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)); Af0E_
} 0tB9X9:,
for(int i=0;i<nEndPos.length-1;i++) Zk}e?Grc
{ rsP-?oD8)
nEndPos = nStartPos[i+1]; $b$r,mc
} yZFvpw|g
nEndPos[nEndPos.length-1] = nFileLength; 6M$.gX G.
} Qq]UEI `Go
} bTHa;* `
^ I,1kl~i
xyz-T1ib
//启动子线程 5 |C;]pq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; XW]|Mv[M
for(int i=0;i<nStartPos.length;i++) %_SE$>v^
{ Yjk A^e
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }.zgVLL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~rY<y%K
nStartPos,nEndPos,i); wQnr*kyza
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K{>O.5
fileSplitterFetch.start(); ^"+cJ)
} #8|;Q`Or:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rT}d<cSf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); o`j%$K4?5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o<l4}~a
nEndPos = " + nFileLength); J(/ eR,ak
// fileSplitterFetch[nPos.length-1].start(); oRWsi/Zf
2#W%--
)vGRfFjw_
//等待子线程结束 Qn%*kU0X
//int count = 0; 5I(` s#O
//是否结束while循环 ;N"XW=F4e
boolean breakWhile = false; S%xGXmZ
[TO:-8$.
3y 3 U`Mo
while(!bStop) ~T4=Id
{ Z/x<U.B
write_nPos(); JG}U,{7(
Utility.sleep(500); xI:;%5{LN
breakWhile = true; ( v ~/glf
Z^GriL
#2HygS
for(int i=0;i<nStartPos.length;i++) aeBth{
{ 1NOz $fW
if(!fileSplitterFetch.bDownOver) 'OX6eY5
{ S-f3rL[?
breakWhile = false; J;T_9
break; 5K6_#g4"
} Va*Uwy?x/)
} s9[v_(W
if(breakWhile) .=@M>TZM
break; dqKTF_+VhA
bh7 1Zu
& vLX
//count++; w@%W{aUC
//if(count>4) ;:$Na=
// siteStop(); @Qc['V)
} qo. 6T
/ V{w<
0U/:Tpyr
System.err.println("文件下载结束！"); *iC t4J
} IG9Q~7@
catch(Exception e){e.printStackTrace ();} [?IERE!xQ
} h0^V!.-5
caj)
G0]n4"~+?
//获得文件长度 10}Zoq|)n
public long getFileSize() *!s4#|h
{ z~VA#8>
int nFileLength = -1; f1~3y}7^Jq
try{ [#9ij3vxd
URL url = new URL(siteInfoBean.getSSiteURL()); BEI/OGp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #JLDj(a?
httpConnection.setRequestProperty("User-Agent","NetFox"); GO?-z0V
~l}TlRqL
%ri4nKGS
int responseCode=httpConnection.getResponseCode(); BklB3*n
if(responseCode>=400) xd .I5
{ O5=ggG
processErrorCode(responseCode); QOF;j#H^
return -2; //-2 represent access is error M3t_!HP}!
} UxS;m4
o"]eAQ
=AKW(v
String sHeader; ^g[])2",
+pcj8K%
HRb_ZJz
for(int i=1;;i++) %cm5Z^B1"
{ a<Ns C1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .y\HQ^j
//Utility.log(in.readLine()); Maa.>2v<
sHeader=httpConnection.getHeaderFieldKey(i); rL,)Tc|"
if(sHeader!=null) ;Q"F@v}18
{ (%P* rl
if(sHeader.equals("Content-Length")) `riv`+J{s
{ H_AV3 ;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); VG8rd'Z
break; O\D({>
} |@@mq!>-
} ./fEx 'E
else C3b'Q
break; y\S7oD(OR
} bL&]3n9Rwu
} )Xh_q3=
catch(IOException e){e.printStackTrace ();} 9e1 6 g
catch(Exception e){e.printStackTrace ();} AngECkF-
-pD&@Wlwak
gOWyV@
Utility.log(nFileLength); mhVoz0%1X
| 5L1\O8#
t~a$|( 9
return nFileLength; .y0]( h
} n5JB'F)
-E500F*b
NuooA
//保存下载信息（文件指针位置） cdfll+
private void write_nPos() g~y9j88?
{ apMYBbC
try{ 2?r8>#_*
output = new DataOutputStream(new FileOutputStream(tmpFile)); r2](~&i2
output.writeInt(nStartPos.length); fM|g8(TK,
for(int i=0;i<nStartPos.length;i++) bK].qN
{ :te xl
// output.writeLong(nPos); 6>L.)V
output.writeLong(fileSplitterFetch.nStartPos); tZ@+18
output.writeLong(fileSplitterFetch.nEndPos); ^2AF:(E
} D}061~zb$
output.close(); _5K_YhT
} k,@J&
catch(IOException e){e.printStackTrace ();} 1IlR
catch(Exception e){e.printStackTrace ();} O\LW 8\M
} =k*0O_
R`**!ku
#PrV)en
//读取保存的下载信息（文件指针位置） wr$}AX
private void read_nPos() g_>ZE
{ vW{cBy
try{ tT8jC:oVa
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _$'Mx'IC=
int nCount = input.readInt(); J@GfO\ o
nStartPos = new long[nCount]; fD~!t 8J
nEndPos = new long[nCount]; #LN I&5
for(int i=0;i<nStartPos.length;i++) 7XDV=PQ[
{ psZeu*/r
nStartPos = input.readLong(); bF KPV%`
nEndPos = input.readLong(); jccW8g~ ~
} +_gT|vlU
input.close(); jSFN/C.9h
} )T64(_TE
catch(IOException e){e.printStackTrace ();} {IMzR'PN
catch(Exception e){e.printStackTrace ();} 0lRH Yu
} pq[mM!;#v
w}.'Tebu
:xw3b)KS
private void processErrorCode(int nErrorCode) I:e2sE ":
{ ^c\IZ5
System.err.println("Error Code : " + nErrorCode); ?:?4rIZ<
} @"I#b99
;ULC|7rL
' 4~5ez|:
//停止文件下载 H<;Fb;b
public void siteStop() *!'&:
{ mU=6"A0 U
bStop = true; +2zuIW.
for(int i=0;i<nStartPos.length;i++) Ib2@Wi
fileSplitterFetch.splitterStop(); xploFw~
s3M84wz
x ctU.)p
} gFT~\3jp=
} t%U[\\ic
//负责部分文件的抓取 CJ?gjV6
**FileSplitterFetch.java m"G N^V7
*/ PEBFN
package NetFox; q~J oGTv
Z% ;4Ed
>'6GcnEb4.
import java.io.*; Nr"N\yOA/
import java.net.*; -m160k3
aE BP9RX}z
{F:v$ K
public class FileSplitterFetch extends Thread { iw fp'
YC]YX H
}%YHm9)
String sURL; //File URL 4VNb`!e
long nStartPos; //File Snippet Start Position }Hz-h4Z
long nEndPos; //File Snippet End Position Q$)|/Y))
int nThreadID; //Thread's ID $a\Uv0:xRx
boolean bDownOver = false; //Downing is over @E}X-r.^f
boolean bStop = false; //Stop identical VK'T[5e
FileAccessI fileAccessI = null; //File Access interface A'(7VJ
*yaX:,'\$
.gN$N=7<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _GO+fB/Q1
{ u`pROd/ R5
this.sURL = sURL; {(OIu]:
this.nStartPos = nStart; e5ru:#P.p
this.nEndPos = nEnd; *>'2$me=
nThreadID = id; h)_Gxe"x
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sJb)HQ,7x
} DAnb.0
8},<e>q
T;4`wB8@
public void run() A,gx5!J
{ }{8Fo4/
while(nStartPos < nEndPos && !bStop) HB7(
{ D4q>R;
YvruK:I
bW9"0=j[{
try{ lB!vF ~A&
URL url = new URL(sURL); ~g1, !Wl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X B*}P
httpConnection.setRequestProperty("User-Agent","NetFox"); m*!f%}T
String sProperty = "bytes="+nStartPos+"-"; ^$IZLM?E~
httpConnection.setRequestProperty("RANGE",sProperty); 14D7U/zer
Utility.log(sProperty); *w/WHQ`xI
_;:rkC fj
8rwYNb.P
InputStream input = httpConnection.getInputStream(); lKEX"KQ!
//logResponseHead(httpConnection); ~pevU`}Uqc
^5]uBOv
N\q)LM !M
byte[] b = new byte[1024]; iS"8X#[]N
int nRead; uyNJN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Vd+Q:L
{ <'[Ku;m
nStartPos += fileAccessI.write(b,0,nRead); d;~ 3P
//if(nThreadID == 1) =dM.7$6) R
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m1-\qt-yy
} -+}5ma
Ud#X@xK<h
rKzlK 'U
Utility.log("Thread " + nThreadID + " is over!"); P>Q{He:
bDownOver = true; 85D^@{
//nPos = fileAccessI.write (b,0,nRead); q[G/}
} #9`rXEz
catch(Exception e){e.printStackTrace ();} (`6%og#8
} B:-U`CHHQ
} -@2'I++"@
A)Qh
Kej|1g1f
//打印回应的头信息 Y}LLOj@L
public void logResponseHead(HttpURLConnection con) ~XUOWY75
{ 0||"r&:X
for(int i=1;;i++) 4;C*Fa
{ $_C+4[R?
String header=con.getHeaderFieldKey(i); _1sMYhI
if(header!=null) L)F1NuR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'j,oIqx
Utility.log(header+" : "+con.getHeaderField(header)); +2DE/wE]e+
else BWUt{,?KU
break; j1YH9T#|D
} o\ngR\>
} py{eX`(MS
x_==Ss
)nwZ/&@
public void splitterStop() H&X:!xa5
{ AJyq>0p
bStop = true; aDL)|>"Q
} [$l"-*s4
%bP~wl~
`c"4PU^
} k6Ihc?HL
d/{Q t
53 @oP
/* (*,8KLV_i
**FileAccess.java 7DtIVMiK
*//文件访问(定位，写) <%z@
package NetFox; -Z%F mv8
import java.io.*; u7;`4P:o@
99e*]')A%
6&89~W{
public class FileAccessI implements Serializable{ 3;*z3;#}
?7#7:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6b?`:$Cw3)
RandomAccessFile oSavedFile; <EMkD1e
long nPos; =m}TU)4.
I>A^I
]gu1#
public FileAccessI() throws IOException 6Rcua<;2P
{ ~TDzq -U)
this("",0); 4`nqAX~'f
} ?6i;)eIOI
L=,OZ9aA
}YQ:6I
public FileAccessI(String sName,long nPos) throws IOException &=6%>
{ <cYp~e%xIw
oSavedFile = new RandomAccessFile(sName,"rw"); &hayR_F9
this.nPos = nPos; cd!|Ne>fe
oSavedFile.seek(nPos); W57&\PXYn
} kMy<G8 s
2H[ ; v+
{Eu'v$c!
public synchronized int write(byte[] b,int nStart,int nLen) T2wv0sHlt
{ {XtoiI
int n = -1; ~r<p@k=.#0
try{ q7,^E`5EgU
oSavedFile.write(b,nStart,nLen); <_9!
n = nLen; s~^*+kq
} 6xHi\L
catch(IOException e) :zlpfm2
{ Ah-8"`E
e.printStackTrace (); xf/m!b"p
} Fn!SGX~kx$
Z,WubX<
%e{(twp
return n; f=o4I2Y[
} <Nex8fiJ9
pI>*u ]x
"u;YI=+
} vM`7s[oAK
JSgpb?(
0Uw ^FcW
/* WSLy}@`Vx
**SiteInfoBean.java :uo[&&c
*/ EKuSnlTXba
package NetFox; %[`a
3_W{T@T
vZ@g@zB4o0
public class SiteInfoBean { XJSa]P^B1
R}r~p?(M
/b#q*x-b
private String sSiteURL; //Site's URL zDDK
private String sFilePath; //Saved File's Path P16YS8$
private String sFileName; //Saved File's Name )~V}oKk0t
private int nSplitter; //Count of Splited Downloading File 5Z{_m;I.
jWvtv ng
B'}"AC"
public SiteInfoBean() +8AvTSgX%
{//nSplitter的缺省值为5 *Y%Jl o
//default value of nSplitter is 5 n'K6vW3
this("","","",5); FLZSK:3B]
} =&7@<vBpy
=i>\2J%'R
_s+c+]bO
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;cKH1
{ ;W{b $k@g
sSiteURL= sURL; MzzKJ;wbC6
sFilePath = sPath; ^e%}[q[>|
sFileName = sName; p@ygne4
this.nSplitter = nSpiltter; r`6:Q&&
5&!'^!
8o|P&q(v*
} ,Ff n)+
gn ?YF`
k4{:9zL1#?
public String getSSiteURL() B +Aj*\Y.
{ J8<J8x4
return sSiteURL; _D,eyP9P
} +xp]:h|
| o0RP|l
*C6D3y
public void setSSiteURL(String value) :#u}.G
{ r_U>VT^E:
sSiteURL = value; uS<_4A;sD,
} $^_|j1z#i
p|qyTeg
CzVmNy)kl
public String getSFilePath() KX3KM!*
{ `8:K[gp
return sFilePath; $`ztiVu3
} ?6P.b6m}0
jL>:>r
8W+5)m.tp
public void setSFilePath(String value) 2) ?q58
{ t-7og;^8k
sFilePath = value; j~`\XX{>
} {]kaJ{U>
U)D[]BVg
-5bA $
public String getSFileName() rmd;\)#*`
{ P)6lu8zQ
return sFileName; 0$HmY2 Men
} .DguR2KT
Vz%OV}\
\9:wfLF8!
public void setSFileName(String value) 4=[7Em?oLb
{ x/mp=
sFileName = value; L{8;Ud_2r
} $_D6_|HK
6f)2F< 7
HpW 42
public int getNSplitter() SVWIEH0?
{ #sB,1"
return nSplitter; 9&Ne+MY^%
} d]wD[]
86qI
PmX2[7
public void setNSplitter(int nCount) sL^yB
{ < <Y}~N
nSplitter = nCount; +K~NV?c
} ^,8R,S\}$
} Bh]!WMAw.
'Ot,H_pE
Yu3zM79'k
/* ~i~%~doa
**Utility.java @jy41eIo
*/ K#mOSY;}
package NetFox; \7v)iG|#G&
QM<y`cZ8
.Y*f2A.v
public class Utility { aP-<4uGx
S* R,FKg
7 sFz?`-
public Utility() y$W|~ H
{ V@vU"
J CGC
Y&.UIosWb
} w:i:~f .
Q<(YP.k
//线程睡眠 e Y$qV}
public static void sleep(int nSecond) Uh6 '$0
{ 1B=>_3_
try{ ,*svtw:2')
Thread.sleep(nSecond); ExBUpDQc
} 8wZf]_
catch(Exception e) PWr(*ZP>hI
{ =8{WZCW5
e.printStackTrace (); +A8j@d#:
} MGpt}|t-
} _BM4>r?\
f3MRD4+-
//日志 &&>tf%[
public static void log(String sMsg) 0(TTw(;
{ RFaSwf,5n
System.err.println(sMsg); Cby;?F6w
} B%s7bS
U7@AC}.+
t= #&fSR
public static void log(int sMsg) =EP13J
{ K=::)/{P
System.err.println(sMsg); 6xK[34~6
} <Zb/
} H}}$V7]^),
O[^%{'
oqd;6[%G
/* _qwQ;!9
**TestMethod.java ;,h/
*/ %ysZ5:X
package NetFox; CY:d`4
~uWOdm-"[
13k !'P
public class TestMethod { !^oV #
kOwMs<1J
g=L]S-e
public TestMethod() 1c4/}3*
{ ///xx/weblogic60b2_win.exe DOS0;^f
try{ 0|4%4Mt
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hwYQGtjF
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); op2Of<{h
SiteFileFetch fileFetch = new SiteFileFetch(bean); F9"w6;hh
fileFetch.start(); xM>W2
} _gj&$zP
catch(Exception e){e.printStackTrace ();} ;*TIM%6#
S[3iA~)Z-
XN=67f$Hw
} ,_.I\EY[
}Db[ 4
3g'S\G@
public static void main(String[] args) %8~Q!=*Iq
{ {P%9
new TestMethod(); u7%D6W~m0
} IY'=DePd
} `>Tu|3%\
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