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)); f9,EWuQNS
} ^QAiySR`0
for(int i=0;i<nEndPos.length-1;i++) JblmXqtC
{ n`)7Y`hBhP
nEndPos = nStartPos[i+1]; (s"iC:D6U
} C6d]tLE
nEndPos[nEndPos.length-1] = nFileLength; )M'UASB;8
} ~"0@u
} -2&i)S0R
JT|u;Z*n
?{: D,{+
//启动子线程 GzFE%< 9F
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,<3uc
for(int i=0;i<nStartPos.length;i++) _IL2-c8
{ 3u*hTT
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wm=RD98
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =x^l[>sz
nStartPos,nEndPos,i); VkpHzr[k
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b(RBG
fileSplitterFetch.start(); 0[lsoYUq
} rQEi/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :wU_-{>>2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *v rWA
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *J_iXu|
nEndPos = " + nFileLength); VD24X
// fileSplitterFetch[nPos.length-1].start(); poD\C;o"
d9Z&qdxTKq
_(6`{PWY
//等待子线程结束 90s;/y(
//int count = 0; T|@#w%c''
//是否结束while循环 Cqgk
boolean breakWhile = false; %f(S'<DhC
JzMZB"Z?
5r4gmy>
while(!bStop) gcg>Gjp
{ i_u {5 U;
write_nPos(); e3eVvl5]
Utility.sleep(500); mF'-Is
breakWhile = true; $(gGoL<
fpvvV(
1OJ*wI*
for(int i=0;i<nStartPos.length;i++) |mxNUo-
{ 3Q"F(uE v^
if(!fileSplitterFetch.bDownOver) .G}k/`a
{ RzS|dGNQE
breakWhile = false; bar0{!Y"
break; st?gA"5w
} 7qg<[
} [5Fd P0
if(breakWhile) i3Hz"Qs;
break; Sty!atEWT
dTN$y\
*bA+]&dj\
//count++; R-pH Quu3
//if(count>4) u 1ZJHry
// siteStop(); mX&xn2}qZ"
} Hz?!BV0
>z=Ou<,
ptpW41t}^
System.err.println("文件下载结束！"); |3{+6cg
} f.oP
catch(Exception e){e.printStackTrace ();} ~BZXt7DE
} 3ai (x1%
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hH%,!tSx
//获得文件长度 -J,Q;tj
public long getFileSize() 7DtIVMiK
{ <%z@
int nFileLength = -1; -Z%F mv8
try{ u7;`4P:o@
URL url = new URL(siteInfoBean.getSSiteURL()); z)lM2x>|*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pkXv.D`
httpConnection.setRequestProperty("User-Agent","NetFox"); 47IY|Jdz
r6`\d k
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int responseCode=httpConnection.getResponseCode(); upypxC
if(responseCode>=400) l'U1 01M>F
{ XOrcygb2
processErrorCode(responseCode); akT|Y4KxD
return -2; //-2 represent access is error Lt1U+o[ot
} Ic'Q5kfM
R]u (l+`
XHxz @_rw
String sHeader; 90~*dNk
-~ 0] 7Cpl
{6'*Phw
for(int i=1;;i++) W`$[j0
{ D?e"U_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U98_M)-%&
//Utility.log(in.readLine()); P5xI
sHeader=httpConnection.getHeaderFieldKey(i); ]pnYvXf>!
if(sHeader!=null) =3*Jj`AV
{ |rMq;Rgu?
if(sHeader.equals("Content-Length")) M% @
{ flG=9~qcGQ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F>N+<Z
break; t5paYw-b
} nfX12y_SXL
} td >,TW=A*
else .Gh%p`<
break; Ah-8"`E
} j 1(T )T
} *>k!hq;j
catch(IOException e){e.printStackTrace ();} $A`xhh[
catch(Exception e){e.printStackTrace ();} EX:{EmaT
gN?0m4[$i
B7HQR{t
Utility.log(nFileLength); >uTPjR[
wcZbmJ:
"tL2F*F"6X
return nFileLength; zPVd(V~(T
} KmQ^?Ad-C
LeSHRoD
lUv=7" [
//保存下载信息（文件指针位置） xW>ySEf
private void write_nPos() SK+@HnKd
{ IIxJqGN:
try{ e_/x&a(i8
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]>D)#
output.writeInt(nStartPos.length); ~:[!Uyp0b
for(int i=0;i<nStartPos.length;i++) ^av6HFQ
{ :a.0hes
// output.writeLong(nPos); ?*H9-2W@
output.writeLong(fileSplitterFetch.nStartPos); 3B{[%#vO
output.writeLong(fileSplitterFetch.nEndPos); ?,07;>&
} d+6]u_J
output.close(); P16YS8$
} BwxnDeG)
catch(IOException e){e.printStackTrace ();} rjUBLY1(
catch(Exception e){e.printStackTrace ();} V^n0GJNo
} 0(gq;H5x'
W"Q!|#;l.
_ h9o@
//读取保存的下载信息（文件指针位置） b`CWp;6Y
private void read_nPos() ; 0ko@ \Lq
{ .:y5U}vR
try{ 5 y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \"x>JW4w
int nCount = input.readInt(); sTkkM9
nStartPos = new long[nCount]; /L&M,OUcr.
nEndPos = new long[nCount]; X|b2c+I
for(int i=0;i<nStartPos.length;i++) 9tK>gwb
{ ^e%}[q[>|
nStartPos = input.readLong(); A WHU'
nEndPos = input.readLong(); r`6:Q&&
} 3qi_]*dD
input.close(); XP-C
} q8xd*--#
catch(IOException e){e.printStackTrace ();} `T"rG}c
catch(Exception e){e.printStackTrace ();} ]^K;goQv
} VFj(M j`}G
*Qkc[XHqy
t> . Fl-
private void processErrorCode(int nErrorCode) 3b!,D
{ c?K~/bx.
System.err.println("Error Code : " + nErrorCode); Ei5wel6!
} uWjU OJEe
zizk7<?L.
lY'N4x7n
//停止文件下载 oNM?y:O
public void siteStop() $^_|j1z#i
{ xWE8Wm
bStop = true; V8PLFt;
for(int i=0;i<nStartPos.length;i++) "DQ'C%sL9
fileSplitterFetch.splitterStop(); m\vmY
pSfYu=#f
f:woP7FP
} @{d\j]Nw
} >7b)y
//负责部分文件的抓取 ZFvyL8o
**FileSplitterFetch.java qX#MV>1
*/ 9+qOP>m
package NetFox; dqc1q:k?$
gR Nv-^
*:hyY!x
import java.io.*; mfom=-q3k
import java.net.*; 4(cJ^]wb^
Z4hLdHo_
'bu)M1OLi
public class FileSplitterFetch extends Thread { W5pb;74|
x/mp=
qlsQ|/'D
String sURL; //File URL O1P=#l iYX
long nStartPos; //File Snippet Start Position qOy=O [+9
long nEndPos; //File Snippet End Position j9R6ta3\l
int nThreadID; //Thread's ID `tEo]p
boolean bDownOver = false; //Downing is over ^G|98yc!'
boolean bStop = false; //Stop identical xT*d/Oaw
FileAccessI fileAccessI = null; //File Access interface Ug%_@t/?
jQh^WmN
5[gh|I;D
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !EBY@ Y1
{ z[nS$]u
this.sURL = sURL; 0g=`DSC<(
this.nStartPos = nStart; "Fnq>iR-
this.nEndPos = nEnd; }|wv]U~
nThreadID = id; :c.JhE3D
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6'C2SihYp
} cYNV\b4-
u0o'K9.r
w?y6nTg<
public void run() xJwG=$o
{ .Y*f2A.v
while(nStartPos < nEndPos && !bStop) aP-<4uGx
{ v?:: |{
kH948<fk3
[xZU!=
try{ OMrc_)he\
URL url = new URL(sURL); `>lzlEhKV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,0N94pKy
httpConnection.setRequestProperty("User-Agent","NetFox"); .12aUXo(
String sProperty = "bytes="+nStartPos+"-"; T*[ VY1
httpConnection.setRequestProperty("RANGE",sProperty); w:i:~f .
Utility.log(sProperty); ,!#ccv+Vm%
S:bC[}
1Sz A3c
InputStream input = httpConnection.getInputStream(); JXqr3Np1
//logResponseHead(httpConnection); l$xxrb9P!
GqKsK r2%
hJ;$A*Y
byte[] b = new byte[1024]; EbY,N:LK
int nRead; ';B#Gx
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3ec`Wa
{ iw9Q18:I}
nStartPos += fileAccessI.write(b,0,nRead); OE`X<h4r
//if(nThreadID == 1) SA"p\}"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <|B1wa:|
} MCTsi:V>+
'lz"2@4{
!CTxVLl"F
Utility.log("Thread " + nThreadID + " is over!"); XMIbUbUk-
bDownOver = true; ~Bi_7 Q
//nPos = fileAccessI.write (b,0,nRead); hT g<*
} `#P$ ]:
catch(Exception e){e.printStackTrace ();} PmpNAVE'
} K2)!h.W
} iBg3mc@OO
b7`D|7D
u{<"NR h
//打印回应的头信息 d3Mva,bw<
public void logResponseHead(HttpURLConnection con) G3i !PwW
{ LNYKm~cN
for(int i=1;;i++) =='Td[
{ r,1e 'd:
String header=con.getHeaderFieldKey(i); fV>CZ^=G
if(header!=null) k?B[>aQn.0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )!bUR\
Utility.log(header+" : "+con.getHeaderField(header)); Uz7oL8
else %r\n%$@_
break; '9p@vi{\
} DOS0;^f
} #6v27:XK
'dG%oDHX]P
;bzX%f?|G
public void splitterStop() 2F{hg%
{ gV;H6"
bStop = true; e}Vw!w
} /^SAC%PD
!|hoYU>@2L
LkruL_E>
} ,_.I\EY[
}Db[ 4
3g'S\G@
/* s8"8y`u
**FileAccess.java {P%9
*//文件访问(定位，写) u7%D6W~m0
package NetFox; IY'=DePd
import java.io.*; ;ea]$9
?Ea;J0V
p@!nYPr.
public class FileAccessI implements Serializable{ $,=6[T!z+e
SvM6iZ]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 S_MyoXV
RandomAccessFile oSavedFile; z}QwP~Z
long nPos; "xI"
aimarU
qU2~fNY
public FileAccessI() throws IOException k %e^kej
{ {R<Ea @LV+
this("",0); >zsid:
} /-_=nf}w
x5`br.b
H`bSYjgM!
public FileAccessI(String sName,long nPos) throws IOException K%<j=c
{ g6@Fp7T
oSavedFile = new RandomAccessFile(sName,"rw"); c .3ZXqpI;
this.nPos = nPos; ,u }XWV
oSavedFile.seek(nPos); $E<Esf$
} _R'Fco
ZRxZume<f
Q)m4_+,d
public synchronized int write(byte[] b,int nStart,int nLen) ?&G`{Ey
{ E1dD7r\
int n = -1; T{wpJ"F5<]
try{ n~"$^Vr
oSavedFile.write(b,nStart,nLen); q5h*`7f
n = nLen; `g8E1-]l
} Q$& sTM
catch(IOException e) w\54j)rb
{ P./V6i<:
e.printStackTrace (); ~7~~S*EQ
} x";w%
{2/LRPT
/kL$4CA
return n; Tus}\0/i>
} f.aSKQD
q{s(.Uq$&
0q>P~]Ow
} D']ZlB'K
bwVPtu`
j?y LDLj
/* 5>3}_
**SiteInfoBean.java d(vsE%/!
*/ 5w%_$x
package NetFox; =U8a ?0
{Q+gZcu
)1N 54FNO
public class SiteInfoBean { Hsih[f
QK0h6CX
vS\%3A4^+5
private String sSiteURL; //Site's URL TG}*5Z`
private String sFilePath; //Saved File's Path 0TfS=scT
private String sFileName; //Saved File's Name ;^*Unyt[4]
private int nSplitter; //Count of Splited Downloading File 4h@Z/G!T3
/9o!*K
o7mZzzP
public SiteInfoBean() !d<"nx[2`
{//nSplitter的缺省值为5 k(zsm"<q
//default value of nSplitter is 5 ?9l [y
this("","","",5); $0bjKy
} 6KD `oUx
<%xS{!'}
kb[P\cRa
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [:xiZ
{ ~m|Mg9-
sSiteURL= sURL; KIR'$ 6pn~
sFilePath = sPath; M?=;JJ:
sFileName = sName; da1]mb=4 5
this.nSplitter = nSpiltter; : ^ 8
(`SRJ$~f
USFDy
} *x)Ozfe
UzXE_S
pO8ePc@=D
public String getSSiteURL() >iS`pb
{ t){"Tfc:
return sSiteURL; -(O-%
} _qbIh
{Fzs@,|W.
WL`9~S
public void setSSiteURL(String value) \*,=S52
{ }g$(+1g
sSiteURL = value; G^q3Z#P
} JG9`h#
;raN
-P&6L\V
public String getSFilePath() K}6dg<
{ )'*5R<#
return sFilePath; 9-]i.y
} w8g,a]p
^F:k3,_[
DE2a5+^
public void setSFilePath(String value) @ym/27cRE
{ ^z,_+},a3T
sFilePath = value; iCHt1VV]
} Bi@&nAhn@
vD 5vbl
C7H/N<VAq
public String getSFileName() DJP2IP
{ -hkQ2[Ew#
return sFileName; [:^-m8QC
} $9S(_xdI&
Y?ez9o:/#
Rq[ M29
public void setSFileName(String value) Q,&/V_
{ e^lWR]v
sFileName = value; y^]tahbo
} u_7~TE3W
*>VVt8*Et
YC_1Ks
public int getNSplitter() &Wf3~hmo
{ >5Wlc$bc
return nSplitter; SZJ$w-<z
} /m!Cc/Hv
)[1)$-Ru
f]7M'sy|
public void setNSplitter(int nCount) LN_xq&.
{ 7Sz?S_N/j
nSplitter = nCount; F @Te@n
} #GJ dZ
} E*?<KZe"
\6;=$f/?t
4mn&4e
/* ;Jd3u -
**Utility.java 6\61~u~
*/ I|# 5NE6
package NetFox; lY*[tmz)
UX]L;kI
F#|:`$t
public class Utility { ,t)x{I;C)
sBV4)xM
1Z{ZV.!
public Utility() O$IjNx
{ m^x6>9,
au,t%8AC
^<X@s1^#
} <L&m4O#|
y<b{Ji e
//线程睡眠 sl2@umR7%(
public static void sleep(int nSecond) Py`N4y~
{ P,sjo u^
try{ j[Uxa
Thread.sleep(nSecond); 7<H |QL&
} LHJ":^
catch(Exception e) XT;u<aJs
{ o!Rd ^
e.printStackTrace (); 'Wa,OFd\8
} si4don
} Dde]I_f}
M4xi1M#%
//日志 0-{tFN
public static void log(String sMsg) 97)/"i e
{ m[k_>e\u
System.err.println(sMsg); b*ef);
} ':R,53tjl
7mm1P9Z
f-nz{U
public static void log(int sMsg) Y'e eA 2O
{ \p%3vRwS%p
System.err.println(sMsg); sZ?mP;Q
} @,XSs
} 2 1PFR:lP7
![f ![l
/t-fjB{=G
/* vd6l7"0/
**TestMethod.java vf4{$Oag
*/ Q]o C47(
package NetFox; ItVugI(^ C
$H$j-)\D
'H7x L
public class TestMethod { d,$d~alY
,.gQ^^+=
;O<9|?
public TestMethod() c)0amM
{ ///xx/weblogic60b2_win.exe $wYFEz
try{ DS|KkTy3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); S>.F_Jl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2Hum!p:1
SiteFileFetch fileFetch = new SiteFileFetch(bean); $4MrP$4TI
fileFetch.start(); @Tfl>/%
} B^%1Rpcn
catch(Exception e){e.printStackTrace ();} -+t]15
*%vwM7
`>o?CIdp
} Dz./w
TE )gVE]
`mT$s,:h
public static void main(String[] args) s}j1"@
{ 7OWbAu;
new TestMethod(); ~afg)[(
} q$G,KRy/
} jgS%1/&
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