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)); ke2M&TV
} P\@efq@!
for(int i=0;i<nEndPos.length-1;i++) {CX06BP
{ dChMjaix
nEndPos = nStartPos[i+1]; AMK(-=
} {.Brh"yC
nEndPos[nEndPos.length-1] = nFileLength; 74c5\UxA
} on1B~?*D
} $Xs`'>,"
Q+O./1x*,
e`K{
//启动子线程 |!CAxE0d$B
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; . \8"f]~
for(int i=0;i<nStartPos.length;i++) O]oH}#5b
{ *De'4r 2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ezS@`_pR;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), s'BlFB n
nStartPos,nEndPos,i); 1=PTiDMJ<*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5!Ovd O}g
fileSplitterFetch.start(); h&rZR`g
} `(E$-m-~jH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [* |+ it+!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4v9d& m!<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", O0eM*~zI
nEndPos = " + nFileLength); O.jCDAP
// fileSplitterFetch[nPos.length-1].start(); eAjsMED
s? 2ikJq
{TDZDH
//等待子线程结束 gSe3S-Lt
//int count = 0; *n6L3"cO
//是否结束while循环 MHA_b^7?
boolean breakWhile = false; HumL(S'm
FbXur-et^
gJ^taUE
while(!bStop) 0g#xQzE
{ fm!\**Q1
write_nPos(); U.Y7]#P:
Utility.sleep(500); 2WE01D9O
breakWhile = true; e`Co ='
m>*~tP
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for(int i=0;i<nStartPos.length;i++) 5<P6PHdY
{ 5=8t<v1Bn
if(!fileSplitterFetch.bDownOver) yI^7sf7k
{ yq[@Cw
breakWhile = false; i1*0'x
break; JEF;Q
} ux6p2Sk;K
} `$q0fTz
if(breakWhile) +=sw&DH
break; nYe:$t3F=
6h0}ZM
I1I-,~hO
//count++; RE1M4UV.
//if(count>4) L~RFI&b
// siteStop(); unKgOvtj
} ~wO-Hgd
u'T-}95 V
l=x(
System.err.println("文件下载结束！"); ae](=OQ
} G,<l}(tEG
catch(Exception e){e.printStackTrace ();} U+C^"[B
} Y?L>KiM$
vKfjP_0$
hDQk zqW
//获得文件长度 k|{ 4"4r
public long getFileSize() }6=? zs}
{ zg$ag4%Qgg
int nFileLength = -1; ]wi0qc2{
try{ N(2M w:}
URL url = new URL(siteInfoBean.getSSiteURL()); c _!!DEe7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (/s~L*gF{
httpConnection.setRequestProperty("User-Agent","NetFox"); &I%E8E
`6;$Z)=.
L\t_zf_0
int responseCode=httpConnection.getResponseCode(); i%, 't
if(responseCode>=400) w'E?L`c
{ R1eWPtWs
processErrorCode(responseCode); XVJH>Zw
return -2; //-2 represent access is error hljKBx~
} Hsd76z#8
B^/k`h6J
S_ UAz
String sHeader; pM}~/
f1;@a>X
*)Cr1d k
for(int i=1;;i++) [;4;.V
{ <XtE|LG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); z(EpJK=`_
//Utility.log(in.readLine()); s`0IyQXVU
sHeader=httpConnection.getHeaderFieldKey(i); pOh<I{r1
if(sHeader!=null) &`m$Zzl;
{ gS@<sO$d>
if(sHeader.equals("Content-Length")) gVI`&W__,
{ ~(7ct*U~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); P}qpy\/(4
break; </1]eDnU
} =N8_S$nx(
} WglpWp)
else >EZZEd
break; iz{TSU
} E@n~ @|10
} p>#q* eU5
catch(IOException e){e.printStackTrace ();} >d *`K
catch(Exception e){e.printStackTrace ();} 57 Bx-
1uCF9P ai
/wl]kGF
Utility.log(nFileLength); Bq1}"092
I|qhj*_C
Q\T?t
return nFileLength; R!lug;u#
} nc\2A>f`
}P-C-L{yE(
:FfEjNil
//保存下载信息（文件指针位置） C/#pK2xY
private void write_nPos() )fxn bBz{
{ S'kgpF"bm
try{ 0NKgtH~+
output = new DataOutputStream(new FileOutputStream(tmpFile)); Zq<j}vVJ
output.writeInt(nStartPos.length); @rDBK] V
for(int i=0;i<nStartPos.length;i++) G%;>_E
{ 5]upfC6
// output.writeLong(nPos); C"B'Dj
output.writeLong(fileSplitterFetch.nStartPos); tHHJ|4C
output.writeLong(fileSplitterFetch.nEndPos); o 9/,@Ri\5
} oP%5ymL%J
output.close(); #D|%r-:"
} :]]x^wony~
catch(IOException e){e.printStackTrace ();} UnP<`z#
catch(Exception e){e.printStackTrace ();} *hJWuMfY,
} HLG5SS7
8ih_S2Cd
9__B!vw:
//读取保存的下载信息（文件指针位置） $/tj<++W
private void read_nPos() sgGA0af
{ e&U$;sS`
try{ ipg`8*My
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [ }Tb2|
int nCount = input.readInt(); doHE]gC2Uz
nStartPos = new long[nCount]; ge.>#1f}
nEndPos = new long[nCount]; law$LL
for(int i=0;i<nStartPos.length;i++) bhIShk[
{ {wj%WSQj/y
nStartPos = input.readLong(); *<y9.\zY<
nEndPos = input.readLong(); oH?:(S(
} v[{7\Hha
input.close(); Xq03o#-p+
} oy5K* }
catch(IOException e){e.printStackTrace ();} oe2*$\?.
catch(Exception e){e.printStackTrace ();} ;-@: }/
} ;nQ=! .#Q
s(5hFuyg
&Tuj`DL
private void processErrorCode(int nErrorCode) :{iH(ae;
{ a^@.C5
System.err.println("Error Code : " + nErrorCode); N>"L2E=z$|
} Fpn*]x
![\P/1p
yq[/9PciA
//停止文件下载 ?O#,{ZZf=
public void siteStop() 0#eb] c
{ H1B%}G*Ir-
bStop = true; .R"VLE|
for(int i=0;i<nStartPos.length;i++) zEtsMU
fileSplitterFetch.splitterStop(); %aMC[i
-d#08\
La9}JvQoX
} 2p\xgAW?
} OObAn^bt
//负责部分文件的抓取 uGb+ *tD
**FileSplitterFetch.java ."^\1N(.n
*/ %sOY:>
package NetFox; g`S;xs
`vAcCahM
?{aJ#w
import java.io.*; 1uj~/M
import java.net.*; >4Tk#+%Jj
WA43}CyAe
cxSHSv1;
public class FileSplitterFetch extends Thread { y,|2hrj/0E
y-nv#Ejr
0{z8pNrc
String sURL; //File URL gFHBIN;u
long nStartPos; //File Snippet Start Position U!r8}@
long nEndPos; //File Snippet End Position v"ORn5
int nThreadID; //Thread's ID NWFh<
boolean bDownOver = false; //Downing is over X5/fy"g&
boolean bStop = false; //Stop identical UH%H9; ,$]
FileAccessI fileAccessI = null; //File Access interface i56Rdb
'vVWUK956
Oj_]`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Os$E,4,py
{ {!wW,3|Pu
this.sURL = sURL; EF\OM?R
this.nStartPos = nStart; C/Z#NP~ *
this.nEndPos = nEnd; s) U1U6O
nThreadID = id; wods
fileAccessI = new FileAccessI(sName,nStartPos);//定位 nfHjIYid
} YFJaf"?8g
^`id/
<Qih&P9;>
public void run() n5UUoBv
{ Lr:n
while(nStartPos < nEndPos && !bStop) Ya\:C]
{ 0>SA90Q
( `bb1gz
Sxc)~y
try{ T})q/oUqK
URL url = new URL(sURL); uCB9;+ Hjw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {v]L|e%{
httpConnection.setRequestProperty("User-Agent","NetFox"); >YWK"~|i~
String sProperty = "bytes="+nStartPos+"-"; o"BED!/
httpConnection.setRequestProperty("RANGE",sProperty); _`;KmD&5
Utility.log(sProperty); m0ra
o[_,r]%+D
i4i9EvWp
InputStream input = httpConnection.getInputStream(); "i#g [x
//logResponseHead(httpConnection); & tT6.@kH
K1J |\!o
zCo$YP#5_
byte[] b = new byte[1024]; vFdI?(c-
int nRead; iZfZF
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1T|")D
{ ,v})
nStartPos += fileAccessI.write(b,0,nRead); 4w ,&#L
//if(nThreadID == 1) G) KI{D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Yh1nXkA!V
} 2! ,ndLA
*Oy* \cX2[
aQL0Sj:,
Utility.log("Thread " + nThreadID + " is over!"); Yz0fOX
bDownOver = true; z4BU}`;b3t
//nPos = fileAccessI.write (b,0,nRead); D`^wj FF
} s(Gs?6}>T
catch(Exception e){e.printStackTrace ();} 5`fUR/|[
} bR"4:b>K
} -JEPh!oTt
PZ6R+n8
f4.jWBF
//打印回应的头信息 wg0_J<y]
public void logResponseHead(HttpURLConnection con) Ey:?!
{ .-HM{6J
for(int i=1;;i++) !Ltx2CB2]
{ AcnY6:3Y|
String header=con.getHeaderFieldKey(i); z{Yfiv\-r
if(header!=null) v=G*K11@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); L3oL>r'|
Utility.log(header+" : "+con.getHeaderField(header)); >2>/ q?
else h@O\j&#
break; x f{`uHa8
} tM\BO0
} }U'9 d#N
g#74c'+
6 M:?W"
public void splitterStop() OHAU@*[lM
{ 9teP4H}m
bStop = true; FYFlh^}
} a_+3, fP
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2 ^"j]g>mj
} 1qAE)8ie
|)>+& xk
M .6BFC
/* R%n*wGi_6b
**FileAccess.java c0e[vrP:
*//文件访问(定位，写) ;|XX^
package NetFox; qm/>\4eLt
import java.io.*; UZFs]z!,k
}XUI1H]jk
]m`:T
public class FileAccessI implements Serializable{ ^NX;zc
e%ro7~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 pFMjfWD,C
RandomAccessFile oSavedFile; 0OG 3#pE
long nPos; 40 u tmC
a.UYBRP/l
v9@_DlV\
public FileAccessI() throws IOException I*f@^(
{ sbVEA
this("",0); pLF,rOb
} k1g-%DB
!jB}}&Ii
aUa+]H[
public FileAccessI(String sName,long nPos) throws IOException QPp31o.!5
{ "h1ek*(?<
oSavedFile = new RandomAccessFile(sName,"rw"); ~~&Bp_9QXN
this.nPos = nPos; b-VQn5W
oSavedFile.seek(nPos); X7K{P_5l
} E[ -yfP~[
{G3Ok++hc
CTg79 ITYk
public synchronized int write(byte[] b,int nStart,int nLen) %/\sn<6C}
{ }+`,AC`RM
int n = -1; yMkR)HY
try{ gGCr~.5
oSavedFile.write(b,nStart,nLen); #sF#<nHZ
n = nLen; .#tA .%
} EGv]K|
catch(IOException e) < <0[PJ
{ f$}g'r zl
e.printStackTrace (); mPPB"uQ
} 3:$@DZT$
m7A3i<6p
P^Og(F8;
return n; sng6U;Z
} z\, lPwB2
]o'dr r
01 +#2~S
} vP'!&}
h0 %M+g
}YC=q
/* 753gcY#i
**SiteInfoBean.java 4R01QSbd
*/ 9.~_swkv
package NetFox; uJ1oo| sn
XF3lS#pt
.;bU["fn)
public class SiteInfoBean { })mD{c/
d{WOO)j
tmoclK-
private String sSiteURL; //Site's URL 3S>rc0]6
private String sFilePath; //Saved File's Path cF9ZnT.
private String sFileName; //Saved File's Name (Cti,g~
private int nSplitter; //Count of Splited Downloading File a|dgK+[
h{~GzrL*
Q0ezeo
public SiteInfoBean() z+0#H39&
{//nSplitter的缺省值为5 \:JY[s/
//default value of nSplitter is 5 ]d|M@v~c4
this("","","",5); @YS,)U)4S
} \\oa[nvL~
SBi4i;qD
JNvgUb'U
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 51AA,"2[_
{ >*l2]3'`
sSiteURL= sURL; G%jV}7h
sFilePath = sPath; >N~jlr|
sFileName = sName; "6%qi qt
this.nSplitter = nSpiltter; ^s=F<_{
h,fahbH-
3][
} kMa|V0
%N7G>_+
OMjx,@9
public String getSSiteURL() ^d9o \
{ 6k7x7z
return sSiteURL; 3)^2X
} .b2%n;_>.
,>pv>)u{
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public void setSSiteURL(String value) eNFA.*p<
{ =k!F`H`/%'
sSiteURL = value; $z@nT.x5
} ?U*sH2F
; ?,'jI*1
`V[ hE r|
public String getSFilePath() +sd':vE
{ Tkh?F5l
return sFilePath; kRiZ6mn
} $yFR{_]
p|)j{nc
. Eb=KG
public void setSFilePath(String value) fAT M?
{ o107.s
sFilePath = value; 8PRB_ny
} *+ O
uKT\\1Jrq
V#DNcF~v]f
public String getSFileName() yyjgPbLN=
{ Op iVQr:
return sFileName; W%#LHluP
} UzkX;UA
hl+ T
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public void setSFileName(String value) oJ0 #U
{ wH qbTA
sFileName = value; X5P1wxk'
} #X<s_.7DJ
1FRpcE
m\|ie8
public int getNSplitter() OFw93UJ Y
{ L?hWH0^3
return nSplitter; &?SU3@3|
} @p7*JLO
Io)@u~yz
,09d"7`X
public void setNSplitter(int nCount) n{.SNipU
{ t=r*/DxX=
nSplitter = nCount; -Wl79lE
} &28%~&L
} nx`I9j\
->U9u lTC
Gn?<~8a
/* B#x.4~YX
**Utility.java }tH6E
*/ q*K.e5"'
package NetFox; ns !Mqcm
kT4Tb%7KM
VH$hQPP5d
public class Utility { 3R$*G8v
s4{>7`N2
8 gzf$Oc
public Utility() U>kL|X3 V
{ co%-d
+d,Z_ 6F
Ln5g"g8gb%
} $2gZpO|
Q96^rjY
//线程睡眠 {Zy)p%j8
public static void sleep(int nSecond) dgM@|&9*m
{ o@tc
try{ Q!G^CG
Thread.sleep(nSecond); ,[<+7
} $[DSe~
catch(Exception e) %.VFj7J
{ ?mJ&zf|B8
e.printStackTrace (); H^C$2f
} j?y_ H[Z
} rRzc"W}K+
K/ 5U;oC
//日志 Sn!5/9Y
public static void log(String sMsg) l's*HExR
{ YPNG9^Y
System.err.println(sMsg); Pmj%QhOYE
} Y('?Z]
A 2Rp
j0+l-]F-
public static void log(int sMsg) hO] vy>i;
{ M"Q{lR
System.err.println(sMsg); 3r-oZ8/n
} #9ZHt5T=$
} @Xg5E
K)[DA*W
GPs//
/* w=feXA3-S
**TestMethod.java ;"Q.c#pA$g
*/ ::R5F4
package NetFox; nBJ'ak
hWD%_"yhd
>JckN4v
public class TestMethod { [h[@?8vB
!}PZCbDhL
b:t|9FE%
public TestMethod() ]L{diD2G
{ ///xx/weblogic60b2_win.exe *9O@DF&*6
try{ PEDV9u[A
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6Mh"{N7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7w51UmO
SiteFileFetch fileFetch = new SiteFileFetch(bean); KIXp+Z
fileFetch.start(); :^H2D=z@
} _`.Wib+
catch(Exception e){e.printStackTrace ();} -"uOh,G}
~KP@wD~
6%L#FSI
} yB2}[1
(j?ckah%V
7tQ?av
public static void main(String[] args) wU(!fw\
{ <\`qRz0/
new TestMethod(); zw[ #B #
} Lq2ZgKd!
} ZgA+$}U)uW
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