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)); H1<>NWm!v7
} 3~,d+P
for(int i=0;i<nEndPos.length-1;i++) ]-oJ[5cQ0v
{ mK+IEZV<3
nEndPos = nStartPos[i+1]; {FRAv(,\
} XBd>tdEP
nEndPos[nEndPos.length-1] = nFileLength; [b%:.bjY
} B\J^=W+`
} V@>r*7\F
GRb*EeT
ur :i)~wXn
//启动子线程 \k;`}3uO
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; V/cP4{L
for(int i=0;i<nStartPos.length;i++) &PkLp4mQ
{ }kw/W#)J
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A+y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7g R@$(1Z
nStartPos,nEndPos,i); ,yd MU\so(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >fH=DOz$&
fileSplitterFetch.start(); V.os
} ^w]/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `:P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [:xiZ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 91Uj}n%
nEndPos = " + nFileLength); .sQ=;w/ZA
// fileSplitterFetch[nPos.length-1].start(); GN KF&M
? uYu`Ojzr
*x)Ozfe
//等待子线程结束 TKk-;Y=N
//int count = 0; jTLSdul+
//是否结束while循环 +C1QY'>I
boolean breakWhile = false; !LkWzn3
)c l5B{1P
{R/C0-Q^^
while(!bStop) 8q1wHZ
{ gN)c
write_nPos(); 5K|"\
Utility.sleep(500); `%09xMPu
breakWhile = true; 5 H#W[^s"
{.yStB.T
`R"I;qV
for(int i=0;i<nStartPos.length;i++) 1sPdz L
{ -s9P8W
if(!fileSplitterFetch.bDownOver) Rb(SBa
{ ^ wY[3"{
breakWhile = false; C>[Uvc
break; %cE2s`
} S(\9T1DVe
} .S(,o.
if(breakWhile) u_7~TE3W
break; 3Vp#a:
ho>k$s?
SZJ$w-<z
//count++; ?|:BuHkT
//if(count>4) G;f/Tch
// siteStop(); = waA`Id
} P ~PIMkt
Jvun?J m
L28*1]\Jh
System.err.println("文件下载结束！"); J[^}u_z
} E9V5$
catch(Exception e){e.printStackTrace ();} *m2=/Sh
} D1nq2GwS
1xv8gC:6
lC=~$c:
//获得文件长度 H5D*|42
public long getFileSize() JoSJH35=:
{ eHDef
int nFileLength = -1; p _d:eZ
try{ erO>1 ,4S
URL url = new URL(siteInfoBean.getSSiteURL()); GWvH[0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9}z0J
httpConnection.setRequestProperty("User-Agent","NetFox"); L.]$6Q0
&sF^Fgg{
r!,}Z=cGe
int responseCode=httpConnection.getResponseCode(); s&GJW@ |
if(responseCode>=400) udeoW-_
{ i|1^+;
processErrorCode(responseCode); xG;-bJu
return -2; //-2 represent access is error D/h/Y) Y
} Jjl`_X$CB
'_b.\_s-d
/*|oL#hK
String sHeader; uIU5.\"s
#2iD'>bQ
|a{Q0:
for(int i=1;;i++) t#!yrQ..'G
{ :a:l j
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K!,<7[MBg
//Utility.log(in.readLine()); I7^zU3]Ul
sHeader=httpConnection.getHeaderFieldKey(i); zS]8V?`
if(sHeader!=null) XR!us/U`a
{ 'H7x L
if(sHeader.equals("Content-Length")) `-3o+ID\
{ ){r2T1+-%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ma|qHg
break; OxGE%R,
} .Yw'oYnS
} F]O$(7*
else FYS/##r
break; /s];{m|>
} moVbw`T
} 81*M= ?
catch(IOException e){e.printStackTrace ();} ~SvC[+t+U
catch(Exception e){e.printStackTrace ();} 5Zw1y@k(
%6--}bY^
p\{-t84n
Utility.log(nFileLength); bqQq=SO
OCy0#aPRS
BnRN;bu
return nFileLength; E\m5%bK\B
} M,}|tsL
.@Ut?G
-YD+(c`l
//保存下载信息（文件指针位置） lO:.OZu
private void write_nPos() Z0De!?ALV\
{ 2DD:~Tbi
try{ R}mn*h6
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^s.V;R
output.writeInt(nStartPos.length); mZIoaF>t
for(int i=0;i<nStartPos.length;i++) n&MG7`]N
{ Z!0]/mCE8
// output.writeLong(nPos); lcV<MDS
output.writeLong(fileSplitterFetch.nStartPos); ET];%~ ^
output.writeLong(fileSplitterFetch.nEndPos); &uUo3qXQ5l
} kF7V.m/~o
output.close(); mJB2)^33a
} |w}xl'>q
catch(IOException e){e.printStackTrace ();} _tr<}PnZ
catch(Exception e){e.printStackTrace ();} U}SXJH&&E
} a(]`F(L
XBQ\_2>
#"fJa:IYG7
//读取保存的下载信息（文件指针位置） ob_I]~^I?|
private void read_nPos() g]UBZ33y
{ ^TB>.c@`*
try{ Q !qrNa6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); B^D(5
int nCount = input.readInt(); 9z?oB&5
nStartPos = new long[nCount]; q %A?V_
nEndPos = new long[nCount]; )5fQ$<(Z
for(int i=0;i<nStartPos.length;i++) HyiFy7j
{ #}^-C&~
nStartPos = input.readLong(); 6mH/ m&
nEndPos = input.readLong(); 4x%(9_8{-
} kX:tc
input.close(); n]+W 3[i
} ^w~23g.
catch(IOException e){e.printStackTrace ();} u9=SpgB#
catch(Exception e){e.printStackTrace ();} YC]L)eafo`
} H;aYiy
|+ge8uu?C
9x+<Ik
private void processErrorCode(int nErrorCode) qC!&x,}3
{ 6a}"6d/sTL
System.err.println("Error Code : " + nErrorCode); $>U# W:
} TO,rxf
`IINq{Zk
ENh!N4vbO
//停止文件下载 @xsCXCRWVV
public void siteStop() Z['\61
{ M\b")Tu{0
bStop = true; QH]M
for(int i=0;i<nStartPos.length;i++) ~tB;@e
fileSplitterFetch.splitterStop(); .ut{,(5
j<%])
2fIRlrA$
} (eCFWmO
} ECa$vvK m
//负责部分文件的抓取 9s +z B
**FileSplitterFetch.java hgRVwX
*/ {J/I-=CmML
package NetFox; vFrt|JC_{
z<gu00U7
t4Z
import java.io.*; O?EB8RB
import java.net.*; 4\.V
+&KQ28r
-G &_^"=R
public class FileSplitterFetch extends Thread { HEqWoV]{d
/W#O +
3>z[PPw
String sURL; //File URL RnfXN)+P
long nStartPos; //File Snippet Start Position +kdySWF
long nEndPos; //File Snippet End Position mxSKG> O
int nThreadID; //Thread's ID o-7>eE}+
boolean bDownOver = false; //Downing is over ngulcv
boolean bStop = false; //Stop identical iNCX:Y
FileAccessI fileAccessI = null; //File Access interface *0Gz)'
v}J;ZIb
i54md$Q^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^C&+ ~+
{ p<WFqLe(":
this.sURL = sURL; 7=4A;Ybq
this.nStartPos = nStart; FDFH,J`_
this.nEndPos = nEnd; RaSz>-3d
nThreadID = id; !/K8xD$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :<#`_K~'
} gM;}#>6
~$O1`IT
09M;}4ev&7
public void run() o7&4G$FX~
{ Jeqxspn T
while(nStartPos < nEndPos && !bStop) %>Xr5<$:&
{ -U2mfW
/7$mxtB5%L
47 u@4"M
try{ &;H{cv`
URL url = new URL(sURL); Iy {U'a!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZeasYSo4P
httpConnection.setRequestProperty("User-Agent","NetFox"); $7I]`Jt
String sProperty = "bytes="+nStartPos+"-"; 5T4"j;_.BL
httpConnection.setRequestProperty("RANGE",sProperty); sc`"P-J+vp
Utility.log(sProperty); {gf>*
e{G_GycH
PX".Km p.
InputStream input = httpConnection.getInputStream(); ApPy]IdwX
//logResponseHead(httpConnection); QL"gWr`R
D_|B2gdZY
hQJWKAf,/
byte[] b = new byte[1024]; >Pe:I
int nRead; P#GD?FUc
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) AZFWuPJo
{ >e5zrgV
nStartPos += fileAccessI.write(b,0,nRead); Q882B1H
//if(nThreadID == 1) r -f
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d+z[\i
} urY`^lX~
o%(bQV-T
/L) 9tt.
Utility.log("Thread " + nThreadID + " is over!"); MQcE6)
bDownOver = true; 5{>0eFzG
//nPos = fileAccessI.write (b,0,nRead); 6X+}>qy
} 67<CbQZoN3
catch(Exception e){e.printStackTrace ();} J;~|ph
} (b/d0HCND
} MM#cLw
&jts:^N>
#dJ 2Q_2
//打印回应的头信息 _=`x])mM
public void logResponseHead(HttpURLConnection con) AvRcS]@=
{ Pw}_[[>$
for(int i=1;;i++) [J\DB)V/
{ +h[e0J|v{
String header=con.getHeaderFieldKey(i); p?rK`$U+J
if(header!=null) cV$lobqO
//responseHeaders.put(header,httpConnection.getHeaderField(header)); L@|#Bbmx
Utility.log(header+" : "+con.getHeaderField(header)); y{rn-?`{
else C@dGWAG
break; F%6*Df;cSe
} #0MK(Ut/
} qR,.W/eS8
*M!kA65'
`ENP=kL(+
public void splitterStop() ./maY1>T
{ 9EgP9up{6!
bStop = true; {Qtq7q.
} jW5iqU"{*
+BB0wY
eYP=T+
} ]UUI~sFE
dt-K
QJ<[Zx
/* n!.2aq
**FileAccess.java t!l%/$-
*//文件访问(定位，写) :4;S"p
package NetFox; u7k|7e=xk
import java.io.*; Jirct,k
4]6Qr
me./o(!?
public class FileAccessI implements Serializable{ 2,AaP*,
D3?N<9g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Qyj(L[KJ
RandomAccessFile oSavedFile; .w'vD/q;
long nPos; R`He^
_@prmSc
/_OOPt=G
public FileAccessI() throws IOException $Xt;A&l2?
{ )Xno|$b5Eo
this("",0); k}BDA|\s
} ]bfqcmh<
N$'>XtO
b[g.}'^yht
public FileAccessI(String sName,long nPos) throws IOException {,f[r*{Y
{ P3$,ca'
oSavedFile = new RandomAccessFile(sName,"rw"); G]lvHD
this.nPos = nPos; :ej_D}
oSavedFile.seek(nPos); AP@<r
} 3i(Jon/p
uu3M{*}
_<u;4RO(s
public synchronized int write(byte[] b,int nStart,int nLen) >-<F)
{ Yq0# #__
int n = -1; X8b#[40:
try{ {bTeAfbf]
oSavedFile.write(b,nStart,nLen); n#>5?W
n = nLen; `cO|RhD@
} *aG"+c6|
catch(IOException e) *:#Z+7x ]
{ Qu}N:P9l?X
e.printStackTrace (); %]GV+!3S
} )OUU]MUH
c!~T2t
e?vj+ZlS$f
return n; b]K>vhQV
} WY.5K =}
U3VT*nj'
S>EDL
} JX&~y.F
;Xh5oB\)W
[0(mFMC`
/* cyb(\ fsC
**SiteInfoBean.java \>;%Ji
*/ j]4,6`b\
package NetFox; S~|tfJpL
D2?S,9+E_
iPkT*Cl8
public class SiteInfoBean { qzlER
t[j9R#02?
2$DSBQEx
private String sSiteURL; //Site's URL 5*XH6g F
private String sFilePath; //Saved File's Path _Ff".t<"
private String sFileName; //Saved File's Name 7?"9J`*
private int nSplitter; //Count of Splited Downloading File ]0YDb~UB
9/Wn!Ld
hOn
public SiteInfoBean() h{H]xe[Q
{//nSplitter的缺省值为5 ax]9QrA
//default value of nSplitter is 5 K /ZHJkJ7
this("","","",5); } Ab_o#Zy
} 6>lW5U^yA\
'F<Sf:?.p
5E.vje{U;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) gQ,4xTX
{ No~6s.H
sSiteURL= sURL; =ty2_6&>
sFilePath = sPath; K]MzP|T,
sFileName = sName; Uk|9@Auav
this.nSplitter = nSpiltter; hvL6zCi
:^.u-bHI
b8e*Pv/
} N&,"kRFFo
{~"Em'}J
YiO3<}Uf
public String getSSiteURL() U#$:\fT
{ tB!|p6
return sSiteURL; gvK"*aIj
} ^:U;rHY
g.=!3e&z%
6iyt2qkh
public void setSSiteURL(String value) Jb6&
{ H'']J9O
sSiteURL = value; Mi;Tn;3er
} :g/{(#E@Z
{YfYIt=.
2t.fD@
public String getSFilePath() TiTYs
{ 5%#i79z&B
return sFilePath; + p'\(Z(
} @}Pw0vC
s?HsUD$b
r@;$V_I
public void setSFilePath(String value) %va[jJ
{ U<|B7t4M
sFilePath = value; "hfw9Qm
} FmR\`yY_,
lej^gxj/2
})q]gMj
public String getSFileName() )~G8 LZ
{ \:C%> .VG
return sFileName; rC~_:uXtE
} "_Zh5 g
mJ/^BT]
QK,=5~IJ
public void setSFileName(String value) C?bXrG\
{ m2wp m_vV#
sFileName = value; 5NFq7&rJ6
} '\4c "Ho
n2H&t>N
t% <pbZO
public int getNSplitter() 5BZ+b_A>VV
{ EwC5[bRjUp
return nSplitter; }`?7\\6
} JHHb|
#V,LNX)
9{T 8M
public void setNSplitter(int nCount) E`U&Z
{ u87=q^$
nSplitter = nCount; rGGS]^
} uT#Acg
} oXvdR(Sb^
ik8|9m4/
9$n+-GSK
/* 7O]J^H+7
**Utility.java "Wxo[I
*/ 1*TXDo_T
package NetFox; -wJ
ccIDMJ=2
6hR^qdHg
public class Utility { '3IkPy1Uz
Cln^1N0
<aD'$(N5
public Utility() jt0H5-x
{ pW`ntE#L
xzuPie\
gF$1wV]e
} !k4 }v'=
0-6:AHix
//线程睡眠 SjFF=ib
public static void sleep(int nSecond) qQwJJjf
{ y^5T/M
try{ Zb12:?
Thread.sleep(nSecond); 8ct+?-3g
} oSpi{ $x
catch(Exception e) oFX"F0rx
{ }(8D!XgWa
e.printStackTrace (); z7D*z8,i
} OaX HJ^k
} \65vfE~ O
f$~ _FX
//日志 {ILp[&sL
public static void log(String sMsg) \HBVNBY
{ !3O,DhH>MC
System.err.println(sMsg); /F\>Z]
} ){?mKB5
u?LW+o
ez{P-qB
public static void log(int sMsg) Lg\8NtP
{ #RCZA4>
System.err.println(sMsg); gPF}aaB6
} U^vUdM"
} tg4LE?nv
V'Sd[*
t?pIE cl
/* Z1XUYe62
**TestMethod.java R!:eYoQ
*/ OqAh4qa,$
package NetFox; m70`{-O
hg<"Yg=
yf0vR%,\
public class TestMethod { 5i}CzA96
cKvAR5|
\;A50U|r
public TestMethod() # CP9^R S
{ ///xx/weblogic60b2_win.exe 7UeE(=Hr5
try{ uD0(aqAZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1Xk{(G<\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); c+)36/; X
SiteFileFetch fileFetch = new SiteFileFetch(bean); kMfc"JXF
fileFetch.start(); dXf]G6
} OX#eLco
catch(Exception e){e.printStackTrace ();} o(v"?Y6
&etL&s v
=!I8vQ>
} u&?yPR
b<29wL1
F``EARG)iu
public static void main(String[] args) I{*.htt{
{ 0{^l2?mgSb
new TestMethod(); Q{ |+3!!'
} -$sl!%HO%
} K#m\qitb
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