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)); py]KTRzy
} #X#8ynt
for(int i=0;i<nEndPos.length-1;i++) /r276Q
{ -7k[Vg?
nEndPos = nStartPos[i+1]; DeH0k[o
} ;xfO16fNk
nEndPos[nEndPos.length-1] = nFileLength; 3FFaEl
} 92ZWU2"
} Ffnk1/Zy
Y!Drb-U?;
y>$1UwQ
//启动子线程 NeHx2m+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; BYS lKTh
for(int i=0;i<nStartPos.length;i++) L~IE,4
{ H#+\nT2m
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O#vn)+Y,*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), q%>7L<r
nStartPos,nEndPos,i); @|BD|{k
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GMz8B-vk
fileSplitterFetch.start(); PkTfJQP8
} J7:9_/e0T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cA<<&C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); H#35@HF*o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3 -tO;GKb
nEndPos = " + nFileLength); Dv@PAnk3C
// fileSplitterFetch[nPos.length-1].start(); s2^B(wP
sm1;MF]/u
Jn=42Q:>
//等待子线程结束 |k6Ox*
//int count = 0; A#(`9
//是否结束while循环 Y.>kO
boolean breakWhile = false; dByjcTPA
\QGa4_#
f3G1r5x
while(!bStop) C,"=}z1P
{ }S*/b1
write_nPos(); sm
Utility.sleep(500); je,c7ZFO
breakWhile = true; qz`rL#W]
ZYa\"zp-
qEQAn/&
for(int i=0;i<nStartPos.length;i++) b,Ke>.m
{ }~F~hf>s
if(!fileSplitterFetch.bDownOver) ^LVk5l)\>g
{ Umz05*
breakWhile = false; ]boE{R!I
break; L6+C]t}>6
} yAG+] r
} C',6%6P
if(breakWhile) xIL#h@dz
break; 0Gsu
!"E-\cc'
(9]6bd
//count++; zT7"VbP
//if(count>4) P$ucL~r
// siteStop(); O#EqG.L5
} <B)
:3^dF}>
p x#suy
System.err.println("文件下载结束！"); #Ao !>qCE
} 1[-vD=
catch(Exception e){e.printStackTrace ();} `*aBRwvK~
} Lc]1$
2JZdw
g*y/j]
//获得文件长度 O9^T3~x[V
public long getFileSize() "Zcu[2,
{ 1`JB)9P
int nFileLength = -1; >3PMnI
try{ )3%@9
URL url = new URL(siteInfoBean.getSSiteURL()); ^H3m\!h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'wvMH;}u
httpConnection.setRequestProperty("User-Agent","NetFox"); >b48>@~bY
SE)nD@:
,q#2:b<E
int responseCode=httpConnection.getResponseCode(); l^W uS|G[
if(responseCode>=400) (.?ZKL
{ NYB "jKMk
processErrorCode(responseCode); . I==-|
return -2; //-2 represent access is error ?:igumeYX
} /e1(? 20
Wp[9beI*M
ar$*a>'?
String sHeader; ?pG/m%[
zkexei4^<
.'T40=7
for(int i=1;;i++) g^l RG3a
{ Ur!~<4GO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); eT[&L @l]b
//Utility.log(in.readLine()); %>zjGF<
sHeader=httpConnection.getHeaderFieldKey(i); ('hT
if(sHeader!=null) 6kR\xP]Kr
{ SK R1E];4
if(sHeader.equals("Content-Length")) %e?fH.)
{ Td hTQ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }mk>!B}=
break; y=Q!-~5|fF
} E\M-k\cSj
} BBnq_w"a
else @iLIU}+
break; +,5-qm)Gh>
} % frfSGf.#
} Sh&PNJ-*
catch(IOException e){e.printStackTrace ();} g"K>5Cb
catch(Exception e){e.printStackTrace ();} 0.Vi97`
a]B[`^`z
U|5-0u5
Utility.log(nFileLength); ,_ .v_
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return nFileLength; |"]PCb)!
} x({C(Q'O
wCCV2tk
u0 y 1
//保存下载信息（文件指针位置） 2@khSWV
private void write_nPos() mLyBm
{ R_N:#K.M
try{ O!&,5Dy
output = new DataOutputStream(new FileOutputStream(tmpFile)); F9flSeN
output.writeInt(nStartPos.length); wtH~-xSB|
for(int i=0;i<nStartPos.length;i++) XP3xJm3
{ "G?Yrh
// output.writeLong(nPos); d 6t:hn
output.writeLong(fileSplitterFetch.nStartPos); 9P WY52!
output.writeLong(fileSplitterFetch.nEndPos); u:dx;*
} cWLqU
output.close(); A''pS
} :/N+;- 18
catch(IOException e){e.printStackTrace ();} /*rhtrS)
catch(Exception e){e.printStackTrace ();} QHlU|dR)Ry
} #hw>tA6
d~9!,6XM
0 n vSvk
//读取保存的下载信息（文件指针位置） 1G^#q,%X_v
private void read_nPos() GJA`l8`SQ
{ cg{AMeW
try{ Log|%P\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S\#17.=
int nCount = input.readInt(); bC6oqF'#
nStartPos = new long[nCount]; 9`B$V##-L
nEndPos = new long[nCount]; T+IF}4ed
for(int i=0;i<nStartPos.length;i++) /)L 0`:I#
{ rcN 9.1
nStartPos = input.readLong(); (u1m]WYL
nEndPos = input.readLong(); ~nY]o"8D
} }q[Bd
input.close(); bPbb\|u0d
} '{b1!nC;
catch(IOException e){e.printStackTrace ();} s60 TxB
catch(Exception e){e.printStackTrace ();} L{fFC%|l2L
} Hi}RZMr1
$E!J:Y=
j\&pej
private void processErrorCode(int nErrorCode) # Su~`]
{ Zjh2{ :
System.err.println("Error Code : " + nErrorCode); [wnDHy6W
} ,5Vt]#F5@
jp2Q9Z
r'7LR
//停止文件下载 S<wj*"|.s
public void siteStop() Af(WV>'
{ pY"O9x
bStop = true; , X{>
for(int i=0;i<nStartPos.length;i++) Zu*K-ep"
fileSplitterFetch.splitterStop(); sW@krBxMv
6<76H
~NcQ1.
} @.C{OSHE
} \wvg,j=
//负责部分文件的抓取 0Q5^C!K
**FileSplitterFetch.java yYZxLJ='
*/ x.mrCJn)
package NetFox; cmwPuK$
TFQ!7'xk)
/8'S1!zc
import java.io.*; 5 `/< v^
import java.net.*; rf&M!d}!
%3r:s`{
KKe8 ly,
public class FileSplitterFetch extends Thread { "tk-w{>
"Zv~QwC
$A_]:qI2
String sURL; //File URL <If35Z)~
long nStartPos; //File Snippet Start Position nw:-J1kWR
long nEndPos; //File Snippet End Position #'baPqdO
int nThreadID; //Thread's ID 9LJZ-/Wq
boolean bDownOver = false; //Downing is over YX*x&5]lq
boolean bStop = false; //Stop identical 8+Llx
FileAccessI fileAccessI = null; //File Access interface c3%@Wj:fo
"/{RhY<
NQHz<3S[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8jlLUG:g
{ yY).mxRN
this.sURL = sURL; ;E^K.6
this.nStartPos = nStart; ZJW[?V\5=
this.nEndPos = nEnd; >/$Fh:R-
nThreadID = id; e.d #wyeX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bpAv1udX-W
} nAJdr*`a,5
V N{NA+I
rh*sbZ68>E
public void run() 1Tp/MV/>
{ $g9**b@
while(nStartPos < nEndPos && !bStop) oPf)be| #
{ KL,/2(
_*M42<wcO
g`^X#-!(
try{ bBcp9C)iY
URL url = new URL(sURL); &C<yfRDu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jhgX{xc
httpConnection.setRequestProperty("User-Agent","NetFox"); *A'FC|\
String sProperty = "bytes="+nStartPos+"-"; DE$q+j0P
httpConnection.setRequestProperty("RANGE",sProperty); g^Yl TB
Utility.log(sProperty); >r@.F%
Bh`N[\r
+avMX&%
InputStream input = httpConnection.getInputStream(); YUU-D(
//logResponseHead(httpConnection); G6P)C##ibn
ji1HV1S
{PU!=IkTS
byte[] b = new byte[1024]; 'wasZ b<^
int nRead; UB`ToE|Ii
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) m><w0k?t
{ N7r_77%m0
nStartPos += fileAccessI.write(b,0,nRead); `$LWmm#
//if(nThreadID == 1) 6DIZ@oi
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g6t"mkMY L
} /&#XhrT
lA(Q@yEW
/'2O.d0}.
Utility.log("Thread " + nThreadID + " is over!"); ) /vhclkb
bDownOver = true; 8F(h*e_?
//nPos = fileAccessI.write (b,0,nRead); C;+(Zp
} @Hb'8F
catch(Exception e){e.printStackTrace ();} fc=Patg
} :#E*Y8-
} @:0ddb71
@!N-RQ&A
_ZB\L^j)
//打印回应的头信息 Gl %3XdU
public void logResponseHead(HttpURLConnection con) TcTM]ixr
{ KOq;jH{$
for(int i=1;;i++) moj]j`P5a
{ / O/`<
String header=con.getHeaderFieldKey(i); 7M_U2cd|TD
if(header!=null) gbeghLP[?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); sxKf&p;
Utility.log(header+" : "+con.getHeaderField(header)); ?^mi3VM
else `nXVE+E@
break; MTER(L
} kqYa*| l
} \6?A!w~6
#o/H~Iv
5Z/GK2[HL
public void splitterStop() hRI"y":zD
{ >7`<!YJkK
bStop = true; =o}"jVE
} eivtH P
Ma*y=d;,1
z{"2S="
} 1be %G [*
1axQ)},o@p
Ab%;Z5$fr
/* EFuvp8^y
**FileAccess.java W!blAkM%i
*//文件访问(定位，写) mME4 l
package NetFox; PjT=$]
import java.io.*; .roqEasu8
v8gdU7Ll,
UtB6V)YI
public class FileAccessI implements Serializable{ =(a1+.O
m=AqV:%|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X{n- N5*
RandomAccessFile oSavedFile; (`>voi<^
long nPos; Z@8vL
f'Iz G.R
.x`M<L#M(
public FileAccessI() throws IOException \;-fi.Hrf$
{ ?&LZB}1R
this("",0); s](aNe2j
} _zt19%Wg
- K%,^6
k%wn0Erd
public FileAccessI(String sName,long nPos) throws IOException V}d9f2
{ IKtB;
oSavedFile = new RandomAccessFile(sName,"rw"); s]T""-He
this.nPos = nPos; lkyzNy9R
oSavedFile.seek(nPos); Mypc3
} &R|/t:DN
fP tm0.r
(>6*#9#p
public synchronized int write(byte[] b,int nStart,int nLen) ~U(,TjJb
{ Qu=LnGo~P
int n = -1; nVu&/
try{ f)c~cJz<q
oSavedFile.write(b,nStart,nLen); Q$obOEr2(
n = nLen; ^_5L"F]sP
} ihh4pD27g
catch(IOException e) Q9d`zR]
{ MS(JR
e.printStackTrace (); yKXff1^M
} FJ*i\Q/D
]sz3]"2
Q%/<ZC.Mz6
return n; ,\ 2a=Fp
} ^l^fD t
J$4wL F3
H/M Au7
} Z3k(P
/vY_Y3k#
87}&`
/* fP3_d
**SiteInfoBean.java 9_\'LJ
*/ 6.5T/D*TT
package NetFox; {X2`&<i6
ml@2wGyf
tNsPB6Z
public class SiteInfoBean { ,D\GGRw
nA|.t[v
S[tE&[$(p
private String sSiteURL; //Site's URL @)kO=E d
private String sFilePath; //Saved File's Path DjU9 uZT
private String sFileName; //Saved File's Name SVjl~U-^
private int nSplitter; //Count of Splited Downloading File Xi?b]Z
pE{yv1Yg
{k4CEt;
public SiteInfoBean() UA[,2MBp
{//nSplitter的缺省值为5 Cv$ SJc
//default value of nSplitter is 5 9Rm/V5
this("","","",5); f<+4rHT
} h/x0]@M&
$^&ig
[Q\GxX.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?u4INZ0W
{ <Dx]b*H
sSiteURL= sURL; b}T6v
sFilePath = sPath; zkTp`>9R
sFileName = sName; |IunpZV
this.nSplitter = nSpiltter; awvDe
KXV[OF&J
AtR?J"3E
} <I}2k
t}v2$<!I
b{fQ|QD{^E
public String getSSiteURL() 0y<wvLv2C
{ 7W6cM%_B
return sSiteURL; R*|LI
} Z~A@o""F
{bO|409>W
Z/^ u
public void setSSiteURL(String value) &a/__c/l
{ USN8N (
sSiteURL = value; "NRDNqj(
} !6Sd(2
!*2%"H*
3E f1bhi
public String getSFilePath() /-6S{hl9Ne
{ qO`)F8
return sFilePath; tpy>OT$
} 6#j$GH *
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7PR#(ftz
public void setSFilePath(String value) B?$ "\;&
{ .^$YfTabq
sFilePath = value; JQ:Ri
} E;21?`x5
#,{+3Y&5-+
^m_yf|D$
public String getSFileName() nm7;ieMfr
{ H:p Z-v*
return sFileName; E~<`/s
} IrMl:+t\
RE.r4uOJg
9Lh|DK,nV/
public void setSFileName(String value) Le"oAA#[
{ syip;;
sFileName = value; lnE+Au'
} -@>BHC
< j$#9QQ1
"RVcA",
public int getNSplitter() (M =Y&M'f
{ m]*Bx%-1c
return nSplitter; vK$"# F~
} *5<Sr q'
1 nvTce
'8Phxx|
public void setNSplitter(int nCount) |*RYq2y
{ T5Dw0Y6u,
nSplitter = nCount; ??hJEE
} %+ZJhHT
} $,xnU.n
bqanFQj
O4<g%.HC6
/* Ev!{n
**Utility.java yT{8d.Rh
*/ 2iu_pjj
package NetFox; ]nhr+;of/-
b;|55Y
KYJjwXT28W
public class Utility { ~)?
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8@NH%zWBp
public Utility() :Q+5,v-c
{ I ];M7
ylKmj]A
9+,R`v
} t6c<kIQ:-O
[P|[vWO
//线程睡眠 1_$xSrwcF
public static void sleep(int nSecond) nN$Y(2ZN
{ 8Ry74|`=R
try{ 5>6PH+Oq
Thread.sleep(nSecond); y}C`&nW[=
} J/7R\;q`~o
catch(Exception e) ?=GXqbS"
{ 8+mH:O
e.printStackTrace (); S'dV>m`
} 6.t',LTB
} I2(zxq&2M\
:a:[.
//日志 iVB^,KQ@
public static void log(String sMsg) [<`SfE
{ |%~+2m
System.err.println(sMsg); QrApxiw
} zF4[}*
,fEO> i
@?C#r.vgp
public static void log(int sMsg) .I3?7
{ ,mPnQ?
System.err.println(sMsg); *M7E#bQ5B
} 1GEK:g2B
} R];Oxe
FZB~|3eq{
$ _8g8r}
/* \yrisp#`
**TestMethod.java :hGPTf
*/ _wb0'xoK"
package NetFox; 93[DAs
RkFD*E$
k\Q,h75
public class TestMethod { d@mo!zu
2A4FaBq"
2?@j~I=s2h
public TestMethod() &Bx J
{ ///xx/weblogic60b2_win.exe -Xz?s
try{ Li 2Zndp
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1Xy]D
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _DRrznaw
SiteFileFetch fileFetch = new SiteFileFetch(bean); W;?(,xx
fileFetch.start(); :5GZ\Z8F
} '2hbJk
catch(Exception e){e.printStackTrace ();} JT[*3h
uhN%Aj\iu(
NGYyn`Lx
} h5 Vv:C
+b;hBb]R
IB.yU,v
public static void main(String[] args) S\y%4}j
{ Z,N$A7SBE
new TestMethod(); 7iuQ9q^&
} - ~O'vLG
} Q5S,{ ZeT
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