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)); ;IR.6k$;
} ,b t j6hg
for(int i=0;i<nEndPos.length-1;i++) rb]?"lizi
{ |}o3EX
nEndPos = nStartPos[i+1]; x-~=@oiv
} Am"&ApK
nEndPos[nEndPos.length-1] = nFileLength; 5wC,:c[H7
} }`+9ie7]/
} -7VQ{nC
2CV?cm
yg82a7D
//启动子线程 ^MvBW6#1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !d1a9los
for(int i=0;i<nStartPos.length;i++) _W>xFBy
{ HnKXO
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QVkrhwp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e. R9:
nStartPos,nEndPos,i); ggy9euWV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CsN^u H
fileSplitterFetch.start(); cT nC
} vU9:`@beu
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L fZF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;]W@W1)$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rXq{WS`
nEndPos = " + nFileLength); EvF[h:C2
// fileSplitterFetch[nPos.length-1].start(); v4,Dt
wQ81wfr1:
No*[@D]g
//等待子线程结束 H`rd bE
//int count = 0; aAgQ^LY
//是否结束while循环 !1/F71l DX
boolean breakWhile = false; +9B .}t#
~re~Ys
f'TEua_`
while(!bStop) k +Cwnp
{ &"^U=f@v
write_nPos(); sEi9<$~R@0
Utility.sleep(500); ZKai*q4?
breakWhile = true; ZWQ/BgKB
Hz>Dp !
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for(int i=0;i<nStartPos.length;i++) ^ U~QQ
{ 8k;il54#
if(!fileSplitterFetch.bDownOver) #gXxBM
{ -! ^D8^s
breakWhile = false; rl]K:8*
break; e/}4Pt
} 5t-,5
} S:1g(f*85
if(breakWhile) ,(NN)Oj
break; zpZfsn!
PJ^qE|X
J|`.d46
//count++; IRTD(7"oyp
//if(count>4) wZWAx
// siteStop(); pj7v{H+
} 1:J+`mzpl
z7TyS.z
q}W})
System.err.println("文件下载结束！"); )W&{OMr
} ~ 7<M6F
catch(Exception e){e.printStackTrace ();} I+ Y{_yw"f
} OsKtxtLO
[pInF Qh6
*D.Ajd.G
//获得文件长度 `@#rAW D
public long getFileSize() b7B|$T,
{ YLuf2ja}X
int nFileLength = -1; ',/2J0_
try{ 2OQ\ z;s
URL url = new URL(siteInfoBean.getSSiteURL()); |#'n VN.;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l z-I[*bA
httpConnection.setRequestProperty("User-Agent","NetFox"); }Eh &'
O&,8X-Ix
}_5R9w]"
int responseCode=httpConnection.getResponseCode(); hw(\3h()
if(responseCode>=400) B<0Kl.V
{ Sb(OG 6
processErrorCode(responseCode); n#@Qd!uzM
return -2; //-2 represent access is error ;%;||?'v
} kpxGC,I^*.
'.k'*=cq0
M=3gV?N
String sHeader; m=SI *V
g/VV2^,
<y?=;54a
for(int i=1;;i++) d</F6aM\
{ GP^.h kVs
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'by+hXk
//Utility.log(in.readLine()); 4u+0 )<
sHeader=httpConnection.getHeaderFieldKey(i); uqLP$At
if(sHeader!=null) @w`wJ*I4,
{ _*MK"
if(sHeader.equals("Content-Length")) {`,)<R>}
{ dqs~K7O^E
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); eze%RjO}
break; pdvnpzj
} W/AF
} eW;3koE
else e['<.Yf+
break; }1W@
} 8KYIHw
} 8QoxU" c&
catch(IOException e){e.printStackTrace ();} 52zE -SY
catch(Exception e){e.printStackTrace ();} i1!1'T8
[:cvy[}v@
=E<H_cUS
Utility.log(nFileLength); 2TNK
kDI?v6y5
UtP|<]{
return nFileLength; : ^("L,AF
} M:b#">M
cqSXX++CS,
_{-[1-lN5_
//保存下载信息（文件指针位置） }>d
private void write_nPos() }}i'8
{ {M5t)-
try{ *} ?
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~f[ Y;
output.writeInt(nStartPos.length); k5Fj"U
for(int i=0;i<nStartPos.length;i++) igW* {)h3
{ -%@ah:iJ
// output.writeLong(nPos); &*%x]fQ@
output.writeLong(fileSplitterFetch.nStartPos); x~vNUyEN)
output.writeLong(fileSplitterFetch.nEndPos); GEA1y^b6"
} QXN_ ?E,g/
output.close(); X-(4/T+v
} JO+tY[q
catch(IOException e){e.printStackTrace ();} &T~X`{V]`
catch(Exception e){e.printStackTrace ();} @OkoT:
} oLh ,F"nB
8-B7_GoJ+B
Kk6=61}A
//读取保存的下载信息（文件指针位置） 1^^8,.'
private void read_nPos() v"W*@7<`S
{ 6(rN(C
try{ T7^;!;i`X
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [ 'lu;1-,
int nCount = input.readInt(); vg1JN"S[
nStartPos = new long[nCount]; hlB\Xt
nEndPos = new long[nCount]; (+[%^96
for(int i=0;i<nStartPos.length;i++) WFh.oe8
{ (D) KU9B>
nStartPos = input.readLong(); $`55 E(
nEndPos = input.readLong(); _p*8ke
} N)GHQlgH
input.close(); G(TFv\`vH
} 9$HBKcO
catch(IOException e){e.printStackTrace ();} )c{>@WM~
catch(Exception e){e.printStackTrace ();} rpK&OR/
} yV )fJ_
0hV#]`9`gN
nqm=snh
private void processErrorCode(int nErrorCode) Z|%h-~
{ _X~O6e-!
System.err.println("Error Code : " + nErrorCode); #-<Go'yF
} 4&sf{tI
hHU=lnO
^2nrA pF
//停止文件下载 9`*Eeb>
public void siteStop() H8FvI"J
{ $_E.D>5^%7
bStop = true; k#Sr;"
for(int i=0;i<nStartPos.length;i++) /HpM17
fileSplitterFetch.splitterStop(); +tT"
~x\uZ^:
>&KH!:OX|
} Q(nTL WW
} q.`<q
//负责部分文件的抓取 $Gv@lZ@=
**FileSplitterFetch.java >kK@tJn
*/ eIY`RMo (
package NetFox; |HD>m'e
"TZY)\{L
"!V`_ S;
import java.io.*; ]s AuL!
import java.net.*; (.cA'f?h
r|u[36NmA
zR?R,k)m
public class FileSplitterFetch extends Thread { _ZK^JS
N*}soMPV^.
N68$b#9Ry
String sURL; //File URL k`8O/J
long nStartPos; //File Snippet Start Position t4_yp_
long nEndPos; //File Snippet End Position ?J2A1iuq3
int nThreadID; //Thread's ID <&l$xn
boolean bDownOver = false; //Downing is over MmN{f~Kq9
boolean bStop = false; //Stop identical #0aBQ+_8H
FileAccessI fileAccessI = null; //File Access interface eTvWkpK+
['=O>YY
"Zgwe,#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException EGUlLqP6e
{ 7,+eG">0
this.sURL = sURL; x?{UWh%
this.nStartPos = nStart; oxlor,lw/
this.nEndPos = nEnd; IDH~nMz
nThreadID = id; 6I +0@,I
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ES&u*X:
} ly17FLJ].
k8+J7(_c
hhy+bA}
public void run() )bOfs*S
{ z/1$G"
while(nStartPos < nEndPos && !bStop) =#Sw.N
{ C!*!n^qA
='o3<}
0w3c8s.
try{ FfJ;r'eGs
URL url = new URL(sURL); ?l/6DT>e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q:(mK* _
httpConnection.setRequestProperty("User-Agent","NetFox"); W/!P1M n
String sProperty = "bytes="+nStartPos+"-"; djOjd,
httpConnection.setRequestProperty("RANGE",sProperty); 3y}E*QE
Utility.log(sProperty); d^aVP
P[ :_"4U
g8##Be
InputStream input = httpConnection.getInputStream(); 51q|-d
//logResponseHead(httpConnection); u]IbTJ'
kWXLncE
PR.3EL
byte[] b = new byte[1024]; ,*XB11P
int nRead; v.-DXQq
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >>P5 4|&
{ <u!cdYo@
nStartPos += fileAccessI.write(b,0,nRead); aZ4EcQ@-$]
//if(nThreadID == 1) +)sX8zb*gY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lA5Dag'
} n^4R]9U
2CzhaO
(?|M'gZ
Utility.log("Thread " + nThreadID + " is over!"); p"ytt|H
bDownOver = true; p0@^1
//nPos = fileAccessI.write (b,0,nRead); GEWjQ;g
} v745FIy<
catch(Exception e){e.printStackTrace ();} {|?^@
} '[{<aEo
} ^HC6v;K
p@Y=6Bw
bqcCA91
//打印回应的头信息 AEyvljv
public void logResponseHead(HttpURLConnection con) /sA&}kX}E
{ UY< PiP
for(int i=1;;i++) %qoS(iO`h
{ ] 4dl6T
String header=con.getHeaderFieldKey(i); y/Xs+ {x
if(header!=null) al9wNtMT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q1,sjLO-a
Utility.log(header+" : "+con.getHeaderField(header)); YExgUE|
else l^lb ^"o
break; M|*YeVs9#
} 7)lEZJK&T
} m-Eh0Zl>Z
dz_S6o ]
R*[sO*h\k
public void splitterStop() =fcg4h5(
{ KxkBP/`3Q
bStop = true; yq%5h[M
} u.GnXuax
1r;zA<<%R
*&NP?-E
} Xqf,_I=V
|THpkfW
:o'x?]
/* o!M8V ^vW
**FileAccess.java 4Z)s8sDKW
*//文件访问(定位，写) ~bLx2=-"
package NetFox; \R#SoOd
import java.io.*; )'djqpM.
%k!CjW3
npdljLN
public class FileAccessI implements Serializable{ 928_e)V
^#Ii=K-[^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <u64)8'
RandomAccessFile oSavedFile; T}#iXgyx
long nPos; Hb)FeGsd).
w' 7sh5
c7e,lgG-
public FileAccessI() throws IOException {X!OK3e
{ /WuYg OI
this("",0); C~ 1]
} VXeO}>2S
EgjJywNhd2
\2\{c1df
public FileAccessI(String sName,long nPos) throws IOException >+2&7u
{ 9kL,69d2
oSavedFile = new RandomAccessFile(sName,"rw"); U+Y(:
this.nPos = nPos; z#*.9/y\^R
oSavedFile.seek(nPos); .xRdKt!p
} y\?ey'o
f"ezmZI
n|i:4D
public synchronized int write(byte[] b,int nStart,int nLen) Rf:.'/<^
{ #<*Vc6pC
int n = -1; AC,RS7
try{ -o ).<&#
oSavedFile.write(b,nStart,nLen); FdU]!GO-X
n = nLen; Gw*Tz"
} {&51@UX
catch(IOException e) 7r:h_r-
{ '~[8>Q>
e.printStackTrace (); 5J5?cs-!
} w#"\*SKK
^tB1Nu%
#Bd]M#J17a
return n; bZnOX*y]
} 5hrI#fpOR
H"A%mrb
>e;-$$e
} qRt!kWW
+?_!8N8
>US*7m }
/* $L/`nd
**SiteInfoBean.java :{7+[LcH7
*/ Xg)8}
package NetFox; KkJqqO"EL
P?0X az
t<H"J__&
public class SiteInfoBean { 86ao{l6lC
.U1wVIM
P'W} ]mCD
private String sSiteURL; //Site's URL Ln+l'&_nb
private String sFilePath; //Saved File's Path wI.aV>
private String sFileName; //Saved File's Name S=UuEmU5N
private int nSplitter; //Count of Splited Downloading File cAWn*%
Uj!3MF
o@:"3s
public SiteInfoBean() - x
{//nSplitter的缺省值为5 9[0iIT$q$
//default value of nSplitter is 5 v] m/$X2
this("","","",5); NoI|Dz
} o4Q?K.9c
QYH-"-)
\nl(tU#j
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) SI7rTJ]/
{ -C=0Pg]ga
sSiteURL= sURL; `[/#,*\
sFilePath = sPath; "5hk%T'
sFileName = sName; U&^q#['
this.nSplitter = nSpiltter; :j\7</uu
&jqaW2
)x.%PUA
} iU)I"#\l'k
T ,lM(2S[
}3Es&p$9
public String getSSiteURL() MxE]EJZ
{ `|t,Uc|7!
return sSiteURL; k&Pt\- 9on
} &YhAB\Rw
w~3X m{
h@,ja
public void setSSiteURL(String value) sy&[Q{,4
{ J%&LQ9
sSiteURL = value; z:QDWH
} bZu'5+(@
R"nB4R0Uh
mqSVd^
public String getSFilePath() }lZEdF9GhG
{ GBJLB
return sFilePath; cO?*(e1m=
} 74%vNKzc~
~1G^IZ6
ptCF))Zm'
public void setSFilePath(String value) T4eJ:u*;
{ I68u%fCv
sFilePath = value; Y{Z&W9U
} 8v$q+Wic
E0Wc8m"
T7[@ lMa?
public String getSFileName() O NabL.CV
{ hx$]fvDevD
return sFileName; J)|3jbX"I]
} 4]d^L>
IwyA4Ak Ru
b?~p/[
public void setSFileName(String value) rj4@
{ 5P,&VB8L
sFileName = value; <A3%182
} ni;_Un~
K~(RV4oF8B
DUOoTlp
public int getNSplitter() g)hEzL0k
{ v\xl?F
return nSplitter; $>rt0LOF
} mGT('iTM4
x9lA';})
AL]gK)R
public void setNSplitter(int nCount) .$U,bE
{ QV|6"4\
nSplitter = nCount; JPI%{@Qc^
} 6 @f>
} vs@d)$N
ETDWG_H |
oz!)x\m*H
/* `z!AjAT-G
**Utility.java z'L0YqXG/
*/ ~Ntk-p
package NetFox; T3w%y`K
*C*J1JYp+
DB}Uzw|
public class Utility { 6-U_TV
9q;O`&
!BQt+4G7
public Utility() $QJ3~mG2
{ *i"9D:
;,{_=n>
E$"NOR
} @@Ib^sB%
?9 huuJs7
//线程睡眠 AR|4^
public static void sleep(int nSecond) 91R#/i
{ YidcVlOsO
try{ Wa;N(zw0h
Thread.sleep(nSecond); O8;/oL4 U
} `d <`>
catch(Exception e) Q{/z>-X\x
{ t=%zY~P
e.printStackTrace (); j0l{Mc5
} J6 ~Sr
} N&8$tJ(hhx
( 5LCy?-6
//日志 P1F-Wy1
public static void log(String sMsg) -}7$;QK&a
{ dL42)HP5
System.err.println(sMsg); {"o9pIh{~
} *@rA7zPFf
]d*9@+Iu
oW~W(h!
public static void log(int sMsg) Zkp~qx
{ F^l1WX6
System.err.println(sMsg); gT}H B.
} 1AJ6NBC&c
} Vgm*5a6t
XIcUoKg^
^".OMS"!
/* & SXw=;B
**TestMethod.java yP58H{hQM8
*/ 7?dWAUF
package NetFox; O-, "/Z
* + T(i
! ._q8q\
public class TestMethod { &}DfIP<
y##h(y
.}__XWK5
public TestMethod() CW1l;uwtU
{ ///xx/weblogic60b2_win.exe 9p_?t'&>q
try{ @a8lF$<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); BlJiHz!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p4T$(]7
SiteFileFetch fileFetch = new SiteFileFetch(bean); b0~r/M;J
fileFetch.start(); n/9afIN
} ':.Hz]]/A
catch(Exception e){e.printStackTrace ();} :1+Aj (
@.;+WQE
}geb959
} ,dRaV</2
93*csO?Db
p%I)&- 8
public static void main(String[] args) N[Z`tk?-
{ &d6@SQ
new TestMethod(); =-sTV\
} u`|%qRt
} jE0oLEg&
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