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)); !. p
} R qnWtE
for(int i=0;i<nEndPos.length-1;i++) @]E]W#xAn
{ pbPz$Y
nEndPos = nStartPos[i+1]; G~S))p
} dDo6fP2
nEndPos[nEndPos.length-1] = nFileLength; i`R(7Z
} m^'~&!ba
} o:H'r7N
5 >'66gZ
WqR7uiCi
//启动子线程 \FVNXUMU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tg3zXJ4k_
for(int i=0;i<nStartPos.length;i++) [z^Od
{ !ZX&r{pJp
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o>.AdZby
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2G ZF/9}
nStartPos,nEndPos,i); K[e`t%2_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jb7iBQ2%
fileSplitterFetch.start(); `t%|.=R
} e~3]/BL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iQu^|,tHEM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |^?`Q.|c$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", gji*Wq
nEndPos = " + nFileLength); Qg[heND
// fileSplitterFetch[nPos.length-1].start(); c5<kbe
7&h\l6}Yh
>B`Cch/'U
//等待子线程结束 *B%y`cj|
//int count = 0; zf`5>h|
//是否结束while循环 (v]P<3%
boolean breakWhile = false; U&`6&$]
5[nmP95YK
!;TR2Zcn
while(!bStop) zaH 5 Km_j
{ J9NsHr:A[
write_nPos(); 'J2ewW5
Utility.sleep(500); JR])xPI`
breakWhile = true; ,tau9>!
cD5w| rm?i
ES^NBI j5P
for(int i=0;i<nStartPos.length;i++) hK Fk$A
{ bAN10U
if(!fileSplitterFetch.bDownOver) mlD%d!.
{ 15o9CaQw4"
breakWhile = false; c^rC8E
break; *U:VM'a
} DE5d]3B
} z'?SRK5+
if(breakWhile) I; ^xAd3G
break; 3T"2S[gT
VIb;96$Or
I+*osk
//count++; B^H4Q 4-
//if(count>4) j'\>Nn+
// siteStop(); >y]?MGk
} (qJIu
;&RUE
pi|\0lH6W
System.err.println("文件下载结束！"); iKohuZr
} ]U_5\$
catch(Exception e){e.printStackTrace ();} p 7 ,f6kG
} 3gC\{y!8
]gH wfqx
TViBCed40
//获得文件长度 {F<)z%^
public long getFileSize() kZJt~}
{ eH ;Wfs2f
int nFileLength = -1; f#*h^91x
try{ f;e_04K
URL url = new URL(siteInfoBean.getSSiteURL()); 2j2mW>Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ga]47pQ"F
httpConnection.setRequestProperty("User-Agent","NetFox"); u9esdOv
`Q:de~+AM{
~&t!$
int responseCode=httpConnection.getResponseCode(); {k kAqJ
if(responseCode>=400) i:C.8hmAE
{ ;+TMx(
processErrorCode(responseCode); h1n*WQ-
return -2; //-2 represent access is error &\JK%X.Jlt
} d,zp`S
Q1aHIc
FX{~"
String sHeader; " ]aQ Hh]f
=n> iQS
=AWX +znP
for(int i=1;;i++) H0: iYHu
{ f1)HHUB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W/#KX}4
//Utility.log(in.readLine()); @~JB\j9
sHeader=httpConnection.getHeaderFieldKey(i); P]|J?$1K
if(sHeader!=null) R1II k
{ !y.ei1diw
if(sHeader.equals("Content-Length")) CW.&Y?>Tv
{ ,Y`'myL8W
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hfJrQhmE
break; b\kN_
} &mX5&e
} Is4%}J!8
else /p[|DJoM
break; b{Z^)u2X
} z8 hTZU
} |Dl*w/n
catch(IOException e){e.printStackTrace ();} sjkWz2]S
catch(Exception e){e.printStackTrace ();} C4&U:y<ju
b7?U8/#'
KC&H*
Utility.log(nFileLength); SNQz8(O
mgmWDtxN
Ah6wU|_-g
return nFileLength; pWWL{@J
} %4?SY82
qFvg}}^y
~5lKL5w
//保存下载信息（文件指针位置） _<u8%\
private void write_nPos() vpZu.#5c
{ 1"8Z y6t
try{ N BV}4
output = new DataOutputStream(new FileOutputStream(tmpFile)); *ah>-}-
output.writeInt(nStartPos.length); v_y!Oh?EG
for(int i=0;i<nStartPos.length;i++) 6a "VCE]
{ z7OZ4R:
// output.writeLong(nPos); *ge].E
output.writeLong(fileSplitterFetch.nStartPos); ^+(A&PyP?
output.writeLong(fileSplitterFetch.nEndPos); *>H M$.?Q
} "6NFe!/Y$*
output.close(); Dj-\))L
} <dju6k7uz
catch(IOException e){e.printStackTrace ();} ;cM8EU^.
catch(Exception e){e.printStackTrace ();} 1x~%Ydy
} 7P3<o!YA
KzEuPJ?
Qv9*p('~A
//读取保存的下载信息（文件指针位置） 2rK-X_}
private void read_nPos() h Jfa_
{ .8u$z`j
try{ "Y"t2l_n
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); FK4nz2&4
int nCount = input.readInt(); A)b)ff,
nStartPos = new long[nCount]; CL)1Q
nEndPos = new long[nCount]; vjexx_fq
for(int i=0;i<nStartPos.length;i++) 8>C; >v
{ .b=M5JsyV
nStartPos = input.readLong(); b*I&k":
nEndPos = input.readLong(); YQN]x}:E+4
} l 'AK
input.close(); (z8]FT
} @-)<|orU4
catch(IOException e){e.printStackTrace ();} P<j4\zJ
catch(Exception e){e.printStackTrace ();} &{-oA_@
} M/::`yJQu
,!o\),N
XM$5S+e
private void processErrorCode(int nErrorCode) fe& t-
{ %NF<bEV
System.err.println("Error Code : " + nErrorCode); wMlf3Uz
} !Z<mrr;T@
`jD8(}_
/|4Q9=
//停止文件下载 OqfhCNAY
public void siteStop() Bo\a
{ ^l]]qdNr
bStop = true; =:xV(GK}
for(int i=0;i<nStartPos.length;i++) ]FY?_DGOA
fileSplitterFetch.splitterStop(); jI*}y[o
&&(4n?
%Y)PH-z
} )@8'k]Glw.
} }<( "0jC
//负责部分文件的抓取 ?D*Hl+iu
**FileSplitterFetch.java KKeb ioW
*/ SY!`a:It
package NetFox; !SLP8|Cd
C:'WX*W
]p4`7@@)*
import java.io.*; <GL}1W"Ay
import java.net.*; ql#{=oGDnA
Q{J"`d2
?6gDbE%
public class FileSplitterFetch extends Thread { dXA{+<!!
Q%,o8E2~
_ 6+,R
String sURL; //File URL "?2
long nStartPos; //File Snippet Start Position F]K$u<U
long nEndPos; //File Snippet End Position \N# HPrv}
int nThreadID; //Thread's ID ]t.WJC %
boolean bDownOver = false; //Downing is over i#pjv'C
boolean bStop = false; //Stop identical Mr5('9%
FileAccessI fileAccessI = null; //File Access interface ^]#Ptoz^(l
[OFTP#}c
LW83Y/7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rQd1Ch
{ )V[w:=*
this.sURL = sURL; yiv RpSL
this.nStartPos = nStart; Gx(KN57D
this.nEndPos = nEnd; wf~5lpI[
nThreadID = id; :,h=2a_ 8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {<- ouD
} Ak\D6eHcB
<'>d0:>N
+BtLyQ
public void run() ND9n1WZ&x
{ u):%5F/
while(nStartPos < nEndPos && !bStop) mC{!8WC@k
{ wS F!Xx0
#K<=xP
K]H"qG.K
try{ z._C*c
URL url = new URL(sURL); d+YVyw.z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q8}TNJsU
httpConnection.setRequestProperty("User-Agent","NetFox"); K%[}[.cW
String sProperty = "bytes="+nStartPos+"-"; 1}n)J6m
httpConnection.setRequestProperty("RANGE",sProperty); )M&Azbu
Utility.log(sProperty); }2iKi(io*
WL)_8!
#"=yQZ6Y
InputStream input = httpConnection.getInputStream(); #GDh/t2@
//logResponseHead(httpConnection); V:,3OLL*
;*>QG6Fh
=\Tud-1Z
byte[] b = new byte[1024]; M@!]U:5~V
int nRead; YWcui+4p}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) h|c:!VN@
{ @mQ/WYs
nStartPos += fileAccessI.write(b,0,nRead); Zi<Sw
//if(nThreadID == 1) y0&V$uv/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |(J ?#?
} Sg_-OX@f
X_0{*!v8
oSu|Yn
Utility.log("Thread " + nThreadID + " is over!"); ${TB2q}%
bDownOver = true; Gpxb_}P
//nPos = fileAccessI.write (b,0,nRead); 2kp|zX(
} :uT fhr
catch(Exception e){e.printStackTrace ();} T_(e(5
} =XRgT1>e
} .^9/ 0.g8t
XDrlJvrPL
)'K!)?&d
//打印回应的头信息 d 40'3]/{
public void logResponseHead(HttpURLConnection con) vZ_DG}n11
{ HAI1%F236
for(int i=1;;i++) Q8gdI
{ cOZajC<G
String header=con.getHeaderFieldKey(i); 9|G=KN)P:
if(header!=null) "b1R5(Ar
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fUL{c,7xda
Utility.log(header+" : "+con.getHeaderField(header)); U"%8"G0)
else -pU\"$nuxH
break; 0-t4+T
} GH; F3s
} O'&X aaZV
fdCxMKlu;
<Hr@~<@~
public void splitterStop() 3*2&Fw!B
{ {Gb)Et]<
bStop = true; gk_Xu
} zM8/s96h
A\PV@w%Ai
.f.j >
} ZAnO$pA
4Ow Vt&
o{-USUGj7
/* [r/Seg"
**FileAccess.java `aX}.{.!
*//文件访问(定位，写) UQji7K }
package NetFox; zOu$H[
import java.io.*; i*cE
0|DG\&?
QLpTz"H
public class FileAccessI implements Serializable{ {7pE9R5
9^Vx*KVrU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d@>k\6%j
RandomAccessFile oSavedFile; bbPd&7
long nPos; i_ODgc`H
1Z$99
<1'X)n&Kw$
public FileAccessI() throws IOException o7 -h'b-
{ Nh7!Ah
this("",0); -)vp&-
} B,VSFpPx
{;z L[AgCg
ae(]9VW
public FileAccessI(String sName,long nPos) throws IOException f@.Q%+!4
{ 6'sFmC
oSavedFile = new RandomAccessFile(sName,"rw"); Vp-OGX[
this.nPos = nPos; cwW~ *90#
oSavedFile.seek(nPos); -m x3^
} n5,Pq+[
&<#BsFz
Kn9=a-b?,
public synchronized int write(byte[] b,int nStart,int nLen) :#&U95EC0
{ T=p}By3a
int n = -1; ~E6+2t*
try{ @Qsg.9N3K
oSavedFile.write(b,nStart,nLen); &40JN}
n = nLen; G'}_ZUy#
} &LxzAL,3!
catch(IOException e) /jL{JF>I
{ RVKaqJ0e<
e.printStackTrace (); ^%OH}Z`ly
} K/.hJ
7rDRu]
PA-0FlV|
return n; 4oaP"T@6
} T[!q&kFB
HOQ _T4
:~A1Ud4c
} Y"\T*lKa
3<'Q`H>
3L!&~'.Ro
/* nTtt$I@hW
**SiteInfoBean.java yI|?iBc7nC
*/ vheAh`u^&
package NetFox; OFAqP1o{$
{j=hQL3
R^O)fL0_
public class SiteInfoBean { LAVt/TcZS|
;eEtdoy
N4]6LA6x6
private String sSiteURL; //Site's URL [N$_@[
private String sFilePath; //Saved File's Path jvKaxB;e
private String sFileName; //Saved File's Name .j<B5/+
private int nSplitter; //Count of Splited Downloading File Hr,lA(
0v)mgrl=,
?bYQZJ>&
public SiteInfoBean() gl\{QcI8<
{//nSplitter的缺省值为5 Qs[EA_
//default value of nSplitter is 5 om39;nk!}
this("","","",5); N*oJ$:#
} pYvF}8
Y&Vbf>Hi+
mE@o27
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /g-X=|?F
{ GDQg:MgX
sSiteURL= sURL; 2uR4~XjF
sFilePath = sPath; sL`D}_:
sFileName = sName; 9l^
this.nSplitter = nSpiltter; M,U=zNPnk
NeZYchR
F4{. 7BT
} 7ofH@U
\^W?
z)y(31K<1
public String getSSiteURL() ph'SS=!.
{ a|{<#<6n(
return sSiteURL; k.R/X
} ZZJ"Ny.2
YZtA:>;p
ZTz(NS EK
public void setSSiteURL(String value) x3F L/^S
{ #K*q(ei,7h
sSiteURL = value; ]x{H
} mb6?$1j
[goPmVe+
#"YWz)8
public String getSFilePath() H9m2Whq
{ ?-v?SN#
return sFilePath; I:)#U[tn0
} 1`JN
soK_l|z:J
\J g#X:d
public void setSFilePath(String value) L#MxB|fcr
{ n8D;6#P^
sFilePath = value; @%85k/(
} 3'uES4+r
) G&3V
UdgI<a~`k6
public String getSFileName() Uy'ZL(2
{ WSccR
return sFileName; 1,D ^,
} aL6 5t\2
@9 tvN}
I{UB!0H
public void setSFileName(String value) qGUe0(
{ <.XoC?j
sFileName = value; ,(?4T~
} RwHXn]1
& b2(Y4
5fv6RQD
public int getNSplitter() %Ne>'252y
{ XE%6c3s
return nSplitter; *njB fH'
} bv"({:x
Bm>(m{sX>
iEO2Bil]
public void setNSplitter(int nCount) Nxk'!:
{ .y/?~+N^
nSplitter = nCount; j-\u_#kx%
} 2_DtzY:=
} Q*o4zW
8j+;Xlh
Rzj!~`&N
/* J=bOw//
**Utility.java WuXRL}!\,
*/ mw.aavB
package NetFox; @D{[Hj`<
!-Q!/?
.b)(_*
public class Utility { pMrfi}esx
<VsZ$
~/[N)RFD
public Utility() ds[~Cp
{ A|nU _*
-<.NEV
#>NZN1
} 1S@k=EKM
(G'ddZAJV
//线程睡眠 ,urkd~
public static void sleep(int nSecond) :Dm@3S$4<
{ 8)ol6Mi{
try{ CBHWMetJ*
Thread.sleep(nSecond); @isqFKjph
} ew~FN
catch(Exception e) 1 SZa\ ][@
{ 5n#&Hjb*F0
e.printStackTrace (); D4T+Gk"n
} |,f6c Omf
} D]_\i[x
Ps-d#~4U;
//日志 _CT|5wQF<
public static void log(String sMsg) wpmtv325
{ qA[}\8}h
System.err.println(sMsg); `buTP?]4.
} aa!c>"g6
N.rB-
pp_ddk
public static void log(int sMsg) l)bUHh5[
{ 0$ EJ4
System.err.println(sMsg); w|#79,&
} 9 f+7vCA
} %QkvBg*
?os0JQVB
EaL+}/q&
/* 1Qkuxw
**TestMethod.java 3g?T,|2K
*/ 8ttw!x69)_
package NetFox; Ric$Xmu
_en8hi@Z
3EdPKM j&
public class TestMethod { :eO0{JN4T
nQC[[G*x
s=+G%B'
public TestMethod() {[dqXG$v `
{ ///xx/weblogic60b2_win.exe o)DKP>IM#
try{ JJa?"82FXZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i[lH@fJm_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O%{>Zo_<
SiteFileFetch fileFetch = new SiteFileFetch(bean); ],m-,K
fileFetch.start(); eSf:[^
} (~4AG \
catch(Exception e){e.printStackTrace ();} =cY]cPO
n9ih^H
?,[w6O*
} ujBADDwOg)
lnUy?0(
Bf'(JJ7&N
public static void main(String[] args) &bNj/n/
{ #/6X44 *u
new TestMethod(); <Do89
} >~:]+q
} "tIx$?I
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