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)); rHk,OC
} WiZTE(NM`
for(int i=0;i<nEndPos.length-1;i++) E@n~ @|10
{ lI+^}-<
nEndPos = nStartPos[i+1]; 8n-Xt7z
} IV1Y+Z )
nEndPos[nEndPos.length-1] = nFileLength; 8S8UV(K0
} TbN{ex*
} ,D]g]#Lq
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\=]`X2Ld
//启动子线程 ~8"oH5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #NYHwO<0-
for(int i=0;i<nStartPos.length;i++) ';c 6
{ ?Zsh\^k.g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9q 2 vT^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *Ms"{+C
nStartPos,nEndPos,i); IkjJqz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6x=w-32+ y
fileSplitterFetch.start(); zSU,le
} }6<5mq)%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [u37Hy_Gi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); I%GQ3D"=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j"aY\cLr t
nEndPos = " + nFileLength); T93st<F=R
// fileSplitterFetch[nPos.length-1].start(); 4y?n62N8$
C/#pK2xY
'Cz*p,
//等待子线程结束 jD}h`(bE
//int count = 0; S'kgpF"bm
//是否结束while循环 O`"~AY&
boolean breakWhile = false; +!E9$U>6%
]!@=2kG4
0a^bAEP
while(!bStop) |WEl5bNc3
{ LME&qKe5
write_nPos(); 'bz&m(!
Utility.sleep(500); 5]upfC6
breakWhile = true; ~zG)<S"q
nE*S3
p<#aXsjy
for(int i=0;i<nStartPos.length;i++) LExm#T`
{ !{+.)%d'g
if(!fileSplitterFetch.bDownOver) \AH5zdK
{ _cj=}!I
breakWhile = false; hliO/3g
break; ,+4T7 UR
} U]_WX(4 @
} eEP{?F^I[
if(breakWhile) "bF52lLu
break; QKB+mjMH#x
K/ &`
,(zV~-:9
//count++; Tsj/alC[
//if(count>4) ~cfXEjE6
// siteStop(); 1K<}
} wy#>Aq
&Tj7qlP\
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System.err.println("文件下载结束！"); 5pe)CjE:
} WZPj?ou`G
catch(Exception e){e.printStackTrace ();} cs.t#C
} O-K*->5S
g,!.`[e'ex
0Xw>_#Y/xS
//获得文件长度 r@qLG"[\c
public long getFileSize() H!u8+
{ ge.>#1f}
int nFileLength = -1; KK2YT/K$SG
try{ {*TB }Xsr,
URL url = new URL(siteInfoBean.getSSiteURL()); -m=A1~|7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yiI oqvP
httpConnection.setRequestProperty("User-Agent","NetFox"); {wj%WSQj/y
=_zo
3Il._]#
int responseCode=httpConnection.getResponseCode(); W;2J~V!c
if(responseCode>=400) qlYi:uygY
{ {FKr^)g
processErrorCode(responseCode); *fIn<Cc
return -2; //-2 represent access is error 6w;`A9G[YI
} zow8 Q6f
V|kN 1 A
&]RE 5!
String sHeader; 5QuRwu_
`[(XZhN
*pSnEWwE
for(int i=1;;i++) 3*2~#dh=
{ R6oD
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \G>C{v;
//Utility.log(in.readLine()); 5[jS(1a`c
sHeader=httpConnection.getHeaderFieldKey(i); 5X+`aB
if(sHeader!=null) }F!Uu KR
{ 2w8cJadT'p
if(sHeader.equals("Content-Length")) w43b=7
{ 4:NMZ `~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^Cp2#d*
break; N\B&|;-V
} h ~yTkN]
} H1B%}G*Ir-
else fuv{2[NV
break; d;0]xG?%=
} `N.:3]B t
} x[0hY0 ?[M
catch(IOException e){e.printStackTrace ();} #&?ER]|3
catch(Exception e){e.printStackTrace ();} KB|mtsi
%A'mXatk
Xm>zT'B_tJ
Utility.log(nFileLength); YW&K,)L@
_.V5-iN
~5%3]
return nFileLength; JZ`h+fAt
} g=Xy{Vm
}EkL[H!
J( XDwt
//保存下载信息（文件指针位置） jQ3dLctn
private void write_nPos() G"J nQ
{ .\ fpjQW
try{ ?{aJ#w
output = new DataOutputStream(new FileOutputStream(tmpFile)); rC_1f3A
output.writeInt(nStartPos.length); pgh(~[
for(int i=0;i<nStartPos.length;i++) K;sC#9m
{ SsW<,T
// output.writeLong(nPos); @9_mk@
output.writeLong(fileSplitterFetch.nStartPos); {G x=QNd
output.writeLong(fileSplitterFetch.nEndPos); IAwS39B
} a`%`9GD
output.close(); d/OP+yzgZ
} e3TKQ(
catch(IOException e){e.printStackTrace ();} saiXFM7J
catch(Exception e){e.printStackTrace ();} 3w"JzC@
} vu^mLc
!(?7V
)AkBo
//读取保存的下载信息（文件指针位置） n:/!{.
private void read_nPos() NWFh<
{ =KOi#;1
try{ hIV]ZYbH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6JZ>&HA
int nCount = input.readInt(); E9j<+Ik
nStartPos = new long[nCount]; -_5Dk'R#`
nEndPos = new long[nCount]; ZM-P
for(int i=0;i<nStartPos.length;i++) 5Ex[}y9L`
{ JFX}))7
nStartPos = input.readLong(); ~^a>C
nEndPos = input.readLong(); T[1iZ
} (:OMt2{r
input.close(); _xePh
} 1q-;+Pd;
catch(IOException e){e.printStackTrace ();} *6AV^^
catch(Exception e){e.printStackTrace ();} *`u|1}h|
} }vU/]0@,E
oJQS&3;/r
/"D,gn1S*
private void processErrorCode(int nErrorCode) lkTA"8d
{ iv+a5
System.err.println("Error Code : " + nErrorCode); g_c@Kyf
} sYDav)L.
c:0n/DC
*izCXfW7
//停止文件下载 Xzg >/w 8J
public void siteStop() vkhPE(f
{ Ly8=SIZ
bStop = true; ^SG>VfgC
for(int i=0;i<nStartPos.length;i++) 0~RD@>]
fileSplitterFetch.splitterStop(); "%D"h
\&kj#)JYA
M KW~rrR
} WFahb3kx
} yXDjM2oR/2
//负责部分文件的抓取 *|W](id7e
**FileSplitterFetch.java wMR,r@}
*/ \h#aPG<yo
package NetFox; ddKP3}
o"BED!/
NO[A00m|OL
import java.io.*; +&VY6(Zj+*
import java.net.*; m0ra
H%Vf$1/TF
vA_,TS#Bo
public class FileSplitterFetch extends Thread { mm+V*L{x
vi^YtA
_";w*lg}
String sURL; //File URL rrRv 7J&Q
long nStartPos; //File Snippet Start Position o5&b'WUJ=
long nEndPos; //File Snippet End Position : pUu_
int nThreadID; //Thread's ID .tG3g:
boolean bDownOver = false; //Downing is over _xh)]R
boolean bStop = false; //Stop identical [q!]Ds" _
FileAccessI fileAccessI = null; //File Access interface Gn^lF7yE
@br)m](@
*w*K&$g
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException , p}:?uR
{ W+Mw:,>*s
this.sURL = sURL; xS12$ib ~G
this.nStartPos = nStart; /}E2Rr?{
this.nEndPos = nEnd; su=MMr>
nThreadID = id; [06m{QJ)1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 lmHQ"z 3G
} iy]L"7&Z2
0~BaQ, A@
7O*Sg2B
public void run() Cn5"zDK$
{ ;E 9o%f:o
while(nStartPos < nEndPos && !bStop) HoAg8siQ
{ RRS)7fFm
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M&/4SVBF
try{ 9yTdbpY
URL url = new URL(sURL); JW0\y+o~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q7KHx b
httpConnection.setRequestProperty("User-Agent","NetFox"); c]x-mj =
String sProperty = "bytes="+nStartPos+"-"; "1Hn?4nz5
httpConnection.setRequestProperty("RANGE",sProperty); 9HFEp-"
Utility.log(sProperty); PZ6R+n8
Q`8-|(ngw
98u@X:3
InputStream input = httpConnection.getInputStream(); e.MyJ:eL
//logResponseHead(httpConnection); eC<RM Q4
V1M|p!
`=hCS0F
byte[] b = new byte[1024]; !c)F;
int nRead; 9F3,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) x1g-@{8]j
{ -j<E_!t
nStartPos += fileAccessI.write(b,0,nRead); &_:9.I1
//if(nThreadID == 1) p:nl4O/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z{Yfiv\-r
} HRE?uBkjf
Sw E7U~
X);'[/]E*
Utility.log("Thread " + nThreadID + " is over!"); >>J$`0kM*
bDownOver = true; /_J{JGp9
//nPos = fileAccessI.write (b,0,nRead); rWJ5C\R
} o?/H<k\5
catch(Exception e){e.printStackTrace ();} {jYVA~.|Z
} P^F3,'N
} \e4AxLP
}U'9 d#N
9a=:e=q3#
//打印回应的头信息 =gSc{ i|
public void logResponseHead(HttpURLConnection con) D~"a"
{ xF3FY0U[
for(int i=1;;i++) L"9Z{o7
{ 8vq-|p
String header=con.getHeaderFieldKey(i); OT$Ne
if(header!=null) "aKlvK:77
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >CrrxiG
Utility.log(header+" : "+con.getHeaderField(header)); +2:HgW
else .zdaY, U
break; 4"eFR'g
} [g}#R#Y)
} <ivG(a*=]
LyvR].p=5*
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public void splitterStop() %`s#p` Ol1
{ R%n*wGi_6b
bStop = true; ]XlBV-@b
} 7=yM40
,OwTi:yDr
b7^q(}qE
} H~JgZ pw
{Lv"wec*x
:F6dXW
/* h`9 & :zr
**FileAccess.java :+\sKEzL
*//文件访问(定位，写) jcJ@A0]
package NetFox; V/\Y(Mxc
import java.io.*; g?xXX /Qe
I:DAn!N-A*
<L8FI78[*
public class FileAccessI implements Serializable{ i75\<X
e%ro7~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 arR<!y7
RandomAccessFile oSavedFile; y,rdyt
long nPos; Tz6I7S-w
dR=sdqS#J
40 u tmC
public FileAccessI() throws IOException _(m455HZ
{ a3MI+
this("",0); *iru>F8r:
} 2Jiy`(P
r<(UN@T}
(p#c p
public FileAccessI(String sName,long nPos) throws IOException &Hf%Va[B
{ $FT6c@&y
oSavedFile = new RandomAccessFile(sName,"rw"); _\IA[-C+O
this.nPos = nPos; $Lfbt=f
oSavedFile.seek(nPos); %e25Z.Se$
} E83$(6z
g*FHZM*N9
E|-5=!]fX
public synchronized int write(byte[] b,int nStart,int nLen) nnBS;5
{ hFycSu
int n = -1; ~~&Bp_9QXN
try{ f-i5tnh
oSavedFile.write(b,nStart,nLen); bYQ@!
n = nLen; w#a`k9y
} *B@#A4f"
catch(IOException e) ]b;a~Y0
{ ;{wzw8!
e.printStackTrace (); h5l_/vd
} ZR=i*y
@mu{*. &
%/\sn<6C}
return n; G2n.NW#d4
} 5FB3w48
yMkR)HY
-@w}}BR
} X xwcvE
cCZ$TH
gIRZkT`
/* 4@F8-V3q4
**SiteInfoBean.java /160pl4
*/ EGv]K|
package NetFox; )!VJ\
$SA @ "
f$}g'r zl
public class SiteInfoBean { KMfIp:~
4Hyp]07
rVOF
private String sSiteURL; //Site's URL )xg8#M=K
private String sFilePath; //Saved File's Path m7A3i<6p
private String sFileName; //Saved File's Name \N|}V.r
private int nSplitter; //Count of Splited Downloading File hB>FJZQ_
e 5(|9*t
)~$ejS
public SiteInfoBean() @HI@PZ>
{//nSplitter的缺省值为5 &uaSp,L
//default value of nSplitter is 5 |Om][z
this("","","",5); hqHk,#
} K0'p*[yO/j
@$p6w
d5 ]-{+V+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "IJ1b~j?
{ )2d1@]6#
sSiteURL= sURL; e :ub]1I=
sFilePath = sPath; .3XSF$;
sFileName = sName; ]CU)#X<J
this.nSplitter = nSpiltter; k&K'FaM!
tycVcr\(
1 Cz}|#U
} eUu<q/FUMj
~(c<M>Q8
:SMf (E 5
public String getSSiteURL() 1z,P"?Q
{ O]="ggq&
return sSiteURL; =NK'xPr
} &jnBDr
P()&?C
rnMi >?
public void setSSiteURL(String value) n sN n>{
{ :zfMRg
sSiteURL = value; RcR-sbR
} D&N3LH
vgNrHq&2q
h^WMv *2
public String getSFilePath() ]w-W
{ +-V4:@
return sFilePath; r_rdd}=b'
} )g-0b@z!n
voP#}fD
Kp;<z<
public void setSFilePath(String value) \\oa[nvL~
{ _S &6XNV
sFilePath = value; F5UHkv"K&O
} [ f<g?w
4w 7vgB
.",BLuce
public String getSFileName() b?M. 0{"H
{ D iHj!tZN
return sFileName; &d!ASa
} >N~jlr|
pZc`!f"
PCBV6Y7r
public void setSFileName(String value) m60hTJ?N)
{ ^6CPC@B1
sFileName = value; axXR-5c
} ;'!h(H
I[06R
op&j4R
public int getNSplitter() S!R(ae^}
{ `X=[ m>
return nSplitter; s9u7zqCF
} (r<F@)J
$S/WAw,/
!.q#X^@>L
public void setNSplitter(int nCount) wv%UsfD
{ ph~#{B(\
nSplitter = nCount; d(Yuz#Qcrh
} M|.ykA<D
} %~Ymb&ugg
Cq\{\!6[
WUx2CK2N
/* etb#/L
**Utility.java =k!F`H`/%'
*/ [S.zWPX9{
package NetFox; z3fU|*_c
TPZ^hL>ao
4]cr1K ^
public class Utility { D_w<igu!3
`V[ hE r|
s"wz !{G4
public Utility() =NRiro
{ Tkh?F5l
dTU`@!f
(b.Mtd
} $yFR{_]
> 3l3
//线程睡眠 K}LF ${bS
public static void sleep(int nSecond) . Eb=KG
{ `|[UF^9
try{ HN&]`cr;
Thread.sleep(nSecond); o107.s
} o|VM{5
catch(Exception e) 3-![%u
{ *+ O
e.printStackTrace (); o-AAx#@
} f(-3d*g
} V#DNcF~v]f
dpcv'cRfw
//日志 r?Pk}Q
public static void log(String sMsg) z8PV&o
{ KZ/2W9r_,
System.err.println(sMsg); %BkPkQA
} ?=Mg"QU
s:sk`~2<gd
).r04)/
public static void log(int sMsg) g$Nsu:L
{ ;q2e[y
System.err.println(sMsg); z-kB!~r
} !wjD6NK
} 8qq'q"g
GYri\<[
xC$CRzAe5p
/* %e=UYBj"
**TestMethod.java l]P3oB}Yo
*/ *3y:Wv T>
package NetFox; f87lm*wZ
YYd!/@|N5
Snas:#B!
public class TestMethod { g6q67m<h
] 2lhJ
@p7*JLO
public TestMethod() F[oTc^dr
{ ///xx/weblogic60b2_win.exe !*B1Eo--cN
try{ ]1KF3$n0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4--[.j*W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r1xhplHH@
SiteFileFetch fileFetch = new SiteFileFetch(bean); -;[,`g(f
fileFetch.start(); -<n]Sv;V
} h&t9CpTfeJ
catch(Exception e){e.printStackTrace ();} +dK;\wT
'$be+Z32
ljO t~@Ea
} 3C;nC?]K
JwmH_nJ(
4kf8Am(
public static void main(String[] args) \&X*-T[]j
{ E#+|.0*!s
new TestMethod(); +C9l7 q
} G(7WUMjl
} 9GVv[/NAb
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