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)); sURUQ H
} c#]'#+aH
for(int i=0;i<nEndPos.length-1;i++) 2U-#0,ll]
{ p.6$w:eV
nEndPos = nStartPos[i+1]; Y\ #.EVz
} i{Y=!r5r
nEndPos[nEndPos.length-1] = nFileLength; Z"teZ0H
} ]>]#zu$=c
} QO1A976o
6i*ArGA
S3%.-)ib
//启动子线程 .WN;TjEg!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I!C(K^
for(int i=0;i<nStartPos.length;i++) qat45O4A1
{ {hW +^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~9`^72
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), g=8|z#S
nStartPos,nEndPos,i); ):|G kSm
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TFiuz;*|
fileSplitterFetch.start(); 7I2a*4}
} SX1Fyy6 w
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T! &[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rahHJp.Ws
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7Va#{Y;Zy
nEndPos = " + nFileLength); n?<# {$
// fileSplitterFetch[nPos.length-1].start(); .N2nJ/
EOd.Tyb!/
*IMF4x5M
//等待子线程结束 Pj1K
//int count = 0; =]5DYRhX]
//是否结束while循环 y]~+`9
boolean breakWhile = false; S0Rf>Eo4
G#9o?
}J'5EAp
while(!bStop) a<a&63
{ E.7AbHph0
write_nPos(); e')&ODQ H
Utility.sleep(500); nN_94 ZqS<
breakWhile = true; !Vp,YN+yN
^C,/T2>
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for(int i=0;i<nStartPos.length;i++) _D7HQ
{ H3UX{|[
if(!fileSplitterFetch.bDownOver) o2 T/IJP
{ 7Ap~7)z[
breakWhile = false; Mc#O+'](f
break; vV:MS O'r
} WwCK K
} LX(iuf+l
if(breakWhile) 4z-,M7iP
break; >[E|p6jgT
Mo/2,DiI5
"df13U"
//count++; A .jp<>
//if(count>4) \gJapx(
// siteStop(); Hb@G*L$
} 7(+OsE
e GqvnNv
pjmGzK
System.err.println("文件下载结束！"); }LHT#{+x
} &bS"N)je
catch(Exception e){e.printStackTrace ();} @gu77^='
} }jyS\drJ
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0$F _hZU
//获得文件长度 0^)8*O9$
public long getFileSize() E{+c*sz
{ 98b9%Z'2f
int nFileLength = -1; Z)6nu)
try{ ZB_16&2Ow
URL url = new URL(siteInfoBean.getSSiteURL()); \^;|S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gn[$;*932z
httpConnection.setRequestProperty("User-Agent","NetFox"); n_xa)
SG+i\yu$h0
\/x)BE,
int responseCode=httpConnection.getResponseCode(); 6ljRV)
if(responseCode>=400) *k@0:a(>
{ |/T<]+X;
processErrorCode(responseCode); JQbMw>Y
return -2; //-2 represent access is error ]` &[Se d
} D"(3VIglq
ai;gca_P#
Vx7Dl{?{'
String sHeader; {Y@-*pL]
hI>rtaY_
.1[2 CjQ
for(int i=1;;i++) hklO:,`
{ dPyBY]`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); z7.C\l
//Utility.log(in.readLine()); faL^=CAe
sHeader=httpConnection.getHeaderFieldKey(i); gQk#l\w_
if(sHeader!=null) ~d#;r5>
{ Y+"hu2aPkY
if(sHeader.equals("Content-Length")) [ilv/V<
{ &"H<+>`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x9o^9QJh
break; xJH9qc ME
} @cTZ`bg
} 'j,Li(@}
else OCOO02Wq1
break; 4f*Ua`E_
} p$b=r+1f
} !ovZ>,1
catch(IOException e){e.printStackTrace ();} cJ(zidf_$
catch(Exception e){e.printStackTrace ();} \dxW44sM
pD}VB6=
_G}CD|Kx
Utility.log(nFileLength); }r<@o3t
{GH`V}Ob
x}8T[
return nFileLength; n.8A Ka6
} +O!M>
&"j).Ogm4
G}?P r4Gj
//保存下载信息（文件指针位置） >y06s{[
private void write_nPos() @#ho(_U8
{ l]klV+9t
try{ Bg+]_:<U
output = new DataOutputStream(new FileOutputStream(tmpFile)); D-+)M8bt
output.writeInt(nStartPos.length); D'sboOY
for(int i=0;i<nStartPos.length;i++) Cp~3Jm3
{ B 1ZHV^
// output.writeLong(nPos); 4M<JfD
output.writeLong(fileSplitterFetch.nStartPos); m|cWX"#g
output.writeLong(fileSplitterFetch.nEndPos); b\|p
} PHiX:0zT
output.close(); cT=wJ
} L};;o+5uJD
catch(IOException e){e.printStackTrace ();} ,w/mk$v
catch(Exception e){e.printStackTrace ();} MCrO]N($b
} l^eNZ3:H
<11Tqb
O]%m{afM
//读取保存的下载信息（文件指针位置） a_iQlsU
private void read_nPos() xP/1@6]_Je
{ |`t!aG8
try{ C7 & 6rUX
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^B6i6]Pd=9
int nCount = input.readInt(); n.qxxzEN
nStartPos = new long[nCount]; Z"%O&O
nEndPos = new long[nCount]; ;R|#ae@
for(int i=0;i<nStartPos.length;i++) ~:b:_ 5"
{ >LaL!PnZ
nStartPos = input.readLong(); 1q233QSW)
nEndPos = input.readLong(); =&*QT&e
} ~G^}2#5
input.close(); QB|fFj58u
} .lF\bA|
catch(IOException e){e.printStackTrace ();} =wR]X*Pan
catch(Exception e){e.printStackTrace ();} 46?F+,Rzl
} U#]eN[
Py25k 0j!
c'Tu,-
private void processErrorCode(int nErrorCode) 7D~O/#dcc
{ SnF[mN'
System.err.println("Error Code : " + nErrorCode); _Il9s#NA%
} qfH~hg
0|>
|e[0Qo@
//停止文件下载 xjbyI_D
public void siteStop() 0S5C7df
{ _}9R}
bStop = true; >=W#z
for(int i=0;i<nStartPos.length;i++) JO^ [@
fileSplitterFetch.splitterStop(); ^FMa8;'o
.rB;zA;4S)
]3y5b9DuW
} &MQt2aL
} #`L}.
//负责部分文件的抓取 &eS70hq
**FileSplitterFetch.java 6'*Uo:]
*/ /uz5V/i0
package NetFox; ?N?pe}
= SJF\Z
%iS]+Sa.K
import java.io.*; +2fJ
import java.net.*; @[kM1:G-F{
Jx>B %vZ\
pD6g+Taj
public class FileSplitterFetch extends Thread { ;I))gY-n
DfzUGX
xv%USm
String sURL; //File URL )W6-h
long nStartPos; //File Snippet Start Position 3XlnI:w=
long nEndPos; //File Snippet End Position MMr7,?,$
int nThreadID; //Thread's ID '=5_u
boolean bDownOver = false; //Downing is over 5 /jY=/0.a
boolean bStop = false; //Stop identical a<"& RnG(
FileAccessI fileAccessI = null; //File Access interface ?_j6})2zY
p}zk&`
sCCr%r]zL
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vrnj}f[h
{ nK'8Mo
this.sURL = sURL; %+B-Z/1}
this.nStartPos = nStart; vG_v89t!ex
this.nEndPos = nEnd; 0t[mhmSU,
nThreadID = id; sr@XumT
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }_/h~D9-T#
} ^W[`##,{Od
4-rI4A<
C(*@-Npf[
public void run() j=QR*8*
{ 2/4x]i H*
while(nStartPos < nEndPos && !bStop) .'mC3E+$
{ S,9WMti4x
14YV#o:
-x\l<\*
try{ c%/&@vs7
URL url = new URL(sURL); UVmyOC[Y{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d?y\~<
httpConnection.setRequestProperty("User-Agent","NetFox"); 0@x$Cp
String sProperty = "bytes="+nStartPos+"-"; B:#0B[
httpConnection.setRequestProperty("RANGE",sProperty); ~)IJE+e>}
Utility.log(sProperty); WJ4UJdf'
@%G"i:HZ&
`/ReJj&~
InputStream input = httpConnection.getInputStream(); uWtS83i
//logResponseHead(httpConnection); 2pNJWYW"
)bU")
fvMhq:Bu
byte[] b = new byte[1024]; bK;aV&
int nRead; IeI%X\G
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |A/_Qe|s2
{ |Pl{Oo+
nStartPos += fileAccessI.write(b,0,nRead); [Q_|6Di
//if(nThreadID == 1) /~huTKA}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LF.~rmPa
} HtYR 0J
n]c,0N
'wlP`7&Tn
Utility.log("Thread " + nThreadID + " is over!"); 6U9Fa=%>}
bDownOver = true; X&oy.Roo
//nPos = fileAccessI.write (b,0,nRead); -vfu0XI~
} mf[79:90^
catch(Exception e){e.printStackTrace ();} o? "@9O?
} WvzvGT=
} 5d{Ggg{s
pcTXTy 28
@wJa33QT
//打印回应的头信息 #|h8u`
public void logResponseHead(HttpURLConnection con) pdqa)>$
{ aMg f6veM
for(int i=1;;i++) IMrOPwjc
{ ?o5#Ve$-X
String header=con.getHeaderFieldKey(i); -mo ' $1
if(header!=null) %)ov,p|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); T\CQ
Utility.log(header+" : "+con.getHeaderField(header)); @Hdg-f>y]
else > 0)`uJ
break; c;}n=7,>:L
} `|?$; )
} @7 HBXP
\J&#C(pn
:Zo2@8@7
public void splitterStop() 5MU@g*gj,C
{ *<QL[qyV
bStop = true; 9sU,.T
} l<_mag/j9o
'6J$X-
Eakjsk
} H4A+Dg,
3zF7V:XH
S9+gVR8]C
/* Dq4}VkY
**FileAccess.java J&1N8Wk)
*//文件访问(定位，写) ~M1%,]
package NetFox; 2]f.mq_PD
import java.io.*; 2+cicBD
lS*.?4zX
3edK$B51;
public class FileAccessI implements Serializable{ , )3+hnFY
ZaindX{.1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 G)|HFcE
RandomAccessFile oSavedFile; jF85bb$
long nPos; 5z]KkPQ
=H?5fT^
oD1=}
public FileAccessI() throws IOException HOb\Hn|6jq
{ Z i&X ,K~
this("",0); d0E5;3tQ
} ED&KJnquWJ
W\Y 4%y}
q`zR6
public FileAccessI(String sName,long nPos) throws IOException S^=/}PT'
{ 30`H Xv@
oSavedFile = new RandomAccessFile(sName,"rw"); n:kxG
this.nPos = nPos; ~36XJ
oSavedFile.seek(nPos); S]@iS[|?
} .sMi"gg
[T|1Qq7
)dDmq
public synchronized int write(byte[] b,int nStart,int nLen) (:]iHg3
{ WTN!2b
int n = -1; ,W;8!n0
try{ /^ 7 9|$E
oSavedFile.write(b,nStart,nLen); kIo?<=F8T
n = nLen; e$I:[>
} -q|M=6gOs
catch(IOException e) Q-CVq_\3I
{ 7@]hu^)rry
e.printStackTrace (); 2mG?ve%m)
} #2,L)E\G8e
;yrcH+I$_
WG4|Jf Y
return n; &_gmQ;%t:
} l%/,Ef*3
$"1&!
U?yXTMD
} u{G6xuPWf
'11hIu=:
Hb4rpAeP
/* (b!DJ;(O9
**SiteInfoBean.java ePdzQsnVe
*/ k Er7,c
package NetFox; :D-vE7
aW5~z^I
]z NL+]1_
public class SiteInfoBean { xSZw,
I!~Omr@P
0Z(b/fdS
private String sSiteURL; //Site's URL VlvDodV
private String sFilePath; //Saved File's Path ypVr"fWB
private String sFileName; //Saved File's Name e@YR/I8my
private int nSplitter; //Count of Splited Downloading File ?Kf@/jv
aS2 Y6
_: x$"i
public SiteInfoBean() e&nw&9vo
{//nSplitter的缺省值为5 VNPdL
//default value of nSplitter is 5 _95tgJy
this("","","",5); ${3OQG
} L.[2lQ
VtFh1FDI\
r?*?iw2g
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) d~%Rnic6*
{ bN)?szh&Y
sSiteURL= sURL; TA5M4r6
sFilePath = sPath; lN"rhZ
sFileName = sName; beoMLHp
this.nSplitter = nSpiltter; so?1lG
}o.ZCACYg
c:5BQr '
} G<DUy^$i
7ac3N
/8R1$7
public String getSSiteURL() E u
{ (reD
return sSiteURL; u:|5jF
} z/=v@@tj
G#>X~qk()
hBw~l?G
public void setSSiteURL(String value) kPe9G
{ hz|$3*q
sSiteURL = value; hJ :+*46
} m? hX=
ap!<8N
!)]3@$#
public String getSFilePath() A`Nb"N$H13
{ up?8Pq*
return sFilePath; *V}}3Degh
} 7Ll(,i<,C
?a}~yz#B(
:OM>z4mQ
public void setSFilePath(String value) \I=:,cz*,
{ + h&V;
sFilePath = value; .^,vK7
} z?^p(UH
%/y/,yd
>v{m^|QqB
public String getSFileName() Qt$Q/<8U
{ ;I0/zeM%
return sFileName; ?{'Q}%
} CpXv?uU
S3m+(N"&
rX[R`,`>Z[
public void setSFileName(String value) O%I'
{ *`W82V
sFileName = value; bH&H\ Mx_k
} 6SwHl_2%
zob-z=='
w_ m
public int getNSplitter() (g\'Zw5bk
{ )yk LUse+
return nSplitter; Sn]A0J_
} W0|?R6|
tg:x}n
V/Tp&+Z.c
public void setNSplitter(int nCount) WJ@,f%=<~
{ 1<F/boF~
nSplitter = nCount; lF<(yF5
} i || /=ai
} Y!H"LI
11uqs S2
wU3Q
/* Q. >"@c[
**Utility.java bCsQWsj^NW
*/ s`{O-
package NetFox; uf6{M_jXZ
:;EzvRy
PHoW|K_e
public class Utility { $8Zw<aEJ
Jad'8}0J
4PdFq*A
public Utility() 0Z\fK>yw
{ 1/z1~:Il
vDemY"wz
S=o/n4@}
} E5rNC/Ul$$
pD{Li\LY
//线程睡眠 1+]e?
public static void sleep(int nSecond) SWu=n1J.?H
{ 84k;d;
try{ Y9C]-zEv
Thread.sleep(nSecond); zr,jaR;
} Cpr}*A
catch(Exception e) QeK~A@|F&
{ jooh`| `P
e.printStackTrace (); X,p&S^
} w/R^Vwq
} 2c}kiqi{
#M:W?&.
//日志 ^E9@L??
public static void log(String sMsg) :Q%&:[2
{ mU*GcWbc+
System.err.println(sMsg); *I~F7Z]|
} e='3gzz
a*=e 3nS
,}NG@JID
public static void log(int sMsg) k;%}%"EVZ
{ sbRg=k&Ns
System.err.println(sMsg); =zsXa=<
} Ws=J)2q
} Z/64E^
(T@ov~@
|(wx6H:
/* k&Sg`'LG8
**TestMethod.java 'h:4 Fzo<
*/ _PuMZjGL
package NetFox; 2 `#|;x^<
%j=7e@
X/@Gx 4
public class TestMethod { pgI@[zp7
sg3%n0Ms.W
k07O.9>
public TestMethod() !a0HF p$9
{ ///xx/weblogic60b2_win.exe U_w)*)F
try{ ':HV9]k
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <)M?qkjb
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]^s4NXf+
SiteFileFetch fileFetch = new SiteFileFetch(bean); p0-\G6
fileFetch.start(); qoEOM%dAqV
} (A1!)c
catch(Exception e){e.printStackTrace ();} }ts?ZR^V,
7UMsKE-
iJ~pX\FKO
} GU=h2LSi]
1aSuRa
$BG9<:p
public static void main(String[] args) pt<84CP
{ g|W~0A@D
new TestMethod(); r8@:Ko= a
} hj-M #a
} E;%{hAD{
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