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)); r/BiR0$E
} `^1&Qz>
for(int i=0;i<nEndPos.length-1;i++) tX.{+yyU
{ 3I.0uLjg^
nEndPos = nStartPos[i+1]; oQ_n:<3X
} cwKOE?!
nEndPos[nEndPos.length-1] = nFileLength; -nKBSls
} J6*B=PX=(
} T7!=KE_z
n+;PfQ|
#zv'N
//启动子线程 Xn:ac^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +H8;*uZ|k,
for(int i=0;i<nStartPos.length;i++) sow/JLlbC
{ &`A2&mZ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Co^a$K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ICI8xP}a?
nStartPos,nEndPos,i); *S>,5R0k
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fP 5!`8
fileSplitterFetch.start(); ?.&?4*u
} tmf=1M
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k.CHMl]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); > [|SF%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s7#|'jhZt
nEndPos = " + nFileLength); D$[/|%3
// fileSplitterFetch[nPos.length-1].start(); kzcD}?mSS
M"$TXXe
j[o5fr)L
//等待子线程结束 J"dp?i
//int count = 0; ALY% h!L
//是否结束while循环 vXi}B
boolean breakWhile = false; ds9`AiCW>
G$HLta
59I}
while(!bStop) Bt^];DjH
{ *>XY' -;2e
write_nPos(); #O.-/&Z
Utility.sleep(500); b1{XGK'
breakWhile = true; .cX,"2;n
lZupn?
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for(int i=0;i<nStartPos.length;i++) E~|`Q6&Y
{ i|Y_X
if(!fileSplitterFetch.bDownOver) "UY.; P
{ 4c_F>Jw[
breakWhile = false; <AB.`["
break; T6ZJSKM
} ,-XJ@@2gM
} V6ioQx=K#
if(breakWhile) NR)[,b\v
break; Eh)VU_D
"rA:;ntz
fJ3qL#'
//count++; ?ixzlDto\
//if(count>4) #2!M+S
// siteStop(); $PQlaivA
} I({ 7a i
\..(!>,%F
3*gWcPGe
System.err.println("文件下载结束！"); {M?!nS6t
} zA/W+j$:
catch(Exception e){e.printStackTrace ();} T7.u7@V2
} `|^<y.-6
E4'D4@\W
r4xq%hy
//获得文件长度 B&m?3w
public long getFileSize() 6YZ&>`a^
{ wzMWuA4vX
int nFileLength = -1; Ye}y_W
try{ n~d`PGs?f
URL url = new URL(siteInfoBean.getSSiteURL()); }m<)$.x|P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dMwVgc:
httpConnection.setRequestProperty("User-Agent","NetFox"); [vaG{4m
^IGTGY]s
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int responseCode=httpConnection.getResponseCode(); Y4Z?`TL
if(responseCode>=400) t747SZWgB
{ NwG&uc+Q
processErrorCode(responseCode); 9CWUhS
return -2; //-2 represent access is error o+O\VNW
} 1*r{%6
FK#>E[[
lm&C!{K
String sHeader; ~::gLm+f
9&W\BQ
=k[!p'~jD
for(int i=1;;i++) 3RRZVc* ^
{ ,U'Er#U
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'U)~|(\i
//Utility.log(in.readLine()); Z3R..vy8
sHeader=httpConnection.getHeaderFieldKey(i); ?#kI9n<O
if(sHeader!=null) -c=IO(B/
{ T[XI
if(sHeader.equals("Content-Length")) o0wep&@
{ w'5~GhnP+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I01On>"@7
break; i*Y/q-N|
} 't{=n[
} U&Ay3/
else \+MR`\|3
break; aG\m3r
} 0{PK]qp7
} d<6L&8)<
catch(IOException e){e.printStackTrace ();} n37( sKG
catch(Exception e){e.printStackTrace ();} kozg8 `\]
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M14_w,
Utility.log(nFileLength); &nn.h@zje
%4L|#^7:
;lAz@jr+
return nFileLength; u3,b,p
} fD\h5`-
FZA8@J|Q4
XpH[SRUx
//保存下载信息（文件指针位置） de1&
private void write_nPos() 2%W(^Lj
{ s !8]CV>
try{ nfDPM\FFD
output = new DataOutputStream(new FileOutputStream(tmpFile)); CsSB'+&{
output.writeInt(nStartPos.length); V6$v@Zq
for(int i=0;i<nStartPos.length;i++) .<42-IEc
{ p]+W1v}V!
// output.writeLong(nPos); 59^@K"J
output.writeLong(fileSplitterFetch.nStartPos); '*3+'>
output.writeLong(fileSplitterFetch.nEndPos); iMp)g%Ng
} 5Ll[vBW
output.close(); %k$C
} dIO\ lL
catch(IOException e){e.printStackTrace ();} }UGPEf\
catch(Exception e){e.printStackTrace ();} Zc9 n0t[
} "-xC59,
:{66WSa@Dd
o3WkbMJWM
//读取保存的下载信息（文件指针位置） KUyua~tF
private void read_nPos() ~+lC%R
{ e-}PJ%!,T
try{ N%B#f\N
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8:&@MZQ&!
int nCount = input.readInt(); Zo0&<QWj
nStartPos = new long[nCount]; ,XA;S5FE
nEndPos = new long[nCount]; Pm?6]] 7
for(int i=0;i<nStartPos.length;i++) ,+X8?9v
{ s*l_O*$'
nStartPos = input.readLong(); |ntJ+
nEndPos = input.readLong(); Pucf0 #
} CYrL|{M]
input.close(); _~cmR<
} OC>" +
catch(IOException e){e.printStackTrace ();} IWT##']G
catch(Exception e){e.printStackTrace ();} e;6Sj
} ;JmD(T7{
sG VC+!E
MJg^ QVM
private void processErrorCode(int nErrorCode) E>g'!
{ ixS78KIr
System.err.println("Error Code : " + nErrorCode); D!mhR?t
} 4_"ZSVq]#
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|M K-~ep
//停止文件下载 )@Zel.XD
public void siteStop() "7<4NV@yQ
{ X&lkA (
bStop = true; ,DE%p +q
for(int i=0;i<nStartPos.length;i++) -%N (X8
fileSplitterFetch.splitterStop(); tRv#%>fj
XW#4C*5?d
[]2GN{m
} z H \*v'
} e.jgV=dT-
//负责部分文件的抓取 Z?x]HB`r
**FileSplitterFetch.java {[9^@k
*/ 'qM3.U
package NetFox; q(r2\
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LTY.i3
import java.io.*; FCe503qND$
import java.net.*; Yj"UD:p
X! ]~]%K$y
wk/->Rz
public class FileSplitterFetch extends Thread { -Qgfo|po
hW},%
7Ow7|
String sURL; //File URL PLY7qMw
long nStartPos; //File Snippet Start Position S77Gc:[;8
long nEndPos; //File Snippet End Position *m"mt
int nThreadID; //Thread's ID 4YCGh
boolean bDownOver = false; //Downing is over YW}/CwB
boolean bStop = false; //Stop identical 95<:-?4C;W
FileAccessI fileAccessI = null; //File Access interface RTU:J67E
S;c=6@"
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W[?B@sdSZ
{ )5t_tPv
this.sURL = sURL; Qpc{7#bp
this.nStartPos = nStart; xl9l>k6,
this.nEndPos = nEnd; MJC Yi<D
nThreadID = id; dg!sRm1iZ:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 UEeqk"t^
} uJO*aA{K
/Yh([P>
Ya. $x~
public void run() us cR/d
{ E.6\(^g
while(nStartPos < nEndPos && !bStop) ~9c9@!RA2
{ aj,ZM,Ad
C[pDPx,#:G
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try{ 5R Hs
URL url = new URL(sURL); }Q=Zqlvz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Mm;)O'XDE
httpConnection.setRequestProperty("User-Agent","NetFox"); 4(&'V+o
String sProperty = "bytes="+nStartPos+"-"; d;^?6V
httpConnection.setRequestProperty("RANGE",sProperty); g3Q #B7A
Utility.log(sProperty); yS43>UK_W+
b?$09,{0
8j$q%g
InputStream input = httpConnection.getInputStream(); 6vA5L_
//logResponseHead(httpConnection); yR!>80$j
R3PhKdQ"
+{I\r|
byte[] b = new byte[1024]; 'KL(A-}!
int nRead; \\qg2yI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?*@h]4+k'
{ dF,FH-
nStartPos += fileAccessI.write(b,0,nRead); 5^dw!^d
//if(nThreadID == 1) `R> O5Rv
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t5k&xV=~ #
} )yP>}ME
o7+/v70D
,54<U~Lg:
Utility.log("Thread " + nThreadID + " is over!"); p(G?
bDownOver = true; t>fB@xHBB
//nPos = fileAccessI.write (b,0,nRead); {<2ZbN?
} fUL"fMoU
catch(Exception e){e.printStackTrace ();} f3>/6C
} ,2`d3u^CW
} {5udol5?
jveRiW@
@\y7 9FX
//打印回应的头信息 JdHc'WtS!|
public void logResponseHead(HttpURLConnection con) ,gvX ~k
{ !D3}5A1,
for(int i=1;;i++) D:(f"
{ >DRs(~|V#
String header=con.getHeaderFieldKey(i); vFOv IVp
if(header!=null) XbC8t &Q],
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ge[i&,.&z
Utility.log(header+" : "+con.getHeaderField(header)); ?5Fj]Bk]
else 0Nu]N)H5<l
break; ,&=`T7i
} _iu|*h1y
} rieQ&Jt"
?N ga
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public void splitterStop() mSfhl(<L
{ =oME~oB~
bStop = true; S;'eoqN8
} c)8wO=!
Ic K=E]p
LXLDu2/@
} 2YKM9Ks
SDIeq
fF("c6:w(
/* -z$0S%2?
**FileAccess.java .;b> T
*//文件访问(定位，写) uKy*N*}
package NetFox; =T)2wcXBB
import java.io.*; lt4jnV2"a
fn OkH
3ms/v:\
public class FileAccessI implements Serializable{ Wts{tb
`4bd,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 shT[|@"C
RandomAccessFile oSavedFile; >@U<?wP
long nPos; >U<nEnB$?
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N o(f0g.
public FileAccessI() throws IOException 2.D!4+&
{ /8}+#h)[
this("",0); A#X.c=
} P|4E1O
]$*{<
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public FileAccessI(String sName,long nPos) throws IOException Jche79B
{ o%%x'uC
oSavedFile = new RandomAccessFile(sName,"rw"); eC?/l*gF3
this.nPos = nPos; rR@n> Xx
oSavedFile.seek(nPos); J&:W4\ m
} $ bNe0
Hi_Al,j:
w3qf7{b
public synchronized int write(byte[] b,int nStart,int nLen) rA,Y_1b *
{ d7J[.^\
int n = -1; q7&yb.<KD.
try{ \>Rwg=Lh
oSavedFile.write(b,nStart,nLen); .)>/!|i
n = nLen; xzl4v=7
} 0 jP00
catch(IOException e) xY0QGQca
{ >J3ja>Gw/
e.printStackTrace (); }c4E 2c
} :.o=F`W
x}<G!*3
o:8S$F`O@
return n; xdfvme[
} X/-KkC
ZBR^[OXO
fslk7RlSKg
} NzAtdcwR
mK40 f
^lai!uZVa
/* LnTe_Q7_
**SiteInfoBean.java G^rh*cb K
*/ qH%L"J
package NetFox; 5u)^FIBj
{0vbC/?]
EO/cW<uV'
public class SiteInfoBean { RO$@>vL
( ssH=a
1gShV ]2
private String sSiteURL; //Site's URL o\ow{gh9
private String sFilePath; //Saved File's Path t+!gzZ
private String sFileName; //Saved File's Name <]Pix)
private int nSplitter; //Count of Splited Downloading File ?PE1aB+{:
vQYfoam;
_`@Xy!Ye
public SiteInfoBean() +z(,A
{//nSplitter的缺省值为5 m0A@jWgd
//default value of nSplitter is 5 B#GZmv1
this("","","",5); !qXq y}?w
} GQ-e$D@SfB
0|s$vqc
udEb/7ZL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )_b@~fC
{ '5xuT _
sSiteURL= sURL; Ec*--]j*c
sFilePath = sPath; ay:\P.`5)
sFileName = sName; NkA6Cp[Q,1
this.nSplitter = nSpiltter; h`EH~W0:z
;;y@z[ >
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} Og$eQS
}`9fZK{. @
e(n2+S#N
public String getSSiteURL() RM^?&PM85
{ or!D
return sSiteURL; ZU|V+yT
} =>:% n
C`)^~C_]`3
N t>HztXd
public void setSSiteURL(String value) P96Cw~<Q?
{ `z$uw
sSiteURL = value; RRI>bh]
} U/3e,`c
nF. ;LM
yo?g"vbE
public String getSFilePath() &Qtp"#{
{ f=_Bx2ub
return sFilePath; b#Fk>j
} M=\d_O#;Z
PK-}Ldj
)-Mn"1ia
public void setSFilePath(String value) do=x9k@Q
{ UPVO~hB;
sFilePath = value; '#McY'.D T
} KM_)7?`
[]=FZ`4
0i`v:Lq%
public String getSFileName() Y uw E 0
{ 2pxWv )0
return sFileName; F;?TR[4!k
} (EOec5qXU
]xJ'oBhy
^Kw&=u
public void setSFileName(String value) a8bX"#OR&N
{ u,Q_WR-wJ
sFileName = value; JO&;bT<
} pu2wEQ
{hs2?#p
, `[Z`SUk`
public int getNSplitter() Qe @A5#
{ =e-a&Ep-z
return nSplitter; XDP6T"h
} rSF;Lp)}
?b*/ddIs
w!B,kqTG
public void setNSplitter(int nCount) r21?c|IP
{ M73VeV3DL
nSplitter = nCount; Y'<uZl^aX
} B c,"12
} fw1;i
v|4STR
nxn[ ~~
/* ?8wwd!)x%
**Utility.java Q8;x9o@p
*/ F1?CqN M
package NetFox; DqurHQ z)m
Ad}-I%Ie
.^[fG59
public class Utility { Jo7fxWO_g
DU/9/ I?~
2_oK5*j
public Utility() Zzw}sZ?8
{ 5(iSOsb
IKMsY5i
36kc4=
} R\9>2*w
dT0^-XSY
//线程睡眠 vWqyZ-p,q
public static void sleep(int nSecond) vI pO/m.3
{ 3t"~F%4-}
try{ @7Q*h
Thread.sleep(nSecond); RMS.1:O
} "xe7Dl
catch(Exception e) k8InbX[
{ 2|0Je^$|
e.printStackTrace (); ;H7EB`
} %K&+~CJE
} %mK3N2N$
8~&F/C*
//日志 6pM"h5hA
public static void log(String sMsg) lF;ziF
{ Z #.GI
System.err.println(sMsg); i#L6UKe:Q
} _9Dn\=g
&#.x)>f
aNOAu/
public static void log(int sMsg) &K9VEMCEX
{ ".~MmF
System.err.println(sMsg); 5z9r S<
} T!m42EvIvE
} ^Ei*M0fF
~I8v5 H
+?URVp
/* MAuM)8_P/|
**TestMethod.java ppwd-^f3j
*/ >%iu!H"
package NetFox; %-@'CNP
rtB|N-
+l2e[P+qA
public class TestMethod { /p"U
g6rv`I$l
RE ![O
public TestMethod() iyA*JCD
{ ///xx/weblogic60b2_win.exe 4/*]`
try{ Ep^B,;~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Kwy1SyU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9>A-$a4R>
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~fyF&+ibp'
fileFetch.start(); XoDJzrL#
} L/qZ ;{
catch(Exception e){e.printStackTrace ();} tpv?`(DDU
oS[W*\7'!
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} Bv;I0i:_
$se !8s"
b*lKT]D,
public static void main(String[] args) S9OxI$6Y
{ hVlyEsLg
new TestMethod(); .LX?VD
} PRMZfYc
} 21.YO]Et
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