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)); DP{kin"4I
} K8`Jl=}z%&
for(int i=0;i<nEndPos.length-1;i++) [ u7p:?WDW
{ F/,K8<|r>
nEndPos = nStartPos[i+1]; 4)MKYhm
} =)_9GO
nEndPos[nEndPos.length-1] = nFileLength; A+Uil\%
} *nJy
} mp]}-bR)
\yt-_W=[
Sl,X*[HGd
//启动子线程 Mj&`Y gW5a
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; D>Ij
for(int i=0;i<nStartPos.length;i++) d&[Ct0!++u
{ ~*"]XE?M
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;#-yyU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), dxHKXw
nStartPos,nEndPos,i); 3j<:g%5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3sr>?/>:
fileSplitterFetch.start(); `;KU^dH
} CB V(H$d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,liFo.kT8%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w_zUA'n+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", X*ZTn 7<
nEndPos = " + nFileLength); '"u>;Bq
// fileSplitterFetch[nPos.length-1].start(); 8 KDF*%7'
'dJ#NT25
{Yq"%n'0
//等待子线程结束 EJC{!06L'/
//int count = 0; )}ygzKEa
//是否结束while循环 }U <T>0
boolean breakWhile = false; uWm,mGd9
G bW1Lq&"
t~_j+k0K#
while(!bStop) `zf,$67>1
{ 2I:x)
write_nPos(); wxC&KrRF
Utility.sleep(500); (4:&tm/;
breakWhile = true; ^G:}%4
j}P xq
)v\zaz
for(int i=0;i<nStartPos.length;i++) M"XILNV-~
{ poLzgd
if(!fileSplitterFetch.bDownOver) G@$Y6To[
{ bogw/)1
breakWhile = false; ,Sz`$'^c
break; \tv^],^`
} tc-pVw:TV
} t<8vgdD
if(breakWhile) Oz8"s4Y7
break; Z8vMVo
Ug :3)q[O
K|n%8hRy
//count++; 8+}yf.`
//if(count>4) RbOEXH*]
// siteStop(); cV;<!f+
} VTS7K2lBvX
9, A(|g
0)<\jo1 F
System.err.println("文件下载结束！"); `O5 Hzb(}
} p2m@0ou
catch(Exception e){e.printStackTrace ();} "gt-bo.,
} 6yn34'yw
T"h@-UcTl
pr~%%fCh
//获得文件长度 )I~U&sT\/
public long getFileSize() o )\\(^ld
{ h=?V)WSM
int nFileLength = -1; PhUG}94
try{ uGXN ciEp`
URL url = new URL(siteInfoBean.getSSiteURL()); ]o!rK<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nK!yu?mS
httpConnection.setRequestProperty("User-Agent","NetFox"); e6G=Bq$
1gK<dg
c>SFttbU
int responseCode=httpConnection.getResponseCode(); +qPpPjG;
if(responseCode>=400) bQ%6z}r
{ f$7Xh~
processErrorCode(responseCode); Np2I*l6W
return -2; //-2 represent access is error CBkI! In2
} &*Sgyk o`
c >O>|*I
B|\JGnNQ
String sHeader; ]n\Qa
EWb'#+BP
7lLh4__;`6
for(int i=1;;i++) A{Kc"s4fO
{ :.VI*X:aQh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); V yOuw9
//Utility.log(in.readLine()); z`}<mY E
sHeader=httpConnection.getHeaderFieldKey(i); %>];F~z
if(sHeader!=null) 0 _n Pq
{ (7X|W<xT
if(sHeader.equals("Content-Length")) RJpRsr
{ zh.^> `
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); o[ Je
break; Kl\g{>{Uz
} mM[KT} A
} .8GX8[t
else :eH*biXy}2
break; }]<Ghns
} xmM!SY>
} 'VMov
catch(IOException e){e.printStackTrace ();} dCb7sqJ%
catch(Exception e){e.printStackTrace ();} ;c/|LXc\
pftnFOLO
$q$G
Utility.log(nFileLength); ~cf*Oq
^cz4nW<
A,'F`au
return nFileLength; 2@Nt6r
} 3 P=I)q
H1t`fyri2
xS'Kr.S
//保存下载信息（文件指针位置） h&|S*
private void write_nPos() ShIJ6LZ
{ ?5IF;vk
try{ !=3Ce3-
output = new DataOutputStream(new FileOutputStream(tmpFile)); w *pTK +
output.writeInt(nStartPos.length); sBq-"YcjR
for(int i=0;i<nStartPos.length;i++) v 1.8]||^
{ /g`!Zn8a
// output.writeLong(nPos); &FpoMW
output.writeLong(fileSplitterFetch.nStartPos); /Kd9UQU
output.writeLong(fileSplitterFetch.nEndPos); L*8U.{NY
} _'*Vcu`Y
output.close(); t?aOZps
} s+-V^{Ht
catch(IOException e){e.printStackTrace ();} {i^F4A@=Z
catch(Exception e){e.printStackTrace ();} $eq*@5B
} c:[8ng 2v
R<<U(.E
Pf:;iXH?
//读取保存的下载信息（文件指针位置） w paI}H#
private void read_nPos() sU$<v( `"
{ #iiXJnG
try{ M*-]<!))7
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +:_;K_h
int nCount = input.readInt(); KXiStwS
nStartPos = new long[nCount]; 1a]P+-@u[
nEndPos = new long[nCount]; J*Q+$Ai~
for(int i=0;i<nStartPos.length;i++) %Q080Ltet
{ ?8/T#ox
nStartPos = input.readLong(); hh[@q*C
nEndPos = input.readLong(); @kPe/j/[1
} fq[1|Q
input.close(); 1xD?cA\vu
} K%g_e*"$
catch(IOException e){e.printStackTrace ();} | 9 <+!t\
catch(Exception e){e.printStackTrace ();} h J H
} LTTMxiq[*
iBt<EM]U/
]~@uStHn
private void processErrorCode(int nErrorCode) 7PW7&]-WQ
{ RxA:>yOPn
System.err.println("Error Code : " + nErrorCode); v&)G~cz
} 0t?g!
re xMS
4J{W8jX
//停止文件下载 |4j'KM;U
public void siteStop() bIXD(5y
{ RgD%pNhI
bStop = true; 3(,c^F
for(int i=0;i<nStartPos.length;i++) bs_< UE
fileSplitterFetch.splitterStop(); ILIv43QKM(
A D%9;KQ8
vhGX&
} UZ;FrQ(l{
} =lmelo#m&
//负责部分文件的抓取 GD1L6kVd1
**FileSplitterFetch.java 2[CHiB*>
*/ rM`z2*7%d
package NetFox; H-qbgd6&>R
"!R*f $
aQj"FUL
import java.io.*; pHzl/b8
import java.net.*; v[\GhVb
{yFMY?6rf
^8=e8O
public class FileSplitterFetch extends Thread { *pYawT
0O?\0k;o
#('GGzL6c
String sURL; //File URL tI<6TE'!p#
long nStartPos; //File Snippet Start Position N *,[(q
long nEndPos; //File Snippet End Position m>^vr7
int nThreadID; //Thread's ID G2dPm}sZG
boolean bDownOver = false; //Downing is over nH}V:C
boolean bStop = false; //Stop identical pN{XGkX.
FileAccessI fileAccessI = null; //File Access interface p+;;01Z+_
6~O;t'd
f{-,"6Y1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException u/apnAW@M
{ #G\Ae:O
this.sURL = sURL; a/n~#5-
this.nStartPos = nStart; (\%J0kR3[
this.nEndPos = nEnd; ~g}blv0q+B
nThreadID = id; lXRB"z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MM*9Q`cB
} eB9F35[
v.53fx
? CU;
public void run() g:YUuZ
{ H<"EE15
while(nStartPos < nEndPos && !bStop) YbF}>1/"
{ ma6Wr !J
n5Mhp:zc,
EX@Cf!GjN
try{ |fY#2\)Yx
URL url = new URL(sURL); #V.u[:mO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XEUS)X)
httpConnection.setRequestProperty("User-Agent","NetFox"); qga\icQr
String sProperty = "bytes="+nStartPos+"-"; rAk;8)O$
httpConnection.setRequestProperty("RANGE",sProperty); ~i0>[S3'
Utility.log(sProperty); D7Y?$=0ycb
69 J4p=c,
I:WPP'L4o
InputStream input = httpConnection.getInputStream(); a1x].{
//logResponseHead(httpConnection); qE.3:bQ!`
S`& yVzv
k>=wwPy
byte[] b = new byte[1024]; hyY^$p+
int nRead; zVis"g`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _TyQC1 d
{ iV:\,<8d
nStartPos += fileAccessI.write(b,0,nRead); AD>/#Ul
//if(nThreadID == 1) 9hgIQl
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s>=$E~qq
} f[q_eY
gX(8V*os^
nv3TxG
Utility.log("Thread " + nThreadID + " is over!"); ?4t~z 1.f
bDownOver = true; MfraTUxIo/
//nPos = fileAccessI.write (b,0,nRead); 212 =+k
} X7SSTcA
catch(Exception e){e.printStackTrace ();} GS*_m4.Ry6
} b/4gs62{k
} N6v*X+4JH
Ls*Vz,3!5
m/WDJ$d
//打印回应的头信息 !lKDNQ8>["
public void logResponseHead(HttpURLConnection con) qv`:o `
{ &{8[I3#@
for(int i=1;;i++) ^y~oXS(
{ a?)g>e HN
String header=con.getHeaderFieldKey(i); kdMB.~(K=
if(header!=null) {"0n^!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !v*#E{r"g=
Utility.log(header+" : "+con.getHeaderField(header)); bBQHxH}vi
else 9lX[rBZ
break; qz 29f
} 1?r$Rx<R
} |[!0ry*N%
xRF_'|e
?h8/\~Dw
public void splitterStop() P.~sNd oJ
{ {h;i x
bStop = true; `KE(R8y
} (JiEV3GH
Si|8xq$E;
7A
} AI .2os*
>Lz2zlZI
pe+m%;nzR
/* 72y!cK6
**FileAccess.java aX~' gq>
*//文件访问(定位，写) efh1-3f
package NetFox; %Jn5M(myC
import java.io.*; d_98%U+u
vf`]
~'):1}KN]
public class FileAccessI implements Serializable{ 7RgnL<t~:8
P2)g%$ME
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 UL" <V
RandomAccessFile oSavedFile; T{T> S%17~
long nPos; 1'5!")r
hflDVGBW
+7K]5p;!~
public FileAccessI() throws IOException YC}$O2
{ p-/}@r3Z+
this("",0); 2aQ}| `
} U7G|4(
Vb2")+*:
*c@]c~hY,
public FileAccessI(String sName,long nPos) throws IOException &J=x[{R
{ S*rcXG6Q^
oSavedFile = new RandomAccessFile(sName,"rw"); YGLR%PYv"
this.nPos = nPos; b$FXRR\G
oSavedFile.seek(nPos); F,XJGD*
} 9a.[>4}
td+[Na0d
1z[blNs&
public synchronized int write(byte[] b,int nStart,int nLen) tQ4{:WPG
{ Zn'y"@%t[
int n = -1; T0}P 'q
try{ ~0n9In%
oSavedFile.write(b,nStart,nLen); !i6 aA1'
n = nLen; ::8E?c
} CY9`HQ1
catch(IOException e) FD}>}fLv
{ g/,O51f'
e.printStackTrace (); J15$P8J
} WTh|7&
?/s=E+
L G9#D
return n; PiIILX{DuH
} 0M>%1*
lc0ZfC
dnTXx*I:
} ?rV c}
7h/{F({r=
o=(>#iVM
/* [ \Aor[(
**SiteInfoBean.java Z8Clm:S
*/ gClDVO
package NetFox; [h2V9>4:
@KYmkxW
-OP5v8c f
public class SiteInfoBean { 2!Ex55
zphStiwIQ
~9ILN~91
private String sSiteURL; //Site's URL v6?<)M%
private String sFilePath; //Saved File's Path ,K[B/tD{j
private String sFileName; //Saved File's Name }~5xlg$B<<
private int nSplitter; //Count of Splited Downloading File K#{E87G(
]H<C Rw
1')/BM2
public SiteInfoBean() s/'gl
{//nSplitter的缺省值为5 _'oy C(:}
//default value of nSplitter is 5 <`m.Vbvm"
this("","","",5); dUJNr_
} g@"6QAP
O^gq\X4}
PZl(S}VY
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =U".L
{ ]QU52R@M
sSiteURL= sURL; cWM|COXL+
sFilePath = sPath; Jq`fD~(7
sFileName = sName; aa1XY&G"!
this.nSplitter = nSpiltter; ;7<a0HZ5!
0?t!tugG
@w:sNXz-
} ;h3*MR
&f qmO>M
bvR*sT#rg
public String getSSiteURL() |,&!Q$<un
{ RN:#+S(8
return sSiteURL; *id|za|:k
} {UZli[W1
h?YjG^'9
TJ5{Ee GV
public void setSSiteURL(String value) A?|cJ"N
{ :7>Si%
sSiteURL = value; 1y"37;x
} U w`LWG3T
+msHQk5#$m
)SUN+YV^
public String getSFilePath() Q84KU8?d
{ W{m0z+N[B
return sFilePath; N<>dg
} _zmx
X7c*T /
Yhw* `"X
public void setSFilePath(String value) khv!\^&DD
{ X-{:.9
sFilePath = value; }\DQxHG
} Sc~kO4
sqZHk+<%
A# M
public String getSFileName() q=1SP@;\6
{ '/ &"
return sFileName; :M[E-j;
} 0RSa{iS*A
4!}fCP ty
4QZy-a*tA
public void setSFileName(String value) B?%D
{ j'J*QK&Q
sFileName = value; \+AH>I;vO
} 5PL,~Y
VDmd+bvJV
c\b>4 &n
public int getNSplitter() !Z'm@,+
{ +li^0+3-'
return nSplitter; ( L6`_)
} #*]= %-A
`A^} X
GKd>AP_
public void setNSplitter(int nCount) 6~/H#8Kdn
{ P*T)/A%4
nSplitter = nCount; )eV40l$ M
} ]Ojt3)fB
} sk3;;<H
0?h .X=G
(_08?cN
/* BmJ?VJ}Y
**Utility.java r#}Sy\
*/ uU\iji\
package NetFox; &^7)yS+C
/&dt!.WY^
/(0d{
public class Utility { zXCIn
tj&A@\/
=% JDo
public Utility() )yK!qu
{ I^|bQ3sor
09?<K)_G
?hu 9c
} O&s6blD11
X>6a@$MxP
//线程睡眠 _#F'rl6'
public static void sleep(int nSecond) uR%H"f
{ <FK><aA_i*
try{ W%W. +f
Thread.sleep(nSecond); QaO`:wJj
} DRIv<=Bt
catch(Exception e) R`&ioRWj
{ J?<L8;$s7
e.printStackTrace (); u~kwNN9t3
} ({9!P30:
} ] 6gu
rh_({rvQ
//日志 <Gw<(M
public static void log(String sMsg) I{PN6bn{>
{ RVsNr rZ
System.err.println(sMsg); $S}x'F!4_
} {EUH#':
IXN4?=)I
M5V1j(URE
public static void log(int sMsg) !%X`c94
{ D+3Y.r9
System.err.println(sMsg); aVYUk7_<
} ,H?p9L; qp
} jb2:O,+!
{\&"I|dpe
#c>MUC(?s:
/* zOOX>3^
**TestMethod.java iFA"m;$
*/ ,lJ6"J\8.
package NetFox; S8RB0^Q7
&3f.78a
jQ)>XOok
public class TestMethod { 5!zvoX9
\G@6jn1G(
SA1/U
public TestMethod() G~L?q~b
{ ///xx/weblogic60b2_win.exe `RcNqPY#S
try{ RX1{?*r]Z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4g9b[y~U
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \ c&)8.r
SiteFileFetch fileFetch = new SiteFileFetch(bean); <yPHdbF
fileFetch.start(); ,9qB}HG
} SEIu4 l$E
catch(Exception e){e.printStackTrace ();} tl5IwrF6;
'[8b0\
:gq@/COo(
} yp^*TD/J
`W n5 .V
BfT,
public static void main(String[] args) 88$Y-g5*
{ uFWgq::\
new TestMethod(); tJPRR_nZv
} &>l8SlC?
} ef;L|b%pp
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