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)); @m V C
} qN@a<row&~
for(int i=0;i<nEndPos.length-1;i++) `xUPML-
{ uNbA>*c4M
nEndPos = nStartPos[i+1]; /<0D E22
} $T6Qg(p
nEndPos[nEndPos.length-1] = nFileLength; IMza 2
} GcR`{ 3hO
} (5~C _Y
c*dww
9#<Og>t2y
//启动子线程 5-^%\?,x
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; j;)g+9`
for(int i=0;i<nStartPos.length;i++) ^%&x{F.
{ $VWzv4^:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [.X%:H+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2JP?6N
nStartPos,nEndPos,i); n5.>;N.*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9Yyg}l:
fileSplitterFetch.start(); K;[%S
} AxlFU~E4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GYC&P]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #OWs3$9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (0W}e(D8
nEndPos = " + nFileLength); jJZsBOW[8
// fileSplitterFetch[nPos.length-1].start(); 8%<`$`FyU
fm%RNAPvc
7Zt\G-QV
//等待子线程结束 gvNZrp>e!
//int count = 0; `{F~'t['
//是否结束while循环 R*Z]
boolean breakWhile = false; |xZcT4
mE`qvavP|/
^,lZ58 2
while(!bStop) {X<4wxeTo
{ xn@0pL3B~
write_nPos(); T[-c|
Utility.sleep(500); ]M;6o@hq
breakWhile = true; @b\ S.
.vS6_
1?|6odc
for(int i=0;i<nStartPos.length;i++) HhmVV"g
{ vt@Us\fI
if(!fileSplitterFetch.bDownOver) `t0f L\T
{ j yRSEk$
breakWhile = false; ~9r!m5ws
break; QaWHz
} $-Pqs ^g
} qQOD
if(breakWhile) _1<'"u#6w
break; ,|X+/|gm
0^_lj9B!
rLh9`0|D
//count++; VS|("**
//if(count>4) X@qk>/
// siteStop(); UIOEkQ\Wl
} Z.':&7Y
BwJ^_:(p~
b/B`&CIA0"
System.err.println("文件下载结束！"); 1N9<d,
} 6WN(22Io
catch(Exception e){e.printStackTrace ();} C`n9/[,#
} i*CQor6|z
rS )b1nPA
wB>S\~i
//获得文件长度 b"M`@';+
public long getFileSize() pEVgJ/>
{ Ah>gC!F^
int nFileLength = -1; 7~"(+f
try{ J+b!6t}mZn
URL url = new URL(siteInfoBean.getSSiteURL()); KO"Jg-6r|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Pc)VK>.fc
httpConnection.setRequestProperty("User-Agent","NetFox"); U2V^T'Y[
g[s\~MF@s
/^LH
int responseCode=httpConnection.getResponseCode(); *)bd1B#
if(responseCode>=400) B9e.-Xaf
{ 'DzBp
processErrorCode(responseCode); 8.CKH4h
return -2; //-2 represent access is error )!k_Gb`#X
} 8b 8\
0^9:KZ.!
Nxb\[
String sHeader; E-sSRt
cc41b*ci$
R6q4 ["
for(int i=1;;i++) iog # ,
{ 8jggc#.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); e(~'pk"mZ
//Utility.log(in.readLine()); :YqQlr\
sHeader=httpConnection.getHeaderFieldKey(i); LiZdRr
if(sHeader!=null) kxm:g)`=[
{ 1GG>.RCP
if(sHeader.equals("Content-Length")) lC=N:=Mu
{ }2ql?K
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]Y4q'KH
break; l*K I
} N )zPxQ
} CYtjY~
else | "Jx
break; "[*S?QO(L
} /WgPXEB
} jj!N39f
catch(IOException e){e.printStackTrace ();} }UKgF.
catch(Exception e){e.printStackTrace ();} WVS$O99Y
\[hn]@@
9DOkQnnc
Utility.log(nFileLength); UU iNR
7`IUMYl#~
cgs3qI
return nFileLength; jq57C}X}2
} E3S%s
4D^ M<Xn
=`qRu
//保存下载信息（文件指针位置） #%?FM>
private void write_nPos() -uA3Y
{ Z}8k[*.
try{ 48tcgFg[
output = new DataOutputStream(new FileOutputStream(tmpFile)); M*5,O
output.writeInt(nStartPos.length); `]`=]*d
for(int i=0;i<nStartPos.length;i++) 17>5#JLP
{ ]?0{(\
// output.writeLong(nPos); E?Zb~xk
output.writeLong(fileSplitterFetch.nStartPos); +65oC x
output.writeLong(fileSplitterFetch.nEndPos); t_dcV%=
} |XKOXa3.
output.close(); 7_9+=. +X5
} _1>SG2h{fV
catch(IOException e){e.printStackTrace ();} [D3+cDph
catch(Exception e){e.printStackTrace ();} bz{^h'
} #V.ZdLo(
PXw| L
[ rQMD^:M$
//读取保存的下载信息（文件指针位置） I&L.;~
private void read_nPos() U^%9 )4bj
{ MV:W@)rg
try{ w4\BD&7V
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); I@n*[EC
int nCount = input.readInt(); EXA^!/)
nStartPos = new long[nCount]; Ci~f#{
nEndPos = new long[nCount]; )]%e
for(int i=0;i<nStartPos.length;i++) (VgNb&Yo9
{ q*\NRq
nStartPos = input.readLong(); :KEq<fEI
nEndPos = input.readLong(); SQ}S4r
} X<(6T
input.close(); 7MY)\aH
} {7vgHutp
catch(IOException e){e.printStackTrace ();} P}HC(S1
catch(Exception e){e.printStackTrace ();} m8'@UzB
} bb|}'
w6vLNX
fO K|:
private void processErrorCode(int nErrorCode) sffhPX\I
{ RX:R*{]-
System.err.println("Error Code : " + nErrorCode); -Q6(+(7_|
} ;0IvF#SJ(.
`9/0J-7*
oP/>ju
//停止文件下载 .iFViVZC
public void siteStop() ^6Yd}
{ 6\NvG,8
bStop = true; -*?p F_*w
for(int i=0;i<nStartPos.length;i++) swttp`
fileSplitterFetch.splitterStop(); ]k[x9,IU\y
E W`W~h[
%/51o6a
} >-!r9"8@
} +A@m9
//负责部分文件的抓取 lbRzx4=\y
**FileSplitterFetch.java {$;2HbM(
*/ @B?FE\
package NetFox; 5J ySFG3
Ua %UbAt
[w!C*_V 9
import java.io.*; G\R*#4cF
import java.net.*; T/ik/lFI
w&%9IJ
sa*g
public class FileSplitterFetch extends Thread { Uo~T'mA"
>?z:2@Q)B
>Iuzk1'S
String sURL; //File URL {@3z\wMK$
long nStartPos; //File Snippet Start Position u$C\E<G^
long nEndPos; //File Snippet End Position h\(B#SN
int nThreadID; //Thread's ID :$NsR*Cq*9
boolean bDownOver = false; //Downing is over FH.f- ZU
boolean bStop = false; //Stop identical !v0"$V5+i
FileAccessI fileAccessI = null; //File Access interface P$g^vS+
(~JwLe@a
i0>]CJG
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !$_~x 8K1-
{ ?\ZL#)hr"p
this.sURL = sURL; 'r\ 4}Ik
this.nStartPos = nStart; %,0%NjK
this.nEndPos = nEnd; OVZP x%a
nThreadID = id; S#tY@h@XV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6ZcXS
} @OzMiN
Hfh!l2P
fN@{y+6
public void run() [ 7g><
{ >%u@R3PH]
while(nStartPos < nEndPos && !bStop) eIH$"f;L
{ 6#U^<`
5Q W}nRCZ
ZWS2q4/S
try{ t8P PE
URL url = new URL(sURL); _g~2R#2Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :|rPT)yT]
httpConnection.setRequestProperty("User-Agent","NetFox"); )n>+m|IqY(
String sProperty = "bytes="+nStartPos+"-"; YlTaN,?j
httpConnection.setRequestProperty("RANGE",sProperty); 7\Co`J>p2
Utility.log(sProperty); ,[* ;UR
Jd_;@(Eg=
,!Q]q^{C:W
InputStream input = httpConnection.getInputStream(); Huc|6~X
//logResponseHead(httpConnection); )hBE11,PB
cLG6(<L
c+g@Z"es
byte[] b = new byte[1024]; `PgdJrE
int nRead; k[%aCGo
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Q,gLi\siI
{ 4jX3lq|
nStartPos += fileAccessI.write(b,0,nRead); LBat:7aH>
//if(nThreadID == 1) 7CGyC[[T~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z8"7u/4v{
} FQk!d$BG
?{6s58Q{
I`T1Pll
Utility.log("Thread " + nThreadID + " is over!"); i7w(S3a
bDownOver = true; H}/05e
//nPos = fileAccessI.write (b,0,nRead); Wpr ,jN8b
} rOcg+5
catch(Exception e){e.printStackTrace ();} Y]Vq\]m\
} BRzfic:e
} 0J9D"3T)
\vRd}
]A^4}CK^<
//打印回应的头信息 "hQgLG
public void logResponseHead(HttpURLConnection con) #$E)b:xj
{ jo9gCP.
for(int i=1;;i++) lyv4fP
{ >P=Q #;v
String header=con.getHeaderFieldKey(i); ;SY\U7B\
if(header!=null) aJzLrX
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cE\>f8 I
Utility.log(header+" : "+con.getHeaderField(header)); !Ms[eB
else yCP4r6X0
break; pr&=n;_ n
} /<{:I \<
} Dd,2;#_
5)UQWnd5
dg_Gs>?2
public void splitterStop() > 'i
{ e#S0Fk)z
bStop = true; Z"y=sDO{
} ^x m$EY*Y,
YlF%UPp
H,y4`p 0
} tU:EN;H
q%i-`S]}qL
=5x&8i
/* Lja7
**FileAccess.java %JyXbv3m,
*//文件访问(定位，写) {<=#*qx[Y!
package NetFox; />44]A<
import java.io.*; @7<uMasfp
(Un_!)
69G`2_eKCp
public class FileAccessI implements Serializable{ Ba'LRz
Bd~1P/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T.mmmT
RandomAccessFile oSavedFile; k[kju%i4
long nPos; ._PzYE|m2
5d\q-d
&ldBv_
public FileAccessI() throws IOException $?P22"/p
{ 4\M.6])_
this("",0); cC'x6\a
} Sa1l=^
jMNU ?m:
Ch \&GzQ
public FileAccessI(String sName,long nPos) throws IOException 3?n>yS
{ w= P9FxB
oSavedFile = new RandomAccessFile(sName,"rw"); L+}n@B
this.nPos = nPos; Iw<i@=V
oSavedFile.seek(nPos); tptN6Isuh
} OTDg5:>
^-z=`>SrS"
W ~f(::
public synchronized int write(byte[] b,int nStart,int nLen) JM- t<.
{ \>QF(J [8
int n = -1; c%m3}mrb
try{ /3B $(
oSavedFile.write(b,nStart,nLen); re?s.djT
n = nLen; ~{,X3-S_H
} 6/V3.UP-
catch(IOException e) y:m_tv0~0
{ e]=lKxFh&l
e.printStackTrace (); a^d8I
} :j }fC8'
zOgTQs"ZH
03E4cYxt5
return n; 4k-+?L!/G
} *jIqAhs0{
' Z0r>.
jw<pK4?y
} 29CINC
a] =
jO*l3:!~\
/* %wcSM~w
**SiteInfoBean.java :+Om]#`Vls
*/ :0& X^]\
package NetFox; k@ZLg9
xj5;: g#!
YW u cvw&
public class SiteInfoBean { ABE@n%|`
:G\<y
I$N8tn+E
private String sSiteURL; //Site's URL t58e(dgi
private String sFilePath; //Saved File's Path )9l^O
private String sFileName; //Saved File's Name !l]dR@e
private int nSplitter; //Count of Splited Downloading File Wjhvxk
&nBa=Enf
AdRX`[ik
public SiteInfoBean() <\kr1qHH
{//nSplitter的缺省值为5 iu&wO<)+?
//default value of nSplitter is 5 AKMm&(fh%
this("","","",5); ^P151*=D
} nWQ;9_qBB
;qHOOT
`W/sP\3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #Zrlp.M4
{ =] *.ZH#h
sSiteURL= sURL; mU}F!J#6
sFilePath = sPath; pvmC$n^zc
sFileName = sName; F1L:,.e`
this.nSplitter = nSpiltter; a:QDBS2Llv
rV08ad
M%jPH
} Y"A/^]
UfS%71l.$
.9Y)AtJTS
public String getSSiteURL() ~3uP6\F
{ V<k8N^
return sSiteURL; .tD*2
} o,|[GhtHqs
[1.+HyJ}
@v}/zS
public void setSSiteURL(String value) UTXSeNP
{ g8PTGz
sSiteURL = value; B&D}F=U
} 6k#Jpmmr
`ZC<W]WYX/
y!!2WHvE
public String getSFilePath() S)DnPjN{
{ xyI}y(CN1
return sFilePath; ai0XL}!+
} (<^yqH?
w*R$o
8By|@LO
public void setSFilePath(String value) L|p Z$HB
{ Ol!ntNhXm
sFilePath = value; _%QhOY5tv"
} 6Fe34n]m
}iuWAFZbGS
j_Yp>=+[
public String getSFileName() I_RsYw
{ fkac_X$7
return sFileName; o}ZdTf=
} YpqrZWvh
=ZqT3_
wiiCd
public void setSFileName(String value) ti#7(^j
{ -\C!I
sFileName = value; i-6Z"b{
} ~c\e'&sc;
Qjb:WC7he
.0es3Rj
public int getNSplitter() p|!
{ #'y#"cmQ.
return nSplitter; 4ecP*g
} <)3u6Vky9
0=?<y'=
9g<7i
public void setNSplitter(int nCount) =zz~kon9
{ #"B\UN
nSplitter = nCount; ^jx7@LgS=
} M]J^N#
} O&Y*pOg
pej|!oX
')$+G152
/* 4qk9NK2 U
**Utility.java 9gmW&{6q
*/ !_Wi!Vr_
package NetFox; a24"yT
o7$'cn
\ZkA>oO".
public class Utility { I"ok&^t^}
f.9SB
p9x(D/YP0
public Utility() 5rU[Tir
{ :>C2gS@
0.@&_XTPl
"/wyZ
} h-[VH%
y2^Y/)
//线程睡眠 jWrj?DV,2N
public static void sleep(int nSecond) ye,>A.
{ R21b!Pd\
try{ p"KFJ
Thread.sleep(nSecond); T:=lz:}I
} fSokm4]vg
catch(Exception e) E S//
{ XzEc2)0'v
e.printStackTrace (); s*-n^o-
} TIQkW,
} I+tb[*X+
tg<EY!WY
//日志 vbyH<LPz5
public static void log(String sMsg) lIW }EM
{ bAx-"Lu
System.err.println(sMsg); =ACVE;L?
} 24z< gO
&tg&5_
zN^n]N_?
public static void log(int sMsg) +nJgl8'^y
{ 2h5nMI]'
System.err.println(sMsg); +lHjC$
} Hl{S]]z
} iT2B'QI=<
J4fi'
,[P{HrHx
/* hpO`]
**TestMethod.java o!kbK#k
*/ ~f$|HP}
package NetFox; SAy=WV
e&&53?
I|^;B8[
public class TestMethod { B><d9d
iKX-myCz
]&lY%"U$i
public TestMethod() ^hZ0IM
{ ///xx/weblogic60b2_win.exe )b)-ZS7
try{ xc=b |:A
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^")Q YE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); lh7jux
SiteFileFetch fileFetch = new SiteFileFetch(bean); W\d{a(*
fileFetch.start(); W3MJr&p
} JB<Sl4
catch(Exception e){e.printStackTrace ();} um!J]N^
Rh_np
O$_)G\\\m
} ]>=}*=
/|C*
S4Y&
public static void main(String[] args) l]Ax:Z
{ }fb#G<3
new TestMethod(); +BETF;0D
} TQpfQ
} ' aq!^!z
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