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)); |[}!E/7>b
} I ;Sm<P7*
for(int i=0;i<nEndPos.length-1;i++) ? @Y'_f
{ <wZ2S3RNA
nEndPos = nStartPos[i+1]; N3J;_=<4
} |B;tv#mKD
nEndPos[nEndPos.length-1] = nFileLength; Ma,2_oq+
} ]V K%6PQ0
} .`3O4]N[
e1j3X\ \
u 6(O;
//启动子线程 yy%'9E ldc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]l WEdf+
for(int i=0;i<nStartPos.length;i++) _c4kj
{ 93*MY7j}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x2bKFJ>e@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), JXIxk"m
nStartPos,nEndPos,i); $kA'9Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i/%+x-#
fileSplitterFetch.start(); -6OgM}
} +(-L
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZCAdCKX|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kgV_*0^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", eJJD'Z
nEndPos = " + nFileLength); x$;I E
// fileSplitterFetch[nPos.length-1].start(); _Fz]QxO
OIMsxXF\J
1]i{b/ 4
//等待子线程结束 bZ$;`F5})
//int count = 0; nM1F4G
//是否结束while循环 =-e`OHA
boolean breakWhile = false; *+ql{\am4N
?B"k9+%5ej
""JTU6]MS
while(!bStop) 8i=c|k,GL.
{ >vPDF+u
write_nPos(); *?a rEYc8
Utility.sleep(500); Az}.Z'LJ
breakWhile = true; 5mxYzu;#]
u._B7R&>
}j/($,
for(int i=0;i<nStartPos.length;i++) #MyR:V*a
{ dp3>G2Yq
if(!fileSplitterFetch.bDownOver) ?W*{%my
{ Nj<}t/e
breakWhile = false; o&GS;{Rs
break; G'5p/:
} /7 CF f&4
} d@a FW
if(breakWhile) *,:>EcDr
break; q*|H*sS
I$Bu6x!
XvU^DEfW
//count++; PtUea
//if(count>4) `5V=U9zdE
// siteStop(); McRAy%{z
} xV_,R'l
f.%mp$~T
.>Gnb2
System.err.println("文件下载结束！"); LX [_6
} \{HbL,s
catch(Exception e){e.printStackTrace ();} rff=ud>Jf
} \pXs&}%1,F
SM;*vkwz~
3++}4%w
//获得文件长度 "%o,P/<X
public long getFileSize() :ub 4p4h*
{ OD*\<Sc
int nFileLength = -1; 7*9a`p3w
try{ lTe7n'y^^
URL url = new URL(siteInfoBean.getSSiteURL()); KxZO.>,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q M#1XbT
httpConnection.setRequestProperty("User-Agent","NetFox"); L9|55z
Ho}"8YEXNV
J4yL"iMt
int responseCode=httpConnection.getResponseCode(); Ry@QJn I<
if(responseCode>=400) UE-<
{ kK27hfsw
processErrorCode(responseCode); E<j}"W$a
return -2; //-2 represent access is error p(jY2&g
} /k$h2,O"*
0]3 ,0s $}
hV(>}hb
String sHeader; WF)(Q~op0U
G E=J Y
I~'%
for(int i=1;;i++) lEcZ/
{ 3@qy}Nm
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1S&GhJ<wJ
//Utility.log(in.readLine()); #H'j;=]:
sHeader=httpConnection.getHeaderFieldKey(i); _2eRH@T
if(sHeader!=null) 6zo'w Wc3
{ LW={| 3}
if(sHeader.equals("Content-Length")) P=.yXirm?
{ mv5=>Xc6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +VJS/
break; laRcEXj
} #Tz$ona
} XX85]49`%
else 4pvT?s>68
break; w\"~*(M
} -C]k YQ
} m#}41<
catch(IOException e){e.printStackTrace ();} 9O8na 'w
catch(Exception e){e.printStackTrace ();} @/MI Oxg[
-/x=`S*
m*Zq3j
Utility.log(nFileLength); :y/1Jf'2f
03ol6y )C
#ujry.m
return nFileLength; 4LEWOWF}
} r8.`W\SKX
Z~g6C0
p<eu0B_V
//保存下载信息（文件指针位置） `!`g&:Y
private void write_nPos() I~^t\iujs
{ 3 291"0
try{ GI+x,p
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6:fHPlqW
output.writeInt(nStartPos.length); 7Ei,L[{\i#
for(int i=0;i<nStartPos.length;i++) ans(^Up$
{ 04K[U9W3
// output.writeLong(nPos); _d|CO
output.writeLong(fileSplitterFetch.nStartPos); iS p +~
output.writeLong(fileSplitterFetch.nEndPos); R[C+?qux
} Kyf,<zF
output.close(); q7}rD$
} Y X`BX$
catch(IOException e){e.printStackTrace ();} ^(j}'p,
catch(Exception e){e.printStackTrace ();} {\1:2UKkr
} 1^f7
b< dwf[
eD|p1+76
//读取保存的下载信息（文件指针位置） YiO3.+H
private void read_nPos() i/vo
{ 2 c 2lK
try{ 8a,uM :
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ww}4
int nCount = input.readInt(); fY4I(~Q
nStartPos = new long[nCount]; ~ u)}/
nEndPos = new long[nCount]; W)_|jpd[
for(int i=0;i<nStartPos.length;i++) Bj=lUn`T:
{ = 9Ow!(!@
nStartPos = input.readLong(); x|b52<dLL&
nEndPos = input.readLong(); i/C`]1R/
} }508wwv
input.close(); \aN*x
} ':>u*
catch(IOException e){e.printStackTrace ();} t3qPocYQ
catch(Exception e){e.printStackTrace ();} Silh[8
} lZ'WFFWLE
qa\e`LD%Y
U<YcUmX
private void processErrorCode(int nErrorCode) tx*L8'jlN
{ mn].8F
System.err.println("Error Code : " + nErrorCode); %(uYYr 6
} r|_@S[hZg
AMw#_8Y
d-sT+4o}
//停止文件下载 Q$yMU[l)
public void siteStop() 5%_aN_1?ef
{ e=cb%
bStop = true; K8=jkU
for(int i=0;i<nStartPos.length;i++) Sx0/Dm
fileSplitterFetch.splitterStop(); hCOCX_
}@y(-7t
oH,{'S@q
} Cqs+ o^q
} W ZT) LYA
//负责部分文件的抓取 YYN'LF#j
**FileSplitterFetch.java 57K\sT4[
*/ BXb=NE
package NetFox; fTOGW`s^
kR+7JUq]
68?>#o865
import java.io.*; +SB>>
import java.net.*; YMU2^,3
%/4_|.8u
0H+!v
public class FileSplitterFetch extends Thread { _UA|0a!-
.6=;{h4cpB
i91 =h
String sURL; //File URL ~m'8<B5+
long nStartPos; //File Snippet Start Position h+ms%tNT
long nEndPos; //File Snippet End Position }G)2HTaZ
int nThreadID; //Thread's ID U*:ju+)k
boolean bDownOver = false; //Downing is over oj(st{,
boolean bStop = false; //Stop identical 4;bc!> sfC
FileAccessI fileAccessI = null; //File Access interface SDc8\ms
4J1_rMfh
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F%:74.]Y
{ k%TBpG:T
this.sURL = sURL; bZ>dr{%%e
this.nStartPos = nStart; #`ZBA>FLaQ
this.nEndPos = nEnd; AxfQ{>)0
nThreadID = id; i5,yrPF
fileAccessI = new FileAccessI(sName,nStartPos);//定位 HU/2P`DGP
} '~9w<dSB!r
q@^^jlHP
!,^y!+,Qy
public void run() 9sN#l
{ ;:,U]@
while(nStartPos < nEndPos && !bStop) bt};Pn{3
{ SsEpuEn
ICEyz| C
}BUm}.-{u,
try{ RW<10:
URL url = new URL(sURL); 4?fpk9c{2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %g~&$oZmq
httpConnection.setRequestProperty("User-Agent","NetFox"); sU+8'&vBp
String sProperty = "bytes="+nStartPos+"-"; 0v,fY2$c
httpConnection.setRequestProperty("RANGE",sProperty); zM(-f|wVI)
Utility.log(sProperty); >V>`}TIH
AQ?;UDqU
t#VX#dJ
InputStream input = httpConnection.getInputStream(); 5WA:gygB&
//logResponseHead(httpConnection); /9A6"Z
D/VEl{ba-
b BiTAP
byte[] b = new byte[1024]; gq]@*C
int nRead; ;Dbx5-t
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ifNyVEHy
{ NcrBp(
nStartPos += fileAccessI.write(b,0,nRead); i6f42]Jy
//if(nThreadID == 1) [C/{ru&E
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gt9(5p
} &Hyy .a
qj/Zk[
WH"'Ju5}
Utility.log("Thread " + nThreadID + " is over!"); BCuoFw)
bDownOver = true; "L;@qCfhO
//nPos = fileAccessI.write (b,0,nRead); po(pi|
} $NCR V:J
catch(Exception e){e.printStackTrace ();} 'd|!Hr<2
} BaWU[*
} *8_Dn}u?Jx
|@~_&g
)Ii`/I^
//打印回应的头信息 fk9q3
public void logResponseHead(HttpURLConnection con) -G~/ GO
{ RU=\eD
for(int i=1;;i++) nLOK1@,4
{ L/E7xLz
String header=con.getHeaderFieldKey(i); }.pqV X{d
if(header!=null) %#o@c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <d"nz:e
Utility.log(header+" : "+con.getHeaderField(header)); Fe %Vp/
else vcCNxIzEG
break; B9Mp3[
} d>NO}MR
} d&AO4^
^<Gxip
A|4om=MO
public void splitterStop() 3AglvGK7{
{ a~J!G:(
bStop = true; 5}Id[%.x
} 8#HnV%|N
jo0XF]
LEOri=?RF
} T*gG <8
%t$KVV
eEfGH
/* tSux5yV
**FileAccess.java ]l C2YD}
*//文件访问(定位，写) V']Z_$_
package NetFox; xY/F)JOeG
import java.io.*; :iLRCK3C
*];QPi~
"dGN0i
public class FileAccessI implements Serializable{ "O-X*>?f
mQ<4(qd)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .p.( \5Fo
RandomAccessFile oSavedFile; )hl7)~S<
long nPos; 10h;N[
8V}|(b#
;N(L,
public FileAccessI() throws IOException rM^2yr7H
{ 9-V'U\}L
this("",0); /t`,7y3T
} sp:4b$zX
k\qFWFR
`)5WA{z
public FileAccessI(String sName,long nPos) throws IOException UGd\`*Cj
{ \+nV~Pi"A
oSavedFile = new RandomAccessFile(sName,"rw"); c-5AI{%bl6
this.nPos = nPos; a]7g\rg)
oSavedFile.seek(nPos); :aBxyS*}G
} ,}]v7DD
M]p-<R\
k7Qs#L
public synchronized int write(byte[] b,int nStart,int nLen) (_!I2"Q*
{ vb?.`B_>&
int n = -1; {aq)Y>o5:T
try{ ~c<8;,cjYR
oSavedFile.write(b,nStart,nLen); S5u$I
n = nLen; kS&>g
} XVqkw@Ia4!
catch(IOException e) @8>bp#x/1
{ _k26(rdI@-
e.printStackTrace (); .D ^~!A
} akNqSZwj
r180vbN$
hSw=Oq82
return n; Ha|}Oj
} 9Q}g Vqn
I<CrEL<5}~
qPD(D{,f$
} qbD 7\%
EpNN!s=Q
\/<VJB uV
/* 7I'C'.6iM
**SiteInfoBean.java ~ z3J4s
*/ >W8"Ar
package NetFox; 1P[x.t#
UO&$1rV
>V?0#f45@
public class SiteInfoBean { h'};spv
B~ i
]vB\yQE
private String sSiteURL; //Site's URL D-LOjMe
private String sFilePath; //Saved File's Path I=#`8deH(
private String sFileName; //Saved File's Name z`t~N
private int nSplitter; //Count of Splited Downloading File NJ.oME@=
>h\u[I$7
Lo_+W1+
public SiteInfoBean() fn,hP_
{//nSplitter的缺省值为5 RC[Sa wA
//default value of nSplitter is 5 3: WEODV2
this("","","",5); wpYk`Lr
} OqIXFX"
5N$XY@
aIFlNS,y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) iLZY6?_^
{ po*8WSl9c[
sSiteURL= sURL; 6];3h>c]N
sFilePath = sPath; QK+,63@D\=
sFileName = sName; KzO"$+M
this.nSplitter = nSpiltter; YwET.(oo
H}5WglV.
s$>n U
} <^Vj1s
:=;{w~D
}R#W<4:
public String getSSiteURL() Ve|:k5z
{ f0sGE5
return sSiteURL; ;j/$%lC
} $Y6\m`
\H:T)EVy
CA0XcLiFt
public void setSSiteURL(String value) rX?ZUw?u&
{ 9/{zS3h3
sSiteURL = value; 8!Wh`n<
} ').)0;
\ m~?yq8H
Zf@B< m
public String getSFilePath() 30uPDDvar
{ #O}}pF
return sFilePath; ;\2Z?Kq
} T9Q3I
o=($'(1
hA5')te<
public void setSFilePath(String value) A\Ib
{ H,L{N'[Xph
sFilePath = value; +m%%Bz>
} Icrnu}pl_
N7J?S~x
8^ f:-5
public String getSFileName() {:uv}4Z
{ BNNM$.ZIQ
return sFileName; lUs$I{2_
} j0mN4Ny
i)|jLrW~e
R*D<M3
public void setSFileName(String value) }l7+W4~
{ rl%,9JD!
sFileName = value; PmE)FthdP(
} @!f4>iUy
NgGMsE\C}
q%dG>!
public int getNSplitter() < v]
{ p 4>ThpX
return nSplitter; 70c]|5
} lJu^Bcrv
{s0%XG1$
Y\-xX:n.\
public void setNSplitter(int nCount) UrvUt$WO
{ dz9U.:C
nSplitter = nCount; Z{0BH{23
} f+ceL'fr
} 8-nf4=ll
c("|xe
oM~y8O
/* jn V=giBu
**Utility.java w7U]-MW6A*
*/ 32\.-v
package NetFox; aP
]WDmx$"&e
^b+>r
public class Utility { RtMI[
v<!S_7h
kKSGC?d
public Utility() +;q\7*
{ C.92FiC
#4'wF4DR@
;yt6Yp.6e
} ?N<My&E
;9T}h2^`B
//线程睡眠 %f1%9YH
public static void sleep(int nSecond) h$l/wn
{ }%jF!d
try{ R#d~a;j
Thread.sleep(nSecond); Zok{ndO@|f
} /YvXyi>^"%
catch(Exception e) Z;.-UXat
{ ]5Uuz?:e
e.printStackTrace (); BkB>eE1)Ea
} 'V:Q :
} /88s~=
%PYl
//日志 ^ F]hW
public static void log(String sMsg) /sKL|]i=
{ l'+3 6
System.err.println(sMsg); lnZ{Ryo(
} !LN8=u.
tUv>1) [
wX"hUu
public static void log(int sMsg) i?6&4
{ G68KoM
System.err.println(sMsg); !,Uo{@E)Y
} M5`v^>
} *DF3juf~
Y.viOHL
q3$8"Q^
/* [A-_?#cZ
**TestMethod.java Nn. 9J
*/ dDaV2:4E
package NetFox; ~`OX}h/Z
?.?)5 &4
e%\^V\L
public class TestMethod { Pp8S\%z~h
Js,!G
;t&q|}x"
public TestMethod() l76=6Vtb
{ ///xx/weblogic60b2_win.exe Xsq@E#@S
try{ *'/,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P>7Xbm,VP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _gT65G~z
SiteFileFetch fileFetch = new SiteFileFetch(bean); '$tCAS
fileFetch.start(); /Y7^!3uM
} <&5z0rDKWw
catch(Exception e){e.printStackTrace ();} pp"X0
}@r23g%
uAO!fE}CJ
} >f]/VaMH{
KUI{Z I
cbzA`b'Mg
public static void main(String[] args) N"S`9B1eD(
{ pi"H?EHk
new TestMethod(); ,-pE/3|(
} uBm"Xkxe|w
} f@OH~4FG
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