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)); h"b;e2
} .Vy*p")"
for(int i=0;i<nEndPos.length-1;i++) Y;JPr
{ }YPW@g
nEndPos = nStartPos[i+1]; fWr6f`de
} }=d]ke9_
nEndPos[nEndPos.length-1] = nFileLength; +Xa^3 =B
} y-Xd~<*Ia
} IB!^dhD!Q
Cpyv@+;D
hJ)>BeH0
//启动子线程 HLjXH#ry
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; W6kDQ&q
for(int i=0;i<nStartPos.length;i++) ) ?AlQA
{ ppwjr +
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y6_%HYI$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), < C{-ph
nStartPos,nEndPos,i); MT`gCvoF4P
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a,B2;4"
fileSplitterFetch.start(); )+'De
} c^N'g!on
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }]8n3&*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2!6+>nvO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0zSRk]i.f
nEndPos = " + nFileLength); dr25;L? B
// fileSplitterFetch[nPos.length-1].start(); FW?zJ
QFg,pTj
)p,uZ`~v
//等待子线程结束 *6Ojv- G|5
//int count = 0; bp'qrcFuiL
//是否结束while循环 (WW*yv.J
boolean breakWhile = false; >g):xi3qK
+Lq;0tRC
$~#N1
while(!bStop) 994
{ ."N`X\
write_nPos(); x2P}8Idg?A
Utility.sleep(500); 3' HtT
breakWhile = true; {I/|7b>@r
lnXb]tm;
pt"yJtM'P
for(int i=0;i<nStartPos.length;i++) qbrf;`
{ yMdAe>@
if(!fileSplitterFetch.bDownOver) 6usy0g D
{ lq4vX^S
breakWhile = false; Lk%u(duU^
break; 6$]p;}#
} _h@s)"
} @,b:s+]rp
if(breakWhile) bzz{ p1e
break; ^8_`IT
Fx^e%":@ip
uO4kCK<7C
//count++; auV'`PR
//if(count>4) Kp_L\'.I5$
// siteStop(); 1P"akc
} =cy;{2S'p
(thDv rT@2
?DAW~+,!7o
System.err.println("文件下载结束！"); P'4oI0Bw
} jU4*fzsZI
catch(Exception e){e.printStackTrace ();} o6@Hj+,,
} kR C0iTV'I
n+5X*~D
:z;}:+7n
//获得文件长度 k\:f2%!!
public long getFileSize() 1|4'3^3
{ |2yTt*!-r
int nFileLength = -1; 1[QH68
try{ $VX<UK$|s
URL url = new URL(siteInfoBean.getSSiteURL()); TEgmE9^`)7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;%Z%]nIS
httpConnection.setRequestProperty("User-Agent","NetFox"); Tum9Xa
%-zAV*>
8vN}v3HV&
int responseCode=httpConnection.getResponseCode(); 9*?H/iN@p?
if(responseCode>=400) T<p,KqH
{ B{ i5UhxD
processErrorCode(responseCode); W]8tp@
return -2; //-2 represent access is error Dxc`K?M
} S-FoyID\H
>[4;K&$B
myp}DI(
String sHeader; Y,v8eOo45S
kg2?IL
?}QHEk:H
for(int i=1;;i++) }m?1IU%q
{ tDuQ+|~M
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); GN36:>VWb
//Utility.log(in.readLine()); yPKDn.1
sHeader=httpConnection.getHeaderFieldKey(i); :U5>. ):
if(sHeader!=null) ^k&T?uU
{ kNX(@f
if(sHeader.equals("Content-Length")) :#M(,S"Qq
{ UX-l`ygl
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8]DN]\\o
break; mp_(ke
} |"[[.Adw9"
} By3/vb)M5
else 5 =Os sAr
break; Zi+>#kDV
} ~I0I#_$'P
} b;!oPT
catch(IOException e){e.printStackTrace ();} st;.Po[h
catch(Exception e){e.printStackTrace ();} Fm\ h883\
.uAOk0^z
NN<kO#c+2
Utility.log(nFileLength); t7VXW{3
:K!@zT=o
@@U'I^iG
return nFileLength; >\Qyg>Md]
} WMB~? EDhv
JwzA'[tM
"RuH"~o
//保存下载信息（文件指针位置） tS2P|fl
private void write_nPos() ]xf lfZ
{ 7y",%WYSD
try{ Qtmsk:qm
output = new DataOutputStream(new FileOutputStream(tmpFile)); MSPzOJQPy
output.writeInt(nStartPos.length); K5x&:z
for(int i=0;i<nStartPos.length;i++) #]G$o?@Y=^
{ 8-cB0F=j_
// output.writeLong(nPos); a#X[V5|6Q
output.writeLong(fileSplitterFetch.nStartPos); s[:e '#^
output.writeLong(fileSplitterFetch.nEndPos); -\;x>=#B
} \h6_m)*H4
output.close(); dQ*3s>B[
} whW"cFg
catch(IOException e){e.printStackTrace ();} f"h{se8C
catch(Exception e){e.printStackTrace ();} a;p3Me7
} F+vgkqs@9
HYgq@47$[
A"S{W^iL
//读取保存的下载信息（文件指针位置） 6MfjB@
private void read_nPos() ;4nz'9+
{ EthnI7Y
try{ clz6;P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); NQq$0<7.=W
int nCount = input.readInt(); GXC:~$N
nStartPos = new long[nCount]; zJ42%0g
nEndPos = new long[nCount]; 7Rr(YoWa
for(int i=0;i<nStartPos.length;i++) C& 0iWY\a
{ /nEh,<Y)
nStartPos = input.readLong(); E Kks8
nEndPos = input.readLong(); [wAI;=.
} "}PaMR]
input.close(); TY"=8}X1
} 6xSdA;<+]
catch(IOException e){e.printStackTrace ();} `gq@LP"o
catch(Exception e){e.printStackTrace ();} 3_(fisvx
} n!mtMPH$
[Q,E( s
uX@RdkC
private void processErrorCode(int nErrorCode) h?2qX
{ 4oLrCQZ\
System.err.println("Error Code : " + nErrorCode); ![os5H.b#q
} Oy$*ZG)
%n`wU-?lK
k<uC[)_
//停止文件下载 sfez0Uqe.~
public void siteStop() vukI`(#
{ ' jFSv|g+0
bStop = true; '+BcPB?E
for(int i=0;i<nStartPos.length;i++) \H+/D &M
fileSplitterFetch.splitterStop(); 4os7tx
Wa~'p+<c~b
pR2QS
} ev>gh0
} b,YTw
//负责部分文件的抓取 sW 7R&t!G
**FileSplitterFetch.java KFHn)+*"
*/ h^ ex?
package NetFox; D0,U2d
hVRpk0IJDK
#KZ6S9>@
import java.io.*; Ji SJi?
import java.net.*; hKb-l`KO
9J_lxy}
X b-q:{r1h
public class FileSplitterFetch extends Thread { A P><l@
g"|QI=&_J
Kx?3]
String sURL; //File URL M(o?I}
long nStartPos; //File Snippet Start Position l)`bm/k]V
long nEndPos; //File Snippet End Position y4s]*?Wz
int nThreadID; //Thread's ID 1]#qxjZ~
boolean bDownOver = false; //Downing is over [;II2[5 ,
boolean bStop = false; //Stop identical ]V J$;v'{[
FileAccessI fileAccessI = null; //File Access interface 3dNOXk,#
6=2M[T
HF}%Ow
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException } pE<P;\]k
{ #/t^?$8\\
this.sURL = sURL; Pq`]^^=be'
this.nStartPos = nStart; ^R\0<\'
this.nEndPos = nEnd; WlU^+ctS
nThreadID = id; b Mi,z3z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Iz^~=yV)
} zh)qo
N~L3 9
k'Fc:T8:~5
public void run() Be"D0=<
{ =mYY8c Yl
while(nStartPos < nEndPos && !bStop) )s1W)J?8
{ tsR\cO~/
F>E'/r*
y/rmxQtP
try{ qsn6i%VH
URL url = new URL(sURL); Fy8KZWim
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !]4'f/
httpConnection.setRequestProperty("User-Agent","NetFox"); ;>Y,b4B;
String sProperty = "bytes="+nStartPos+"-"; ,%e.nj9
httpConnection.setRequestProperty("RANGE",sProperty); s QfP8}U
Utility.log(sProperty); .T?9-`I9
XHcT7}]
HcwqVU
InputStream input = httpConnection.getInputStream(); %,$/wh)<V
//logResponseHead(httpConnection); qQ[&FjTO`
(1gfb*L
sL]KBux
byte[] b = new byte[1024]; '`=z52
int nRead; J_]?.V*A
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ZP5.?A-=C
{ v|`f8M2
nStartPos += fileAccessI.write(b,0,nRead); R"#DR^.;
//if(nThreadID == 1) "WR)a`$UR
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MHmaut#
} vs;T}'O
|H 0+.f;
Fp..Sjh 6
Utility.log("Thread " + nThreadID + " is over!"); q:@$$}FjL
bDownOver = true; !q;EC`i#
//nPos = fileAccessI.write (b,0,nRead); %YLdie6c
} J4!Om&\@
catch(Exception e){e.printStackTrace ();} E]V:@/(M'
} v+A$CGH96
} ,2S w6u
j+NOT`&
C4e3Itc9X
//打印回应的头信息 $EHAHNL?Lx
public void logResponseHead(HttpURLConnection con) d-nqV5
{ W*iPseXq
for(int i=1;;i++) x0B|CO
{ WgPpW!`
String header=con.getHeaderFieldKey(i); 4tU3+e5h
if(header!=null) 2i`N26On
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _svY.ps*
Utility.log(header+" : "+con.getHeaderField(header)); &NiDv
else Dz;^'
break; VqV6)6
} 3\WLm4
} ]+x;tPo
26un=
0@z=0}0Z
public void splitterStop() /M(FuV
{ cN_e0;*Ua
bStop = true; \xJTsdd
} /Ps}IW
pfsRV]
fl>*>)6pm
} @/i{By^C
T(%U$ea-S
3OTq
/* n.P$7%G`2
**FileAccess.java {t`UV,
*//文件访问(定位，写) (cJb/|?3
package NetFox; F }l_=
import java.io.*; Kg^L 4Q
q@1!v
J&4LyIpQ
public class FileAccessI implements Serializable{ pv8"E?9,k
,!U5;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]^:l?F\h
RandomAccessFile oSavedFile; Vvu+gP'z.
long nPos; A7SBm`XJ)p
1V(tt{
i3g;B?54
public FileAccessI() throws IOException 9NLO{kN
{ {FyGh */
this("",0); nsk`nck
} Tx"}]AyB6
0p\R@{
fXCx!3m
public FileAccessI(String sName,long nPos) throws IOException Zo
{ 6N[XWyS
oSavedFile = new RandomAccessFile(sName,"rw"); d51l7't
this.nPos = nPos; 4SSq5Ve<
oSavedFile.seek(nPos); (r,tU(
} d4<Ic#
uV?[eiezD0
)>08{7
public synchronized int write(byte[] b,int nStart,int nLen) Kt3/C'zu
{ *L>gZ`Q
int n = -1; `~Nd4EA)2
try{ =;Gy"F1 dp
oSavedFile.write(b,nStart,nLen); "pTyQT9P
n = nLen; "Wd?U[[
} C'3/B)u}l
catch(IOException e) tAH,3Sz( /
{ NidG|Yg~Z
e.printStackTrace (); 8$}1|"F
} AU@K5jwDwQ
zn|~{9>y
{:M5t1^UC
return n; `vWFTv
} xq1=O
u1d{|fF
|Q2H^dU'rQ
} &z;F'>"
h7mJXS)t|
bAv>?Xqa
/* (@Q@B%!!K
**SiteInfoBean.java 3#vhQ*xU
*/ fhlhlOg
package NetFox; xh Sp<|X_
vG9A'R'P
,W"Q)cL
public class SiteInfoBean { uTY5.8
Y%OE1F$6NN
TGx:#x*k
private String sSiteURL; //Site's URL |pk1pV |
private String sFilePath; //Saved File's Path D(6d#c
private String sFileName; //Saved File's Name ]l.y/pRP5[
private int nSplitter; //Count of Splited Downloading File :=x-b3U
=BW>jD
l(|@ dp
public SiteInfoBean() [H$37Hx!
{//nSplitter的缺省值为5 N9IBw',
//default value of nSplitter is 5 _ Js& _d
this("","","",5); ka3Jqy4[
} sS#Lnj^`%
;\yY*
> E;`;b
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Wi]Mp7b
{ ]0<T,m Z
sSiteURL= sURL; sLh9=Kh`
sFilePath = sPath; BhC.#u/
sFileName = sName; 6u^MfOc
this.nSplitter = nSpiltter; rxtp?|v9
r<4FF=
{2?o:
} qv|geBW
7N0V`&}T
3uA%1 E
public String getSSiteURL() .zf#S0y%(
{ aV3:wp]Gn
return sSiteURL; !IlsKMZ
} a!YpSFr
mD`v>L
*ZP$dQ
public void setSSiteURL(String value) m }I@:s2
{ '&4W@lvyz
sSiteURL = value; I\J^@&JE
} _IiTB
P wL]v.:
d>@&[C!28
public String getSFilePath() Yg@k+
{ P}B{FIpNG
return sFilePath; V;$ME4B\{
} MzLnD D^
W]cJP
lrg3n[y-l
public void setSFilePath(String value) ?.66B9Lld
{ gB1w,96J
sFilePath = value; H(bR@Qok
} ab4(?-'-
D9`J||]E
OL|_@Fv`A
public String getSFileName() O^(ji8[l
{ .: ~);9kj
return sFileName; RL0,QC)e#@
} GZgu1YR
2uw1R;zw
9&e=s<6dO
public void setSFileName(String value) {,z$*nf
{ w~EBm=v_>
sFileName = value; 1"k"<{%
} y7J2:/@[x
Dj!v+<b
CjRI!}S
public int getNSplitter() =@w,D.5h
{ Cz@[l=-T7
return nSplitter; 4E[ 9)n+YV
} hkOhY3K5
W8hf Qpw
y;W|)
public void setNSplitter(int nCount) Z9rmlVU6!
{ $*EK v'g[n
nSplitter = nCount; d$~q
} R7YLI1ov
} (3kz(6S
3(D!]ku~m
_ZUtQ49
/* Y] Q=kI
**Utility.java NYopt?Xg
*/ {.=4;
package NetFox; !Cse,6/Z
UzZzt$Kw
.|=~x3mPw
public class Utility { ;{@ [ek6
HPM ggRs
$kPC"!X\
public Utility() >|h$d:~n
{ 8BP.VxX
^~iu),gu
.{,PC
} %-C
pRS+vV3
//线程睡眠 @ 63Uk2{W>
public static void sleep(int nSecond) Jv*[@ -.k
{ rGjP|v@3^
try{ iDp'M`(6h
Thread.sleep(nSecond); ico%_fp
} xb`,9.a7
catch(Exception e) ktQMkEj#
{ cs0;:H*N*
e.printStackTrace (); 09FHE/L
} ~dkN`1$v
} 05_aL` &eb
=2;2_u?
//日志 Zx&gr|)}
public static void log(String sMsg) 0K/?8[#
{ alu3CE
System.err.println(sMsg); Q4;eN w
} r3.A!*!
M[aF3bbN
1eiV[z$?
public static void log(int sMsg) M'Fa[n*b?!
{ 3Yu1ZuIR
System.err.println(sMsg); A6D.bJ)
} 5LJUD>f9Z
} L< 3U)Gp
4x8e~/
7S"W7O1>
/* {J_1.uN=
**TestMethod.java D|zlC,J,
*/ =*K~U# uoC
package NetFox; VXr'Z
(N63k1M
=b\k$WQ_(
public class TestMethod { Vaj4p""\F
a~#MMl
ci]IH]x
public TestMethod() 6$42-a%b
{ ///xx/weblogic60b2_win.exe ~nul[>z
try{ >cVEr+r9t
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); kGaK(^w
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cRt[{HE
SiteFileFetch fileFetch = new SiteFileFetch(bean); )"Ef* /+
fileFetch.start(); kJ^)7_3
} mM*jdm(!
catch(Exception e){e.printStackTrace ();} cT8b$P5w
cM9z b6m
W*D]?hXU;
} 0MV^-M
be^09'
4}mp~AXy;z
public static void main(String[] args) CHeU`!:
{ /$]#L%
new TestMethod(); p8yn? ~]^
} U%E6"Hg
} Dm=d
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