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)); 2Nj0 Hqjq
} GN{.R7
for(int i=0;i<nEndPos.length-1;i++) *.K}`89T
{ ~E`l4'g?
nEndPos = nStartPos[i+1]; UkGUxQ,GU
} _]Hn:O"o
nEndPos[nEndPos.length-1] = nFileLength; 3Zbvf^
} ]IoS-)$Z/
} .lE"N1
sB"]R%`_
Y${ $7+@
//启动子线程 *F9uv)[kz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [` i;gx[^
for(int i=0;i<nStartPos.length;i++) [}VEDx
{ )@sz\yI%U
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -MU^%t;-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `rM-b'D
nStartPos,nEndPos,i); EGa}ml/G
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SWmdU]
fileSplitterFetch.start(); czT$mKj3
} Aimgfxag
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ukPV nk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); zz$*upxK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4f/8APA
nEndPos = " + nFileLength); \dCdyl6V
// fileSplitterFetch[nPos.length-1].start(); $QY(7Z"
g,q&A$Wi
a(<nk5
//等待子线程结束 OgzPX^q/=
//int count = 0; DG& kY+
//是否结束while循环 MqNp*n2
boolean breakWhile = false; i.'f<z$<
XBDlQe|>
0ogTQ`2Z:
while(!bStop) 9x:c"S*
{ <4VUzgX2
write_nPos(); 3 =S.-
Utility.sleep(500); f:=?"MX7
breakWhile = true; $A-b-`X
mH8"k+k
=?/J.[)<*
for(int i=0;i<nStartPos.length;i++) \?}ZXKuJj
{ 0{jRXa-(
if(!fileSplitterFetch.bDownOver) !e%#Zb MIo
{ kdv>QZ
breakWhile = false; 2R)Y}*VX
break; le1'r>E$
} s^E%Ukm
} ANWa%%\T
if(breakWhile) Z3Viil:
break; z:acrQwJ?1
)!OEa]
6 .*=1P*?
//count++; ZOU$do>O
//if(count>4) g~`UC
// siteStop(); PvO>}(=
} K.1#cf ^'
x2tx{Z
bhFzu[B
System.err.println("文件下载结束！"); ~s !+9\Fi
} Ldig/:
catch(Exception e){e.printStackTrace ();} *VD-c
} 8_:jPd!3
+nZx{d,wt
!,I}2,1%k
//获得文件长度 *O+N4tq
public long getFileSize() B` n!IgF8
{ yA6"8fr
int nFileLength = -1; K0b(D8!
try{ 2N>:GwN
URL url = new URL(siteInfoBean.getSSiteURL()); S=o Ab&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j'v2m6/
httpConnection.setRequestProperty("User-Agent","NetFox"); xeZ,}YP)
wG-X833\(
zg"<N
int responseCode=httpConnection.getResponseCode(); 2pZ|+!xc+
if(responseCode>=400) ^[5yff 4
{ ]"F0"UH,
processErrorCode(responseCode); v k<By R
return -2; //-2 represent access is error ;ML21OjgN
} O.!|;)HQ
2#p6.4h=
rq+E"Uj?
String sHeader; RW%e%
tEZ@v(D
^e)KEkh
for(int i=1;;i++) R ]HHbD&;
{ & [4Gv61
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _g 3hXsA
//Utility.log(in.readLine()); Un7jzAvQ
sHeader=httpConnection.getHeaderFieldKey(i); bluhiiATd
if(sHeader!=null) }Vk#w%EJ
{ f%d7?<rw
if(sHeader.equals("Content-Length")) U%"v7G-
{ sJMT _yt;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h=?#D0
break; tP7l ;EX4
} ]B\H
} 7H9&\ur9+
else "1WwSh}Z
break; S9U`-\L0
} MejM(o_kk
} _6xC4@~h*
catch(IOException e){e.printStackTrace ();} jDOB(fE
catch(Exception e){e.printStackTrace ();} %Q]m6ciAM
m)g:@^$
xyBWV]Y
Utility.log(nFileLength); R$_#7>3
6-j><'
evz{@;.R
return nFileLength; 0LN"azhz
} eG=Hyc
E2+O-;VN
gT?:zd=;
//保存下载信息（文件指针位置） FK{Vnj0
private void write_nPos() R~PD[.\u
{ (TgLCT[@T
try{ tg.[.vKs
output = new DataOutputStream(new FileOutputStream(tmpFile)); Fzt{^%\`
output.writeInt(nStartPos.length); lN-vFna
for(int i=0;i<nStartPos.length;i++) <$qe2FtUq
{ ^yyL4{/
// output.writeLong(nPos); vYcea
output.writeLong(fileSplitterFetch.nStartPos); NirG99kyo
output.writeLong(fileSplitterFetch.nEndPos); |W:xbtPNy
} JPRo<jt=
output.close(); &,JrhMr\
} W0R<^5_
catch(IOException e){e.printStackTrace ();} 8t25wPlx
catch(Exception e){e.printStackTrace ();} )E;B'^RVR
} U\s.fIr
Mj2`p#5wKh
lhZXq!2p
//读取保存的下载信息（文件指针位置） Eg$ I
private void read_nPos() 7A<X!a
{ x2%xrlv<J/
try{ qkPvE;"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o'+p,_y9Y@
int nCount = input.readInt(); S ( e]@
nStartPos = new long[nCount]; DI"KH)XD
nEndPos = new long[nCount]; vtk0 j
for(int i=0;i<nStartPos.length;i++) .hPk}B/KV
{ =ss(~[
nStartPos = input.readLong(); Bi:%}8STH
nEndPos = input.readLong(); ] -iMo4H
} lkl+o&D9
input.close(); THEpW{.E
} 8A'oK8Q
catch(IOException e){e.printStackTrace ();} "tdF#>x
catch(Exception e){e.printStackTrace ();} .FYxVF.
} w#0/&\b=
}$ C;ccWL
YS],o'T
private void processErrorCode(int nErrorCode) C&wp*
{ }w&W\g+E$
System.err.println("Error Code : " + nErrorCode); w=JO$7
} {8p<iY- %
@$mh0K>
^__';! e
//停止文件下载 .6C9N{?Tqf
public void siteStop() %'+}-w
{ ?gYQE&M !
bStop = true; 'vCl@x$
for(int i=0;i<nStartPos.length;i++) [/E|n[Bx
fileSplitterFetch.splitterStop(); [L(qrAQ2|z
wB'GV1|jL
^jhc(ZW"
} GW{e"b/x
} 9 n0?0mk
//负责部分文件的抓取 =2XAQiUR\
**FileSplitterFetch.java -,:^dxE'
*/ ZQ1,6<^9i[
package NetFox; D`c&Q4$:
o{]2W `0r
aoqG*qh}b
import java.io.*; =Vie0TV&h
import java.net.*; \0j-p
fbg:rH\_
Dm{9;Abs%
public class FileSplitterFetch extends Thread { p ;]Qxh
|-l9Z
p`qy57
String sURL; //File URL @V}!elV
long nStartPos; //File Snippet Start Position +,c]FAx4
long nEndPos; //File Snippet End Position MZd?cS
int nThreadID; //Thread's ID 2^w8J w9
boolean bDownOver = false; //Downing is over F%< ZEVm
boolean bStop = false; //Stop identical +khVi}
FileAccessI fileAccessI = null; //File Access interface .D3k(zZ
V*6o|#
{Qba`lOkq
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException z&wJ"[nOC
{ p!/!ZIo
this.sURL = sURL; @b&_xT
this.nStartPos = nStart; um,G^R
this.nEndPos = nEnd; ]621Z1
nThreadID = id; 4$oDq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dD351!-
} b9R0"w!ml
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A<}nXHs-
public void run() 7TW&=(
{ e+~@"^|
while(nStartPos < nEndPos && !bStop) =|LB,REN
{ imc1rY!~'
:8t;_f
LK|1[y^h
try{ W:VX^8</
URL url = new URL(sURL); 7TtDI=f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B4/\=MXb
httpConnection.setRequestProperty("User-Agent","NetFox"); 7u`:e,'
String sProperty = "bytes="+nStartPos+"-"; A$3ll|%j
httpConnection.setRequestProperty("RANGE",sProperty); W"!{f
Utility.log(sProperty); Egt!N
#g#[|c.
.QW@rV:T
InputStream input = httpConnection.getInputStream(); }D]y-BbA.
//logResponseHead(httpConnection); * ,Le--t
"M3S
s5\<D7
byte[] b = new byte[1024]; sK@]|9ciQ
int nRead; r XT6u
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) K-b`KcX
{ fl8eNiE|
nStartPos += fileAccessI.write(b,0,nRead); .4J7 ^l
//if(nThreadID == 1) 9fy[%M
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b5)1\ANq
} NT=)</v
)8E[xBaO
eGW h]%
Utility.log("Thread " + nThreadID + " is over!"); 3Yf~5csY
bDownOver = true; OUhlQq\
//nPos = fileAccessI.write (b,0,nRead); .I Io
} e}NB ,o
catch(Exception e){e.printStackTrace ();} \E1CQP-
} =F% <W7
} 1*?XI
2)Q%lEm`SP
;TKsAU
//打印回应的头信息 R8>17w.
public void logResponseHead(HttpURLConnection con) X`C ozyYuD
{ ;w;+<Rd
for(int i=1;;i++) u p zBd]
{ V]Kk=
String header=con.getHeaderFieldKey(i); 0DaKd<Scv
if(header!=null) I6i qC"BK
//responseHeaders.put(header,httpConnection.getHeaderField(header)); jZk dTiI
Utility.log(header+" : "+con.getHeaderField(header)); !{F\\D/
else rRXF@
break; -amNz.`[PR
} 8dh ?JqX
} &,QBJx<#
_'K6S
Y,m=&U
public void splitterStop() m~tv{#Y
{ A |P wm`
bStop = true; %_(^BZd
} B A i ^t
Ju"/#@
[U,hb1Wi3
} s(:N>K5*
PKZMuEEy,
-n:;/ere7-
/* g*WY kv
**FileAccess.java *|,ye5"
*//文件访问(定位，写) lQL/I[}
package NetFox; B$G9#G6pZ
import java.io.*; h^f?rWD:nz
o,qUf
LYuMR,7E
public class FileAccessI implements Serializable{ _6`H`zept
qgxGq(6K
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :n OCs
RandomAccessFile oSavedFile; g6h=Q3@
long nPos; Yq:+.UU
l]L"Ex{
$VeQvm*
public FileAccessI() throws IOException L;U?s2&Y
{ (Bss%\
this("",0); +;a\ gF^
} c^~R%Bx
lT8^BT
l Ma||
public FileAccessI(String sName,long nPos) throws IOException |~+bbN|b
{ `pXPF}T
oSavedFile = new RandomAccessFile(sName,"rw"); /~+j[oB
this.nPos = nPos; op,mP0b
oSavedFile.seek(nPos); #;\tgUQ
} in>?kbaG+
Np?/r}
#U6~U6@
public synchronized int write(byte[] b,int nStart,int nLen) ,o\~d?4
{ B7n1'?
int n = -1; Lw6}bB`}
try{ HHZrovA#
oSavedFile.write(b,nStart,nLen); Ku8qn\2"
n = nLen; }q)dXFL=I#
} r#c+{yY
catch(IOException e) `L"l{^cH
{ 85{@&T
e.printStackTrace (); V7?Pv Q
} Vah.tOU
Zzv,p
N#^o,/
return n; 1ifPc5j}
} ?dvcmXR
S^)xioKsJ
\; zix(N[5
} %`j2?rn
N lB%Qu
b|U3\Fmc
/* b(_PV#@$
**SiteInfoBean.java 5xc-MkIRL
*/ -P'c0I9z
package NetFox; eSSv8[u
0*:4@go0}i
XtIY8wsP
public class SiteInfoBean { ^oZD44$
KCfcEz
E>rWm_G
private String sSiteURL; //Site's URL A w)P%r
private String sFilePath; //Saved File's Path "0{t~?ol
private String sFileName; //Saved File's Name T0BM:ofx
private int nSplitter; //Count of Splited Downloading File W4=<hB
7;NvR4P%
(L"G,l
public SiteInfoBean() k5)e7Lb(
{//nSplitter的缺省值为5 xcN >L
//default value of nSplitter is 5 ]dHV^!
this("","","",5); WC 5v#*Jd
} y_Nn%(j
+WSM<S2 U
#}zL?s^G
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {pEbi)CF,}
{ U=ie| 3
sSiteURL= sURL; v,mn=Q&9
sFilePath = sPath; ?)XPY<
sFileName = sName; ^BQ*l5K
this.nSplitter = nSpiltter; @Ke3kLQ_\X
xkkW?[&
'q{|p+
} m>-(c=3
:_+Fe,h>|
O\zGN/!
public String getSSiteURL() }t.VH:02y
{ D(Yq<%Q
return sSiteURL; 3,{tGNl|
} /yL:_6c-
\:91BQP c
]73BJ
public void setSSiteURL(String value) VTxLBFK;
{ hG.~[#[&6
sSiteURL = value; _z \PVTT
} ahm@ +/2
2~SjRIpUw
j!QP>AM|`
public String getSFilePath() vq*)2.
{ ]0)=0pc]E
return sFilePath; UZqk2D
} V7i1BR8G
|.[4$C
""^.fh
public void setSFilePath(String value) a |+q:g0M
{ kDr0D$iE
sFilePath = value; b7? 2Pu
} [lX3":)
-(+/u .
7=x]p
public String getSFileName() z'ZGN{L
{ zq&,KZ
return sFileName; >L>t$1hXM
} e{33%5
QH_I<Y:n
5\$8"/H
public void setSFileName(String value) p;m2RHYF
{ }w8:`g'T0/
sFileName = value; 1A b=1g{
} kKRZ79"7s
_<1uO=km6
o]|a5.O
public int getNSplitter() ^gD%#3>X
{ 5KFd/9
return nSplitter; =e$6o2!'}
} eb>YvC
v(2|n}qY
|,Xrt8O/[
public void setNSplitter(int nCount) ghd*EXrF H
{ 1f^4J~{
nSplitter = nCount; C) "|sG
} *R^ulp[W
} h_Cac@F0
-(fvb
'@<aS?@!t
/* pu +"bq
**Utility.java aPMqJ#fIr
*/ aD:vNX
package NetFox; KW.QVBuVO#
(C EXPf
4_w+NI,;
public class Utility { uZ(j"y
vQpR0IEf]e
:D'#CoBA
public Utility() +B#3!
{ @fWmz,Ngl
UR&Uwa&.
c~+;P(>
} U,4:yc,)s
v8xNtUxN
//线程睡眠 6T5nr
public static void sleep(int nSecond) Cq,ox'kGl
{ YdK]%%
try{ PDnwaK
Thread.sleep(nSecond); zi*2>5g
} `2@t) :
catch(Exception e) OyG$ ]C
{ P]@m0f
e.printStackTrace (); [fU2$(mT+
} )MKzAAt~
} =-c"~4
t$z FsFTQ
//日志 D$RQD{*
public static void log(String sMsg) 9 1r"-%(r
{ idf~"a
System.err.println(sMsg); #Pz},!7
} iraO/KhD*3
bS+by'Ea1W
Dm1;mRS+
public static void log(int sMsg) y+XB
{ .`OdnLGy
System.err.println(sMsg); I =t{ u;
} Zq--m/
} Ny>tJ~I
4 }l,F
r2T-=XWB
/* / W}Za&]
**TestMethod.java 0.+"K}
*/ P{eL;^I
package NetFox; !S[8w9q
tIgKnKr^)
aD~3C/?aW
public class TestMethod { m>gok0{pm
c8sY#I
:o}Ju}t
public TestMethod() tVZjtGz=
{ ///xx/weblogic60b2_win.exe xFpMn}CD
try{ ;2vHdN
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^3Ni
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K YFumR
SiteFileFetch fileFetch = new SiteFileFetch(bean); i51~/ R
fileFetch.start(); &P%3'c}G
} vv _I o
catch(Exception e){e.printStackTrace ();} 1FS Jqad
\k1psqw^O
J(0.eD91v
} D5]sf>~
Nw}y_Qf{
!aD/I%X
public static void main(String[] args) Zi=Nr3b
{ ?L$ Dk5-W
new TestMethod(); f~u]fpkz
} 4}{HRs?
} SLL%XF~/Sb
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