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)); {GT*ZU*
} & bm 1Fz
for(int i=0;i<nEndPos.length-1;i++) "m$##X\
{ IZ-1c1
nEndPos = nStartPos[i+1]; w>&aEv/f
} PCee<W_%YE
nEndPos[nEndPos.length-1] = nFileLength; / y40(l?
} \[i1JG
} `,*3[
9 RgVK{F
6dr%;Wp
//启动子线程 PcMD])Z{G
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0cH`;!MZ
for(int i=0;i<nStartPos.length;i++) |-67\p]
{ <]t%8GB2V
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :as$4|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wo{gG?B
nStartPos,nEndPos,i); qbN =4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \fLMr\LL&
fileSplitterFetch.start(); \A#41
} Q~]uC2Mw
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F`W?II?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :K,i\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T@B/xAq5!
nEndPos = " + nFileLength); /N10
// fileSplitterFetch[nPos.length-1].start(); k/_ 59@)
dh iuI|?@
E?f-wQF
//等待子线程结束 ;%9|kU
//int count = 0; 9!\B6=r y4
//是否结束while循环 DH!~ BB;
boolean breakWhile = false; N7zft
?pmHFlx
[-K&R
while(!bStop) B)g[3gQ
{ N0Lw}@p
write_nPos(); !dnH7"
Utility.sleep(500); `:KY\
breakWhile = true; Ykw*&opz
>Eto( y"q
K#d`Hyx
for(int i=0;i<nStartPos.length;i++) ;(Or`u]Dr
{ 9ULQrq$?
if(!fileSplitterFetch.bDownOver) S!CC }3zw
{ AM\'RHL
breakWhile = false; cd_yzpL@}J
break; :J@gmY:C
} xwq (N_
} L|7R9+ZG
if(breakWhile) c ( C%Hld
break; C`9+6T
I-*S&SiXjI
BhGu!Y6f
//count++; 5r|,CQ7o
//if(count>4) OX!tsARC@
// siteStop(); ~rKrpb]ow
} L|xbR#v
0RLg:SV
YnAm{YyI
System.err.println("文件下载结束！"); $k%2J9O
} 7(8;to6(
catch(Exception e){e.printStackTrace ();} <{cQM$#
} _C?hHWSf"
9~XAq^e
hx%v+/
//获得文件长度 Rtl"Ub@HV
public long getFileSize() WX?IYQ+
{ J=I:CD%
int nFileLength = -1; PiIpnoM
try{ Vn}0}Jz
URL url = new URL(siteInfoBean.getSSiteURL()); K7:)nv E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WPMSm<[
httpConnection.setRequestProperty("User-Agent","NetFox"); )9`qG:b'
KL57#gV
,T$U'&;
int responseCode=httpConnection.getResponseCode(); +gtbcF@rx
if(responseCode>=400) mSF(q78?
{ E A1?)|}n
processErrorCode(responseCode); WiR(;m<g
return -2; //-2 represent access is error d#4**BM
} )23H1
l'.VKh\C
"(~^w=d:$
String sHeader; <uw9DU7G
x2\qXN/R
f+,qNvBY/
for(int i=1;;i++) [!#L6&:a8
{ w-MCZwCr)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); X51:
//Utility.log(in.readLine()); Fj3a.'
sHeader=httpConnection.getHeaderFieldKey(i); 0gr/<v
if(sHeader!=null) xy[3u?,&s!
{ | rtD.,m
if(sHeader.equals("Content-Length")) Yu^4VXp~M%
{ ~Otoqu|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); mnX2a
break; 7WS p($
} {qJ1ko)$
} G@X% +$I
else BG]#o|KW
break; 9-a0:bP
} '$(^W@M#6
} E]n&=\
catch(IOException e){e.printStackTrace ();} H3=qe I
catch(Exception e){e.printStackTrace ();} s)D;a-F
!``,gExH
u^I|T.w<r6
Utility.log(nFileLength); LYK"(C
{]@= ijjf
YZ8>OwQz2
return nFileLength; [<yaXQxl
} vw/J8'
uh>; 8
q{LF>Wi
//保存下载信息（文件指针位置） G}raA%
private void write_nPos() Z0", !6nS
{ L^?qOylu
try{ +lcbi
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~P**O~
output.writeInt(nStartPos.length); :{l_FY436
for(int i=0;i<nStartPos.length;i++) #r\4sVg
{ yq\K)g*=
// output.writeLong(nPos); A]oV"`f
output.writeLong(fileSplitterFetch.nStartPos); "JV_2K_i
output.writeLong(fileSplitterFetch.nEndPos); hD!7Cl Q
} wc4{)qDE
output.close(); By4<2u38u
} '-XXo=>0MV
catch(IOException e){e.printStackTrace ();} 2eY_%Y0
catch(Exception e){e.printStackTrace ();} bwMm#f
} w;amZgD>
~HsJUro
N5 6g+,w%)
//读取保存的下载信息（文件指针位置） `d`T*_
private void read_nPos() :OT0yA=U
{ Y]2A&0
try{ K Z91-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n 0L^e
int nCount = input.readInt(); S|N_o
nStartPos = new long[nCount]; =X:Y,?
nEndPos = new long[nCount]; E*K;H8}s
for(int i=0;i<nStartPos.length;i++) 0~/_|?]`7
{ 7[XRd9a5(
nStartPos = input.readLong(); -C]5>& W
nEndPos = input.readLong(); >KhOz[Zg
} nmKp[-5
input.close(); [hv~o~q
} GGs}i1m
catch(IOException e){e.printStackTrace ();} fr6fj
catch(Exception e){e.printStackTrace ();} {hrX'2:ClT
} Ai3*QX
I,vJbvvl!
lX4 x*
private void processErrorCode(int nErrorCode) ~=l;=7 T
{ ENs&RZ;
System.err.println("Error Code : " + nErrorCode); B[?Ng}<g`
} A$0fKko
qu{&xjTH8
g1"kTh
//停止文件下载 Dp-z[]})1
public void siteStop() ]Q)OL
{ DsCcK3 k
bStop = true; BUXpCxQ
for(int i=0;i<nStartPos.length;i++) 'zuIBOH`j3
fileSplitterFetch.splitterStop(); 1\2no{Vh
>U27];}y
fJ!R6D
} fuf"Ae
} `Eo.v#<
//负责部分文件的抓取 J}K$(;:
**FileSplitterFetch.java n9ej7oj
*/ ,R* ]>'
package NetFox; p6!x=cW
sS'm!7*(3
T}v4*O.,
import java.io.*; cU!vsdR3
import java.net.*; [5Mr@f4I
~U&AI1t+J
[?N~s:}
public class FileSplitterFetch extends Thread { ope^~+c~\
~dTrf>R8M
z_4J)?3
String sURL; //File URL v;D~Pa
long nStartPos; //File Snippet Start Position YO}<Ytx
long nEndPos; //File Snippet End Position M&9+6e'-F
int nThreadID; //Thread's ID LBDjIpR6
boolean bDownOver = false; //Downing is over HvJs1)Wo&
boolean bStop = false; //Stop identical _ *Pf
FileAccessI fileAccessI = null; //File Access interface +Q"4Migbe@
VQOezQs\
n<R?ffy
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "'?>fe\qG
{ {8bSB.?R
this.sURL = sURL; ^>v+( z5R
this.nStartPos = nStart; f\L0xJ
this.nEndPos = nEnd; B>P{A7Q
nThreadID = id; )R1<N
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^RIl
} w@w(-F!%l
8P&:_T!
|z^^.d~a0
public void run() ZyFjFHe+
{ ?)d~cJ
while(nStartPos < nEndPos && !bStop) e^1Twz3z
{ gT6jYQ
Ok=hT|}Y
)oPBa
try{ bq0zxg%
URL url = new URL(sURL); )irEM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'YSHi\z ](
httpConnection.setRequestProperty("User-Agent","NetFox"); z9Rp`z&`E
String sProperty = "bytes="+nStartPos+"-"; U9MxI%tb
httpConnection.setRequestProperty("RANGE",sProperty); oE]QF.n#
Utility.log(sProperty); AFE~ v\Gz
G2: agqL/
4ID5q~
InputStream input = httpConnection.getInputStream(); +A?U{q
//logResponseHead(httpConnection); <=C!VVk4f
)MTOU47U
#Ki[$bS~6
byte[] b = new byte[1024]; &\*(Q*2N
int nRead; d5:c^`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) j*r{2f4Rt
{ /hyN;.hpOO
nStartPos += fileAccessI.write(b,0,nRead); *VxgARIL
//if(nThreadID == 1) i?^L/b`H
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /aZ`[m2
} I^$fMdT
smo~7;
bY~pc\V:`w
Utility.log("Thread " + nThreadID + " is over!"); PALc;"]O
bDownOver = true; :,6\"y-
//nPos = fileAccessI.write (b,0,nRead); aO4?m+
} draN0vf
catch(Exception e){e.printStackTrace ();} wNdisI
} PB\x3pV!}
} u.xnOcOH!
s?L
*u;Iw{.{
//打印回应的头信息 1#+S+g@#
public void logResponseHead(HttpURLConnection con) p H2Sbs:Tk
{ ]Er$*7f
for(int i=1;;i++) ;>7De8v@@
{ 0YDR1dO(*
String header=con.getHeaderFieldKey(i); nZYBE030
if(header!=null) ^^D0^k!R
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7WZ+T"O{I
Utility.log(header+" : "+con.getHeaderField(header)); k@W1-D?
else hM@>q&q_
break; A6(/;+n
} .,6-u
} P\k# >}}
c\AfaK^KF
;u)I\3`*!
public void splitterStop() 1yu4emye4
{ [`7ThHX
bStop = true; wz%NbLy-
} *gWwALGo5
$-sHWYZ
@E|}Y
} ?gGHj-HYJ
:"/d|i`T
G" "ZI$`
/* 9'bwWBf7
**FileAccess.java R8'RA%O9J
*//文件访问(定位，写) Ds:'Lb
package NetFox; rFL;'Cj@
import java.io.*; P/_['7
j&qub_j"xX
/9fR'EO{x
public class FileAccessI implements Serializable{ O:Tj"@h
Xc&9Glf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Qzw;i8n{
RandomAccessFile oSavedFile; /mzlH
long nPos; P~X2^bw
EXqE~afm2
}0Ed]
public FileAccessI() throws IOException CzrC%xy
{ b d!Y\OD
this("",0); t"oeQ*d%
} I-l_TpM)
X=&KayD
hp|YE'uYT
public FileAccessI(String sName,long nPos) throws IOException U&qZ"
{ /cP"h!P}~~
oSavedFile = new RandomAccessFile(sName,"rw"); ?%[jR=w
this.nPos = nPos; IW] rb/H
oSavedFile.seek(nPos); ysY*k`5
} T]~xj4
pTLCWbF?
6.yu-xm
public synchronized int write(byte[] b,int nStart,int nLen) x7 ,5
{ tc_3sC7jN
int n = -1; 7HYwLG:\~
try{ @f3E`8
oSavedFile.write(b,nStart,nLen); %d9uTm;
n = nLen; { 2f-8Z&>
} rjnrju+
catch(IOException e) e$Pj.>-<=
{ mQ"-,mMI
e.printStackTrace (); pOoEI+t
} _6vWF
dG?*y
]3Sp W{=^(
return n; |M;7>'YNC*
} =[7Av>
8zW2zkv2|#
=41?^1\
} =Nr-iae#
g*+>H1}
[v!f<zSQK
/* _7_Y={4=`
**SiteInfoBean.java 19%imf
*/ \1M4Dl5!
package NetFox; _;\_l
M/`lM$98:
ysnx3(+|
public class SiteInfoBean { ('+d.F[109
vKAN@HSYr
K_}K@'
private String sSiteURL; //Site's URL >Y@H4LF;1x
private String sFilePath; //Saved File's Path M x"\5i
private String sFileName; //Saved File's Name Q^^niVz
private int nSplitter; //Count of Splited Downloading File tw)mepwB
^E>3|du]O
~WF\
public SiteInfoBean() 5~DJWi,
{//nSplitter的缺省值为5 Xne1gms
//default value of nSplitter is 5 dft!lBN
this("","","",5); 4 s9LB
} t\O16O7S
4Ftu
N!tX<u~2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R[+<^s}p/
{ SOaoo^,O
sSiteURL= sURL; <qt|d&
sFilePath = sPath; +R75v)
sFileName = sName; gf\oC> N
this.nSplitter = nSpiltter; +R:(_:7
1s;Saq+
&=mtc%mL
} 6j|{`Zd)G
)%fH(ns(
(S Yln>o
public String getSSiteURL() gbD KE{
{ 2y1Sne=<Kb
return sSiteURL; HTTCTR
} % |L=l{g
`){.+S(5C
:\_ 5oVb
public void setSSiteURL(String value) Qn2&nD%zi
{ buHJB*?9
sSiteURL = value; $3kH~3{]
} 7F~X,Dk_
9} .z;prz
es0hm2HT3
public String getSFilePath() sV*H`N')S
{ wVtwx0|1
return sFilePath; ChQxa
} Lu%b9Jk
G=bCNn<
[()koU#w.
public void setSFilePath(String value) 5SQ8}Or3
{ [mueZQyI?0
sFilePath = value; YuwI&)l
} |;{6&S
7_[L o4_
-$Ih@2"6
public String getSFileName() ~)M~EX&pK
{ %\:Wi#w>
return sFileName; dqcL]e
} @>7%qS
`">=
V0Hj8}l;M
public void setSFileName(String value) %B?=q@!QWn
{ iH'p>s5L
sFileName = value; hgE71H\s
} akTk(
1k^oS$UT
?Q;=v~-Q
public int getNSplitter() 2st3
{ #Bw0,\
return nSplitter; IdN41
} U #0Cx-E
0PCGDLk8
\z)%$#I
public void setNSplitter(int nCount) JK]PRDyD
{ %@Jsal'
nSplitter = nCount; MnHNjsO#
} ue>D7\8
} /g.U&oI]D
.fs3>@T"#
7uk[Oy<_
/* UC$ppTCc?
**Utility.java yWf`rF{
*/ zKK9r~ M
package NetFox; HK%7g
l%=;
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public class Utility { V]?R>qhgu
l}P=/#</T
u$`a7Lp,n
public Utility() 9jGu}Vo
{ -F3-{E
EiaW1Cs
wdoR%b{M
} qxJ\ye+'*
.X;K%J2
//线程睡眠 "uf%iJ:%
public static void sleep(int nSecond) *=xr-!MEk
{ _','9|
try{ c1gQ cqF
Thread.sleep(nSecond); hCo|HB
} FC4wwzb
catch(Exception e) f,Ghb~y
{ !TcJ)0
e.printStackTrace (); bN=P*hdf
} [PbOfxxgA
} $Z>'Jp
7PF%76TO
//日志 YHl;flv
public static void log(String sMsg) [KQ6Ta.
{ f<6lf7qzC
System.err.println(sMsg); L4l!96]a
} 8JUwf
NZz8j^
,wPr"U+7
public static void log(int sMsg) W(/h Vt
{ k|f4Cf,
System.err.println(sMsg); CTA3*Gn
} |gY^)9ei
} ]}X
,"0:3+(8;
P1f[%1
/* 7IM@i>p%
**TestMethod.java K~EmD9
*/ pmYHUj #
package NetFox; r,2g^K)6
|sZHUf_
eJ81-!)
public class TestMethod { j*m%*_kO
9(<@O%YU
Yu`~U,m
public TestMethod() r:TH]hs12+
{ ///xx/weblogic60b2_win.exe wwcBsJ1{
try{ ^LzF@{ G
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _h1mF<\ X^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7Fsay+a
SiteFileFetch fileFetch = new SiteFileFetch(bean); @9|hMo
fileFetch.start(); PeEj&4k
} U,1-A=Og{o
catch(Exception e){e.printStackTrace ();} ={Qi0Pvt
| VDV<g5h
IO:G1;[/2L
} Y\'}a+:@Ph
Wh{tZ~c
%e}Saf
public static void main(String[] args) bi;1s'Y<D
{ g< .qUBPKX
new TestMethod(); Rbv;?'O$L
} "-V"=t'
} o#1 $q`Z
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