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)); B7]MGXC
} ]vuwkn+)
for(int i=0;i<nEndPos.length-1;i++) _ 84ut
{ /rSH"$
nEndPos = nStartPos[i+1]; F5o+kz$;
} TwgrRtj'
nEndPos[nEndPos.length-1] = nFileLength; } (!EuLL
} ,!U=|c"k)
} |^@dFOz
ul*Qt}
"O(9m.CZ
//启动子线程 }pJwj
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "1,pHR-+R
for(int i=0;i<nStartPos.length;i++) 0T46sm r
{ ;qBu4'C)T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T9s2bC.z55
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @gG<le6
nStartPos,nEndPos,i); ES40?o*]x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8zMu7,E
fileSplitterFetch.start(); IT$25ZF
} t]Xw{)T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2<}NB?f`N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); n9s iX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $[yFsA6
nEndPos = " + nFileLength); j!3 Gz
// fileSplitterFetch[nPos.length-1].start(); Uo2GK3nT
;`6^6p\p
|2KAo!PI
//等待子线程结束 cp o-.
//int count = 0; U)3DQ6T99
//是否结束while循环 ]KJj6xn
boolean breakWhile = false; R i^[i}
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W2.qhY5
while(!bStop) vv=VRhwF
{ /q5:p`4{J
write_nPos(); IUwm}9Q!
Utility.sleep(500); ]Zmj4vK J
breakWhile = true; (T2m"Yi:
~}<DG1!
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for(int i=0;i<nStartPos.length;i++) B,{K*-7)MX
{ be +4junf
if(!fileSplitterFetch.bDownOver) +a*tO@HG
{ \G-KplKS
breakWhile = false; #UbF9})q
break; cH>%r^G\
} R+CM`4CD
} O|w J)
if(breakWhile) nR`ov1RH
break; ;amXY@RmH
B7!3-1<k>
!o$!Frc
//count++; aE2.L;Tk?
//if(count>4) M|Rb&6O
// siteStop(); x*/S*!vx\
} oJfr +3I
5L!y-3
tToTxf~
System.err.println("文件下载结束！"); 7nuU^wc
} `]W|8M
catch(Exception e){e.printStackTrace ();} |6<p(i7
} L`24?Y{
Z4\=*ic@
w4gg@aO
//获得文件长度 6R^^.tCs
public long getFileSize() 8-O)Xx}cU
{ LGtIm7
int nFileLength = -1; k1!@^A
try{ Sy 'Dp9!|
URL url = new URL(siteInfoBean.getSSiteURL()); ow]053:i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D gaMO,
httpConnection.setRequestProperty("User-Agent","NetFox"); $ , u+4h
X*\J_
#{\%rWnCm
int responseCode=httpConnection.getResponseCode(); /Sh#_\x
if(responseCode>=400) 6AhM=C
{ S;- LIv
processErrorCode(responseCode); ctGL-kp
return -2; //-2 represent access is error GN2Sn`;
} yNbjoFM.i
pfI"36]F
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String sHeader; jB(|";G
9B9(8PVG
5^x1cUB]
for(int i=1;;i++) y_?Me]
{ j?+X\PtQ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -jiG7OL
//Utility.log(in.readLine()); OtNd,U.dE
sHeader=httpConnection.getHeaderFieldKey(i); 1 9CK+;b
if(sHeader!=null) n<u $=H
{ X)% A6M
if(sHeader.equals("Content-Length")) qXwPDq/
{ &mx)~J^m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Dg?:/=,=9r
break; Bf8jPa/
} v%iflCK
} ;-qO'V:;
else ~W-PD
break; .P"D
} c(~[$)i6
} IqoR7ajA
catch(IOException e){e.printStackTrace ();} 5wDg'X]>V
catch(Exception e){e.printStackTrace ();} XD2v*l|Po
)'+8}T]xQ
WA&!;Zq
Utility.log(nFileLength); <Pi|J-Y
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ilqy/fL#
return nFileLength; qO|R^De
} m*kl
|mw.qI|
=UfsL%
//保存下载信息（文件指针位置） W*I(f]8:y`
private void write_nPos() ?o|f':
{ mmk=97
try{ #iHs* /85
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ev}C<zk*
output.writeInt(nStartPos.length); TJR:vr
for(int i=0;i<nStartPos.length;i++) fNW"+ <W
{ 0a XPPnuX
// output.writeLong(nPos); ]Yn_}Bq
output.writeLong(fileSplitterFetch.nStartPos); Y<%@s}zc
output.writeLong(fileSplitterFetch.nEndPos); UWo]s.
} pz.JWCU1
output.close(); XLrwxj0
} }*S `qW;B
catch(IOException e){e.printStackTrace ();} yvO{:B8%
catch(Exception e){e.printStackTrace ();} YF>m$?;
} #6HA\dE
t,+nQ9
wG-HF'0L
//读取保存的下载信息（文件指针位置） 85Otss/mM
private void read_nPos() R[hzMU}KB
{ 4J/}]Dr5
try{ 4?q<e*W
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >]vlkA(
int nCount = input.readInt(); 2OVRf0.R~
nStartPos = new long[nCount]; waj0"u^#
nEndPos = new long[nCount]; =E#%'/ A;c
for(int i=0;i<nStartPos.length;i++) vkEiOFU!u
{ sW'2+|3"
nStartPos = input.readLong(); T~##,qQ
nEndPos = input.readLong(); ;"~ fZ2$U
} x#xFh0CA
input.close(); j~jV'f.:H
} =*c7i]@}
catch(IOException e){e.printStackTrace ();} /n{omx
catch(Exception e){e.printStackTrace ();} A#J`;5!Sc
} >8#X;0\Kj
SPY|K
ORJIo
private void processErrorCode(int nErrorCode) mQ|v26R
{ g'n7T|h ~
System.err.println("Error Code : " + nErrorCode); 9\mLW"
} Vg>dI&O
ic#`N0s?
MS 81sN\d
//停止文件下载 8h*Icf
public void siteStop() tne ST.
{ L"1}V
bStop = true; #(N+(():
for(int i=0;i<nStartPos.length;i++) f$Fhf?'
fileSplitterFetch.splitterStop(); qGB{7-ru
yDegcAn?
Kzm+GW3o[
} AicBSqUke
} R\G0'?h >
//负责部分文件的抓取 bU2Z[sn.
**FileSplitterFetch.java YA_c N5p/@
*/ IID-k
package NetFox; zck#tht4 n
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1AM!8VR2
import java.io.*; $!-c-0ub
import java.net.*; R6kD=JY/!
4gz H8sF
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public class FileSplitterFetch extends Thread { ( u\._Gwsx
7e|s wJ>4
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String sURL; //File URL q1"$<# t
long nStartPos; //File Snippet Start Position F@'Jbd`
long nEndPos; //File Snippet End Position BW}U%B^.
int nThreadID; //Thread's ID W14 J],{L
boolean bDownOver = false; //Downing is over !Sh&3uy_qN
boolean bStop = false; //Stop identical p6#g;$V$
FileAccessI fileAccessI = null; //File Access interface i1NY9br
t\~P:"
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /v1Q4mq
{ w[zjerH3
this.sURL = sURL; =hC,@R>;
this.nStartPos = nStart; 93("oBd[s(
this.nEndPos = nEnd; 1{ ~#H<K
nThreadID = id; p.v0D:@&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 s E2D#D
} 8D3OOab
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K/j3a[.
public void run() A@1W}8qY:
{ F4}]b(L
while(nStartPos < nEndPos && !bStop) Z<1FSk,[
{ -:Da&V
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-Ta9 pxZk
try{ Xqg@ e:g
URL url = new URL(sURL); Ce9|=Jx!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "GMBjT8
httpConnection.setRequestProperty("User-Agent","NetFox"); P;=n9hgHI
String sProperty = "bytes="+nStartPos+"-"; B}Z63|/N
httpConnection.setRequestProperty("RANGE",sProperty); MDhRR*CBh
Utility.log(sProperty); |:q=T ~x
8<S~Z:JK
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InputStream input = httpConnection.getInputStream(); %Gz0^[+
//logResponseHead(httpConnection); )t0$qd ]
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rzhWw-GY
byte[] b = new byte[1024]; \o}xF@sM5
int nRead; z;{iM/Xe
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %p^wZtm
{ 8=B|C'>
nStartPos += fileAccessI.write(b,0,nRead); :DrWq{4
//if(nThreadID == 1) nBjqTud
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [R(`W#W
} Y!~49<;
+7D|4
0=@?ob7
Utility.log("Thread " + nThreadID + " is over!"); bv]`!g: C
bDownOver = true; S!jTyY7e
//nPos = fileAccessI.write (b,0,nRead); /32Fy`KV
} X@+{5%
catch(Exception e){e.printStackTrace ();} A-Sv;/yD_
} L-jJg,eY
} bhTb[r
u)X=Qm)
,&]S(|2%>t
//打印回应的头信息 3}TaF~
public void logResponseHead(HttpURLConnection con) >Ea8G,
{ ~ -4{B
for(int i=1;;i++) 4IB9,?p
{ p `8s
String header=con.getHeaderFieldKey(i); 0bceI
if(header!=null) .0S~872
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Uol|9F
Utility.log(header+" : "+con.getHeaderField(header)); 1n >X[! 8x
else AF;)#T<
break; rn/ /%
} <r.)hT"0
} bR*-Ht+wd
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public void splitterStop() +X#vVD3"
{ "cE7 5
bStop = true; V]|^&A_c
} Q8:Has
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} 5A)2} D]
|4)>:d
;,C)!c&
/* WZ-s--n#
**FileAccess.java 0t^M3+nc
*//文件访问(定位，写) ?J%1#1L"/
package NetFox; B-?6M6#
import java.io.*; h;C5hU4P
L"E7#}
j@W.&- _
public class FileAccessI implements Serializable{ '-r).Xk
6LOnU~l,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &vo--V1|
RandomAccessFile oSavedFile; 9v;Vv0k_
long nPos; Od)Uv1
H{@Yo\J
#o=y?(
public FileAccessI() throws IOException b(*!$EB
{ ?x$"+,
this("",0); i2@VB6]?
} }\z.)B4,
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v6=RY<l"m
public FileAccessI(String sName,long nPos) throws IOException RHaI~jb
{ _D+}q_
oSavedFile = new RandomAccessFile(sName,"rw"); )#BMTKA^
this.nPos = nPos; NTdixfR
oSavedFile.seek(nPos); (_niMQtF}
} \a5U8shc
]9YJ,d@J
$yn];0$J
public synchronized int write(byte[] b,int nStart,int nLen) 8UW^"4
{ J ][T"K
int n = -1; q-
try{ W^0w
oSavedFile.write(b,nStart,nLen); jlkmLcpf
n = nLen; 3p39`"~
} @KWb+?_H{<
catch(IOException e) H35S#+KX
{ J}htu
e.printStackTrace (); 3/aMJR:o
} Hc! mB
B( ]M&
i'a?kSy
return n; .\[`B.Q
} xAqb\|$^
w zYzug
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} NE"@Bk cm
p6]7&{>
xO$lsZPG
/* $:cE ^8K
**SiteInfoBean.java tR}MrM
*/ C\3y {s
package NetFox; ~8~aJ^[
c2h{6;bfY
&qMPq->
public class SiteInfoBean { w:%o?pKet1
hXfQ)$J
H(R1o~
private String sSiteURL; //Site's URL I CZ4A{I
private String sFilePath; //Saved File's Path CpA|4'#
private String sFileName; //Saved File's Name qS403+Su1=
private int nSplitter; //Count of Splited Downloading File dq7x3v^"ZG
bHPYp5UwN
y-T| #
public SiteInfoBean() ^M3~^lV
{//nSplitter的缺省值为5 )`SES."
//default value of nSplitter is 5 !Nu<xq@!
this("","","",5); ?p9VO.^5
} fdxLAC
VO,!x~S!
RS"H8P4W
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e>7]w,*|
{ u}>#Eb
sSiteURL= sURL; )'Oh`$M
sFilePath = sPath; $56Z#'(D
sFileName = sName; V_C-P[2~
this.nSplitter = nSpiltter; AjmVc])
B\<Q ;RI2;
Ao&\EcIOT
} G'rxXJq
IC#>X5
D;oe2E{I
public String getSSiteURL() +!k&Yje
{ H9KKed47d/
return sSiteURL; N8!cO[3Oh
} {s)+R[?m<o
p`mS[bxv!
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public void setSSiteURL(String value) AK&S5F>D+B
{ &J55P]7w
sSiteURL = value; R?v>Q` Qi
} Tu@8}C
;lq;X{/
,/YF-L$(t
public String getSFilePath() {_b%/eR1
{ mYxuA0/k
return sFilePath; il}%7b-
} <DMl<KZ
vh"R'o
kUq=5Y `D
public void setSFilePath(String value) W!%]_I!&K
{ ` BDLW%aL
sFilePath = value; 0n@rLF
} ^:K3vC[h;c
unshH<
FjK3 .>'
public String getSFileName() m*ISa(#(,
{ ]P#XVDn+;
return sFileName; H70LhN
} 8j Mk)-
@'YS1N<
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public void setSFileName(String value) &/mA7Vf>eR
{ nS/)P4z
sFileName = value; d1T,eJ}
} B,M(@5wz
UV5Ie!\nm
1lq(PGX)
public int getNSplitter() %F\?R[^5
{ zBo1P(kek
return nSplitter; f_[<L
} i7]4W
t/ +=|*
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public void setNSplitter(int nCount) 7P"| J\
{ :Nu^
nSplitter = nCount; M54j@_81pX
} H:!7:
} >G);j@Q
g1XZ5P} f
S7=Bd[4
/* q+P|l5_ t
**Utility.java aT_&x@x
*/ 8S>&WR%jH]
package NetFox; ([ jF4/
`n$I]_}/%
%R@X>2l/_
public class Utility { 7+]=-
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D-8O+.@
public Utility() 6WV\}d:
{ GMMp|WV|
+hn+K1
@b"t]#V(E
} ZPiq-q
}MRd@ 0-?!
//线程睡眠 MHSs!^/g5
public static void sleep(int nSecond) tYZ[68
{ }Mo=PWI1?
try{ _Xnqb+
Thread.sleep(nSecond); Is]aj-#r
} ]GN7+8l
catch(Exception e) ^ s1Q*He
{ *&?c(JU;<
e.printStackTrace (); O?U'!o=
} Nndddk`
} ?dD&p8{
! vP[;6
//日志 f~Fm4>\(
public static void log(String sMsg) hy}8Aji&
{ $wmvKQc{lx
System.err.println(sMsg); CF+_/s#j^
} &n6$rBr%
U"q/rcA
S>.SSXlM
public static void log(int sMsg) s4 6}s{6
{ t=_J9|
System.err.println(sMsg); 1"/He ` 4
} Sl-v W
} Ul2R'"FB
!,[C]Q1
=Vy`J)z9
/* '3TW [!m
**TestMethod.java Xv<B1
*/ @?=|Y
package NetFox; N` aF{3[
HHq_P/'
q6_u@:3u
public class TestMethod { nA P.^_K
BYs-V:
FL(6?8zK
public TestMethod() \"CZI<=TB
{ ///xx/weblogic60b2_win.exe Gp4A.\7
try{ 2WtRJi?b|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #+$G=pS'v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); MS0Fl|YA
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?CC"Yij
fileFetch.start(); 356>QW'm
} KN7^:cC
catch(Exception e){e.printStackTrace ();} )K,F]fc+O
p"l3e9&'j
6)vSG7Ise
} jV? }9L^;
TUHi5K
mN!lo;m5
public static void main(String[] args) h~(G$':^
{ L]d-hs
new TestMethod(); t5'V6nv
} S,<EEtXQ
} wY~&Q}U
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