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)); 6(PM'@i
} @{Gncy|
for(int i=0;i<nEndPos.length-1;i++) E7-@&=]v
{ Ov<NsNX]
nEndPos = nStartPos[i+1]; fhB}9i^]tg
} 0p89: I*0
nEndPos[nEndPos.length-1] = nFileLength; UA|u U5Q
} 1}~(Yj@f%
} A 7[:5$
'vNG(h#%d
)8g(:`w
//启动子线程 A$6$,h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; SwZA6R&
for(int i=0;i<nStartPos.length;i++) e{Z &d
{ EJ2yO@5O
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <FZ@Q[RP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e}1uz3Rh
nStartPos,nEndPos,i); ^pHq66d%Z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); },|M9I0
fileSplitterFetch.start(); +^;JS3p@\
} <$JaWL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s(W|f|R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); A_KW(;50
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >M&3Y XC
nEndPos = " + nFileLength); ](|\whI
// fileSplitterFetch[nPos.length-1].start(); 0Won9P
QY== GfHt
Y3Q9=u*5
//等待子线程结束 $ImrOf^qt
//int count = 0; Y`?-VaY
//是否结束while循环 Dc)dE2
boolean breakWhile = false; s.8{5jVG
Z1"v}g
X.:]=,aGW
while(!bStop) 2;w*oop,O
{ 5h;+Ky!I
write_nPos(); ->N8#XH2=
Utility.sleep(500); zXRlo]
breakWhile = true; CirZ+o
6Cp]NbNrq
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for(int i=0;i<nStartPos.length;i++) 23gPbtq/
{ AlJ} >u
if(!fileSplitterFetch.bDownOver) r(9~$_(vK
{ XVU2T5s}
breakWhile = false; kZ"BBJ6w
break; =FD;~
} B5$kHM%p
} :,)lm.}]t
if(breakWhile) _o8?E&d
break; o=1X^,
/&4U6a
X]y)qV)a[c
//count++; Z@r.pRr'
//if(count>4) 6^DR0sO
// siteStop(); $q 2D+_
} q:g2Zc'Y~W
)vxUT{;sH
A`R{m0A
System.err.println("文件下载结束！"); /t(C>$ }p
} mx=BD'
catch(Exception e){e.printStackTrace ();} U,LTVYrO
} %Rsp;1Z
xMBaVlEN
- |gmQG
//获得文件长度 LW(6$hpPp
public long getFileSize() !kC*g
{ 8,uB8C9
int nFileLength = -1; Nv"EV;$
try{ )RcL/n
URL url = new URL(siteInfoBean.getSSiteURL()); ]~3U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V(E/'DR
httpConnection.setRequestProperty("User-Agent","NetFox"); ccL~#c0P7
9H%X2#:fH
h;0S%ZC
int responseCode=httpConnection.getResponseCode(); VJS8)oI~
if(responseCode>=400) YX#-nyK
{ I"`M@ %
processErrorCode(responseCode); e>AE8T
return -2; //-2 represent access is error {`w;39$+
} R=KQ
vI@%Fg+D
|n] d34E
String sHeader; FJd]D[h
jQ)T67
Mec5h}^
for(int i=1;;i++) [n/hkXa$\
{ .c$316
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }-@`9(o`)
//Utility.log(in.readLine()); }RP@!=
sHeader=httpConnection.getHeaderFieldKey(i); *Aa?yg:=
if(sHeader!=null) !3ctB3eJ
{ n\Lb.}]1~
if(sHeader.equals("Content-Length")) =J~ x
{ &>Vfa
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [0D Et
break; _(KbiEB{
} 3@]SKfoo1
} /g4f`$a
else aT`%;i^
break; <Z/x,-^*<
} r4#o+qE
} Ggb5K8D*
catch(IOException e){e.printStackTrace ();} <=,6p>Eo[
catch(Exception e){e.printStackTrace ();} -uy`!A
Kx%Sku<F'
2j&AiD
Utility.log(nFileLength); cSm%s
B9J&=6`)
(V HL{rj
return nFileLength; y(xJTj
} jfqopiSi
H_QsNf
P$-X)c$&
//保存下载信息（文件指针位置） DX|# gUAm
private void write_nPos() f^.AD-
{ X<*U.=r)
try{ Alxx[l\<J
output = new DataOutputStream(new FileOutputStream(tmpFile)); eD#hpl
output.writeInt(nStartPos.length); 2TA*m{\Hr
for(int i=0;i<nStartPos.length;i++) /ID?DtJ
{ x>Jr_A(
// output.writeLong(nPos); GbaEgA'fa
output.writeLong(fileSplitterFetch.nStartPos); f-71~
output.writeLong(fileSplitterFetch.nEndPos); x UD-iSY
} qZA).12qS
output.close(); `FC(
} Kc^;vT>3
catch(IOException e){e.printStackTrace ();} LoGVwRmoC
catch(Exception e){e.printStackTrace ();} +PuPO9jKO@
} #&7}-"Nd
2m2;t0
=7o"u3hG
//读取保存的下载信息（文件指针位置） ?%y?rk <
private void read_nPos() ) v,:N.@Q
{ Ck|8qUz-
try{ Ht4;5?/y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5kz)5,KjM
int nCount = input.readInt(); ,c)uX#1
nStartPos = new long[nCount]; 4%3Mb-#Y]
nEndPos = new long[nCount]; QhK#Y{xY
for(int i=0;i<nStartPos.length;i++) SE~[bT
{ ..R-Ms)k=
nStartPos = input.readLong(); [bk?!0]aV
nEndPos = input.readLong(); KFwzy U"
} yu/`h5&*
input.close(); |1>*;\o-
} c*@E_}C#
catch(IOException e){e.printStackTrace ();} g'm+/pU)w)
catch(Exception e){e.printStackTrace ();} 1OF& *
} E3iW-B8u8
A`}rqhU.{-
^:Gie
private void processErrorCode(int nErrorCode) n= u&uqA*
{ &sL&\+=<(
System.err.println("Error Code : " + nErrorCode); ?28N ^
} M%0C_=zg
JQ@E>o7_
[YcG(^^
//停止文件下载 McQe1
public void siteStop() d$Pab*
{ 2FW\O0U
bStop = true; oczN5YSt
for(int i=0;i<nStartPos.length;i++) \0f{S40
fileSplitterFetch.splitterStop(); W0]gLw9*
5qP:/*+
qDfd.gL
} [F6U+1n8e
} SK#(#OQoh
//负责部分文件的抓取 *9{Z$IA9w
**FileSplitterFetch.java 7F{3*`/6
*/ '5|h)Q5
package NetFox; |]X
k<\$OoOZ
&E=>Hj(dTG
import java.io.*; UaB @
import java.net.*; 8{X"h#
3^6 d]f
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public class FileSplitterFetch extends Thread { H,u<|UMM_
eF3,2DDC
{>)#HD
String sURL; //File URL G8Y<1%`<
long nStartPos; //File Snippet Start Position % V8U(z
long nEndPos; //File Snippet End Position #Ibp(
int nThreadID; //Thread's ID 2P@sn!*{1
boolean bDownOver = false; //Downing is over uvG]1m#
boolean bStop = false; //Stop identical dKxyA"@
FileAccessI fileAccessI = null; //File Access interface _`:1M2=
csW43&
L=sYLC6d
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [S>2ASj
{ AGYc |;
this.sURL = sURL; 7*Ej. HK
this.nStartPos = nStart; j+,d^!
this.nEndPos = nEnd; @-!}BUs?
nThreadID = id; suzZdkMA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 65aK2MS@
} %YC_Se7
1BpiV-]=
hj.a&%
public void run() bKN@j'M
{ <yH4HY
while(nStartPos < nEndPos && !bStop) +yD`3` E
{ <,e+ kL{
v63"^%LX
?I~()]k5
try{ <yNM%P<Oy
URL url = new URL(sURL); V13N}]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 70Wggty
httpConnection.setRequestProperty("User-Agent","NetFox"); ?1K#dC52#
String sProperty = "bytes="+nStartPos+"-"; vbC\?\_
httpConnection.setRequestProperty("RANGE",sProperty); W1|0Yd ;P
Utility.log(sProperty); K#=*9S
EH! q=&d
< F.hZGss7
InputStream input = httpConnection.getInputStream(); 3GhRWB-U
//logResponseHead(httpConnection); !~rY1T~
NP/Gn6fr
P<a)25be/
byte[] b = new byte[1024]; jT]0WS-b
int nRead; :6Lx@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Yd=>K HVD
{ sEGO2xeI
nStartPos += fileAccessI.write(b,0,nRead); [8*jw'W|[
//if(nThreadID == 1) ^!<BQP7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L"4mL,
} ^5h]Y;tx
;E3>ay6m8
SfaQvstN
Utility.log("Thread " + nThreadID + " is over!"); $4 S@
bDownOver = true; [nrYpb4
//nPos = fileAccessI.write (b,0,nRead); G?;e-OhV
} f-`)^5E
catch(Exception e){e.printStackTrace ();} 6MT1$7|P&x
} Z:sg}
} YH\OFg@7
)\J+Kiy)
1Y7Eajt-5
//打印回应的头信息 V4'YWdTi
public void logResponseHead(HttpURLConnection con) HoRg^Ai?\
{ )quM4=u'
for(int i=1;;i++) A|X">,A
{ /7|V+6jV
String header=con.getHeaderFieldKey(i); ; Q3n
if(header!=null) 'kL#]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <~n"m
Utility.log(header+" : "+con.getHeaderField(header)); %)/P^9I6
else ;kS&A(
break; ~&7MkkftM
} 06c>$1-?
} OHb[qX\
+RYls|f
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public void splitterStop() ]pNvxXbeW
{ 1+jAz`nA:T
bStop = true; qQ?"@>PALD
} -y8`yHb_
=E.t`x=
]%wVHC
} N`L0Vd
=WyZX 7@R
LE9(fe) fe
/* ToXki,
**FileAccess.java MbZJ;,e?
*//文件访问(定位，写) N D(/uyI
package NetFox; di6QVRj1
import java.io.*; _/6!yyl
zxbpEJzpn
rA5=dJ"I
public class FileAccessI implements Serializable{ #xQr<p$L6
p~BRh
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,!Z*5
RandomAccessFile oSavedFile; DRp~jW(\y
long nPos; :UF%K>k2
lyy W
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public FileAccessI() throws IOException \eT5flC
{ bzuEfFaL
this("",0); r^3acXl
} -EkWs/'h
'B 43_
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public FileAccessI(String sName,long nPos) throws IOException z$/_I0[
{ ;*:]*|bw
oSavedFile = new RandomAccessFile(sName,"rw"); f78An 8
this.nPos = nPos; >0ph9$
oSavedFile.seek(nPos); Mn2QZp4
} lOuHVa*}
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pb ~uE
public synchronized int write(byte[] b,int nStart,int nLen) ]* F\"C@
{ j.w@(<=x
int n = -1; aI6$?wus
try{ h]5C|M|
oSavedFile.write(b,nStart,nLen); JORGj0v
n = nLen; aB{vFTD5
} )z73-M V"
catch(IOException e) q Gw -tPD<
{ /%}*Xh
e.printStackTrace (); u09:Z{tL;@
} -0$55pa/@:
>VP=MbN
`\gnl'
return n; E*V`":efS
} s.N7qO^:E
K1r#8Q!t
8S mCpg
} H:t$'kb`
E9Np0M<
pQ=>.JU
/* Y;@>b{s
**SiteInfoBean.java 1zm ulj%&
*/ Z~oo;xE
package NetFox; 5iz{op<$,
5!DBmAB
wQP^WzNE
public class SiteInfoBean { e vrXo"3
[SHXJ4P*
%k-3?%&8
private String sSiteURL; //Site's URL ein4^o<f.
private String sFilePath; //Saved File's Path CFzNwgv]z
private String sFileName; //Saved File's Name Rzbj
private int nSplitter; //Count of Splited Downloading File s>;v!^N?u
4zev^FR
bJRN;g
public SiteInfoBean() 66/3|83Z
{//nSplitter的缺省值为5 5][Ztx
//default value of nSplitter is 5 5R@
this("","","",5); \6E|pbJ}x
} <j*;.yyC
iOR_[y,
F(k.,0Nc
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !MYSfPdS
{ hAYTj0GZ
sSiteURL= sURL; x }\64
sFilePath = sPath; k7?N ?7w
sFileName = sName; }.3nthgz
this.nSplitter = nSpiltter; 1|kvPo#
;1`fC@rI
sYe?M,
} R< ,`[*Z
-8eoNzut
-=)+dCyB^
public String getSSiteURL() E*.{=W }C
{ e,F1Xi#d
return sSiteURL; k9:{9wW
} y.e^hRKb
o<<xY<
ohFJZ'
public void setSSiteURL(String value) F~%]6^$w
{ [Sr,h0h6
sSiteURL = value; 8YZbP5'
} U=DmsnD,
A<5ZF27
dx;Ysn0-
public String getSFilePath() o.w\l\
{ A?CcHw rT
return sFilePath; KM}f:_J*lg
} r"``QmM
%X4xv_o`f
WF1px%
public void setSFilePath(String value) 8P^ITL z%
{ Rv#]I#O
sFilePath = value; E~%jX }/
} r\b3AKrIN
mQCeo}7N5
WFO4gB*
public String getSFileName() }4Tc
{ YVYu:}e3)
return sFileName; $}J5xG,}$
} /tP|b_7O
:rHJ4Tl
J8S'/y(LE<
public void setSFileName(String value) U7`A497Z
{ yRSTk2N@
sFileName = value; biSz?DJ>
} MaRi+3F
zo+nq%=
~%^ tB
public int getNSplitter() bu:S:`
{ ln?v j)j
return nSplitter; (@%gS[]
} V.O(S\
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giZP.C"0
public void setNSplitter(int nCount) +Vm}E0Ov
{ 2q3+0Et8
nSplitter = nCount; )Y2{_ bx4"
} Gnfd;. (.
} 4US"hexE<
#0ETY\}ZD
S{;sUGcu
/* Pl=ZRKn
**Utility.java R%Q@
*/ b~'"^ Bts*
package NetFox; V,q](bg
Pa{%\dsv
BFL`!^
public class Utility { uT}' Y)m
5]n[]FW
V}dJ.I /#
public Utility() FrTi+& <
{ AWP"b?^G|
]|MEx{BG-
.Xce9C0SW
} ( M7pT
[x9KVd ^d
//线程睡眠 1+9W+$=h2
public static void sleep(int nSecond) POvP]G9'"
{ Z8rvWH9
try{ clNkph
Thread.sleep(nSecond); R{ a"Y$
} Q^ pmQ
catch(Exception e) B[V+ND'(
{ U<CTubF
e.printStackTrace (); p1&b!*o-&
} 7g%E`3)"
} Z?%zgqTXb
`&D|>tiz
//日志 }oL'8-y
public static void log(String sMsg) ~ ip,Nl
{ QV{}K
System.err.println(sMsg); K{[%7AM
} '7+4`E
cIav&Zko
QlJ)F{R8il
public static void log(int sMsg) ~NQ72wph{
{ )xbHCoU,
System.err.println(sMsg); /Y'Vh^9/T
} AQ_|:
} 73xAG1D$r
+tVaBhd!
So0f)`A
/* kdl:Wt*4o
**TestMethod.java SzjkI+-$:
*/ s (zL
package NetFox; gREzZ+([
my}-s
f ` R/ i
public class TestMethod { <4P4u*/o
B5X(ykaX~
f6p-s y>
public TestMethod() G5CI<KRK#
{ ///xx/weblogic60b2_win.exe *q()f\
try{ @>p<3_Y1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); j!]YNH@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O*0l+mop
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8=gjY\Dp
fileFetch.start(); M+w=O!dq
} ptU\[Tq
catch(Exception e){e.printStackTrace ();} *T5!{
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UPG9)aF
} DP3PYJ%+B
\'|>p/5I
mGJasn
public static void main(String[] args) i(>4wK!!
{ ;*:Pw?'
new TestMethod(); R'C2o]
} /+@p7FqlE
} }Q=!Y>Tc
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