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)); '*Z1tDFS
} `XJG(Oas\
for(int i=0;i<nEndPos.length-1;i++) R
{ ?fQ'^agq
nEndPos = nStartPos[i+1]; @bi}W`
} RF`.xQ26=
nEndPos[nEndPos.length-1] = nFileLength; S4Pxc ]!
} (9tX5$e6N
} EGGWrl}1
4n#M
.8 2P(}h
//启动子线程 XD!W: uvb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]tim,7s
for(int i=0;i<nStartPos.length;i++) `}D,5^9]
{ Q{O+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Giid~e33
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), S){)Z
nStartPos,nEndPos,i); M-$%Rzl_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lXx=But
fileSplitterFetch.start(); ^6jV_QM#
} ^4y,W]JUDt
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6,^>mNm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g1;:KzVv
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zv|2:4H
nEndPos = " + nFileLength); l^! ?@Kg,z
// fileSplitterFetch[nPos.length-1].start(); 5us:adm[pD
X@--m6-
^3G{|JB!+
//等待子线程结束 eln)BW#
//int count = 0; HSw;^E)1
//是否结束while循环 2% MC Yn
boolean breakWhile = false; FVMD>=k
/{EP*,/*
E`kG-Q5Dw
while(!bStop) P:hBt\5B
{ U2ohHJ``
write_nPos(); 6gkV*|U,e
Utility.sleep(500); /?wtF4
breakWhile = true; nyX2|m&
aFl;BhM
Ozw.siD
for(int i=0;i<nStartPos.length;i++) '<gI8W</
{ g!|=%(G=
if(!fileSplitterFetch.bDownOver) <3oWEm
{ I~[F|d>
breakWhile = false; ;/bewivNJ
break; H/"-Z;0{
} vRznw&^E
} q?H|o(
if(breakWhile) }V'}E\\
break; 2pZXZ
R &nPj~
DKH-Q(M56
//count++; n#cC+>*>+
//if(count>4) %7QV&[4!
// siteStop(); }cM}Oavh
} V~UN
*o]L|Vu
>;jZa
System.err.println("文件下载结束！"); 3(``#7
} `b?R#:G
catch(Exception e){e.printStackTrace ();} M5i%jZk
} [ieI;OG;
jxP;>K7O
$ux,9H'[
//获得文件长度 +*\u :n
public long getFileSize() Cw~q4A6'
{ Vo4,@scG
int nFileLength = -1; j SHk{T!J
try{ .L+6 $8m
URL url = new URL(siteInfoBean.getSSiteURL()); ?#Ge.D~u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ah1]Y}sy
httpConnection.setRequestProperty("User-Agent","NetFox"); M "ui0 ac
hz{`h
C2.HMgL
int responseCode=httpConnection.getResponseCode(); .7O*pJ2(H
if(responseCode>=400) 0q^>ZF-@
{ x!hh"x
processErrorCode(responseCode); # '=a=8-$
return -2; //-2 represent access is error jY&k
} uY0lR:|
T!uM+6|Y
QER?i;-wb
String sHeader; !zBhbmlKt
\h+AXs<j
JX<)EZ!F
for(int i=1;;i++) &g#@3e1>
{ }?lrU.@zg
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sm9k/(-
//Utility.log(in.readLine()); t1]K<>g
sHeader=httpConnection.getHeaderFieldKey(i); C=-=_>Q,L<
if(sHeader!=null) 3W V"U
{ 3\AU 72-
if(sHeader.equals("Content-Length")) '-wj9OU
{ ( B!uy`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <xup'n^7C
break; "WlZ)wyF%
} 6d:zb;Iz
} <<UB ^v m
else 6o^,@~:R
break; `34zkPB??
} j 'FVz&
} ?}qttj
catch(IOException e){e.printStackTrace ();} '|ad_M
catch(Exception e){e.printStackTrace ();} Ig$(3p
?llXd4
i|c'Lbre`
Utility.log(nFileLength); U1Q:= yD
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}~2LW" 1'
return nFileLength; \1d(9jR
} ~W*FCG#E
=pr`'
Q[Z8ok
//保存下载信息（文件指针位置） }I2wjO
private void write_nPos() T _r:4JS
{ oVnvO iAc
try{ y>:N{|
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1}S S+>`
output.writeInt(nStartPos.length); rUwZMli
for(int i=0;i<nStartPos.length;i++) bw(a6qKK
{ #:jHp44J
// output.writeLong(nPos); V4hiGO[
output.writeLong(fileSplitterFetch.nStartPos); Fiv3 {.
output.writeLong(fileSplitterFetch.nEndPos); ,ZaRy$?
} {SOr#{1z*
output.close(); <5d~P/,
} FO+Zue.RS
catch(IOException e){e.printStackTrace ();} svsqg{9z
catch(Exception e){e.printStackTrace ();} B|Du@^$
} ]Gzm^6v
D!@Ciw
Wfu(*
//读取保存的下载信息（文件指针位置） '>NCMB{*
private void read_nPos() 7X`l&7IXP
{ bW$,?8(
try{ )}g(b=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); XYjV.j\
int nCount = input.readInt(); H >j
nStartPos = new long[nCount]; +j#+8Ze
nEndPos = new long[nCount]; c7<wZ
for(int i=0;i<nStartPos.length;i++) u$h 4lIl
{ i% w3/m
nStartPos = input.readLong(); 8k2?}/+
nEndPos = input.readLong(); F7 5#*
} ?e`^P
input.close(); rTM}})81
} *7:>EP
catch(IOException e){e.printStackTrace ();} Nc1"g1JR
catch(Exception e){e.printStackTrace ();} &@G:G(
} PZ2;v<
:C7_Jp*Qv
LVX[uWEM
private void processErrorCode(int nErrorCode) [\'%?BH(^
{ t;\kR4P
System.err.println("Error Code : " + nErrorCode); 81](T<
} !4]TXH0f
]-PH^H
{^ qcx8
//停止文件下载 6,o~\8ia
public void siteStop() |_LU~7./
{ H0:E(}@
bStop = true; gGvz(R:y
for(int i=0;i<nStartPos.length;i++) c*(bO3 b
fileSplitterFetch.splitterStop(); |^0XYBxQ
H]P. x!I
T,7Y7c/3V
} _7<FOOM%8y
} J{'>uD.@
//负责部分文件的抓取 .nB0 h
**FileSplitterFetch.java 83E7k]7]
*/ uya.sF0]9B
package NetFox; ;l4[%xld
#G.ulX
_|iSF2f,X
import java.io.*; wi;Br[d
import java.net.*; }]e-{C}
?Fi=P#
]|!OP
public class FileSplitterFetch extends Thread { F{Z~ R
}e!x5g
N+++4;
String sURL; //File URL ! _f9NK
long nStartPos; //File Snippet Start Position YT8vP~
long nEndPos; //File Snippet End Position 5}:-h>
int nThreadID; //Thread's ID ?u-|>N>
boolean bDownOver = false; //Downing is over ZNJ@F<
boolean bStop = false; //Stop identical %+f>2U4I
FileAccessI fileAccessI = null; //File Access interface >,TUZ
V:qSy#e
,3?Q(=j
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S\4tzz @
{ B&\IGWG(
this.sURL = sURL; mIurA?&7!
this.nStartPos = nStart; ^]7}YF2|
this.nEndPos = nEnd; AZ0;3<FfLp
nThreadID = id; H+1-]'g`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,X#2\r<|
} 9G9fDG#F\I
"k/;[ Wt]
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public void run() BZ:H`M`n
{ --PtZ]Z
while(nStartPos < nEndPos && !bStop) A$<.a'&T!
{ @AGn{q
Lilr0|U+
l%[EXZ
try{ ?6yjy<D)$e
URL url = new URL(sURL); lU@]@_<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Xp >7iX!:
httpConnection.setRequestProperty("User-Agent","NetFox"); u&`XB|~
String sProperty = "bytes="+nStartPos+"-"; >CrA;\l
httpConnection.setRequestProperty("RANGE",sProperty); <<@bl@9'
Utility.log(sProperty); 0>C T=(A
n.T&}ZPz\v
,#Iu 7di
InputStream input = httpConnection.getInputStream(); EwuO&q
//logResponseHead(httpConnection); q-.,nMUF
^c<ucv6.
a&tSj35*6
byte[] b = new byte[1024]; ]4~lYuI4
int nRead; K#EvFs`s;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) p!>oo1&
{ vtw6FX_B
nStartPos += fileAccessI.write(b,0,nRead); =G]1LTI
//if(nThreadID == 1) FB _pw!z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s8-<m,*
} _(Sa4Vb=Q6
HGXt
>*]Hq.&8
Utility.log("Thread " + nThreadID + " is over!"); %C$%!C
bDownOver = true; M4zm,>?K
//nPos = fileAccessI.write (b,0,nRead); Ey_" ~OB
} ZYI{i?Te#
catch(Exception e){e.printStackTrace ();} /]=C{)8
} wp#'nO
} 9S-Z&2L
PUF/#ck
|o{:ZmzM
//打印回应的头信息 /`f^Y>4gD
public void logResponseHead(HttpURLConnection con) B-.gI4xa
{ AmaT0tzJC
for(int i=1;;i++) sArhZ[H
{ Y<mej][
String header=con.getHeaderFieldKey(i); E}Y!O"CAV
if(header!=null) hJn%mdx~w|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); crqpV F]1]
Utility.log(header+" : "+con.getHeaderField(header)); V=zi >o`
else %1H[Wh(U
break; 33#0J$j7
} &{>cZh}\
} ~p1j`r;
]%|GmtqZs,
#bMuvaP~
public void splitterStop() WOQP$D9
{ Pf|siC^;s~
bStop = true; QrfG^GID
} 'qjeXqGH$
>H'4{|
{7$c8i
} WKT4D}{1
`wus\&!W
3D`YZ#M
/* l%?T2Fm3>
**FileAccess.java Q,p}:e
*//文件访问(定位，写) Db)?i?o}t
package NetFox; Kz>3 ic$I
import java.io.*; gUxP>hB
4"{ooy^Q
2ggdWg7z
public class FileAccessI implements Serializable{ 0o+6Q8q
u:[vaBh91
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V\u>"3BQw
RandomAccessFile oSavedFile; MO&}r7qq
long nPos; odPL{XFj
%K\?E98M
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public FileAccessI() throws IOException Cz72?[6
{ +)j$|x~(A
this("",0); IkBei&4F`
} Pm lx8@D
nX(+s*Y+w
%;e/7`>Ma
public FileAccessI(String sName,long nPos) throws IOException aCQ?fq
{ >Y #t`6,!
oSavedFile = new RandomAccessFile(sName,"rw"); 11<Qxu$rL
this.nPos = nPos; #tZ4N7
oSavedFile.seek(nPos); Z0o~+Ct$
} $4tWI O
}&n<uUDH
BB~OqZIP
public synchronized int write(byte[] b,int nStart,int nLen) D&}3$ 7>
{ Uc_'(IyO
int n = -1; y>72{
try{ e '2F#
oSavedFile.write(b,nStart,nLen); 3E>frR\!I
n = nLen; !R1.7}O
} h&Efg
catch(IOException e) mH Ic f{RG
{ ?RK]FP"A
e.printStackTrace (); HRiL.DS
} <FWF<r3F
PNaay:a|
BO~PT,QrF
return n; EX?MA6U
} >S'17D
+RnkJ* l
J(c{y]`J
} s<oNE)xe
1_\;- !t
!1q 9+e
/* E}sO[wNPf
**SiteInfoBean.java q)Fq i
*/ $: ]o]a
package NetFox; FI3)i>CnW
4$*%gL;f^
zgs(Dt;
public class SiteInfoBean { g>dA$h%
{_S}H1,
zipS ]YD
private String sSiteURL; //Site's URL =dII- L=`
private String sFilePath; //Saved File's Path )yTm.F
private String sFileName; //Saved File's Name qEpi]=|
private int nSplitter; //Count of Splited Downloading File 1jc, Y.mP
yqi^>Ce0
H&]gOs3So
public SiteInfoBean() yil[gPy4B
{//nSplitter的缺省值为5 p;W.lcO`0
//default value of nSplitter is 5 DdVF,
this("","","",5); kAu+zX>S+
} pek%08VSEU
wi4=OU1L)a
1RK=,Wx
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?r?jl;A&
{ 6(G?MW.
sSiteURL= sURL; Gi "941zVl
sFilePath = sPath; 'B@e8S)y
sFileName = sName; Y]L9Y9
this.nSplitter = nSpiltter; iVG-_RsKK
#m[|2R
gFHTG
} ,4ei2`wV
sO.`x*
L2, 1Kt7
public String getSSiteURL() z.Y$7bf)
{ d)pV;6%[$q
return sSiteURL; QF&W`c
} r=6v`)Qr
w~ [b*$
f|R"uW +
public void setSSiteURL(String value) u%/goxA
{ #*TEq
sSiteURL = value; `;>= '"O!\
} 5g9; +}X;
DSt]{fl`P
nzmDA6d
public String getSFilePath() jcI&w#re
{ YhY:~
return sFilePath; NMww>80
} vP!{",>
K^B%/T]d
J,zO2572u
public void setSFilePath(String value) 4"xPr[=iG
{ cCa|YW^j
sFilePath = value; NcP.;u;`
} kI:}| _
qQ0cJIISb\
\mV'mZ9>
public String getSFileName() 7f~Sf
{ _L@2_#h!
return sFileName; ^b7GH9<&
} rtL}W__
5cEcTJL[C
Y_]De3:V0B
public void setSFileName(String value) i:Zm*+Gi
{ $2u 'N:o
sFileName = value; WdnIp!
} A0Zt8>w
bzvh%RsW
E@P %v{)
public int getNSplitter() :_@JA0n
{ `\m*+Bk[5
return nSplitter; 1*dRK6
} r" K':O6y
lRveHB&V
3q`)*
public void setNSplitter(int nCount) SL,p36N
{ 2e|N@j &
nSplitter = nCount; ^qC;Nh4F
} Ton94:9bZ
} gt/zpiKmV
;L,mBQB?0b
|gsE2vV
/* ]>+PnP35G
**Utility.java Z*])6=2Q
*/ OQ,NOiNkap
package NetFox; ?_v{| YI=
V13BB44
o,xxh
public class Utility { h(F<h_
@]![o %
+n7?S~R$
public Utility() l27\diKPJ
{ TuW/N L|
1Jj Y!
CEC nq3
} YFTjPBV
fPR$kch
//线程睡眠 W$'R}L
public static void sleep(int nSecond) sg8/#_S1i
{ M{$j
try{ )LdyC`S\c
Thread.sleep(nSecond); -_<}$9lz
} |Xw/E)jA
catch(Exception e) 7#~+@'Oe
{ l9Q(xuhv
e.printStackTrace (); j+^oz'q
} 7c;9$j
} jr)7kP@
Ed:eGm }
//日志 Cn_$l>
public static void log(String sMsg) Iu{kPyx
{ wP57Pf0
System.err.println(sMsg); [j"9rO" +
} *#TYqCc+g
zz^F k&
2>\v*adG
public static void log(int sMsg) }/,HM9Ke
{ *-12VIG'H
System.err.println(sMsg); S=xA[%5
} XUF\r]B,9
} ^0#;YOk
.c#y%S
rS0DSGDq
/* fRfn2jA)d
**TestMethod.java Y $u9%0q|?
*/ 4HAp{a1
package NetFox; ||zb6|7I4
:iiw3#]
>I<r)w]
public class TestMethod { jt@SZI`
<F )_!0C
0A:n0[V:]
public TestMethod() KK,Z"){
{ ///xx/weblogic60b2_win.exe QaGlR`Y
try{ 9 C{;h
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); OgcHS?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {} Bf
SiteFileFetch fileFetch = new SiteFileFetch(bean); '&99?s`u
fileFetch.start(); xcJ`1*1N
} QW_agm
catch(Exception e){e.printStackTrace ();} ]?h`:,]
xBFJ} v
a,Gxm!
} KI]wm
yIb,,!y9{
\]9.zlB
public static void main(String[] args) {"vkji>
{ W- $a Y2
new TestMethod(); 5/QRL\
} 1shBY@mlq
} WU4UZpz
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