc%qt-l
import java.io.*; /4]M*ls
QOkPliX
n=n!Hn
public class FileAccessI implements Serializable{ fNc3&=]]
LzS@@']
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RUmJ=i'4/
RandomAccessFile oSavedFile; ZUb6d*B
long nPos; \&J7>vu^y
-1~bWRYq
Mjrl KI}f/
public FileAccessI() throws IOException Cw`v\ 9
{ E3y"
this("",0); g&H6~ +\
} ewSFB< N
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G_g~-[O
public FileAccessI(String sName,long nPos) throws IOException J A ]s
{ #n7uw
oSavedFile = new RandomAccessFile(sName,"rw"); ao<@a{G
this.nPos = nPos; BM#cosV7%h
oSavedFile.seek(nPos); "8aw=3A
} iNgHx[*?
XS]=sfN
M& GA:`
public synchronized int write(byte[] b,int nStart,int nLen) =usx' #rb
{ r"SuE:D
int n = -1; yK<%AV@v
try{ utC]GiR
oSavedFile.write(b,nStart,nLen); JB a:))lw
n = nLen; h&||Ql1
} impzqQlZ,
catch(IOException e) -82Rz
{ 16[>af0<g
e.printStackTrace (); 0}k[s+^
} ig]*Z
P'GX-H
TGGeTtk=
return n; j8!fzJG
} [L8Bgw1
_K>cB<+d
L{;q^
} qCn(~:
I3D8xl>P\
q4PRc<\^
/* hVI $r
**SiteInfoBean.java Z16G
*/ WaQCq0Enj
package NetFox; /NaIMo5
c$Js<[1
?&ThMWl
public class SiteInfoBean { jm'(t=Ze
SJ;u,XyWn
a1]k(AuQrC
private String sSiteURL; //Site's URL d {a^
private String sFilePath; //Saved File's Path oorit
private String sFileName; //Saved File's Name -kxNJ Gc?
private int nSplitter; //Count of Splited Downloading File qdrk.~_
W`K XO|'p@
xxgS!J
public SiteInfoBean() f@+[-yF
{//nSplitter的缺省值为5 as- Z)h[B
//default value of nSplitter is 5 &!vJ3:
this("","","",5); kN>%y&cK
} c%r?tKG6
}kdYR#{s
pj G6v(zK
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) z_~f/
{ &i4*tE3],
sSiteURL= sURL; Gvw4ot/
sFilePath = sPath; u[dR*o0'
sFileName = sName; Ey=(B'A~
this.nSplitter = nSpiltter; M2_sxibI
jzSh|a9_
]d}Z2I'
} <ZxxlJS)6
k:Sxs+)?1
$R%xeih1fz
public String getSSiteURL() pHEhB9_A!
{ YA O, rh
return sSiteURL; Wo2TU!
} I.A7H'j
,5HQHo@
B1oi]hDy
public void setSSiteURL(String value) :XEP:8
{ q [Rqy !,
sSiteURL = value; c_<m8b{AEF
} X"YH49?
R:P'QM
*x2+sgSf_0
public String getSFilePath() |Xk'd@<
{ _>%P};G{>
return sFilePath; 2i*-ET
} mBSa*s)
S)of.Nq.;
l9"0Wu@_x
public void setSFilePath(String value) b26#0;i
{ $Mm=5K%
sFilePath = value; `@q[&^
} u~7mH
-"[o|aa^
|} ;&xI
public String getSFileName() X:bv ?o>Y
{ ~q4KQ&.!
return sFileName; %bgjJ`
} orYE&
#'fh'$5"
t=o0 #jo
public void setSFileName(String value) lxx)l(&
{ Yb\t0:_
sFileName = value; wl1i@&9
} htX;"R&
DW&%"$2
CRf!tsj@
public int getNSplitter() B:#5U85m
{ 2K4Jkyi
return nSplitter; b<>GF-`w
} :kz*.1
_^;+_6&[
QPB@qx#@
public void setNSplitter(int nCount) 5[}3j1
{ Osncl5PD)
nSplitter = nCount; sS(t }$
} &NZl_7PL
} =(:{>tO_"
(? j $n?p
8}z]B^?Fy
/* yH5^EY7rQ
**Utility.java 5S`_q&
*/ XG FjqZr`
package NetFox; oU`8\n](
<"F\&M`G
@zo}#.g
public class Utility { wZB:7E%
2(M^8Bl
S`g:zb_
public Utility() 1.*VliY
{ &<hDl<E
,(&jG^IpVJ
uyBmGS2
} IlQNo 1
ATx6YP@7~
//线程睡眠 mOgsO
public static void sleep(int nSecond) &AM<H}>
{ };;\&#
try{ l3kYfq{";"
Thread.sleep(nSecond); +TzZ
} hbl%<ItI49
catch(Exception e) (1pI#H"f9
{ /Iht,@%E
e.printStackTrace (); \1|]?ZQ\K
} aK>5r^7S
} !kCMw%[
b-4gHW
//日志 7OuzQzhcK
public static void log(String sMsg) n[DQ5l
{ &D@/_m $
System.err.println(sMsg); n.9k<
} '](4g/%
T,N"8N{K"
rHe*/nN%*
public static void log(int sMsg) [MLJs-*
{ >d#oJ?goX
System.err.println(sMsg); YDh6XD<Z
} }xhat,9
} L(Ww6oj
O`Ht|@[6
CUJP"u>8M
/* :eIPPh|\
**TestMethod.java &XG k
*/ 5A|4
package NetFox; vwy10PlqL
UrAg*v!Qy
V.<$c1#=$
public class TestMethod { >JdA,i}1
>6 p <n
~9#x/EG/
public TestMethod() 5gP<+S#>T
{ ///xx/weblogic60b2_win.exe X( Q*(_
try{ %1f, 8BM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "V/|RC
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j5hM|\]
SiteFileFetch fileFetch = new SiteFileFetch(bean); lIR0jgP@z
fileFetch.start(); !%w#h0(b
} D2hEI2S
catch(Exception e){e.printStackTrace ();} OPm?kr
g7*"*%v 2
F\pw0^K;N
} \=n0@1Q=>
O<}^`4d
/WIO@c
public static void main(String[] args) Z)iRc$;
{ r]!<iw
new TestMethod(); b1X.#pz7F
} nq'vq]]
} ?gZJ v
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