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)); 3 ,f3^A
} . #FJM2Xk
for(int i=0;i<nEndPos.length-1;i++) Y2TXWl,Jk
{ m S4N%Q
nEndPos = nStartPos[i+1]; /8? u2 q
} h J H
nEndPos[nEndPos.length-1] = nFileLength; g7;OZ#\
} XOoz.GSQ
} Djr/!j
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tuslkOE#
//启动子线程 O>LqpZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; KIGMWS^^
for(int i=0;i<nStartPos.length;i++) 0F%/R^mw
{ N[zR%(YS
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o}=c(u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8xb({e4
nStartPos,nEndPos,i); 0B]c`$"aD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |%g)H,6c
fileSplitterFetch.start(); ]p@q.P
} DP.Y<V)B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^ AJ_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +7mUX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", A D%9;KQ8
nEndPos = " + nFileLength); vhGX&
// fileSplitterFetch[nPos.length-1].start(); UZ;FrQ(l{
4d8}g25C
"H\R*\-0
//等待子线程结束 B.4Or]
//int count = 0; 98Y1-Z^ .
//是否结束while循环 RDOV+2K
boolean breakWhile = false; oi7Y?hTj
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n+1`y8dy
while(!bStop) )tx2lyY:
{ @;X#/dZe
write_nPos(); d-jZ5nl(
Utility.sleep(500); \HL66%b[
breakWhile = true; RN2z/FUf
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G2dPm}sZG
for(int i=0;i<nStartPos.length;i++) ZfibHivz
{ pN{XGkX.
if(!fileSplitterFetch.bDownOver) ]$!7;P
{ w:9M6+mM^
breakWhile = false; ge]Z5E(1
break; tP89gN^PA|
} KP_7h/e
} zHD8\*
if(breakWhile) wAo6:)
break; qGi\*sc>x
F8xu&Vk0:
e8&7W3 m
//count++; bQ-n<Lx
//if(count>4) (_R!:H(]m
// siteStop(); w19OOD
} EY@KWs3"H
Q2'`K|T
sWKv>bx
System.err.println("文件下载结束！"); kbSl.V%)
} ;;N#'.xD
catch(Exception e){e.printStackTrace ();} +4F; m_G6
} _^D-nk?
F$S/zh$)0
y]g5S-G
//获得文件长度 [W99}bi$
public long getFileSize() g,B@*2Uj
{ d*$x|B|V
int nFileLength = -1; @QDUz>_y
try{ j:$Z-s
URL url = new URL(siteInfoBean.getSSiteURL()); USJ4Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I:WPP'L4o
httpConnection.setRequestProperty("User-Agent","NetFox"); 1U(!%},
cR/e Zfl
Gh}* <X;N
int responseCode=httpConnection.getResponseCode(); hyY^$p+
if(responseCode>=400) zVis"g`
{ P]7s1kgaS
processErrorCode(responseCode); iV:\,<8d
return -2; //-2 represent access is error AD>/#Ul
} 9hgIQl
1[-RIN;U8
rIX 40,`
String sHeader; gX(8V*os^
x[R?hS,0t
X;v{,P=J
for(int i=1;;i++) MfraTUxIo/
{ 212 =+k
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); X7SSTcA
//Utility.log(in.readLine()); GS*_m4.Ry6
sHeader=httpConnection.getHeaderFieldKey(i); b/4gs62{k
if(sHeader!=null) N6v*X+4JH
{ fO837
if(sHeader.equals("Content-Length")) z=4E#y`?U
{ \}Kad\)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); N@"e^i
break; r<;Y4<,BZ
} `F~Fb S
} <)+;Bg
else +B7UGI
break; =H"%{VeC5
} _+gpdQq\p
} ZJQkZ_9@2
catch(IOException e){e.printStackTrace ();} V/ZWyYxjLi
catch(Exception e){e.printStackTrace ();} @^`5;JiUk
)5TX3#=;(G
hDbZ62DDN
Utility.log(nFileLength); ]@qD4:
|[!0ry*N%
xRF_'|e
return nFileLength; <JZa
} yCv"(fNQ
.yb8<qs
s%?<:9
//保存下载信息（文件指针位置） fVq,?
private void write_nPos() ktv{-WG2_
{ ve4QS P
try{ *T{KpiuP
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ds\f?\Em
output.writeInt(nStartPos.length); aX~' gq>
for(int i=0;i<nStartPos.length;i++) xH-} <7
{ 5;9.&f
// output.writeLong(nPos); iz-O~T/^
output.writeLong(fileSplitterFetch.nStartPos); )Y?E$=M+B
output.writeLong(fileSplitterFetch.nEndPos); _K~?{".
} +*RpOtss
output.close(); bL5dCQxty
} S1!_ IK$m
catch(IOException e){e.printStackTrace ();} os(}X(
catch(Exception e){e.printStackTrace ();} /`w'X/'VJ
} XB%`5wwd
n4 Y ]v
gKb5W094@
//读取保存的下载信息（文件指针位置） *oIKddZh
private void read_nPos() h#8{fr)6
{ s'@@q
try{ bre6SP@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :Czvwp{z
int nCount = input.readInt(); !" : arK
nStartPos = new long[nCount]; *c@]c~hY,
nEndPos = new long[nCount]; &J=x[{R
for(int i=0;i<nStartPos.length;i++) S*rcXG6Q^
{ t*Wxvoxk
nStartPos = input.readLong(); gOk^("@
nEndPos = input.readLong(); n6*; ~h5
} q5w)i
input.close(); /h@rLJ)o>
} q{.~=~
catch(IOException e){e.printStackTrace ();} %;G!gJeE
catch(Exception e){e.printStackTrace ();} 2K'}Vm+
} ^[zF IO
l1RFn,Tzr
{K2F(kz?T
private void processErrorCode(int nErrorCode) ,@2d4eg4
{ Vs[!WJ 7
System.err.println("Error Code : " + nErrorCode); \y/+H
} JDC,]
"(?[$R
wT\dzp>/
//停止文件下载 $E@ke:
public void siteStop() o6 [i0S
{ _d<\@Tkw
bStop = true; #60<$HO:Z
for(int i=0;i<nStartPos.length;i++) 4>@-1nt}
fileSplitterFetch.splitterStop(); ;D<rGkry
,<-a 6
&nZ.$UK<
} ]cI(||x
} ]%%cc
//负责部分文件的抓取 k<S!|
**FileSplitterFetch.java Z8Clm:S
*/ AwL;-|X
package NetFox; [h2V9>4:
@KYmkxW
e3>k"
import java.io.*; YuDNm}r[
import java.net.*; ?)5M3lV3k
iF]vIg#h
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public class FileSplitterFetch extends Thread { gM3gc;
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>Y/1%Hp9
String sURL; //File URL z'X_s.9F
long nStartPos; //File Snippet Start Position :ui1]its4
long nEndPos; //File Snippet End Position ]# T9v06w
int nThreadID; //Thread's ID WJL,L[XC
boolean bDownOver = false; //Downing is over ]t3 NA*mM
boolean bStop = false; //Stop identical P.1iuZ "w
FileAccessI fileAccessI = null; //File Access interface I!Za2?
`P4qEsZE>`
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }fs;yPl,
{ |wj/lX7y
this.sURL = sURL; egi?Qg
this.nStartPos = nStart; 2jx+q
this.nEndPos = nEnd; z95V 7E
nThreadID = id; K+mtuB]yr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Qi7^z;
} ,K6]Q|U@r
{1YT a:evl
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public void run() XT_BiZ%l5O
{ "$8<\k$LGT
while(nStartPos < nEndPos && !bStop) et]*5Y6
{ ;3sT>UB
F]?$Q'U
w }2|Do$5
try{ T}]Ao
URL url = new URL(sURL); z_l3=7R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S8vmXlD
httpConnection.setRequestProperty("User-Agent","NetFox"); C127he
String sProperty = "bytes="+nStartPos+"-"; l7J_s?!j
httpConnection.setRequestProperty("RANGE",sProperty); pN]Hp"v
Utility.log(sProperty); 2i(|?XJ^
qc'tK6=jp
v981nJ>w,
InputStream input = httpConnection.getInputStream(); 7RD` *s
//logResponseHead(httpConnection); PvT8XSlTx!
D&9j$#9Rh
*Ucyxpu~$
byte[] b = new byte[1024]; ::T<de7
int nRead; :g9z^ $g
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JkxS1
{ FvI`S>
nStartPos += fileAccessI.write(b,0,nRead); L kq>>?T=
//if(nThreadID == 1) (Fgt#H(B
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Nyqm0C6m^
} Dfhs@ z
|f?C*t',
*E)Y?9u"
Utility.log("Thread " + nThreadID + " is over!"); F<(xz=
bDownOver = true; .DvAX(2v
//nPos = fileAccessI.write (b,0,nRead); LMG\jc?,
} M<~F>(wxA
catch(Exception e){e.printStackTrace ();} NxX1_d
} N[+dX_h
} =;/h{ t
usTCn3u
V!<#E)-?<
//打印回应的头信息 l*:p==
public void logResponseHead(HttpURLConnection con) S8)awTA9
{ B-gr2-
for(int i=1;;i++) 3MzY]J y(
{ M7>\Qk
String header=con.getHeaderFieldKey(i); iRVLo~
if(header!=null) %-'U9e KN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .CpF0
Utility.log(header+" : "+con.getHeaderField(header)); 7:j #1N[p
else `(a^=e5
break; U;q)01
} 5~"=Fm<uD
} Ul'G g
)w`Nkx
Hf-F-~E
public void splitterStop() %ej"ZeM
{ BmJ?VJ}Y
bStop = true; r#}Sy\
} uU\iji\
&^7)yS+C
/&dt!.WY^
} <C{5(=X{
y d$37G|n
2Ls<OO
/* t]o gn(
**FileAccess.java l&A`
*//文件访问(定位，写) :gVjBF2
package NetFox; (os7Q?
import java.io.*; O9yQ9sl
'~cEdGD9H
D_)vGvv3;.
public class FileAccessI implements Serializable{ 7A|jnm
4>E2G:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t;1NzI$^
RandomAccessFile oSavedFile; ~GeYB6F
long nPos; ,'673PR
FS}z_G|4]
)-{Qa\6(%
public FileAccessI() throws IOException MnI $%
{ L' pZ
this("",0); ({9!P30:
} ?f`-&c;
F1=+<]!
v8IL[g6"
public FileAccessI(String sName,long nPos) throws IOException Z9D4;1
{ 5xHiq&d.E
oSavedFile = new RandomAccessFile(sName,"rw"); /fq6-;co+
this.nPos = nPos; PS22$_}
oSavedFile.seek(nPos); ("oA{:@d
} 0R]CI
g3XAs@
A!kyga6F5
public synchronized int write(byte[] b,int nStart,int nLen) Mt Z(\&~
{ aVYUk7_<
int n = -1; ,H?p9L; qp
try{ jb2:O,+!
oSavedFile.write(b,nStart,nLen); c" 7pf T
n = nLen; hrD6r=JT<~
} q':wSu u
catch(IOException e) <.B s`P
{ 8TPm[r]
e.printStackTrace (); KIFx&A
} 9gg,Dy
w0!,1 Ry
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return n; g4X,*H
} #U}U>4'
d/>,U7eS[+
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} $hQg+nY.
Snu;5:R
DV\ei")
/* g8"7wf`0k
**SiteInfoBean.java h12wk2@P/]
*/ \xxVDr.
package NetFox; i 8Xz
~a%hRJg
:gq@/COo(
public class SiteInfoBean { yp^*TD/J
`W n5 .V
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private String sSiteURL; //Site's URL Zg&\K~OC
private String sFilePath; //Saved File's Path d6EY'*0
private String sFileName; //Saved File's Name Dj+Osh
private int nSplitter; //Count of Splited Downloading File &>l8SlC?
}YP7x|
L"I] mQvd
public SiteInfoBean() 7yTe]O
{//nSplitter的缺省值为5 Xh"iP%
//default value of nSplitter is 5 n;-r W;ZO
this("","","",5); _%vqBr*
} +[/r^C
gj,J3x4TK/
y UAn~!s
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ue"?S6
{ t1{}-JlA
sSiteURL= sURL; v|(b,J3
sFilePath = sPath; "D(8]EG=
sFileName = sName; -3tBN*0+
this.nSplitter = nSpiltter; QCfpDE}
OX/.v?c
PX2k,%
} oQnk+>}%
XFTMT'9
vGwD~R
public String getSSiteURL() ;Ph)BY<
{ uO(guA,C
return sSiteURL; -==qMrKP
} dm=F:\C
t}k'Ba3]:Y
gQ[^gPWP"
public void setSSiteURL(String value) IWo~s
{ BemkCj2
sSiteURL = value; K]!u@I*K"
} 'Q>z**
psX%.95Y
SM+fG:4d
public String getSFilePath() kdh9ftm*\
{ @1?]$?u&
return sFilePath; [Cqqjv;_
} |p -R9A*>h
OsL%SKs|
Vnj/>e3
public void setSFilePath(String value) `uZv9I"
{ BDkBYhz;7
sFilePath = value; }K80G~O2<
} ^Lmc%y
C'czXZtn
nQ17E{^pR
public String getSFileName() :LiDJF
{ Z3So|M{v
return sFileName; xY'qm8V
} Vt=(2d5:p
(F[/~~
V9j1j} r
public void setSFileName(String value) A1QI4.K
{ 3E}NiD\V}
sFileName = value; O| J`~Lk
} u] U)d$|
RC{Z)M{~
aXbNDj ][
public int getNSplitter() B UQn+;be
{ ~8xh0TSi
return nSplitter; )d(0Y<e@
} XyM(@6,'
2K rqY
Y3$PQwn .P
public void setNSplitter(int nCount) "Z2Tc)
{ |@ZqwC=
nSplitter = nCount; c Z6p^
} P%+or*
} Wda\a.bXT
P"9@8aLB
0L0Jc,(F+
/* 3Wb2p'V7$?
**Utility.java +*_fN ]M
*/ )'!ml
package NetFox; ]bN&5.|
,t%CK!8
?S@R~y0K
public class Utility { <Hh5u~
;4kx>x*H
te;Ox!B&
public Utility() @0ov!9]Rw-
{ oB0 8
] `B,L*m6
N$%61GiulT
} <,@H;|mZ
&*aer5?`
//线程睡眠 y Tw',N{
public static void sleep(int nSecond) w.D4dv_H
{ 1]>$5 1Q
try{ eyf4M;goz}
Thread.sleep(nSecond); /~Zc}o,J
} OgKWgvy
catch(Exception e) <+\k&W&Y|y
{ ~TG39*m
e.printStackTrace (); ]^; b
} B9LSxB
} R2N^'
13.{Y)
//日志 i0'Xy>l
public static void log(String sMsg) U+.PuC[3
{ .>kccLr:z
System.err.println(sMsg); t}]9VD9
} XhE$&Ff
abICoP1zQ
,Um5S6 Z
public static void log(int sMsg) rT flk
{ (F,(]71Z+
System.err.println(sMsg); (|<h^] y3
} Bw3F7W~l
} p;qRm} 0}
h-r6PY=i
Nt zq"ces)
/* QT1:>k
**TestMethod.java ^V<J69ny|9
*/ 6%ZHP?
package NetFox; H_?;h-Y]
1UW s_|X!
e(}oq"'z
public class TestMethod { h4XcKv+
WYwzo V-
n2n00%Wu[
public TestMethod() #"Eks79s
{ ///xx/weblogic60b2_win.exe t7|MkX1
try{ OgEUq''
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); k40Ep(M}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); vIVw'Z(g}
SiteFileFetch fileFetch = new SiteFileFetch(bean); # #k #q=4
fileFetch.start(); @A [)hk&(R
} M5']sdR(l
catch(Exception e){e.printStackTrace ();} /rIm7FW)
-l-AToO4
=<[7J]%
} t/JOERw
xw4ey<"I
m!#_CQ:
public static void main(String[] args) hz<|W5
{ !~K=#"T
new TestMethod(); \R86;9ov
} @Pxw hlxa
} 6oj4Rg+(
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