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)); q w"e0q%)
} J~:kuf21
for(int i=0;i<nEndPos.length-1;i++) 2%*|fF}I
{ :nTkg[49pJ
nEndPos = nStartPos[i+1]; )8\Z=uC
} C=M?
nEndPos[nEndPos.length-1] = nFileLength; FJ nG<5Rh
} l!Nvn$hm
} AZ}%MA;q
/}[zA@
o(BYT9|.kw
//启动子线程 7?*~oVZW
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wP+'04H0
for(int i=0;i<nStartPos.length;i++) 8HB?=a2Q<'
{ _6| /P7"
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s-y'<(ll
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), z, :+Oc
nStartPos,nEndPos,i); I(F1S,7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L'zdsa}Et
fileSplitterFetch.start(); QZ_nQ3K
} Ynv 9v\n|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,[+ZjAyG}#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g(M(Hn7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \q|e8k4p
nEndPos = " + nFileLength); [UUM^!1
// fileSplitterFetch[nPos.length-1].start(); >V3W>5X
2I9{+>k
3Ro7M=]
//等待子线程结束 #{.pQi})
//int count = 0; =#J9
//是否结束while循环 h%4~0
boolean breakWhile = false; ^2(";.m
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D}3cW2!9
while(!bStop) wpJ^}+kF
{ ^2P;CAjj-
write_nPos(); 2-/YYe;C
Utility.sleep(500); 5LnB]dW
breakWhile = true; Qq6%53
m mw)C"
t(Cq(.u`:
for(int i=0;i<nStartPos.length;i++) !:`Ra
{ a'(lVZA;
if(!fileSplitterFetch.bDownOver) C&qDvvk
{ gqKC4'G0
breakWhile = false; 1mkQ"E4
break; zcbA)
} 9;'>\ImI
} jFK9?cLT
if(breakWhile) uT@8 _9
break; E}E7VQjM
!dYX2!lvT
%6vMpB`g
//count++; EC:x,i
//if(count>4) _~(MA-l
// siteStop(); kY0g}o'<
} AF07KA#
S<)RVm,!e
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System.err.println("文件下载结束！"); 6-Vl#Lyb
} Ra*k
catch(Exception e){e.printStackTrace ();} S@l a.0HDA
} &St~!y6M?
ueS[sN!
cviN$oL
//获得文件长度 F\YcSDM
public long getFileSize() cPa 0n4
{ ACMpm~C8Gu
int nFileLength = -1; 8O}A/*1FJ
try{ -+Awm{X_@
URL url = new URL(siteInfoBean.getSSiteURL()); +$an*k9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5Od(J5`
httpConnection.setRequestProperty("User-Agent","NetFox"); Qg86XU%l
;Ln7_
ph5xW<VNP
int responseCode=httpConnection.getResponseCode(); {jCu9 ]c!
if(responseCode>=400) B_6v'=7]
{ vf/$`IJ
processErrorCode(responseCode); 6='_+{
return -2; //-2 represent access is error tleK(^
} 7m@^=w
Z"PDOwj5
K{7S
String sHeader; )x5$io
"m\UqQGX
3IRRFIiO
for(int i=1;;i++) cC(ubUR
{ FK/ro91L
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9x 6ca
//Utility.log(in.readLine()); 1Tts3O.
sHeader=httpConnection.getHeaderFieldKey(i); yQQDGFTb!=
if(sHeader!=null) n=Z[w5
{ CgPZvB[
if(sHeader.equals("Content-Length")) :@z5& h
{ *X=f
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); M<|~MR
break; PK|`}z9
} Z-;uzx
} n?ZH2dI\0
else :[ZC-hc\
break; h-)A?%Xt
} J 6d n~nPK
} @a7(*<".
catch(IOException e){e.printStackTrace ();} K:Xrfn{s
catch(Exception e){e.printStackTrace ();} Rh-8//&vZ/
qS[p|*BL
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Utility.log(nFileLength); n3@g{4~
(B~V:Yt
VHY<(4@
return nFileLength; vGMOXbq4&
} OYRR'X.E
vN6]6nUOiT
~Hs]}Xo
//保存下载信息（文件指针位置） h0EGhJs
private void write_nPos() m6ZbYF-7W
{ ZJJl944
try{ ,uD*FSp>
output = new DataOutputStream(new FileOutputStream(tmpFile)); G5eLs
output.writeInt(nStartPos.length); v!v0,?b*
for(int i=0;i<nStartPos.length;i++) B}xo|:f!zj
{ @_weMz8}
// output.writeLong(nPos); yK2*~T,6@
output.writeLong(fileSplitterFetch.nStartPos); 7{/:,
output.writeLong(fileSplitterFetch.nEndPos); rF j)5~
} u=UM^C!
output.close(); *R~(:z>>
} E0?\DvA
catch(IOException e){e.printStackTrace ();} do?n /<@o
catch(Exception e){e.printStackTrace ();} R?e7#HsJ
} MBTt'6M
Exo`Z`m`U
HjY-b*B
//读取保存的下载信息（文件指针位置） 7g<`wLAH
private void read_nPos() DEeL48{R
{ xo"4mbTV
try{ 5Vm}<8{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); QCY{D@7T
int nCount = input.readInt(); !A<XqzV]
nStartPos = new long[nCount]; NS/L! "g
nEndPos = new long[nCount]; nO7o7bc
for(int i=0;i<nStartPos.length;i++) D+U/]sW
{ y&I|m
nStartPos = input.readLong(); X52jqXjg
nEndPos = input.readLong(); 4lKbw4[a
} Gw\HL
input.close(); r.G/f{=<@
} v'~nABYH
catch(IOException e){e.printStackTrace ();} a0j.\g
catch(Exception e){e.printStackTrace ();} U;A5-|C
} {q>4:lsS
Vv"wf;#
$.]t1e7s
private void processErrorCode(int nErrorCode) ,,j=RG_
{ )A+j
System.err.println("Error Code : " + nErrorCode); s^X/ Om
} vi.AzO
D]`B;aE>A*
bb_jD^
//停止文件下载 OcS`Fxs
public void siteStop() 6V?&hq&t
{ |JQP7z6j]
bStop = true; XGl13@=O
for(int i=0;i<nStartPos.length;i++) 8'\,&f`Y
fileSplitterFetch.splitterStop(); e/#&5ISk
?GfA;O
(pK4i5lT
} ?m7"G)
} Tb6x@MorP
//负责部分文件的抓取 "._WdY[
**FileSplitterFetch.java +Y^F>/4=Y
*/ ^znv[
package NetFox; `; %aQR
3\.)y49,1
fQA)r
import java.io.*; vl(v1[pU
import java.net.*; t-'GRme
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public class FileSplitterFetch extends Thread { v#2qwd3x
(_5+`YsV
!3v"7l{LF
String sURL; //File URL snNg:rTL
long nStartPos; //File Snippet Start Position U)1qsUDF
long nEndPos; //File Snippet End Position P87Fg
int nThreadID; //Thread's ID {OoNhN9
boolean bDownOver = false; //Downing is over toZI.cSg4
boolean bStop = false; //Stop identical M<m64{m1
FileAccessI fileAccessI = null; //File Access interface F+9`G[
)H,<i{80c
M!DoR6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C$;s+ALy[
{ !VTS $nJ4
this.sURL = sURL; H 6<@
this.nStartPos = nStart; 5j01Mx A
this.nEndPos = nEnd; |MrH@v7S
nThreadID = id; DL!s)5!M
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LZ]pyoi
} 07Cuoqt2
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public void run() x=+I8Q4:
{ k<hO9;#qpL
while(nStartPos < nEndPos && !bStop) I~6 ;9TlQ
{ 6oBt<r?CJ
<aD+Ki6
s'=]a-l~
try{ .Vjpkt:H
URL url = new URL(sURL); ZKTBjOa]*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $iJ #%&D
httpConnection.setRequestProperty("User-Agent","NetFox"); ,$[lOFs
String sProperty = "bytes="+nStartPos+"-"; >2a#|_-T
httpConnection.setRequestProperty("RANGE",sProperty); &4iIzw`
Utility.log(sProperty); /VZU3p<~
iW$i%`>
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InputStream input = httpConnection.getInputStream(); P#1y
//logResponseHead(httpConnection); V$D d 7
nu-wQr
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byte[] b = new byte[1024]; y>18)8
int nRead; ;BvWU\!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /qze
{ .}>[Kr
nStartPos += fileAccessI.write(b,0,nRead); >Cc$ P
//if(nThreadID == 1) /bk} J:QRg
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NFPkK?+
} t!N>0]:mo
39eoL;O_
Wm_-T]#_
Utility.log("Thread " + nThreadID + " is over!"); ^O"`.2O1
bDownOver = true; `Yve
//nPos = fileAccessI.write (b,0,nRead); 4D$E
} Q+N @j]'
catch(Exception e){e.printStackTrace ();} Y" |U$
} w$HC!
} w]XBq~KO
k/Q]Ke
kS!*kk*a
//打印回应的头信息 % m$Mnx
public void logResponseHead(HttpURLConnection con) PrxXL/6
{ 5%/%i}e~(
for(int i=1;;i++) 2ARh-zLb
{ 3Mt6iZW
String header=con.getHeaderFieldKey(i); a$A S?`L
if(header!=null) t|_g O!w8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); h|Qh/jCX
Utility.log(header+" : "+con.getHeaderField(header)); D=]P9XDvb.
else 7.-|3Wcg
break; CeemR>\t
} ~8E rl3=5{
} T]k@g_
r|8..Ll
``D-pnKK
public void splitterStop() tzPe*|m<
{ Hqv(X=6E0
bStop = true; ]F!,Jx
} d4tVK0 ~
$>Do&TU
<L0_<T
} iLei-\w6y
vzPrG%Uu7g
-K4RQ{=>UZ
/* >ZWm0nTr
**FileAccess.java ='azVw%_
*//文件访问(定位，写) )JON&~C
package NetFox; J3vuh#
import java.io.*; +(T,d]o]
:}cAq/
EY(4<;)
public class FileAccessI implements Serializable{ NKN!X/P
Ns{4BM6j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4BX*-t
RandomAccessFile oSavedFile; cA,xf@itp
long nPos; ,0O!w>u_]J
lU3wIB
u5,<.#EVY
public FileAccessI() throws IOException Q}]un]]Zt
{ &3MHe$
this("",0); f.WtD`Oas
} p+Xz9A"
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R8_qZ;t:z
public FileAccessI(String sName,long nPos) throws IOException !+U.)u9 '
{ na>B{6
oSavedFile = new RandomAccessFile(sName,"rw"); YjT #^AH
this.nPos = nPos; >"b"K{t
oSavedFile.seek(nPos); O4{&B@!
} O1PdM52
"wc $'7M
7O j9~3o4
public synchronized int write(byte[] b,int nStart,int nLen) z;)% i f6
{ pw8'+FX
int n = -1; a?dM8zAnc
try{ LBzpaLd
oSavedFile.write(b,nStart,nLen); X^`ld&^*({
n = nLen; K7U<~f$OiN
} qW9|&GuZ$
catch(IOException e) gKnAw+u\
{ _*_zyWW_j
e.printStackTrace (); uxBk7E%6
} t+ @F"[j
/TdTo@
:Wln$L$
return n; =KMck=#B
} 3)sqAs(
9;jfg|x1[
-HOCxR
} Z|.z~53;
1*5n}cU~
fw5AZvE6$
/* 3!I8J:GZ:
**SiteInfoBean.java l[gL(p"W
*/ 5|Uub,
package NetFox; iw%DQ }$
| e+m!G1G
15B$Sp!/`e
public class SiteInfoBean { ZD*>i=S
g`6S*&8I
K%;O$ >
private String sSiteURL; //Site's URL !zeBxR$&o
private String sFilePath; //Saved File's Path ^^Y0 \3.
private String sFileName; //Saved File's Name H74hv`G9
private int nSplitter; //Count of Splited Downloading File x&sF_<[
({)_[dJ'
q /#O :Q
public SiteInfoBean() $O[ut.
{//nSplitter的缺省值为5 M30_b8[Y_
//default value of nSplitter is 5 w ^A0l.{
this("","","",5); M9MEQK
} e.Ii@<
@{j-B IRZ0
?r/7:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lD(d9GVm{z
{ fK[9<"PC0
sSiteURL= sURL; :geXplTx
sFilePath = sPath; g&"Nr aQM9
sFileName = sName; E:7vm@+
this.nSplitter = nSpiltter; g wk\[I`;
*J6qL! ["
E-RbFTVBA
} 0pu'K)Rb
:]x)lP(3E
dX<UruPA
public String getSSiteURL() (7"qT^s3
{ i"r=b%;;
return sSiteURL; 7+ c?eH
} G|o-C:~
&" b0`&l
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public void setSSiteURL(String value) G"'DoP7p9
{ PRs[:we~~
sSiteURL = value; A!NT 2YdHZ
} C~ >'pS6%5
-Z:al\e<g
371E S4
public String getSFilePath() &c A?|(7-
{ u*"tZ+|m
return sFilePath; yfV{2[8ux
} gxJ(u{2
Q_ $AGF
hcej?W8j
public void setSFilePath(String value) i;)88
{ 1r@v \#P
sFilePath = value; ! $n^Ze2 !
} h~dM*yo;
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1wwhTek
public String getSFileName() U5Rzfm4
{ }D0j%~&"e
return sFileName; K^Xg^9
} WS;3a}u
F M`pPx
n6oVx5/
public void setSFileName(String value) |ek*wo
{ e&E*$G@.7
sFileName = value; qWo|LpxWt
} DD;PmIW
Vb/J`
|GIT{_JE
public int getNSplitter() #*w$JH
{ X]`\NNx
return nSplitter; 5^pQ=Sgt
} eK]GyY/Y
Z$2mVRS`c
)M1.>?b
public void setNSplitter(int nCount) K":-zS
{ XfB;^y=u8
nSplitter = nCount; 2 !{P<
} .3$iOMCH
} IN_GL18^MV
#E>f.:)
|i1z47jN6P
/* UUX _x?BD
**Utility.java s*rtm
*/ DT_012z
package NetFox; x!S8'
10*U2FY)]
Rnj2Q!C2
public class Utility { =_=jXWOQv
H3MT.Cpd
1w?X~VZAX
public Utility() ZSxKk6n}J
{ !iITX,'8
5PdC4vI*+
vVE^Y
} `lr\V;o!
Jg^tr>I~
//线程睡眠 SxMh '
public static void sleep(int nSecond) I#9A\.pO
{ g=a-zg9LX
try{ ""TRLs!:M
Thread.sleep(nSecond); h%#@Xd>.
} v)BUt,A
catch(Exception e) I9B B<~4o
{ Bojm lVg
e.printStackTrace (); r)ga{Nn,.
} sd Z=3)
} obUh+9K
`4XfT.9GT
//日志 k5W5 9tz
public static void log(String sMsg) uPb9j;Q?
{ s|dL.@0,L
System.err.println(sMsg); RtK/bUa
} VM|8HR7U
rY88xh^
PLwa!j
public static void log(int sMsg) ?DM-C5$
{ dDAdZxd
System.err.println(sMsg); cND2(<jx:
} Wu%;{y~#}
} (,HAOs
}?"f#bI
Z$Qlr:7
/* wHdq:,0-!
**TestMethod.java bMf+/n
*/ ;v#~o*
package NetFox; k:R9wo
LKztGfy
Q-BciBh$
public class TestMethod { Ywlym\ [+
=v1s@5;~
R>#T{<<L
public TestMethod() t:$p8qR
{ ///xx/weblogic60b2_win.exe t4h5R
try{ H<dm;cU
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); j @sd x)1+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7vgz=- MZ#
SiteFileFetch fileFetch = new SiteFileFetch(bean); dEns|r
fileFetch.start(); si0jXue~j\
} }4\>q$8'
catch(Exception e){e.printStackTrace ();} X=_N7!
;\(wJ{u?Y
\Ui8Sgeei
} v:<u0B-)$
j =[Td
(~,Q-w"
public static void main(String[] args) D6c4tA^EO
{ 8V.x%T
new TestMethod(); 4e1Zyi!
} rQ.j$U
} O zY&^:>
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