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)); 4~Qnhv7
} FO/cEu
for(int i=0;i<nEndPos.length-1;i++) Tw';;euw
{ t{c:<nN
nEndPos = nStartPos[i+1]; :;_}Gxx
} I/w;4!+)
nEndPos[nEndPos.length-1] = nFileLength; X{x(p
} ,a&,R*r@&
} :,l16{^
sgOau\E
>c_fUX={
//启动子线程 lW5Lwyt8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E0I/]0
for(int i=0;i<nStartPos.length;i++) /wEl\Kx
{ oz=V|7,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'ge$}L}4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +\ftSm>
nStartPos,nEndPos,i); IoLP*D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H<|}pZ
fileSplitterFetch.start(); sg=G<50i
} dDA8IW![S
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I=dn]}b#P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pfZ[YC-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;.AMP$o`(Y
nEndPos = " + nFileLength); cO]w*Hti
// fileSplitterFetch[nPos.length-1].start(); lD0a<L3
@U!&XZ]h
Xps \+l%i
//等待子线程结束 MhA4C 8
//int count = 0; gbYM1guiD
//是否结束while循环 ~D@YLW1z(
boolean breakWhile = false; U%pB
C)c*s C5N
DTH}=r-
while(!bStop) 5wW5 n5YS
{ lv?`+tU2_
write_nPos(); c/ImK`:)4a
Utility.sleep(500); I(AlRh
breakWhile = true; }j2;B 8j
}'tJc $!
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for(int i=0;i<nStartPos.length;i++) OD7^*j(p`
{ w0;4O)H$O
if(!fileSplitterFetch.bDownOver) ilQ}{p6I
{ <[n:Ij
breakWhile = false; tl /i
break; QxG^oxU}
} eI"pRH*f
} @5wc 3y
if(breakWhile) ,,G"EF0A
break; Eoixw8hz
7b08Lo7b
%y9sC1T
//count++; 6)0.q|Q
//if(count>4) n%29WF6Zf
// siteStop(); sgP{A}4 W
} "`cN k26JZ
#<==7X#
~b*]jZwT
System.err.println("文件下载结束！"); (/<Nh7C1c
} 9tv,,I;iU
catch(Exception e){e.printStackTrace ();} 2DPv7\fW
} q/zU'7%@
al}J^MJ
s&pnB
//获得文件长度 9vyf9QE;
public long getFileSize() 2? yo
{ xE;O =mI
int nFileLength = -1; G3:!]}
try{ g/f6N z
URL url = new URL(siteInfoBean.getSSiteURL()); 17?YN<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]i(/T$?~
httpConnection.setRequestProperty("User-Agent","NetFox"); X-nC2[tu'W
yIn$ApSGY
d2Q*1Q@u
int responseCode=httpConnection.getResponseCode(); hT1JEu
if(responseCode>=400) So!=uYX
{ h_#=f(.'j
processErrorCode(responseCode); V6P-?Nd
return -2; //-2 represent access is error CnL=s6XD'
} -O\i^?lD;
"g5{NjimY
l90"1I A
String sHeader; B2j1GJEO
I4jRz*Ufe?
:Q"|%#P
for(int i=1;;i++) 1}a4AGAp
{ KWY_eY_|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); V>T?'GbS
//Utility.log(in.readLine()); y8s!sO
sHeader=httpConnection.getHeaderFieldKey(i); an"~n`g
if(sHeader!=null) )L:e0u
{ ?Q-Tyf$3
if(sHeader.equals("Content-Length")) HQm_ K0$
{ #{|cSaX<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); op9dYjG7
break; x']'ODs
} ?'P}ZC8P
} {7goYzQsi%
else To>,8E+GAb
break; klJ21j0Bb2
} Q"qI'*Kgt
} l{Df{1b.
catch(IOException e){e.printStackTrace ();} h[]9F.[
catch(Exception e){e.printStackTrace ();} pc*)^S
uTR^K=Ve
\_1a#|97e
Utility.log(nFileLength); tsc`u>
vv ,4n&D
A0)^I:&
return nFileLength; Vbl-Ff
} {zAI-?#*u
hU#e\L 7
#; ?3kuq(
//保存下载信息（文件指针位置） w95M B*N
private void write_nPos() !CYC7HeF
{ =D/zC'l
try{ )JS6W
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0y9 b0G
output.writeInt(nStartPos.length); U7s$';y"%
for(int i=0;i<nStartPos.length;i++) GF ux?8A:%
{ yc](
// output.writeLong(nPos); nzflUR{`-
output.writeLong(fileSplitterFetch.nStartPos); 2 kDsIEA
output.writeLong(fileSplitterFetch.nEndPos); Z0Z6aZeb
} EraGG"+
output.close(); h+[6i{
} `t U
catch(IOException e){e.printStackTrace ();} 3gi)QCsk
catch(Exception e){e.printStackTrace ();} *1dDs^D#|
} AYbO~_a\N
KMRPleF
)Z/"P\qo
//读取保存的下载信息（文件指针位置） @gI1:-chB
private void read_nPos() |H5.2P&9-5
{ Tz]R}DKB&
try{ !ZBtXt#P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \Rny*px
int nCount = input.readInt(); K!-OUm5A
nStartPos = new long[nCount]; n"(!v7YNp
nEndPos = new long[nCount]; "}]$ag!`q$
for(int i=0;i<nStartPos.length;i++) jo`ZuN{
{ Jxe+LG
nStartPos = input.readLong(); T D_@0Rd
nEndPos = input.readLong(); BN_h3|)
} 3'4+3Xo
input.close(); ywa*?3?c
} 3z+l-QO8
catch(IOException e){e.printStackTrace ();} YFO{i-*q
catch(Exception e){e.printStackTrace ();} {a7~P0$
} bNea5u##
UnhVppnex
ZwmucY%3
private void processErrorCode(int nErrorCode) %**f`L%jN
{ [^5\Ww
System.err.println("Error Code : " + nErrorCode); g*Y,.
} ";K w?
q-F K=r 5
EApKN@<"
//停止文件下载 )[Y B&
public void siteStop() &k}f"TX2
{ *%j$i_
bStop = true; P6:C/B
for(int i=0;i<nStartPos.length;i++) l:85 _E
fileSplitterFetch.splitterStop(); %$!3Pbui
/ ;]5X
:KLXrr
} z|l*5@p
} .Mt3ec<
//负责部分文件的抓取 G.W !
**FileSplitterFetch.java Yd^@Ei9
*/ ;a:H-iC
package NetFox; YDt+1Kw}D
$<}c[Nm
{MUB4-@?F$
import java.io.*; W'lqNOX[v
import java.net.*; Swi#^i
UtZ,q!sg
sibYJKOy
public class FileSplitterFetch extends Thread { }cKB)N BJb
._mep\#.:
Rj8%% G-pt
String sURL; //File URL #&Sr;hAJ
long nStartPos; //File Snippet Start Position 1yy?1&88S
long nEndPos; //File Snippet End Position )Fw/Cu
int nThreadID; //Thread's ID V~J5x >O
boolean bDownOver = false; //Downing is over vF$i"^;tJ;
boolean bStop = false; //Stop identical 'rQ"Dc1D
FileAccessI fileAccessI = null; //File Access interface bDI%}k9#
@f!X%)\;x
IK~&`n](>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException QLA.;`HIE
{ .n-#A
this.sURL = sURL; y_]+;%w:
this.nStartPos = nStart; 5j%G7.S\
this.nEndPos = nEnd; C0rf
nThreadID = id; ; * [:~5Wc
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4w4B\Na>l
} *{o7G a
>@ t
(~T*yH ~
public void run() H=t"qEp
{ 7*/{mK)
while(nStartPos < nEndPos && !bStop) &4#Zi.]
{ s0kp(t!fiu
Ic&h8vSU
8~sP{V%
try{ vDy&sgS$<
URL url = new URL(sURL); +2tQFV;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >4 OXG7.&f
httpConnection.setRequestProperty("User-Agent","NetFox"); jvT'N@
String sProperty = "bytes="+nStartPos+"-"; dWqn7+:
httpConnection.setRequestProperty("RANGE",sProperty); {4"V)9o-1>
Utility.log(sProperty); K%^n.
?b7\m":'
3} A$+PX
InputStream input = httpConnection.getInputStream(); Bq0 \T 0,
//logResponseHead(httpConnection); 0p.bmQSH
n ]ikc|
WJ7|0qb
byte[] b = new byte[1024]; 4s\spvJ
int nRead; >r.]a`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) pYO =pL^Q
{ 0=d2_YzSf
nStartPos += fileAccessI.write(b,0,nRead); rIb+c=|F
//if(nThreadID == 1) VYyija:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *kr/,_K
} eH&F gmU
T U%@_vYR
+A9~h/"kt
Utility.log("Thread " + nThreadID + " is over!"); Cu"Cpt[
bDownOver = true; }r}*=;Ea
//nPos = fileAccessI.write (b,0,nRead); :1v,QEb\
} qsj{0Go
catch(Exception e){e.printStackTrace ();} Obdn#Wm=
} W{p}N
} ul{x|R
9tiZIm93]
*4,Q9K_
//打印回应的头信息 J0G@]H
public void logResponseHead(HttpURLConnection con) t0)1;aBZ
{ )0{`}7X
for(int i=1;;i++) +X?ErQm
{ _0/unJl`
String header=con.getHeaderFieldKey(i); dBWny&
if(header!=null) )m%uSSx#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _0H oJ
Utility.log(header+" : "+con.getHeaderField(header)); ;m/e|_4;y
else pP<8zTLn
break; 8f@}-
} CK* *RZ
} F!z0N&#
f@*69a8
5Rqdo\vE
public void splitterStop() 'Waazk[@O
{ &OR(]Wt0
bStop = true; 0b&#w
} <'Q6\R}:vC
|k a _Zy
:;?$5h*|`
} 0Tj,TF
osV6=
w OL,LU
/* Z0gtliJ@
**FileAccess.java *PmZqe
*//文件访问(定位，写) CS^6$VL7e
package NetFox; 5K vp%
import java.io.*; y6(PG:L
mV0,T*}e
)f?I{
public class FileAccessI implements Serializable{ /9vi
]#0 (
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T(|'.&a
RandomAccessFile oSavedFile; S-t#d7'B
long nPos; 41 F;X{Br
~nZcA^b#DQ
y)kxR
public FileAccessI() throws IOException dsTX?E<R
{ YRZ\nun
this("",0); #W\}v(Ke
} wAh]C;+{
*85N_+Wv!
Gxr\a2Z&r%
public FileAccessI(String sName,long nPos) throws IOException +pd,gG?dW
{ zt.kNb
oSavedFile = new RandomAccessFile(sName,"rw"); ~yv7[`+Tgg
this.nPos = nPos; s'HsLe0|
oSavedFile.seek(nPos); @SX%q&-
} 4m*)("H
sn"((BsO<
aZ@pfWwa:
public synchronized int write(byte[] b,int nStart,int nLen) /x3*oO1
{ MA .;=T
int n = -1; \,R;
try{ s`yzeo
oSavedFile.write(b,nStart,nLen); 2A_1E\
n = nLen; [@@{z9c
} _8G w Mj
catch(IOException e) qbyYNlXqm
{ *aErwGLB8
e.printStackTrace (); Q,?_;,I}
} a (U52dO,
ERPg TZT
- 2)k!5X=
return n; 5CK+\MK
} sL@\,]Y
_E'?U
gvP-doA7W
} ?/|Xie
UPtj@gtcY
461g7R%r
/* j]Gn\QF
**SiteInfoBean.java FJn-cR.n
*/ jNj;#C)
package NetFox; "B'c;0@q
r<!hEWO>v
]SJ#:7
public class SiteInfoBean { W.3b]zcV
xPZ>vCg
V$ZclV2:Ih
private String sSiteURL; //Site's URL @c^ Dl
private String sFilePath; //Saved File's Path L:HvrB~
private String sFileName; //Saved File's Name fd[N]I3
private int nSplitter; //Count of Splited Downloading File `W86]ut[
O2fq9%lk
DS?.'"n[u
public SiteInfoBean() 3(e_2v
{//nSplitter的缺省值为5 _?-oPb
//default value of nSplitter is 5 :k\#=u(
this("","","",5); *2Pr1U
} U:8[%a
40?RiwwD
+2`BZ}5y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Qvp"gut)%X
{ Y w0,K&
sSiteURL= sURL; u1meysa{0
sFilePath = sPath; X['9;1Xr
sFileName = sName; '=0}2sF>
this.nSplitter = nSpiltter; 8m"k3:e^
wPg/.N9H
HAjl[c
} 811>dVq3/
}JFTe g
F*P0=DD
public String getSSiteURL() 0O"W0s"T#
{ mG S4W;
return sSiteURL; -;9 }P
} @` KYgjjH
n#+EG3
v@$N,g
public void setSSiteURL(String value) Cu7{>"
{ 3y)\dln
sSiteURL = value; ~xd?y*gk;
} L('1NN2
) lUS'I
IQJ"B6U)
public String getSFilePath() 6nTM~]5.
{ I/7!5Z*
return sFilePath; g,d_
} ,)`_?^\$f
{VAih-y
p{Q6g>?[
public void setSFilePath(String value) h /
{ `N\ ^JAGW
sFilePath = value; -K/+}4i3N
} gBqDx|G
C&z!="hMhR
# `=Zc7gf
public String getSFileName() XO]^+'U}p
{ rMwa6ZO'm;
return sFileName; ^BF}wQb:j
} MT/jpx
k3bQ32()
ZO/e!yju
public void setSFileName(String value) CE3l_[c
{ &>qUT]w
sFileName = value; /MtmO$.
} eu5te0{G
)|*Qs${tF
=n,;S W
public int getNSplitter() CFFb>d
{ z)T-<zWO;
return nSplitter; 3A,N1OXG
} Zbnxs.i!
$U[d#:]
2 `AdNt,
public void setNSplitter(int nCount) Ke4oLF2
{ wNi%u{T
nSplitter = nCount; LtB5;ByeQ0
} |*?N#0s5h
} d~8U1}dP
e]1=&:eX#d
x/<ow4C
/* TFkG"ev
**Utility.java \hX,z =
*/ .OJGo<#$f
package NetFox; LGL;3EI
P'VHga
Z0&^(Fb
public class Utility { 1te^dh:Vp
<qR$ `mLN
}4>u_)nt
public Utility() SGl|{+(A
{ mRx `G(u:v
7Q/H+)
KJFQ)#SW!
} c&T5C,]
2M+RA}dX
//线程睡眠 I0Do%
public static void sleep(int nSecond) b#I,Z+0ry
{ %# uw8V
try{ .g/!u(iy
Thread.sleep(nSecond); il>+jVr
} ?e-rwaW
catch(Exception e) Y<;C>Rs
{ L^e*_q2d:>
e.printStackTrace (); eQQVfEvS
} V.3#O^S
} n^QDMyC;I
s;h`n$
//日志 yHM29fEZk
public static void log(String sMsg) hak#Iz0[C
{ Db2#QQ
System.err.println(sMsg); leHKBu'd
} ,dba:D=l
NZ`6iK-V_
vasw@Uto)
public static void log(int sMsg) J>dj]1I
{ z*nztvY@e
System.err.println(sMsg); 7# 'j>]
} \yymp70w
} _BG`!3U+
qjfv9sU
A f?&VD4K
/* mp3Dc
**TestMethod.java .f!'>_
*/ M-Nn \h$,
package NetFox; m";8 nm
)P1NX"A
?{Xp'D\z
public class TestMethod { ;Xidv9c
tSDp>0yZ3
ziW[qH {
public TestMethod() ~R|fdD/%
{ ///xx/weblogic60b2_win.exe i\36 s$\
try{ VyU!r* o
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); suj}A
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); h\-jqaq
SiteFileFetch fileFetch = new SiteFileFetch(bean); jP@t!=
fileFetch.start(); n O}x,sG2'
} 0@f7`D
catch(Exception e){e.printStackTrace ();} Q[O U`
ZG)C#I1;O
Qzk/oHs
} G[yN*C
\v_t: "
YpZ9h@,
public static void main(String[] args) .+AO3~Dg
{ ^_ZQf
new TestMethod(); 1/qiE{NW
} %@M/)"k
} ]O&A:Us
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